Foldable push cart

Abstract

To provide a foldable push cart that can be smoothly switched between an unfolded state and a folded state. [Solution] A push cart includes a first frame, a second frame rotatably connected to the first frame, a loading platform, at least one connecting rod rotatably connected to the second frame and the loading platform, a handle frame rotatably connected to the second frame, and a bottom frame rotatably connected to the loading platform and also to the handle frame. When the handle frame is moved, the second frame and the bottom frame rotate relative to the first frame in a first rotation direction, and the bottom frame rotates relative to the handle frame in a second rotation direction opposite to the first rotation direction.

Description

[Technical Field]

[0001] The present invention relates to a foldable push cart, and more particularly to a foldable and unfoldable push cart with a multi-stage connecting rod and frame structure that provides stable support and smooth rotation during unfolding and folding operations. [Background technology]

[0002] Currently, a wide variety of push carts are available on the market, and are widely used in daily transportation, shopping, travel, logistics, and other situations. Among them, foldable push carts have become the mainstream in the market due to their small size and convenient storage and portability. However, current foldable push carts still have some technical limitations and inconveniences in practical use.

[0003] Many conventional folding push carts use a simple hinge mechanism to fold the cart body and the loading platform, which allows for volume reduction, but the unfolding and folding process requires the user to simultaneously operate multiple components, such as pressing a snap lock while unfolding the loading platform or stand, making them difficult to operate.In addition, some mechanisms are not securely fixed when unfolded, making them prone to wobbling, reducing loading stability and safety during use.

[0004] Furthermore, some designs do not take into account the need for the cart to remain stable and self-standing even when folded, requiring it to be placed against a wall or stand or flat on the ground after folding, which not only takes up space but also increases the risk of tipping over. If the wheels are not always in contact with the ground during the unfolding and folding process, momentary instability can cause the cart to tip over, posing a potential danger to the user. Summary of the Invention [Means for solving the problem]

[0005] The present disclosure provides a push cart including a main frame, a handle frame, a bottom frame, and four wheels. The main frame includes a first sub-frame, a second sub-frame, a bottom loading platform, a first connecting rod, and a second connecting rod. The first sub-frame includes a first side rod having a first end, a second side rod having a second end, and a cross rod connecting the first end and the second end; the second sub-frame includes a third side rod having a third end, and a fourth side rod having a fourth end, the third end of the third side rod being pivotally connected to the first side rod, and the fourth end of the fourth side rod being pivotally connected to the second side rod. the side edge is rotatably connected to the horizontal rod of the first subframe, the bottom loading platform is positioned near the first end and the second end, the first connecting rod is rotatably connected to the third side rod of the second subframe and a second side edge of the bottom loading platform opposite the first side edge, and the second connecting rod is rotatably connected to the fourth side rod of the second subframe and the second side edge of the bottom loading platform. The handle frame includes a fifth side rod having a fifth end, a sixth side rod having a sixth end, and a handle horizontal rod connecting the fifth and sixth side rods, the fifth side rod of the handle frame being rotatably connected to the third side rod of the second subframe, and the sixth side rod of the handle frame being rotatably connected to the fourth side rod of the second subframe. The bottom frame comprises a seventh side rod having a seventh end and an eighth side rod having an eighth end, the seventh end of the seventh side rod being rotatably connected to the third side edge of the bottom loading platform, the eighth end of the eighth side rod being rotatably connected to the second side edge opposite the fourth side edge of the bottom loading platform, the fifth end of the fifth side rod of the handle frame being rotatably connected to the ninth end opposite the seventh end of the seventh side rod, and the sixth end of the sixth side rod of the handle frame being rotatably connected to the tenth end opposite the eighth end of the eighth side rod.Two of the four wheels are respectively connected to the first side rod and the second side rod of the first frame of the main frame and are located near the first end and the second end, and the remaining two of the four wheels are respectively connected to the fifth side rod and the sixth side rod of the handle frame and are located near the fifth end and the sixth end. When the second sub-frame of the main frame rotates relative to the first sub-frame, the handle frame moves relative to the second sub-frame, and simultaneously the bottom frame rotates relative to the handle frame and the bottom load platform, and further the bottom load platform rotates relative to the first sub-frame of the main frame, so that the push cart assumes a folded state or an unfolded state.

[0006] The above has outlined rather broadly the technical features of the present disclosure to facilitate a better understanding of the detailed description of the present disclosure that follows. Below, we describe other technical features of the present disclosure that form the subject matter of the claims. Those skilled in the art will appreciate that they can easily achieve the same objectives of the present disclosure by modifying or designing other structures or processes based on the concepts and specific embodiments disclosed below. Those skilled in the art will also appreciate that such equivalent constructions do not depart from the spirit and scope of the present disclosure, as defined by the appended claims.

[0007] Aspects of the present disclosure can be best understood from the following embodiments and accompanying drawings, in which: It should be noted that, in accordance with standard practice in the art, the features in the drawings are not drawn to scale, and in fact the dimensions of some features may be intentionally increased or decreased for clarity of illustration. [Brief explanation of the drawings]

[0008] [Figure 1A] 1 is a schematic three-dimensional view of a push cart in an unfolded state according to an embodiment of the present disclosure; [Figure 1B] FIG. 10 is another schematic three-dimensional view of the push cart in an unfolded state according to an embodiment of the present disclosure. [Figure 1C]1 is a schematic side view of a push cart in an unfolded state according to an embodiment of the present disclosure; FIG. [Figure 2A] 1 is a schematic three-dimensional view of a push cart in a folded state according to an embodiment of the present disclosure; FIG. [Figure 2B] FIG. 10 is another schematic three-dimensional view of the push cart in a folded state according to an embodiment of the present disclosure. [Figure 2C] FIG. 1 is a schematic side view of a push cart in a folded state according to an embodiment of the present disclosure. [Figure 3A] 1 is a schematic diagram illustrating a state in which a push cart according to an embodiment of the present disclosure changes from an unfolded state to a folded state. FIG. [Figure 3B] 1 is a schematic diagram illustrating a state in which a push cart according to an embodiment of the present disclosure changes from an unfolded state to a folded state. FIG. [Figure 3C] 1 is a schematic diagram illustrating a state in which a push cart according to an embodiment of the present disclosure changes from an unfolded state to a folded state. FIG. [Figure 4A] 1 is a schematic diagram illustrating a state in which a push cart according to an embodiment of the present disclosure changes from a folded state to an unfolded state. FIG. [Figure 4B] 1 is a schematic diagram illustrating a state in which a push cart according to an embodiment of the present disclosure changes from a folded state to an unfolded state. FIG. [Figure 4C] 1 is a schematic diagram illustrating a state in which a push cart according to an embodiment of the present disclosure changes from a folded state to an unfolded state. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following disclosure provides many different embodiments and examples for implementing different features of the present disclosure. To simplify the present disclosure, specific examples of components and arrangements will be described below. It goes without saying that these are merely examples and are not intended to be limiting. For example, in the following description, "a first member is formed above a second member, or a first member is formed on a second member" may include not only an embodiment in which the first member and the second member are in direct contact with each other, but also an embodiment in which an additional member is formed between the first member and the second member so that the first member and the second member are not in direct contact with each other. Furthermore, the present disclosure may repeat the reference numerals and / or letters of components in each example. This repetition is for the purpose of simplicity and clarity and does not represent a relationship between the described embodiments and / or configurations.

[0010] Spatially relative terms such as "below," "below," "under," "above," "on," and "above" may be used herein to describe the relationship of one component or element to another component or elements, as illustrated. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. The device may have other orientations (rotated 90 degrees or at other orientations), which may also be used, as appropriate, to describe the spatially relative terms used herein.

[0011] As used herein, terms such as "first," "second," and "third" are intended to describe various components, members, regions, layers, and / or sections, but are not intended to limit these components, members, regions, layers, and / or sections. These terms may be used only to distinguish one component, member, region, layer, or section from another. The use of terms such as "first," "second," and "third" in this specification does not denote any order or importance unless clearly indicated by context.

[0012] As used herein, the terms "approximately," "substantially," "substantial," and "about" are used to describe and interpret small variations. When these terms are used in conjunction with an event or condition, they are intended to include not only embodiments in which the event or condition occurs exactly, but also embodiments in which the event or condition occurs very similarly. For example, when used in conjunction with a numerical value, the term can refer to a range of variation of within ±10% of the numerical value, e.g., within ±5%, ±4%, ±3%, ±2%, ±1%, ±0.5%, ±0.1%, or ±0.05%. Two numerical values ​​can be considered "substantially" the same or equivalent if the difference between them is within ±10% of their mean value (e.g., within ±5%, ±4%, ±3%, ±2%, ±1%, ±0.5%, ±0.1%, or ±0.05%). For example, "substantially" parallel may include an angle variation range of within ±10° relative to 0°, e.g., within ±5°, ±4°, ±3°, ±2°, ±1°, ±0.5°, ±0.1°, or ±0.05°. For example, "substantially" perpendicular may include an angle variation range of within ±10° relative to 90°, e.g., within ±5°, ±4°, ±3°, ±2°, ±1°, ±0.5°, ±0.1°, or ±0.05°.

[0013] The present disclosure relates to a foldable push cart, which comprises a main frame, at least one pair of connecting rod mechanisms, a loading platform, a handle frame, and a bottom frame, and the rotation and interlocking relationships between each component allow the overall structure to smoothly switch between an unfolded state and a folded state, and in any state, the push cart can stand stably and independently with all four wheels in contact with the ground.

[0014] 1A and 1B are schematic three-dimensional views of a push cart 100 according to an embodiment of the present disclosure in an unfolded state, as viewed from two angles. FIG. 1C is a schematic side view of the push cart 100 according to an embodiment of the present disclosure in an unfolded state. As shown in FIGS. 1A, 1B, and 1C, the push cart 100 may include a main frame 1, a handle frame 2, a bottom frame 3, connecting rods 4 and 5, and wheels 61, 62, 63, and 64.

[0015] 1A, 1B, and 1C, the main frame 1 may include sub-frames 11, 12, and 13 and a bottom loading platform 15. In some embodiments of the present disclosure, the sub-frame 11 may include side rods 111 and 112 and cross rods 113 and 115. In some embodiments of the present disclosure, the side rods 111 and 112 extend substantially parallel to one another. The side rod 111 may have ends 1111 and 1112, and the side rod 112 may have ends 1121 and 1122. The cross rod 113 may connect the end 1111 of the side rod 111 to the end 1121 of the side rod 112, and the cross rod 115 may connect the end 1112 of the side rod 111 to the end 1122 of the side rod 112. Therefore, the subframe 11 may be a substantially rectangular frame. When the push cart 100 is in the unfolded state and supported on the ground, the side bars 111 and 112 of the subframe 11 extend substantially perpendicular to the ground.

[0016] In some embodiments of the present disclosure, the subframe 12 may comprise a generally U-shaped frame. The subframe 12 comprises side rods 121 and 122 and a cross rod 123 connecting the side rods 121 and 122. The side rod 121 is rotatably connected to the side rod 111 of the subframe 11, and the side rod 122 is rotatably connected to the side rod 112 of the subframe 11. In some embodiments of the present disclosure, the connection between the side rod 121 and the side rod 111 is located near the end 1111 of the side rod 111 and / or the end 1211 of the side rod 121, and the connection between the side rod 122 and the side rod 112 is located near the end 1121 of the side rod 112 and / or the end 1221 of the side rod 122. In some embodiments of the present disclosure, the end 1111 of the side rod 111 and the end 1211 of the side rod 121 are pivotally connected to each other, and the end 1121 of the side rod 112 and the end 1221 of the side rod 122 are pivotally connected to each other, thereby allowing the subframe 12 to rotate relative to the subframe 11. When the push cart 100 is in the unfolded state and supported on the ground, the side rods 121 and 122 of the subframe 12 extend approximately horizontally relative to the ground.

[0017] In some embodiments of the present disclosure, the subframe 13 may include a generally U-shaped frame. The subframe 13 includes side rods 131 and 132 and a cross rod 133 connecting the side rods 131 and 132. The side rod 131 is rotatably connected to the side rod 111 of the subframe 11, and the side rod 132 is rotatably connected to the side rod 112 of the subframe 11. In some embodiments of the present disclosure, the connection portion between the side rod 131 and the side rod 111 is located between the end 1111 and the end 1112 of the side rod 111, and the connection portion between the side rod 132 and the side rod 112 is located between the end 1121 and the end 1122 of the side rod 112. This allows the subframe 13 to rotate relative to the subframe 11. When the push cart 100 is in the unfolded state and supported on the ground, the side bars 131 and 132 of the subframe 13 extend substantially horizontally relative to the ground.

[0018] The bottom loading platform 15 is configured to carry luggage transported by the push cart 100. A rear side edge 151 of the bottom loading platform 15 is rotatably connected to the horizontal rod 115 of the subframe 11. As shown in FIGS. 1A and 1B , two hook portions 1511 extending from the rear side edge 151 of the bottom loading platform 15 are rotatably hooked onto the horizontal rod 115 of the subframe 11, thereby allowing the bottom loading platform 15 to rotate relative to the subframe 11.

[0019] In some embodiments of the present disclosure, the bottom loading platform 15 includes a grid structure. When the push cart 100 is in the unfolded state and supported on the ground, the bottom loading platform 15 is approximately parallel to the ground. When the push cart 100 is in the unfolded state, the bottom loading platform 15 and the sub-frames 11, 12, and 13 can define the main frame 1 in a basket-like shape, allowing cargo to be stably held on the bottom loading platform 15.

[0020] In some embodiments of the present disclosure, the handle frame 2 may include a substantially U-shaped frame. The handle frame 2 may include side rods 21, 22 and a handle cross rod 23 connecting the side rods 21 and 22. The side rod 21 is rotatably connected to the side rod 121 of the subframe 12, and the side rod 22 is rotatably connected to the side rod 122 of the subframe 12. Referring to FIGS. 1A, 1B, and 1C, when the push cart 100 is in the unfolded state, the side rod 21 of the handle frame 2 may extend crosswise with the side rod 121 of the subframe 12 and the side rod 131 of the subframe 13, and the side rod 22 of the handle frame 2 may extend crosswise with the side rod 122 of the subframe 12 and the side rod 132 of the subframe 13.

[0021] In some embodiments of the present disclosure, the bottom frame 3 may include a substantially U-shaped frame. The bottom frame may include side rods 31, 32 and a cross rod 33 connecting the side rods 31 and 32. The side rod 31 is rotatably connected to the side rod 21 of the handle frame 2, and the side rod 32 is rotatably connected to the side rod 22 of the handle frame 2. In some embodiments of the present disclosure, an end 311 of the side rod 31 and an end 211 of the side rod 21 are pivotally connected to each other, and an end 321 of the side rod 32 and an end 221 of the side rod 22 are pivotally connected to each other. This allows the bottom frame 3 to rotate relative to the handle frame 2.

[0022] The end 312 of the side rod 31 of the bottom frame 3 is connected to the side edge 153 of the bottom loading platform 15 so as to be approximately rotatable, and the end 322 of the side rod 32 is connected to the side edge 154 of the bottom loading platform so as to be approximately rotatable. The side edge 153 and the side edge 154 of the bottom loading platform 15 face each other. This allows the bottom frame 3 to rotate relative to the bottom loading platform 15.

[0023] The cross rod 33 of the bottom frame 3 is connected to the end 311 of the side rod 31 and the end 321 of the side rod 32. When the push cart 100 is in the unfolded state, the side rod 31 of the bottom frame 3 extends approximately along the side edge 153 of the bottom loading platform 15, and the side rod 32 of the bottom frame 3 extends approximately along the side edge 154 of the bottom loading platform 15. Furthermore, when the push cart 100 is in the unfolded state, the cross rod 33 extends below the bottom loading platform 15 and can function as a reinforcing member for the bottom loading platform 15.

[0024] Connecting rod 4 may be pivotally connected to side rod 121 of subframe 12, side rod 131 of subframe 13, and side edge 153 of bottom load platform 15, and connecting rod 5 may be pivotally connected to side rod 122 of subframe 12, side rod 132 of subframe 13, and side edge 154 of bottom load platform 15. Thus, by moving connecting rods 4 and 5, subframe 12, subframe 13, and bottom load platform 15 can be rotated synchronously and in the same direction.

[0025] The wheel 61 is rotatably connected to the end 1112 of the side rod 111 of the subframe 11, the wheel 62 is rotatably connected to the end 1122 of the side rod 112 of the subframe 12, the wheel 63 is rotatably connected to the end 211 of the side rod 21 of the handle frame 2, and the wheel 64 is rotatably connected to the end 221 of the side rod 22 of the handle frame 2. In some embodiments of the present disclosure, the central axes of the wheels 61 and 62 may be approximately aligned with the cross rod 115 of the subframe 11. In some embodiments of the present disclosure, the central axes of the wheels 63 and 64 may be approximately aligned with the cross rod 33 of the bottom frame 3. When the push cart 100 is in the unfolded state, the push cart 100 can move on the ground by the wheels 61, 62, 63, and 64.

[0026] 2A and 2B are schematic three-dimensional views of the push cart 100 according to one embodiment of the present disclosure in a folded state, as viewed from two angles. FIG. 2C is a schematic side view of the push cart 100 according to one embodiment of the present disclosure in a folded state. Referring to FIGS. 2A, 2B, and 2C, when the push cart 100 is in the folded state, the main frame 1 of the push cart 100 is folded and the bottom frame 3 is stored so as to closely contact the handle frame 2, thereby folding the entire push cart 100 to its minimum volume.

[0027] 2A, 2B, and 2C, when the push cart 100 is in the folded state, the position and state of the sub-frame 11 of the main frame 1 are substantially the same as when the push cart 100 is in the unfolded state. The sub-frames 12 and 13 of the main frame 1 are closely fitted to each other, and the side rod 121 of the sub-frame 12 extends substantially upward from the connection portion with the side rod 111 of the sub-frame 11, and the side rod 122 of the sub-frame 12 extends substantially upward from the connection portion with the side rod 112 of the sub-frame 11. The side rod 131 of the sub-frame 13 extends substantially upward from the connection portion with the side rod 111 of the sub-frame 11, and the side rod 132 of the sub-frame 13 extends substantially upward from the connection portion with the side rod 112 of the sub-frame 11. The horizontal rod 133 of the subframe 13 is higher than the horizontal rod 113 of the subframe 11, and the horizontal rod 123 of the subframe 12 is higher than the horizontal rod 123 of the subframe 12.

[0028] The bottom loading platform 15 extends substantially vertically and is substantially flush with the subframe 11, with a side edge 153 of the bottom loading platform 15 extending substantially upward from the rear side edge 151, and a side edge 154 of the bottom loading platform 15 extending substantially upward from the rear side edge 151. In some embodiments of the present disclosure, the front side edge 152 of the bottom loading platform 15 is slightly higher than the cross rod 113 of the subframe 11.

[0029] When the push cart 100 is in the folded state, the height maintained by the cross bars 33 of the bottom frame 3 is approximately the same as the height of the cross bars 33 of the bottom frame 3 when the push cart 100 is in the unfolded state, but the cross bars 33 of the bottom frame 3 are in close contact with the sub-frame 11. The side bars 31 of the bottom frame 3 extend substantially downward from the connection with the side edge 153 of the bottom loading platform 15, and the side bars 32 of the bottom frame 3 extend substantially downward from the connection with the side edge 154 of the bottom loading platform 15.

[0030] The side rods 21 of the handle frame 2 extend in nearly close contact with the side rods 111 of the subframe 11 of the main frame, the side rods 121 of the subframe 12, and the side rods 131 of the subframe 13, and the side rods 22 of the handle frame 2 extend in nearly close contact with the side rods 112 of the subframe 11 of the main frame, the side rods 122 of the subframe 12, and the side rods 132 of the subframe 13. In other words, the side rods 111 of the subframe 11, the side rods 121 of the subframe 12, and the side rods 131 of the subframe 13 extend nearly along the side rods 21, and the side rods 112 of the subframe 11, the side rods 122 of the subframe 12, and the side rods 132 of the subframe 13 extend nearly along the side rods 22. In addition, the end 211 of the side rod 21 of the handle frame 2 is close to the end 1112 of the side rod 111 of the subframe 11 , and the end 221 of the side rod 22 of the handle frame 2 is close to the end 1122 of the side rod 112 of the subframe 11 .

[0031] Referring to Figures 2A and 2B, the connecting rod 4 is in close contact with the side rod 121 of the subframe 12 of the main frame 1 and the side rod 131 of the subframe 13, and extends along the side rod 121 of the subframe 12 and the side rod 131 of the subframe 13, while the connecting rod 5 is in close contact with the side rod 122 of the subframe 12 of the main frame 1 and the side rod 132 of the subframe 13, and extends along the side rod 122 of the subframe 12 and the side rod 132 of the subframe 13.

[0032] Wheels 61 and 63 are in close contact with each other because end 211 of side rod 21 of handle frame 2 is close to end 1112 of side rod 111 of sub-frame 11, and wheels 62 and 64 are in close contact with each other because end 221 of side rod 22 of handle frame 2 is close to end 1122 of side rod 112 of sub-frame 11. When the push cart 100 is in a folded state, wheels 61, 62, 63, and 64 can simultaneously touch the ground, allowing the folded push cart 100 to stand stably on the ground, and a user can push the push cart 100 across the ground using wheels 61, 62, 63, and 64.

[0033] 3A, 3B, and 3C are schematic diagrams showing how the push cart 100 according to one embodiment of the present disclosure changes from an unfolded state to a folded state. The applicant intends to explain how the push cart 100 changes from an unfolded state to a folded state through the disclosure of FIGS. 3A, 3B, and 3C, and for convenience of explanation, the left side of the push cart 100 is used as the observation angle.

[0034] 3A shows the push cart 100 in an unfolded state, with the main frame 1 fully unfolded. The side rods 121 of the subframe 12, the side rods 131 of the subframe 13, and the side edges 153 of the bottom loading platform 15 extend substantially perpendicular to the side rods 111 of the subframe 11, i.e., the side rods 111 of the subframe 11 extend substantially perpendicular to the ground, while the side rods 121 of the subframe 12, the side rods 131 of the subframe 13, and the side edges 153 of the bottom loading platform 15 extend horizontally to the ground. The side rods 31 of the bottom frame 3 extend along the side edges 153 of the bottom loading platform 15, i.e., the side rods 31 of the bottom frame 3 extend substantially perpendicular to the ground. The connecting rod 4 is connected to the side rod 121 of the sub-frame 12, the side rod 131 of the sub-frame 13 and the side edge 153 of the bottom loading platform 15, and extends substantially horizontally to the ground.

[0035] The side rods 21 of the handle frame 2 are connected to the side rods 121 of the subframe 12 and the side rods 31 of the bottom frame 3, and extend at an angle from above the side rods 111 of the subframe 11 toward the bottom frame 3. The wheels 61, 63 may be located on approximately the same horizontal plane.

[0036] When a user wants to switch the push cart 100 from the unfolded state to the folded state, as shown in FIG. 3B , the user can rotate / move the handle frame 2 to gradually approach the sub-frame 11 of the main frame 1. For example, the user can apply force to rotate / move the end 211 of the side rod 21 of the handle frame 2 toward the sub-frame 11.

[0037] This rotational movement causes the bottom frame 3 to rotate accordingly, thereby rotating the rotatably connected bottom loading platform 15. Since the connecting rod 4 is rotatably connected to the bottom loading platform 15, the sub-frames 12, and the sub-frames 13, when the bottom loading platform 15 is driven to rotate by the bottom frame 3, the connecting rod 4 also synchronously rotates the sub-frames 12, 13 toward the sub-frame 11 of the main frame 1, bringing them closer.

[0038] As another folding method, the user can directly rotate the subframe 12 and move it closer to the subframe 11 of the main frame 1. For example, the user can rotate the entire subframe 12 to a position close to the subframe 11 by lifting the horizontal rod 123 of the subframe 12 upward.

[0039] When the subframe 12 rotates, the subframe 13 and the bottom loading platform 15, which are rotatably connected via the connecting rod 4, also rotate accordingly, and both move closer to the subframe 11. Furthermore, since the bottom loading platform 15 is rotatably connected to the bottom frame 3, and the bottom frame 3 is rotatably connected to the handle frame 2, the bottom frame 3 and the handle frame 2 also rotate in synchronization with the rotation of the bottom loading platform 15, and ultimately move closer to the subframe 11.

[0040] 3B, when the push cart 100 is being switched from the unfolded state to the folded state, as viewed from the left side, the side rod 121 of the subframe 12, the side rod 131 of the subframe 13, and the side edge 153 of the bottom loading platform 15 rotate counterclockwise around the connection with the side rod 111 of the subframe 11. Meanwhile, the side rod 31 of the bottom frame 3 rotates clockwise around the connection with the side rod 21 of the handle frame 2. It can be seen that the side rod 121 rotates counterclockwise around the end 1211, the side rod 131 also rotates counterclockwise together with the side rod 121, the side edge 153 rotates counterclockwise around the cross rod 115, and the side rod 31 rotates clockwise around the cross rod 33.

[0041] It can be seen that the rotation direction of the sub-frames 12, 13 and bottom loading platform 15 is opposite to that of the bottom frame 3 during the process of switching the push cart 100 from the unfolded state to the folded state.

[0042] In some embodiments of the present disclosure, the wheels 61 and 63 can be maintained on the same horizontal plane during the process of switching the push cart 100 from the unfolded state to the folded state. In other words, the wheels 61 and 63 can always be in contact with the ground during the process of switching the push cart 100 from the unfolded state to the folded state.

[0043] Finally, by rotating the sub-frames 12, 13 and bottom loading platform 15, the main frame 1 can be completely folded, and by rotating the handle frame 2 and bottom frame 3, the overall length of the push cart 100 is reduced to a minimum, and finally the push cart 100 is in the folded state (Figure 3C).

[0044] 4A, 4B, and 4C are schematic diagrams showing how the push cart 100 according to one embodiment of the present disclosure changes from a folded state to an unfolded state. The applicant intends to explain how the push cart 100 changes from a folded state to an unfolded state through the disclosure of FIGS. 4A, 4B, and 4C, and for convenience of explanation, the left side of the push cart 100 is used as the observation angle.

[0045] 4A shows the push cart 100 in a folded state. As shown in FIG. 4A, the sub-frames 11, 12, and 13 of the main frame 1 are closely packed together, allowing the main frame 1 to be completely folded, and the handle frame 2 is also closely packed against the sub-frame 11, thereby minimizing the overall length of the push cart 100.

[0046] When a user wishes to switch the push cart 100 from the folded state to the unfolded state, as shown in Figure 4B, the user can rotate the handle frame 2 to gradually move it away from the sub-frame 11 of the main frame 1. For example, the user can apply force to move the end 211 of the side rod 21 of the handle frame 2 in a direction away from the sub-frame 11.

[0047] This rotational movement causes the bottom frame 3 to rotate accordingly, thereby rotating the rotatably connected bottom loading platform 15. Since the connecting rod 4 is rotatably connected to the bottom loading platform 15, the subframe 12, and the subframe 13, when the bottom loading platform 15 is driven to rotate by the bottom frame 3, the connecting rod 4 also synchronously rotates the subframes 12 and 13 in a direction away from the subframe 11.

[0048] As another deployment method, the user can directly rotate the subframe 12 to separate it from the subframe 11 of the main frame 1. For example, the user can move the horizontal rod 123 of the subframe 12 downward to rotate the entire subframe 12 to a position separated from the subframe 11.

[0049] When the subframe 12 rotates, the subframe 13 and bottom loading platform 15, which are rotatably connected via the connecting rod 4, also rotate accordingly, and both rotate in a direction away from the subframe 11. Furthermore, since the bottom loading platform 15 is rotatably connected to the bottom frame 3, and the bottom frame 3 is rotatably connected to the handle frame 2, the bottom frame 3 and the handle frame 2 also rotate in sync with the rotation of the bottom loading platform 15, and eventually move away from the subframe 11 together.

[0050] 4B , when the push cart 100 is being switched from the folded state to the unfolded state, as viewed from the left side, the side rod 121 of the subframe 12, the side rod 131 of the subframe 13, and the side edge 153 of the bottom loading platform 15 rotate clockwise around the connection with the side rod 111 of the subframe 11. Meanwhile, the side rod 31 of the bottom frame 3 rotates counterclockwise around the connection with the side rod 21 of the handle frame 2. It can be seen that the side rod 121 rotates clockwise around the end 1211, the side rod 131 also rotates clockwise together with the side rod 121, the side edge 153 rotates clockwise around the cross rod 115, and the side rod 31 rotates counterclockwise around the cross rod 33.

[0051] It can be seen that the rotation direction of the sub-frames 12, 13 and bottom loading platform 15 is opposite to that of the bottom frame 3 during the process of switching the push cart 100 from the folded state to the unfolded state.

[0052] In some embodiments of the present disclosure, the wheels 61 and 63 can be maintained on the same horizontal plane during the process of switching the push cart 100 from the folded state to the unfolded state. In other words, the wheels 61 and 63 can always be in contact with the ground during the process of switching the push cart 100 from the folded state to the unfolded state.

[0053] Finally, by rotating the sub-frames 12, 13 and bottom loading platform 15, the main frame 1 can be fully unfolded, and by rotating the handle frame 2 and bottom frame 3, the overall length of the push cart 100 is extended to its maximum, and finally the push cart 100 reaches the unfolded state (Figure 4C).

[0054] The present disclosure provides a foldable push cart with a multi-frame linkage mechanism, which allows the push cart to smoothly switch between an unfolded state and a folded state through the relative rotation relationships between the main frame, handle frame, bottom frame, loading platform, and multiple sets of connecting rods. The main features are as follows:

[0055] 1. Modular structural design: This device uses multiple sets of relatively rotatable subframes and connecting rods. Through the design of geometric correspondence and rotation restrictions, each component is linked during the unfolding and folding process, achieving smooth operation without the need for complex mechanisms.

[0056] 2. Mutual coordination of rotation directions: During the folding or unfolding process, the rotation directions of each set of components are designed to complement each other, ensuring stability and symmetry when the structure is folded or unfolded, and reducing the risk of structural interference or snagging.

[0057] 3. Stable ground contact with four wheels: Whether unfolded or folded, all four wheels can always be in contact with the ground, ensuring excellent stability and preventing tipping over whether the cart is stationary or moving.

[0058] 4. Freestanding storage: The structural design of this invention allows the push cart to stand on its own even when folded, making it convenient for temporary storage or upright storage, improving usability.

[0059] 5. One-touch unfolding and folding: Users can unfold or fold the entire interlocking mechanism simply by pushing or pulling the handle frame, improving intuitive operability and efficiency. [Industrial Applicability]

[0060] In summary, this invention not only improves the operational convenience and structural stability of the push cart, but also effectively solves the problems of the prior art, such as the complexity of unfolding and folding, unstable storage, and inconvenience of use, and has high practicality and industrial application value.

[0061] The above description briefly outlines the features of some embodiments of the present disclosure, allowing those skilled in the art to more fully understand each aspect of the present disclosure. It will be apparent to those skilled in the art that, based on the present disclosure, they can easily design or modify other manufacturing processes and structures to achieve the same objectives and / or advantages as the embodiments of the present disclosure. It will be apparent to those skilled in the art that these equivalent embodiments still fall within the spirit and scope of the present disclosure, and that various modifications, substitutions, and variations can be made thereto without departing from the spirit and scope of the present disclosure. [Explanation of symbols]

[0062] 1. Mainframe 2 Handle frame 3 Bottom Frame 4 connecting rod 5 Connecting rod 11 Subframe 12 subframes 13 Subframe 15 Bottom loading platform 21 Side beam 22 Side beam 23 horizontal rod 31 Side beam 32 Side beam 33 Horizontal rod 61 wheels 62 wheels 63 wheels 64 wheels 100 Push Carts 111 Side beam 112 Side beam 113 Horizontal rod 115 Horizontal rod 121 Side beam 122 Side beam 123 Horizontal rod 131 Side beam 132 Side beam 133 Horizontal rod 151 Posterior side 152 Front side 153 side 154 Side 211 End 221 End 311 End 312 End 321 End 322 End 1111 End 1112 End 1121 End 1122 End 1511 Hook part

Claims

1. a first subframe including a first side rod having a first end, a second side rod having a second end, and a horizontal rod connecting the first end and the second end; a second subframe including a third side rod having a third end and a fourth side rod having a fourth end, the third end of the third side rod being rotatably connected to the first side rod and the fourth end of the fourth side rod being rotatably connected to the second side rod; a bottom loading platform having a first side pivotally connected to the cross rod of the first subframe and positioned adjacent the first end and the second end; a first connecting rod rotatably connected to the third side rod of the second sub-frame and a second side edge of the bottom loading platform opposite to the first side edge; a second connecting rod rotatably connected to the fourth side rod of the second sub-frame and the second side edge of the bottom loading platform; a mainframe comprising: a handle frame including a fifth side rod having a fifth end, a sixth side rod having a sixth end, and a handle cross rod connecting the fifth side rod and the sixth side rod, wherein the fifth side rod is rotatably connected to the third side rod of the second subframe, and the sixth side rod is rotatably connected to the fourth side rod of the second subframe; a bottom frame including a seventh side rod having a seventh end and an eighth side rod having an eighth end, the seventh end of the seventh side rod being rotatably connected to a third side edge of the bottom loading platform, the eighth end of the eighth side rod being rotatably connected to a fourth side edge of the bottom loading platform opposite the third side edge, the fifth end of the fifth side rod of the handle frame being rotatably connected to a ninth end opposite the seventh end of the seventh side rod, and the sixth end of the sixth side rod of the handle frame being rotatably connected to a tenth end opposite the eighth end of the eighth side rod; four wheels, two of which are connected to the first side rod and the second side rod of the first frame of the main frame, respectively, and are located near the first end and the second end, and the remaining two of which are connected to the fifth side rod and the sixth side rod of the handle frame, respectively, and are located near the fifth end and the sixth end; A push cart comprising: When the second sub-frame of the main frame rotates relative to the first sub-frame, the handle frame moves relative to the first sub-frame, and at the same time, the bottom frame rotates relative to the handle frame and the bottom loading platform, and further, the bottom loading platform rotates relative to the first sub-frame of the main frame, causing the push cart to assume a folded state or an unfolded state.

2. 2. The push cart of claim 1, wherein, when the push cart is placed on the ground in the unfolded state, the first and second side rods of the first sub-frame of the main frame extend substantially perpendicular to the ground, the third and fourth side rods of the second sub-frame extend substantially horizontally to the ground, and the third and fourth side edges of the bottom loading platform extend substantially parallel to the third and fourth side rods of the second sub-frame, respectively.

3. 2. The push cart of claim 1, wherein, when the push cart is placed on the ground in the folded state, the first side rod of the first sub-frame, the third side rod of the second sub-frame, and the seventh side rod of the bottom frame extend substantially closely to the fifth side rod of the handle frame, the second side rod, the fourth side rod, and the eighth side rod extend substantially closely to the sixth side rod, the third side edge of the bottom loading platform extends substantially closely to the first side rod of the first sub-frame, and the fourth side edge extends substantially closely to the second side rod.

4. 4. The push cart according to claim 3, wherein when the push cart is placed on the ground in the folded state, the four wheels simultaneously contact the ground and are supported by the ground, allowing the push cart to stand on the ground without tipping over.

5. 2. The push cart according to claim 1, wherein the four wheels can always contact the ground during the process of changing the push cart from the folded state to the unfolded state or during the process of changing the push cart from the unfolded state to the folded state.

6. 2. The push cart of claim 1, wherein, when observed from the side, during the process of the push cart changing from the unfolded state to the folded state, the third side rod of the second sub-frame rotates approximately around the third end along a first rotation direction, the fourth side rod rotates approximately around the fourth end along the first rotation direction, the seventh side rod of the bottom frame rotates approximately around the fifth end along a second rotation direction opposite to the first rotation direction, and the eighth side rod rotates approximately around the sixth end along the second rotation direction.

7. 2. The push cart of claim 1, wherein the main frame further comprises a third subframe pivotally connected to the first subframe and disposed between the second subframe and the bottom loading platform.

8. The push cart of claim 1 , wherein the bottom loading platform comprises a grid structure.

9. A first frame; a second frame rotatably connected to the first frame; a loading platform rotatably connected to the first frame; at least one connecting rod pivotally connected to the second frame and the loading platform; a handle frame rotatably connected to the second frame; a bottom frame rotatably connected to the loading platform and also rotatably connected to the handle frame; A push cart comprising: When observed from the side, when the handle frame is moved, the second frame and the bottom frame rotate relative to the first frame in a first rotation direction, and the bottom frame rotates relative to the handle frame in a second rotation direction opposite to the first rotation direction, thereby switching the push cart between an unfolded state and a folded state.

10. Further provided with four wheels, Two of the four wheels are provided at the connection portion between the first frame and the bottom frame, 10. The push cart according to claim 9, wherein the remaining two of the four wheels are provided at the connection between the handle frame and the bottom frame, respectively.

11. 11. The push cart of claim 10, wherein the four wheels are always maintained on the same horizontal plane during the process of switching the push cart between the unfolded state and the folded state.

12. 10. The push cart of claim 9, wherein when the push cart is in the unfolded state, the side rods of the second frame, the side edges of the loading platform, and the side rods of the bottom frame are perpendicular to the side rods of the first frame, and when the push cart is in the folded state, the extension directions of the side rods of the second frame, the side edges of the loading platform, and the side rods of the bottom frame are substantially the same as the extension directions of the side rods of the first frame.

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