Turnover structure of folding linkage wheel of cart

Abstract

The utility model provides a turnover structure of a folding linkage wheel of a cart, which comprises a pair of side rods, a pair of lower side rods, a carrying frame and a pair of side bottom rods, the tail ends of the lower side rods are pivoted with the side bottom rods, the two side rods and a pair of supporting handles are pivoted with the carrying frame, the front parts of the side bottom rods are pivoted with a front wheel group, the rear parts of the side bottom rods are pivoted with a rear wheel group, and the lower side rods and the supporting handles are in an X-shaped crossed state; the folding cart is mainly characterized in that a pair of movable rods respectively penetrate into and can move in the side bottom rods, when the cart is folded, the movable rods are linked together to move backwards, and the movable rods move backwards to drive the front wheel set and the rear wheel set to be turned and folded inwards.

Description

[Technical Field]

[0001] This utility model relates to a folding and retracting mechanism for a trolley, specifically a folding and retracting mechanism that simultaneously causes the front and rear wheel sets to fold inwards during the folding and retracting action of the trolley, thereby reducing its height without requiring a separate action to fold the front and rear wheel sets inwards. [Background Technology]

[0002] Traditional baby strollers are designed to make it easy for caregivers to place their babies inside and push them around, allowing the babies to experience the outdoors. They are also easy to carry and are an essential baby accessory for most parents and caregivers, relieving the inconvenience of parents having to hold the baby in their arms. However, the function of baby strollers is not limited to this. They can also be folded up, reducing their size and making them easier to fit into vehicles without taking up much space. This also makes them convenient for transportation and storage. Baby strollers must have a folding structure to meet the needs of the general public.

[0003] However, although traditional strollers have folding and unfolding structures, the front and rear wheels always take up a certain amount of space (height). If there is not enough storage space inside the mini stroller, the folded stroller is not easy to put into the mini stroller, which is very troublesome for caregivers.

[0004] Currently available work trolleys on the market typically have a platform, a handle, two front wheels, and two rear wheels. The platform is used for carrying goods, the handle is pivotally connected to the rear end of the platform, and the two front wheels and two rear wheels are pivotally connected to the bottom of the platform. There is also a handle folding device, a front wheel folding device, and a rear wheel folding device. The handle folding device allows the handle to be folded or unfolded. The front wheel folding device allows the two front wheels to be flipped inwards or unfolded into a standing position. The rear wheel folding device allows the two rear wheels to be flipped inwards or unfolded into a standing position. Folding the work trolley requires a specific sequence of actions: first, fold the two front wheels inwards, then fold the two rear wheels inwards, and finally fold the handle forwards to lie flat on the platform. This requires three actions to complete the folding process. Although folding reduces the size and height, it is not very convenient for the operator, requiring three precise steps to fold, which is time-consuming and laborious.

[0005] Currently, traditional baby strollers only have a folding mechanism, lacking a folding front and rear wheel flip mechanism, or a mechanism that simultaneously flips the front and rear wheels when folding. If a baby stroller could fold with the front and rear wheels flipping simultaneously, it would not only reduce the overall size of the stroller but also allow for a single, easy folding action, which would be a great benefit to parents or caregivers. Similarly, work strollers also lack a folding mechanism that simultaneously flips the front and rear wheels, which is indeed inconvenient for users.

[0006] The above problems clearly need to be improved. [Utility Model Content]

[0007] This utility model discloses a flipping structure for a stroller's folding and rotating wheels. Its purpose is: 1. To provide a system where, when folding the stroller, both front and rear wheel sets flip simultaneously, eliminating the need for a second flip, thus greatly facilitating user operation. 2. To reduce the height and size of the folded stroller, making it easier to store and transport. 3. To allow the stroller to be fully unfolded in a single operation, without requiring a second flip of the front and rear wheel sets. 4. This folding and rotating wheel structure has wide applicability; it can be pushed, pulled, used to carry items, used as a baby stroller, a camping cart, or a shopping cart.

[0008] To achieve the above objectives, this utility model provides a folding and flipping structure for a trolley with folding linkage wheels. The trolley includes:

[0009] A pair of side bars, with a handrail attached above the side bar and a turning latch attached below the side bar. The turning latch is pivotally connected to a lower side bar, and the end of the lower side bar is pivotally connected to a side base bar. A push button is located on the inside of the side bar, which is connected to a steel cable to the turning latch. Sliding the push button releases the latch between the side bar and the lower side bar, and the side bar and the lower side bar change from their original straight extended state to a folded state. The bottom of the lower side bar is connected to the side base bar. A front wheel set is pivotally connected to the front of the side base bar, and a rear wheel set is pivotally connected to the rear.

[0010] A loading frame is a frame body with each side pivotally connected to a two-sided rod. A pair of support handles are pivotally connected at the upper end to the loading frame, at the lower end to a movable rod, and at the middle end to the inner side of the lower rod, so that the lower rod and the support handles are in an X-shaped cross state.

[0011] Its features include: the side bottom rod has a front tube, a connecting handle, and a rear tube, the connecting handle connecting the front tube and the rear tube, the movable rod passing through it, the movable rod having two symmetrical front protrusions at the front and two symmetrical rear protrusions at the rear, a front sleeve inserted above the top of the front wheel assembly, the front sleeve having two symmetrical front arc-shaped grooves, the front protrusions entering the front arc-shaped grooves, a rear sleeve inserted above the top of the rear wheel assembly, the rear sleeve having two symmetrical rear arc-shaped grooves, the rear protrusions entering the rear arc-shaped grooves, when the stroller is folded, the support handle changes from an inclined state to a more inclined state, pulling the movable rod backward, the movable rod causing the front sleeve and the rear sleeve to turn, causing the front wheel assembly and the rear wheel assembly to turn inward and fold simultaneously.

[0012] The lower end of the rod has a pivot double lug and a short round tube, which is used to connect the front tube.

[0013] The front tube of the side bottom rod is provided with a front sliding groove, which allows the front protrusion of the movable rod to enter and move. The rear tube of the side bottom rod is provided with a rear sliding groove, which allows the rear protrusion of the movable rod to enter and move.

[0014] The front wheel assembly has a front cross tube on top, which is connected to a front sleeve by a front pin, so that the front cross tube and the front sleeve turn synchronously. The rear wheel assembly has a rear cross tube on top, which is connected to a rear sleeve by a rear pin, so that the rear cross tube and the rear sleeve turn synchronously.

[0015] There is a gap between the front tube and the rear tube, and a connecting handle is provided in the gap. The gap allows the movable rod to move and the support handle to connect.

[0016] The top of the support handle is pivotally connected to the carrying frame with a double lug, and the bottom is pivotally connected to the lower side rod with a bottom ring.

[0017] The push button on the inner side of the side rod has a connecting protrusion, and a straight groove is provided on the inner side of the side rod for the displacement of the connecting protrusion. The connecting protrusion is connected to a pull block, the pull block is connected to a steel cable, and the top of the pull block presses against a spring. A limiting component is positioned inside the side rod for the pull block and spring to be assembled inside.

[0018] The turn-lock button comprises an inner shell, a miniature compression spring, a rotating assembly, a lower side rod top locking component, a side rod bottom locking component, a locking pin assembly, a compression spring, and an outer shell. The inner shell has a shaft, and the outer shell has a shaft hole, connected by a stud. The two components are assembled together, forming the miniature compression spring, the rotating assembly, the lower side rod top locking component, the side rod bottom locking component, the locking pin assembly, and the compression spring. A handle is located at the bottom of the inner shell. The rotating assembly rotates due to a steel cable connected to the push-button mechanism, pressing against the miniature compression spring. The rotating assembly has two symmetrical arc-shaped grooves on its outer surface, with the depth of the grooves gradually increasing. The lower side rod top locking component is a circular plate. There are several locking holes. Below the lower side rod top locking member is a lower handle. The lower handle is connected to the lower handle of the inner shell. After the lower handle is joined together, it is inserted into the top of the lower side rod. The side rod bottom locking member is a ring with two locking notches inside. Above the side rod bottom locking member is an upper handle. The locking pin assembly is a circular plate with two protruding locking plates on the outer circumference and several protruding locking pins on the inner surface. The locking plates can be locked into the locking notches of the side rod bottom locking member. The locking pins can be inserted into the locking holes of the lower side rod top locking member. The locking pin assembly is supported by a compression spring located inside the outer shell. Above the outer shell is an upper handle. A positioning upper handle is used to connect the upper handle and the lower handle of the side rod bottom locking member and is inserted into the bottom end of the side rod.

[0019] The front end of the vehicle frame is pivotally connected to a front pull handle.

[0020] Three bridging rods are provided between the bottom rods on both sides.

[0021] The advantages and beneficial effects of this utility model are as follows: When folding the stroller, both front and rear wheel sets are flipped simultaneously, eliminating the need for a second flip, which is very convenient for the user. After folding, the stroller's height is reduced and its size decreased, making it easy to store and transport. When fully unfolded, the stroller unfolds in a single operation, without requiring a second flip of the front and rear wheel sets. This folding and flipping wheel structure has wide applicability; it can be pushed, pulled, used to carry items, used as a baby stroller, a camping cart, or a shopping cart. [Attached Image Description]

[0022] Figure 1 This is a three-dimensional exploded view of the present invention.

[0023] Figure 2 This is a three-dimensional exploded view of the side bottom rod, lower side rod, and movable rod of this utility model.

[0024] Figure 3 This is a three-dimensional exploded view of the turning lever button of this utility model.

[0025] Figure 4 This is a three-dimensional combined schematic diagram of the present invention.

[0026] Figure 5 This is a three-dimensional schematic diagram of the present invention in its semi-folded state.

[0027] Figure 6 This is a three-dimensional schematic diagram of the present invention in its folded-down state.

[0028] Figure 7 This is a cross-sectional schematic diagram of the push button inside the side rod of this utility model.

[0029] Figure 8 This is a cross-sectional schematic diagram of the locking state of the turning lever button of this utility model.

[0030] Figure 9 This is a cross-sectional schematic diagram of the release state of the turn-locking button of this utility model.

[0031] Figure 10 This is a three-dimensional schematic diagram of the front wheel assembly of this utility model in an upright position.

[0032] Figure 11 This is a three-dimensional schematic diagram of how the movable rod of this utility model drives the front wheel assembly to flip inward.

[0033] The labels in the diagram are explained as follows:

[0034] 1. Stroller; 10. Side bars; 20. Handrails; 30. Turning levers / buttons

[0035] 40 lower side rail, 50 side bottom rail, 60 front wheel assembly, 70 rear wheel assembly

[0036] 80 Loading frame 11 Push button 12 Steel cable 111 Connecting protrusion

[0037] 112 Straight groove 13 Pull block 14 Spring 15 Limiting assembly

[0038] 90 Support handle 100 Movable rod 91 Double lugs 92 Bottom ring

[0039] 110 Front pull handle 120 Bridge rod 31 Inner shell 32 Miniature compression spring

[0040] 33 Rotating assembly; 34 Lower side rod top locking component; 35 Side rod bottom locking component; 36 Locking pin assembly

[0041] 37 Compression spring; 38 Housing; 311 Shaft; 381 Shaft hole

[0042] 383 stud, 312 lower shank, 331 arc-shaped groove, 341 locking hole

[0043] 342 Lower Handle, 351 Card Miss, 352 Upper Handle, 361 Card Plate

[0044] 362 Locking pin, 382 Upper handle, 39 Positioning side upper handle, 51 Front tube

[0045] 52 Connecting handle 53 Rear tube 521 Notch 41 Pivot double lug

[0046] 42 Short round tube 101 Front protrusion 102 Rear protrusion 61 Front sleeve

[0047] 611 Front arc-shaped slide groove; 62 Front cross cylinder; 63 Front pin; 71 Rear sleeve

[0048] 711 Rear arc-shaped slide rail; 72 Rear cross cylinder; 73 Rear pin; 511 Front slide rail

[0049] 531 rear slide

Detailed Implementation Methods

[0050] This utility model discloses a folding and flipping structure for a trolley's folding linkage wheels, such as... Figure 1-4 As shown, the trolley 1 includes a pair of side rods 10, a handrail 20, two pivot latches 30, a pair of lower side rods 40, a pair of side bottom rods 50, a pair of front wheel sets 60, a pair of rear wheel sets 70, and a carrying frame 80. An inverted U-shaped handrail 20 is attached above the side rods 10, and a pivot latch 30 is attached below the side rods 10. The pivot latch 30 is pivotally connected to the lower side rods 40, and the end of the lower side rods 40 is pivotally connected to the side bottom rods 50. A push button 11 is provided on the inner side of the side rods 10, connecting a steel cable 12 to the pivot latch 30. The push button 11 on the outer side of the inner side of the side rods 10 has a connecting protrusion 111 (e.g., ...). Figure 7As shown), a straight groove 112 is provided on the inner side of the side rod 10 for the displacement of the connecting protrusion 111. The connecting protrusion 111 is connected to a pull block 13, which is connected to a steel cable 12. The top of the pull block 13 presses against a spring 14. A limiting component 15 is positioned inside the side rod 10. The limiting component 15 is closed at the top and bottom, allowing the pull block 13 and spring 14 to be assembled inside. The pull block 13 can return to its original position when pressed by the spring 14. Sliding the push button 11 pulls the steel cable 12, and the linkage of the steel cable 12 releases the jamming between the side rod 10 and the lower side rod 40 (as described later). The side rod 10 and the lower side rod 40 can change from the original straight extended state to a folded state. The bottom of the lower side rod 40 is connected to the side bottom rod 50. A front wheel assembly 60 is pivotally connected to the front of the side bottom rod 50, and a rear wheel assembly 70 is pivotally connected to the rear.

[0051] A carrying frame 80 is a frame composed of several rods. The sides of the carrying frame 80 are pivotally connected to the two side rods 10 at a short distance behind the middle. The two sides of the carrying frame 80 are pivotally connected to the lower part of the carrying frame 80 at a short distance forward from the middle. The lower end of the support handle 90 is pivotally connected to a movable rod 100, and the middle end of the support handle 90 is pivotally connected to the inner side of the lower side rod 40 at a position about the middle, so that the lower side rod 40 and the support handle 90 are in an X-shaped cross state. The top of the support handle 90 is pivotally connected to the carrying frame 80 by a double lug 91, and the bottom end is pivotally connected to the lower side rod 40 by a bottom ring 92. The front end of the carrying frame 80 is pivotally connected to a front pull handle 110 (optional). Three transverse bridging rods 120 are provided between the two bottom rods 50.

[0052] like Figure 1 , 3 As shown, the pivot latch 30 includes an inner shell 31, a miniature compression spring 32, a rotating assembly 33, a lower rod top latch 34, a side rod bottom latch 35, a latching pin assembly 36, a compression spring 37, and an outer shell 38. The inner shell 31 has a shaft 311, and the outer shell 38 has a shaft hole 381, which is connected by a stud 383 (e.g., Figure 8-9 As shown), a miniature compression spring 32, a rotating assembly 33, a lower rod top locking member 34, a side rod bottom locking member 35, a locking pin assembly 36, and a compression spring 37 are assembled together. The inner shell 31 has a lower handle 312 at its bottom. The rotating assembly 33 is subjected to... Figure 7 The push button 11 is connected to the steel cable 12 and rotates in conjunction with it. The rotating component 33 presses against the miniature compression spring 32, and the rotating component 33 can return to its original position due to the pressure of the miniature compression spring 32. The rotating component 33 has two symmetrical arc-shaped grooves 331 on its outside. The depth of the arc-shaped grooves 331 gradually increases from low to high, forming a low contact surface to a high contact surface (e.g., Figure 3 , 8As shown in Figure 9), the lower rod top locking member 34 is a circular plate with several locking holes 341. Below the lower rod top locking member 34 is a lower handle 342, which is connected to the lower handle 312 of the inner shell 31. After the lower handle 342 is combined with the lower handle 312, it is inserted into the top of the lower rod 40. The side rod bottom locking member 35 is a circular ring with two locking notches 351 inside. Above the side rod bottom locking member 35 is an upper handle 352. The locking pin assembly 36 is a circular plate with two protruding locking plates 361 on the outer periphery and several protruding locking pins 362 on the inner surface. 361 can be locked in the notch 351 of the side rod bottom locking member 35, and the locking pin 362 can be inserted into the locking hole 341 of the lower side rod top locking member 34 and press against the arc-shaped groove 331 of the rotating component 33. The outside of the locking pin assembly 36 is pressed against by the compression spring 37 located inside the housing 38. The locking pin assembly 36 can return to its original position by being pressed against by the compression spring 37. There is an upper handle 382 on the upper part of the housing 38, and a positioning side upper handle 39 is used to connect the upper handle 382 and the secondary upper handle 352 of the side rod bottom locking member 35 and are inserted into the bottom end of the side rod 10. (The above structure and device are conventional and commonly used technologies, and their operation is the same as conventional methods.)

[0053] like Figure 1-2As shown, the feature of this case is that: the side bottom rod 50 is a combination of a front tube 51, a connecting handle 52 and a rear tube 53. The connecting handle 52 connects the front tube 51 and the rear tube 53. The outer diameter of the movable rod 100 is slightly smaller and can pass through the front tube 51 and the rear tube 53. There is a gap 521 between the front tube 51 and the rear tube 53. The connecting handle 522 is provided in the gap 521. The gap 521 allows the movable rod 100 to move at the pivot point with the support handle 90. The bottom end of the lower side rod 40 has a A double lug 41 and a short round tube 42 are pivotally connected. The short round tube 42 is used to connect the front tube 51. The movable rod 100 has two symmetrical front protrusions 101 at the front and two symmetrical rear protrusions 102 at the rear. A front sleeve 61 is inserted into the top of the front wheel assembly 60. The front sleeve 61 has two symmetrical front arc-shaped sliding grooves 611. The front protrusions 101 are inserted into the front arc-shaped sliding grooves 611. The top of the front wheel assembly 60 has a front cross tube 62. The front cross tube 62 is connected to the front sleeve by a front pin 63. 61. The front cross tube 62 and the front sleeve 61 turn synchronously. A rear sleeve 71 is inserted into the top of the rear wheel assembly 70. The rear sleeve 71 has two symmetrical rear arc-shaped sliding grooves 711. The rear protrusion 102 is inserted into the rear arc-shaped sliding grooves 711. The top of the rear wheel assembly 70 has a rear cross tube 72. The rear cross tube 72 is connected to the rear sleeve 71 by a rear pin 73, so that the rear cross tube 72 and the rear sleeve 71 turn synchronously. The front tube 51 of the side bottom rod 50 is provided with a front sliding groove 511. 511 allows the front protrusion 101 of the movable rod 100 to enter displacement. The rear tube 53 of the side bottom rod 50 is provided with a rear sliding groove 531, which allows the rear protrusion 102 of the movable rod 100 to enter displacement. When the stroller 1 is folded, the support handle 90 changes from an inclined state to a more inclined state, and the movable rod 100 is pulled backward. The movable rod 100 is linked to the front sleeve 61 and the rear sleeve 71 to turn, so that the two front wheel sets 60 and the two rear wheel sets 70 turn inward and fold in the same direction at the same time.

[0054] As can be seen from the above structure, the operation is the same as pushing a cart normally, without any additional actions required. Figure 1 , 7 As shown in Figures 8 and 9, firstly, use the fingers of both hands to simultaneously push the two push buttons 11 on the inner side of the two rods 10 upwards. The push buttons 11 pull the steel cable 12 upwards, and the steel cable 12 then pulls the rotating component 33 of the turning latch 30 to rotate at an angle (the actions up to this point are the same as in the traditional operation). The arc-shaped groove 331 of the rotating component 33 rotates and moves from the lower contact surface to the higher contact surface. The latch 362 abuts against the higher contact surface of the arc-shaped groove 331, which will push the latch component 36 outwards (as shown in Figure 9). Figure 9As shown), the locking plate 361 of the locking pin assembly 36 can disengage from the locking notch 351 of the side rod bottom locking member 35. At this time, the lower side rod top locking member 34 and the outer shell 38 are in a released state, and the pair of side rods 10 can move forward, so that the side rod 10 and the lower side rod 40, which were originally in a straight line, become an angle. When the angle is formed, the locking pin 362 will also disengage from the locking hole 341. Then, the handrail 20 is pressed down, and the lower side rod 40 and the support handle 90, which were originally in an X-shaped cross state, will gradually move closer together. At this time, the lower side rod 40 is positioned. The front tube 51 of the side bottom rod 50 remains unchanged, while the end of the support handle 90 moves backward. The end of the support handle 90 is connected to the movable rod 100, causing the movable rod 100 to move backward a short distance. As the movable rod 100 gradually moves backward, both the front protrusion 101 and the rear protrusion 102 of the movable rod 100 move backward. The front protrusion 101 is located in the front arc-shaped groove 611 of the front sleeve 61. At this time, the front sleeve 61 does not move but rotates, causing the front wheel assembly 60 to flip inward (e.g., Figure 5 , 10 (as shown in Figure 11); Similarly, the rear protrusion 102 is located in the rear arc-shaped groove 711 of the rear sleeve 71. At this time, the rear sleeve 71 does not move but rotates, driving the rear wheel assembly 70 to flip inward until the stroller 1 is completely folded up. The inward flipping of the front wheel assembly 60 and the rear wheel assembly 70 will (as shown in Figure 11). Figure 6 As shown, the front wheel assembly 60 and the rear wheel assembly 70 are placed in a horizontal position to reduce the volume of the upright front wheel assembly 61 and the rear wheel assembly 70, and to lower the height of the folded baby stroller 1.

[0055] This utility model allows the front wheel assembly 60 and rear wheel assembly 70 to be flipped simultaneously when the trolley 1 is folded up, eliminating the need for a second flipping action. This greatly facilitates user operation and lowers the height of the folding trolley 1, making it easy to store. Furthermore, when the trolley 1 is unfolded, the lower side rod 40 and support handle 90 gradually move from a nearly close position to their original X-shaped cross position, and the side rod 10 and lower side rod 40 gradually move from an angle to a straight line. The movable rod 100 moves forward, and the front protrusion 101 and rear protrusion... All the columns 102 move forward, and the front protruding column 101 is located in the front arc-shaped slide groove 611 of the front sleeve 61. At this time, the front sleeve 61 does not move but rotates, and drives the front wheel assembly 60 to flip outward into an upright position. The rear protruding column 102 is located in the rear arc-shaped slide groove 711 of the rear sleeve 71. At this time, the rear sleeve 71 does not move but rotates, and drives the rear wheel assembly 70 to flip outward into an upright position. The trolley 1 is fully unfolded, which is also an unfolding action. There is no need for a second action to flip the front wheel assembly 60 and the rear wheel assembly 70 into an upright position.

Claims

1. A folding and flipping structure for a trolley with folding linkage wheels, the trolley comprising: A pair of side bars, with a handrail attached above the side bar and a turning latch attached below the side bar. The turning latch is pivotally connected to a lower side bar, and the end of the lower side bar is pivotally connected to a side base bar. A push button is located on the inside of the side bar, which is connected to a steel cable to the turning latch. Sliding the push button releases the latch between the side bar and the lower side bar, and the side bar and the lower side bar change from their original straight extended state to a folded state. The bottom of the lower side bar is connected to the side base bar. A front wheel set is pivotally connected to the front of the side base bar, and a rear wheel set is pivotally connected to the rear. A loading frame is a frame body with each side pivotally connected to a two-sided rod. A pair of support handles are pivotally connected at the upper end to the loading frame, at the lower end to a movable rod, and at the middle end to the inner side of the lower rod, so that the lower rod and the support handles are in an X-shaped cross state. Its features are: The side bottom rod has a front tube, a connecting handle, and a rear tube. The connecting handle connects the front tube and the rear tube, and the movable rod passes through it. The movable rod has two symmetrical front protrusions at the front and two symmetrical rear protrusions at the rear. A front sleeve is inserted above the top of the front wheel assembly. The front sleeve has two symmetrical front arc-shaped grooves, and the front protrusions are inserted into the front arc-shaped grooves. A rear sleeve is inserted above the top of the rear wheel assembly. The rear sleeve has two symmetrical rear arc-shaped grooves, and the rear protrusions are inserted into the rear arc-shaped grooves. When the stroller is folded, the support handle changes from an inclined state to a more inclined state. Pulling the movable rod backward causes the movable rod to rotate the front sleeve and the rear sleeve, causing the front wheel assembly and the rear wheel assembly to fold inward simultaneously.

2. The folding and turning structure of the trolley's folding linkage wheels according to claim 1, characterized in that: The bottom end of the lower rod has a pivot double lug and a short round tube, which is used to connect the front tube.

3. The folding and turning structure of the trolley's folding linkage wheels according to claim 1, characterized in that: The front tube of the side bottom rod is provided with a front sliding groove, which allows the front protrusion of the movable rod to enter and move. The rear tube of the side bottom rod is provided with a rear sliding groove, which allows the rear protrusion of the movable rod to enter and move.

4. The flipping structure of the folding linkage wheel of the trolley according to claim 1, characterized in that: The front wheel assembly has a front cross tube on top, which is connected to a front sleeve by a front pin, so that the front cross tube and the front sleeve turn synchronously. The rear wheel assembly has a rear cross tube on top, which is connected to a rear sleeve by a rear pin, so that the rear cross tube and the rear sleeve turn synchronously.

5. The flipping structure of the folding linkage wheel of the trolley according to claim 1, characterized in that: There is a gap between the front tube and the rear tube, and a connecting handle is provided in the gap. The gap allows the movable rod to move at the pivot point of the support handle.

6. The flipping structure of the folding linkage wheel of the trolley according to claim 1, characterized in that: The top of the support handle is pivotally connected to the carrying frame with a double lug, and the bottom is pivotally connected to the lower side rod with a bottom ring.

7. The flipping structure of the folding linkage wheel of the trolley according to claim 1, characterized in that: The push button on the inner and outer sides of the side rod is equipped with a connecting protrusion. The inner side of the side rod is equipped with a straight groove for the displacement of the connecting protrusion. The connecting protrusion is connected to a pull block, which is connected to a steel cable. The top of the pull block presses against a spring. A limiting component is positioned inside the side rod for the pull block and spring to be assembled inside.

8. The flipping structure of the folding linkage wheel of the trolley according to claim 1, characterized in that: The turn-lock button comprises an inner shell, a miniature compression spring, a rotating assembly, a lower side rod top locking element, a side rod bottom locking element, a locking pin assembly, a compression spring, and an outer shell. The inner shell has a shaft, and the outer shell has a shaft hole, connected by a stud. The two are assembled together to form the miniature compression spring, the rotating assembly, the lower side rod top locking element, the side rod bottom locking element, the locking pin assembly, and the compression spring. A handle is located at the bottom of the inner shell. The rotating assembly rotates due to a steel cable connected to the push-button mechanism, pressing against the miniature compression spring. The rotating assembly has two symmetrical arc-shaped grooves on its outer surface, with the depth of the grooves gradually increasing. The lower side rod top locking element is a circular plate with... Several locking holes are present. Below the lower side rod top locking member is a lower handle, which is connected to the lower handle of the inner shell. After the lower handle is joined together, it is inserted into the top of the lower side rod. The side rod bottom locking member is a ring with two locking notches inside. Above the side rod bottom locking member is an upper handle. The locking pin assembly is a circular plate with two protruding locking plates on the outer circumference and several protruding locking pins on the inner surface. The locking plates can be locked into the locking notches of the side rod bottom locking member, and the locking pins can be inserted into the locking holes of the lower side rod top locking member. The locking pin assembly is supported by a compression spring located inside the outer shell. Above the outer shell is an upper handle, and a positioning upper handle is used to connect the upper handle and the secondary upper handle of the side rod bottom locking member, which are inserted into the bottom end of the side rod.

9. The flipping structure of the folding linkage wheel of the trolley according to claim 1, characterized in that: The front end of the vehicle frame is pivotally connected to a front pull handle.

10. The flipping structure of the folding linkage wheel of the trolley according to claim 1, characterized in that: Three bridging rods are provided between the bottom rods on both sides.

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