Linkage unlocking structure of folding cart

Abstract

The invention relates to a linkage unlocking structure of a folding cart, which comprises a handle pipe, a main body pipe, a front leg pipe and a rear leg pipe, an auxiliary joint comprises a handle joint seat and a main body upper joint seat, a locking mechanism and an unlocking mechanism are arranged between the handle joint seat and the main body upper joint seat, a first joint shaft is mounted on the handle joint seat, and a second joint shaft is mounted on the main body upper joint seat. The locking mechanism comprises a locking wheel and a locking spring, the unlocking mechanism comprises a top wheel and a first inhaul cable, an ejection wedge block is fixed to the end face of the handle joint seat in a protruding mode, an ejection wedge groove matched with the ejection wedge block is formed in the end face of the top wheel, a linkage piece is arranged on the main body upper joint seat and inserted into an unlocking caulking groove, and the main body upper joint seat is fixedly connected with the main body upper joint seat. The outer wall of the locking wheel is provided with a notch communicated with the unlocking caulking groove, a touch block sliding in the notch is fixed to the linkage piece in a protruding mode, and after the locking protruding teeth of the locking wheel are disengaged from the first tooth groove, the touch block protrudes out of the end face, away from the linkage piece, of the locking wheel. A linkage protruding block which abuts against the touch block to drive the linkage piece to rotate is fixed to the inner wall of the handle joint base in a protruding mode.

Description

Technical Field

[0001] This application relates to the field of stroller technology, and in particular to a linkage unlocking structure for a folding stroller, applicable to children's strollers, pet strollers, and toy strollers. Background Technology

[0002] Strollers play a crucial role in daily life as an essential mode of transportation. Based on the items they carry, strollers are mainly divided into children's strollers and pet strollers, providing convenience for infants and pets. With social development and improved living standards, the demand for strollers has become increasingly diversified. To meet the needs of use and storage in different scenarios, foldable strollers have gradually become the mainstream in the market.

[0003] Existing folding stroller frames consist of a handlebar tube, main body tube, front leg tube, and rear leg tube. The handlebar tube and main body tube are connected by a sub-joint for folding, while the front leg tube, rear leg tube, and main body tube are connected by a main joint for folding. However, the existing sub-joints and main joints each have locking and unlocking mechanisms, requiring the operator to disengage multiple unlocking mechanisms, thus increasing the difficulty of folding and storing the stroller. Therefore, further improvements are needed. Summary of the Invention

[0004] To improve the folding efficiency of the trolley, this application provides a linkage unlocking structure for a folding trolley.

[0005] The linkage unlocking structure for a folding trolley provided in this application adopts the following technical solution: A linkage unlocking structure for a folding trolley includes a handle tube, a main body tube, a front leg tube, and a rear leg tube. The handle tube and the main body tube are rotatably connected via a secondary joint, and the front leg tube, rear leg tube, and main body tube are rotatably connected via a primary joint. The secondary joint includes a handle joint seat fixedly connected to the lower end of the handle tube and a main body upper joint seat fixedly connected to the upper end of the main body tube and rotatably connected to the handle joint seat. A locking mechanism and an unlocking mechanism are provided between the handle joint seat and the main body upper joint seat. A first joint shaft is coaxially mounted on the handle joint seat. The locking mechanism includes a mechanism coaxially rotatably sleeved on the first joint shaft and capable of moving along the first joint shaft. The mechanism includes a locking wheel that slides axially along the first joint axis and a locking spring that forces the locking wheel to slide towards the handlebar joint seat under normal conditions. The inner circumferential wall of the handlebar joint seat has a first toothed groove, and the outer wall of the locking wheel has a locking tooth protruding and fixedly inserted into the first toothed groove. The unlocking mechanism includes a top wheel that is coaxially rotatably sleeved on the first joint axis and can slide axially along the first joint axis, and a first cable built into the handle tube and fixed at one end to the top wheel to drive the top wheel to rotate around its own axis. The end face of the handlebar joint seat has a protruding wedge block fixedly attached, and the end face of the top wheel has an ejection wedge groove that cooperates with the ejection wedge block. The end of the locking wheel away from the top wheel... The surface has an unlocking groove, and the main body joint seat is provided with a linkage plate that is rotatably sleeved on the first joint shaft. The linkage plate is inserted into the unlocking groove. The outer wall of the locking wheel has a notch communicating with the unlocking groove. The linkage plate protrudes and is fixed with an actuating block that slides in the notch. After the locking tooth of the locking wheel disengages from the first tooth groove, the actuating block protrudes from the end face of the locking wheel away from the linkage plate. The inner wall of the handle joint seat protrudes and is fixed with a linkage protrusion that abuts against the actuating block to drive the linkage plate to rotate. The main joint includes a main body lower joint seat fixedly connected to the lower end of the main body tube, a front leg joint seat fixedly connected to the upper end of the front leg tube, and a fixed connection. At the upper end of the rear leg tube, the rear leg joint seat and the lower joint seat of the main body are coaxially fixed with a second joint shaft. The front leg joint seat and the rear leg joint seat are coaxially rotatably sleeved on the second joint shaft. The front leg joint seat and the rear leg joint seat have a locking groove extending radially and an unlocking arc groove connected at one end to the end of the locking groove. The axis of the unlocking arc groove coincides with the axis of the second joint shaft. The lower joint seat of the main body is provided with a locking pin. The locking pin is parallel to the second joint shaft and slides radially to the lower joint seat of the main body. The linkage plate is provided with a leg tube linkage unlocking component that drives the locking pin to slide from the locking groove into the unlocking arc groove.

[0006] By adopting the above technical solution, during folding, the first cable drives the top wheel to rotate. When the top wheel rotates, it slides along its own axis towards the joint seat of the main body under the cooperation of the ejection wedge groove and the ejection wedge block. This causes the locking wheel to slide along the axis of the first joint, causing the locking protrusion to disengage from the first tooth groove, thereby unlocking the secondary joint. Then, the operator applies force to the upper end of the handle tube, causing the handle tube to fold forward and downward towards the main body tube. After the handle tube is folded at a large angle, the linkage protrusion on the inner wall of the handle joint seat abuts against the touch block. The handle tube continues to rotate at a small angle, thereby driving the linkage plate to rotate around the first joint axis. During the rotation of the linkage plate, the locking pin is driven from the locking slide groove into the unlocking arc groove through the leg tube linkage unlocking component, thereby unlocking the main joint. This simultaneously unlocks the front leg tube, the rear leg tube, and the main body tube. Then, the upper part of the main body tube is rotated and folded around the axis of the second joint towards the rear leg tube. The front push tube and the rear leg tube rotate and fold in opposite directions, improving the folding efficiency of the trolley.

[0007] Preferably, the leg tube linkage unlocking assembly includes a linkage sleeve slidably connected to the lower inner cavity of the main tube, a linkage cam rotatably connected to the inner wall of the main tube, a second cable passing through the inner cavity of the main tube and fixedly connected between the linkage cam and the linkage plate, and a sleeve return spring disposed on the inner wall of the lower joint seat of the main body to force the linkage sleeve to slide and reset. A locking pin is fixed to the linkage sleeve, and a linkage key abutting against the linkage cam is fixedly connected to one end of the linkage sleeve. The abutting point between the key and the linkage cam and the connection point between the linkage cam and the second cable are respectively located on both sides of the linkage cam axis.

[0008] By adopting the above technical solution, the linkage sleeve, linkage cam, second cable, and sleeve return spring are designed so that after the handle tube is folded into place, the rotation of the linkage plate can drive the linkage cam to rotate through the second cable. The linkage cam pushes the linkage sleeve to slide, thereby driving the locking pin from the locking groove of the main joint into the unlocking arc groove, realizing the linkage unlocking of the main joint and the secondary joint, and improving the folding efficiency of the trolley.

[0009] Preferably, it also includes a seat tube, and the main joint also includes a seat joint seat rotatably connected to the inner side of the rear leg joint seat. The seat tube is fixedly connected to the seat joint seat, and the seat joint seat is coaxially rotatably sleeved on the second joint shaft. A rear leg piece is fixedly connected inside the rear leg joint seat. A seat lock groove is radially formed on the outer wall of the rear leg piece. A seat lock tongue is radially slidably connected to the seat joint seat and is engaged in the seat lock groove. A seat linkage unlocking component is provided between the second joint shaft and the seat joint seat to drive the seat lock tongue to slide out of the seat lock groove.

[0010] By adopting the above technical solution, adding a seat tube and a seat joint seat, the seat locking tongue can be engaged with the seat locking groove to lock the seat joint seat and the rear leg joint seat. The seat linkage unlocking component can drive the seat locking tongue to disengage from the seat locking groove, thereby unlocking the seat joint seat. This facilitates the folding operation of the seat part when folding the stroller and improves the folding efficiency of the stroller.

[0011] Preferably, the seat linkage unlocking assembly includes a latch linkage block that is radially slidably connected to the seat joint seat and fixedly connected to the seat latch, a seat cam disc fixedly sleeved on the second joint axis, and a seat lock spring disposed between the seat joint seat and the latch linkage block. The seat cam disc has an unlocking part and an anti-rotation part. Under normal conditions, the seat lock spring forces the latch linkage block to slide towards the direction close to the second joint axis, causing the latch linkage block to abut against the outer peripheral wall of the unlocking part of the seat cam disc. Under normal conditions, the side wall of the anti-rotation part of the seat cam disc abuts against the lower outer side wall of the latch linkage block, thereby restricting the rotation of the second joint axis.

[0012] By adopting the above technical solution, when the main tube rotates and folds towards the rear leg tube, it drives the lower joint seat, the second joint shaft, and the seat cam plate to rotate. During the rotation of the seat cam plate, the diameter of the outer peripheral wall of the unlocking part gradually increases, thereby forcing the locking tongue linkage block to slide away from the second joint shaft, and then forcing the seat locking tongue to slide out of the seat locking groove, thereby unlocking the seat joint seat. Subsequently, the folding seat tube can be rotated, which improves the overall linkage and folding efficiency of the folding trolley.

[0013] Preferably, the seat joint is rotatably connected to a backrest connecting tube, and the backrest connecting tube is fixedly connected to a backrest support.

[0014] By adopting the above technical solution, the seat joint seat is rotatably connected to the backrest connecting tube, and the backrest connecting tube is connected to the backrest support body, which can provide back support for the user and improve riding comfort.

[0015] Preferably, it also includes a handrail tube, and the main joint further includes a handrail joint seat located between the lower joint seat of the main body and the front leg joint seat. The handrail tube is fixedly connected to the handrail joint seat, and a handrail plate is fixedly connected to the inner cavity of the handrail joint seat. The handrail plate includes a handrail rotating plate coaxially rotatably sleeved on the second joint axis and a handrail connecting plate fixedly connected between the outer wall of the handrail rotating plate and the handrail joint seat. The outer wall of the handrail connecting plate has a handrail anti-rotation surface that abuts against the outer peripheral wall of the locking pin, and a handrail is provided on the outer peripheral wall of the handrail rotating plate. The locking groove has a handrail anti-rotation pawl hinged to the inner wall of the front leg joint seat. The free end of the handrail anti-rotation pawl protrudes and is fixed with a handrail locking tongue that is locked in the handrail locking groove. The front leg joint seat is provided with a handrail locking spring that forces the free end of the handrail anti-rotation pawl to swing toward the direction of the handrail rotating plate. The free end of the handrail anti-rotation pawl is located on the sliding trajectory of the locking pin in the unlocking arc groove. The free end of the handrail anti-rotation pawl has a handrail unlocking guide surface that allows the outer peripheral wall of the locking pin to abut against, so as to force the free end of the handrail anti-rotation pawl to swing away from the rotating plate.

[0016] By adopting the above technical solution, in the unfolded state, the anti-rotation surface of the armrest connecting piece abuts against the locking pin to limit the armrest tube. When the main body tube rotates and folds towards the rear leg tube, it drives the locking pin to slide in the unlocking arc groove. When the main body tube rotates and folds to a large angle, the locking pin abuts against the armrest unlocking guide surface of the armrest anti-rotation claw. After the main body tube continues to rotate to a small angle, the locking pin forces the free end of the armrest anti-rotation claw to swing away from the rotating piece, thereby causing the armrest locking tongue to disengage from the armrest locking groove and unlocking the armrest joint seat. Then the folding armrest tube can be rotated, improving the overall linkage and folding efficiency of the folding trolley.

[0017] Preferably, the inner wall of the front leg joint seat is provided with a handrail spring groove, the middle of the handrail anti-rotation claw is hinged with a handrail swing plate, the other end of the handrail swing plate protrudes and is fixed with a handrail sliding protrusion that is slidably connected to the handrail spring groove, the handrail locking spring is built into the handrail spring groove, one end of the handrail locking spring is fixed or abuts against the handrail spring groove, and the other end of the handrail locking spring is fixed or abuts against the handrail sliding protrusion.

[0018] By adopting the above technical solution, the handrail spring groove, handrail swing plate, handrail sliding protrusion and handrail locking spring are designed so that the handrail anti-rotation claw can swing stably under the action of the handrail locking spring, realizing reliable locking and unlocking of the handrail rotating plate, and improving the linkage stability and operational reliability of the handrail tube related structures.

[0019] Preferably, the front leg joint seat is located between the rear leg joint seat and the armrest joint seat. The arc length of the unlocking arc groove of the rear leg joint seat is smaller than that of the front leg joint seat. A front leg locking pin is fixedly inserted through the inner wall of the front leg joint seat. The axial direction of the front leg locking pin is parallel to the axial direction of the second joint axis. One end of the armrest anti-rotation claw is rotatably sleeved on the front leg locking pin. The end of the front leg locking pin extends into the inner cavity of the rear leg joint seat. A rotating arc groove is opened on the end face of the rear leg joint seat for the front leg locking pin to slide through. The axis of the rotating arc groove coincides with the axis of the second joint axis. When the front leg locking pin abuts against one end of the rotating arc groove, the locking slide groove of the front leg joint seat and the locking slide groove of the rear leg joint seat coincide and align. When the front leg locking pin abuts against the other end of the rotating arc groove, the rear leg joint seat indicates that it has been folded and rotated into place.

[0020] By adopting the above technical solution, when the main tube rotates and folds towards the rear leg tube, during the sliding process of the locking pin in the unlocking groove, the locking pin first abuts against the end of the unlocking arc groove of the rear leg joint seat. As the main tube continues to rotate and fold, the locking pin drives the rear leg joint seat to rotate, causing the rear leg tube to rotate and fold towards the front leg tube. When the front leg locking pin abuts against one end of the rotating arc groove, the locking groove of the front leg joint seat and the locking groove of the rear leg joint seat coincide and align, and the rear leg joint seat is in the unfolded state. When the front leg locking pin abuts against the other end of the rotating arc groove, the rear leg joint seat indicates that the folding rotation is in place and is in the folded state.

[0021] Preferably, the main tube has a rotatable hook seat rotatably connected to its side wall, and a trolley hook arm is fixedly protruding from the outer wall of the trolley hook seat. The front leg tube has a front leg limiting rod fixedly connected to its side wall. After the trolley is folded, the hook head of the trolley hook arm is hooked onto the front leg limiting rod.

[0022] By adopting the above technical solution, after the trolley is folded and folded into place, the folding hook seat is rotated so that the folding hook arm on the folding hook seat can hook onto the front leg limit rod of the front leg tube, which can fix the folded state of the trolley and prevent the trolley from being accidentally unfolded after folding.

[0023] In summary, this application includes at least one of the following beneficial technical effects: During folding, the first cable drives the top wheel to rotate. When the top wheel rotates, it slides along its own axis towards the joint seat of the main body under the cooperation of the ejection wedge groove and the ejection wedge block. This causes the locking wheel to slide along the axis of the first joint, causing the locking protrusion to disengage from the first tooth groove, thereby unlocking the secondary joint. Then, the operator applies force to the upper end of the handle tube, causing the handle tube to fold forward and downward towards the main body tube. After the handle tube is folded at a large angle, the linkage protrusion on the inner wall of the handle joint seat abuts against the touch block. The handle tube continues to rotate at a small angle, thereby driving the linkage plate to rotate around the first joint axis. During the rotation of the linkage plate, the locking pin is driven from the locking slide groove into the unlocking arc groove through the leg tube linkage unlocking component, thereby unlocking the main joint. This simultaneously unlocks the front leg tube, the rear leg tube, and the main body tube. Then, the upper part of the main body tube is rotated and folded around the axis of the second joint towards the rear leg tube. The front push tube and the rear leg tube rotate and fold in opposite directions, improving the folding efficiency of the trolley. The combination of the linkage sleeve, linkage cam, second cable, and sleeve return spring allows the linkage plate to rotate after the handle tube is folded into place. This rotation of the linkage plate drives the linkage cam to rotate via the second cable. The linkage cam then pushes the linkage sleeve to slide, thereby causing the locking pin to move from the locking groove of the main joint into the unlocking groove. This achieves linkage unlocking between the main joint and the secondary joint, improving the folding efficiency of the trolley. After the trolley is folded and stowed in place, rotate the folding hook seat so that the folding hook arm on the folding hook seat can hook onto the front leg limit bar of the front leg tube, which can fix the folded state of the trolley and prevent the trolley from being accidentally unfolded after folding. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the unfolded state of the folding cart.

[0025] Figure 2 This is a schematic diagram of the main joint.

[0026] Figure 3 This is a schematic diagram of the accessory joint.

[0027] Figure 4 This is a schematic diagram of the unlocking mechanism.

[0028] Figure 5 This is a schematic diagram of the handle joint seat.

[0029] Figure 6 This is a schematic diagram of the joint seat on the main body.

[0030] Figure 7 This is a structural diagram of the unlocking core and button base.

[0031] Figure 8 This is a schematic diagram of the internal structure of the unlocking core.

[0032] Figure 9 This is a schematic diagram of the button structure.

[0033] Figure 10 This is a schematic diagram of the structure of the lower joint seat of the main body.

[0034] Figure 11 This is a structural diagram of the locking groove and the unlocking arc groove.

[0035] Figure 12 This is a structural diagram of the leg tube linkage unlocking component.

[0036] Figure 13 This is a schematic diagram of the front leg joint seat.

[0037] Figure 14 This is a schematic diagram of the connection structure between the hind leg joint seat and the seat joint seat.

[0038] Figure 15 This is a structural diagram of the seat linkage unlocking component.

[0039] Figure 16 This is a structural diagram of the take-off coupler seat and the take-off coupler arm.

[0040] Figure 17 This is a schematic diagram of the folded state of the folding stroller.

[0041] Explanation of reference numerals in the attached drawings: 10. Handlebar tube; 101. Push tube; 102. Unlocking core seat; 103. Button seat; 104. Handlebar cover; 105. Core bar; 106. Limiting block; 107. First wedge block; 108. Button reset spring; 20. Main tube; 201. Locking pin; 202. Retracting hook seat; 203. Retracting hook arm; 30. Front leg tube; 301. Front leg limiting rod; 40. Rear leg tube; 50. Seat tube; 501. Seat plate; 60. Armrest tube; 70. Seat connecting tube; 80. Backrest connecting tube; 801. Backrest support; 1. Sub-joint; 11. Handlebar. 111. Handle plug sleeve; 112. Ejector wedge; 113. First tooth groove; 114. Linkage protrusion; 12. Upper joint seat of main body; 121. Main body plug sleeve; 122. Second tooth groove; 123. Linkage plate; 124. Actuating block; 125. Cable fixing block; 126. Limiting arc groove; 13. First joint shaft; 14. Canopy rotating seat; 2. Main joint; 21. Lower joint seat of main body; 211. Main body socket; 22. Armrest joint seat; 221. Armrest socket; 222. Armrest plate; 223. Armrest rotating plate; 224. Armrest connecting plate; 225. Armrest anti-rotation surface; 226. 23. Armrest lock slot; 231. Front leg joint seat; 232. Front leg plug; 233. Front leg catch; 234. Armrest anti-rotation claw; 235. Armrest lock tongue; 236. Armrest unlocking guide surface; 237. Armrest lock spring; 238. Armrest swing plate; 249. Front leg limiting protrusion; 240. Rear leg joint seat; 241. Rear leg plug; 242. Rear leg plate; 243. Seat lock slot; 244. Rotating arc groove; 25. Seat joint seat; 251. Seat insert; 252. Seat socket; 253. Seat lock tongue; 254. Seat limiting protrusion; 26. Inner cover; 27. Second joint shaft; 28. Lock 29. Anti-slip groove; 3. Unlocking arc groove; 4. Locking mechanism; 5. Locking wheel; 6. Locking spring; 7. Locking tooth; 8. Notch; 9. Unlocking slot; 10. Unlocking mechanism; 11. Top wheel; 12. First cable; 13. Button; 14. Push-out wedge groove; 15. Second wedge block; 16. Leg tube linkage unlocking assembly; 17. Linkage sleeve; 18. Linkage cam; 19. Second cable; 20. Sleeve return spring; 21. Linkage key; 22. Seat linkage unlocking assembly; 33. Lock tongue linkage block; 44. Seat cam plate; 55. Seat lock spring; 66. Anti-rotation part; 77. Unlocking part. Detailed Implementation

[0042] The following is in conjunction with the appendix Figure 1-17 This application will be described in further detail.

[0043] This application discloses a linkage unlocking structure for a folding trolley, referring to... Figure 1 , Figure 2The trolley includes a foldable handle tube 10, a main body tube 20, a front leg tube 30, a rear leg tube 40, a seat tube 50, and an armrest tube 60. The handle tube 10 and the main body tube 20 are rotatably connected by a sub-joint 1, and the front leg tube 30, rear leg tube 40, seat tube 50, armrest tube 60, and main body tube 20 are rotatably connected by a main joint 2. In this embodiment, the trolley is described in its unfolded state. The handle tube 10 is located above the main body tube 20 and is parallel to the main body tube 20. A push tube 101 is integrally formed and fixed between the upper ends of the two handle tubes 10.

[0044] Reference Figure 1 , Figure 3 , Figure 4 The secondary joint 1 includes a handle joint seat 11 fixedly connected to the lower end of the handle tube 10 and a main body upper joint seat 12 fixedly connected to the upper end of the main body tube 20 and rotatably connected to the handle joint seat 11 via a first joint shaft 13. In this embodiment, the main body upper joint seat 12 is located outside the handle joint seat 11. The first joint shaft 13 is coaxially fixedly inserted through the main body upper joint seat 12. A canopy rotating seat 14 is rotatably connected to the outside of the main body upper joint seat 12. The canopy rotating seat 14 is rotatably sleeved on the first joint shaft 13. The canopy rotating seat 14 is used to install the canopy front rod. There is rotational damping between the canopy rotating seat 14 and the main body upper joint seat 12.

[0045] Reference Figure 4 , Figure 5 , Figure 6 A handle plug 111 is fixedly protruding from the upper outer wall of the handle joint seat 11, and the lower end of the handle tube 10 is fixedly sleeved on the handle plug 111. A push-out wedge 112 is fixedly protruding from the inner end face of the handle joint seat 11. The inner peripheral wall of the handle joint seat 11 has a first toothed groove 113, and the inner peripheral wall of the main body upper joint seat 12 has a corresponding second toothed groove 122. A main body plug 121 is fixedly protruding from the lower outer wall of the main body upper joint seat 12, and the upper end of the main body tube 20 is fixedly sleeved on the main body plug 121.

[0046] A locking mechanism 3 and an unlocking mechanism 4 are provided between the handle joint seat 11 and the upper joint seat 12 of the main body. The locking mechanism 3 includes a locking wheel 31 that is coaxially rotatably sleeved on the first joint shaft 13 and can slide along the first joint shaft 13 axially, and a locking spring 32 that forces the locking wheel 31 to slide towards the handle joint seat 11 under normal conditions. The outer wall of the locking wheel 31 has a locking protrusion 33 that slides and is inserted into the first tooth groove 113 and the second tooth groove 122. In the unfolded state, part of the locking protrusion 33 is inserted into the first tooth groove 113 and the other part is inserted into the second tooth groove 122, thereby restricting the relative rotation of the handle joint seat 11 and the upper joint seat 12 of the main body.

[0047] The unlocking mechanism 4 includes a top wheel 41 that is coaxially rotatably sleeved on the first joint shaft 13 and can slide along the first joint shaft 13 axially, a first pull cable 42 that is built into the handle tube 10 and one end is fixed to the top wheel 41 to drive the top wheel 41 to rotate around its own axis, and a button 43 that is provided on the push tube 101 for pulling the first pull cable 42. The top wheel 41 is built into the handle joint seat 11. The end face of the top wheel 41 near the upper joint seat 12 of the main body abuts against the end face of the locking wheel 31. The top wheel 41 has a cable hole for fixing one end of the first cable 42. The end face of the top wheel 41 away from the locking wheel 31 is provided with an ejection wedge groove 44 that cooperates with the ejection wedge block 112. When the top wheel 41 rotates, the top wheel 41 can slide axially toward the upper joint seat 12 of the main body under the cooperation of the ejection wedge groove 44 and the ejection wedge block 112, so that the locking protrusion 33 slides out of the first tooth groove 113 and is fully inserted into the second tooth groove 122.

[0048] The main body upper joint seat 12 is provided with a linkage plate 123 rotatably sleeved on the first joint shaft 13. The end face of the locking wheel 31 away from the top wheel 41 has an unlocking groove 35. The locking spring 32 is a compression spring built into the unlocking groove 35. One end of the locking spring 32 abuts against the inner wall of the unlocking groove 35, and the other end of the locking spring 32 abuts against the linkage plate 123. The outer wall of the locking wheel 31 has a notch 34 communicating with the unlocking groove 35. The linkage plate 123 protrudes and is fixed with an actuating block 124 that slides in the notch 34. The outer peripheral wall of the actuating block 124 protrudes and is fixed with a cable fixing block 125. The inner peripheral wall of the main body upper joint seat 12 is provided with a limiting arc groove 126 for the cable fixing block 125 to slide. The limiting arc groove 126 restricts the linkage plate 123 to only rotate at a small angle. After the locking tooth 33 of the locking wheel 31 slides out of the first tooth groove 113, the actuating block 124 protrudes from the end face of the locking wheel 31 away from the linkage plate 123, and the inner wall of the handle joint seat 11 protrudes and is fixed with a linkage protrusion 114 that abuts against the actuating block 124 to drive the linkage plate 123 to rotate.

[0049] Reference Figure 7 , Figure 8 , Figure 9The push tube 101 is fixedly connected to an unlocking core seat 102 and a button seat 103 covering the unlocking core seat 102. The button seat 103 is detachably connected to the push tube 101 via a handle cover 104. A core hole communicating with the inner cavity is opened on the lower outer wall of the push tube 101. Through holes communicating with the inner cavity are opened on both outer walls of the unlocking core seat 102. A core strip 105 is slidably connected to the unlocking core seat 102 in the horizontal direction. The core strip 105 passes through the through holes and extends into the inner cavity of the push tube 101. The two core strips 105 are staggered. The end of the first pull cable 42 is fixedly connected to one end of the core strip 105, and the other end of the core strip 105 is fixedly connected to a limiting block 106 built into the unlocking core seat 102. A first wedge block 107 is fixedly connected to the outer wall of the limiting block 106, and the wedge surfaces of the first wedge blocks 107 of the two limiting blocks 106 are in opposite directions.

[0050] Button 43 is slidably inserted into the lower part of button base 103. Unlock core base 102 is provided with button reset spring 108 that forces button 43 to slide away from unlock core base 102 under normal conditions. The upper end surface of button 43 is protruding and fixedly connected with a second wedge block 45 that cooperates with the first wedge block 107 to force the core bar 105 to slide. There are two corresponding second wedge blocks 45. When button 43 is pressed and moved, the two second wedge blocks 45 respectively abut against the wedge surface of the first wedge block 107 on the two limit blocks 106, thereby forcing the two core bars 105 to slide towards each other, thereby pulling the first cable 42.

[0051] Reference Figure 10 , Figure 11 , Figure 12 The main joint 2, from the outside in, includes a main body lower joint seat 21, an armrest joint seat 22, a front leg joint seat 23, a rear leg joint seat 24, and a seat joint seat 25, which are rotatably connected to each other via a second joint shaft 27. A main body socket 211 is fixedly connected to the upper rear outer wall of the main body lower joint seat 21, and the lower part of the main body tube 20 is fixedly inserted into the main body socket 211. The lower end of the main body tube 20 extends into the inner cavity of the main body lower joint seat 21, and the second joint shaft 27 is fixed to the lower end of the main body tube 20.

[0052] Both the front leg joint seat 23 and the rear leg joint seat 24 have radially extending locking grooves 28 and unlocking arc grooves 29 connected to the end of the locking grooves 28. The axis of the unlocking arc grooves 29 coincides with the axis of the second joint axis 27. The lower part of the main body tube 20 is provided with locking pins 201 that pass through the front leg joint seat 23, the armrest joint seat 22 and the rear leg joint seat 24. The locking pins 201 are parallel to the second joint axis 27 and slide radially to the main body tube 20. In the unfolded state, the locking pins 201 are embedded in the locking grooves 28 to restrict the relative rotation of the front leg joint seat 23, the rear leg joint seat 24 and the lower joint seat 21 of the main body.

[0053] The linkage plate 123 is equipped with a leg tube linkage unlocking assembly 5 that drives the locking pin 201 to slide from the locking slide groove 28 into the unlocking arc groove 29. The leg tube linkage unlocking assembly 5 includes a linkage sleeve 51 that slides along the length of the main tube 20 and is connected to the lower inner cavity of the main tube 20; a linkage cam 52 that is rotatably connected to the lower inner wall of the main tube 20; a second cable 53 that passes through the inner cavity of the main tube 20 and is fixedly connected between the linkage cam 52 and the cable fixing block 125; and a sleeve return spring 54 that is provided on the inner wall of the lower joint seat 21 of the main body to force the linkage sleeve 51 to slide and return to its original position. The locking pin 201 is fixedly inserted into the linkage sleeve 51. The linkage sleeve 51 has a first clearance groove for the end of the second joint shaft 27 to slide through. Both the main tube 20 and the lower joint seat 21 of the main body have a second clearance groove for the locking pin 201 to slide through.

[0054] One end of the linkage sleeve 51 is fixedly connected to a linkage key 55 that abuts against the linkage cam 52. The linkage cam 52 has a cable hole for fixing the end of the second cable 53. The contact point between the key and the linkage cam 52 and the cable hole of the linkage cam 52 are located on both sides of the axis of the linkage cam 52. The sleeve return spring 54 is a compression spring. One end of the sleeve return spring 54 is fixedly connected to the inner wall of the lower joint seat 21 of the main body, and the other end of the sleeve return spring 54 is fixedly connected to the linkage sleeve 51. When the second cable 53 is pulled, it drives the linkage cam 52 to rotate. The linkage cam 52 pushes the linkage sleeve 51 to slide through the linkage key 55, thereby causing the locking pin 201 to slide towards the second joint axis 27, so that the locking pin 201 enters the unlocking arc groove 29 from the locking groove 28.

[0055] The armrest joint seat 22 is a sleeve. An armrest socket 221 is fixed to the upper front outer wall of the armrest joint seat 22, and the end of the armrest tube 60 is fixedly inserted into the armrest socket 221. An armrest piece 222 is fixedly connected to the inner cavity of the armrest joint seat 22. The armrest piece 222 includes an armrest rotating piece 223 coaxially rotatably sleeved on the second joint shaft 27 and an armrest connecting piece 224 fixedly connected between the outer wall of the armrest rotating piece 223 and the armrest joint seat 22. The armrest connecting piece 224 is fixedly inserted into the armrest socket 221.

[0056] Reference Figure 11 , Figure 13The outer peripheral wall of the armrest rotating plate 223 is provided with an armrest locking groove 226. The inner wall of the front leg joint seat 23 is hinged with an armrest anti-rotation claw 233. The free end of the armrest anti-rotation claw 233 protrudes and is fixed with an armrest locking tongue 234 that is locked in the armrest locking groove 226. The front leg joint seat 23 is provided with an armrest locking spring 236 that forces the free end of the armrest anti-rotation claw 233 to swing toward the armrest rotating plate 223. The inner end face of the front leg joint seat 23 is provided with an armrest spring groove. The middle part of the armrest anti-rotation claw 233 is hinged with an armrest swing plate 237. The other end of the armrest swing plate 237 protrudes and is fixed with an armrest sliding protrusion that is slidably connected to the armrest spring groove. The armrest locking spring 236 is built into the armrest spring groove. One end of the armrest locking spring 236 is fixed or abuts against the armrest spring groove, and the other end of the armrest locking spring 236 is fixed or abuts against the armrest sliding protrusion. The free end of the handrail anti-rotation pawl 233 is located on the sliding trajectory of the locking pin 201 in the unlocking arc groove 29. The free end of the handrail anti-rotation pawl 233 has a handrail unlocking guide surface 235 for the outer peripheral wall of the locking pin 201 to abut against, thereby forcing the free end of the handrail anti-rotation pawl 233 to swing away from the rotating plate. The outer wall of the handrail connecting piece 224 has a handrail anti-rotation surface 225. In the unfolded state, the handrail anti-rotation surface 225 of the handrail connecting piece 224 abuts against the locking pin 201, thereby restricting the handrail tube 60 from swinging backward. The handrail locking tongue 234 of the handrail anti-rotation pawl 233 is engaged in the handrail locking groove 226, restricting the handrail tube 60 from swinging forward.

[0057] Reference Figure 13 , Figure 14 A front leg plug 231 is fixedly connected to the lower front outer wall of the front leg joint seat 23, and the upper end of the front leg tube 30 is fixedly sleeved on the front leg plug 231. A front leg limiting protrusion 238 is fixedly protruding from the upper rear outer wall of the front leg joint seat 23. A rear leg plug 241 is fixedly connected to the lower rear outer wall of the rear leg joint seat 24, and the upper end of the rear leg tube 40 is fixedly sleeved on the rear leg plug 241. The arc length of the unlocking arc groove 29 of the rear leg joint seat 24 is smaller than that of the unlocking arc groove 29 of the front leg joint seat 23. A front leg locking pin 232 is fixedly inserted through the inner wall of the front leg joint seat 23. The axial direction of the front leg locking pin 232 is parallel to the axial direction of the second joint axis 27. One end of the armrest anti-rotation claw 233 is rotatably sleeved on the front leg locking pin 232, and the end of the front leg locking pin 232 extends into the inner cavity of the rear leg joint seat 24. The end face of the rear leg joint seat 24 is provided with a rotating arc groove 244 for the front leg locking pin 232 to slide through. The axis of the rotating arc groove 244 coincides with the axis of the second joint axis 27. When the front leg locking pin 232 abuts against one end of the rotating arc groove 244, the locking groove 28 of the front leg joint seat 23 and the locking groove 28 of the rear leg joint seat 24 coincide and align. When the front leg locking pin 232 abuts against the other end of the rotating arc groove 244, the rear leg joint seat 24 is folded and rotated into place.

[0058] Reference Figure 14 , Figure 15A seat insert 251 is fixedly connected to the front outer wall of the seat joint seat 25, and the end of the seat tube 50 is fixedly sleeved on the seat insert 251. A seat socket 252 is fixedly fixedly attached to the end face of the seat joint seat 25 away from the rear leg joint seat 24, and a seat connecting tube 70 is fixedly inserted into the seat socket 252. A seat plate 501 is installed on the seat tube 50 and the seat connecting tube 70. A rear leg piece 242 is fixedly connected inside the rear leg joint seat 24. The rear leg piece 242 also has a locking groove 28 and an unlocking arc groove 29, which are the same as those of the rear leg joint seat 24. A seat lock groove 243 is radially formed on the outer wall of the rear leg piece 242, and a seat lock tongue 253 that is engaged in the seat lock groove 243 is radially slidably connected to the seat joint seat 25. A seat linkage unlocking component 6 is provided between the second joint shaft 27 and the seat joint seat 25 to drive the seat lock tongue 253 to slide out of the seat lock groove 243.

[0059] The seat linkage unlocking assembly 6 includes a latch linkage block 61 that is radially slidably connected to the end face of the seat joint seat 25 away from the rear leg joint seat 24 and fixedly connected to the seat latch 253; a seat cam disc 62 fixedly sleeved on the second joint shaft 27; and a seat locking spring 63 disposed between the seat joint seat 25 and the latch linkage block 61. The seat locking spring 63 is a torsion spring, with one end fixedly connected to the seat joint seat 25 and the other end fixedly connected to the latch linkage block 61. The seat cam disc 62 has an unlocking part 65 and an anti-rotation part 64. The seat locking spring 63 forces the latch linkage block 61 to slide towards the second joint shaft 27, causing the latch linkage block 61 to abut against the outer peripheral wall of the unlocking part 65 of the seat cam disc 62. In the unfolded state, the side wall of the anti-rotation part 64 of the seat cam disc 62 abuts against the lower outer wall of the latch linkage block 61, thereby restricting the second joint shaft 27 to rotate only in one direction.

[0060] Reference Figure 11 , Figure 15 , Figure 16 A seat limiting protrusion 254 is fixedly attached to the upper rear outer wall of the seat joint seat 25. The seat limiting protrusion 254 is located on the moving path of the front leg limiting protrusion 238, so that the seat limiting protrusion 254 abuts against the front leg limiting protrusion 238. When the front leg joint seat 23 is folded and rotated, the front leg limiting protrusion 238 can push the seat joint seat 25 to fold and rotate through the seat limiting protrusion 254. An inner cover 26 is fixedly connected to the inner side of the seat joint seat 25. The inner cover 26 is rotatably connected to the backrest connecting tube 80. The backrest connecting tube 80 is fixedly connected to the backrest support body 801. A trolley hook seat 202 is rotatably connected to the side wall of the main body tube 20. A trolley hook arm 203 is fixedly attached to the outer wall of the trolley hook seat 202. A front leg limiting rod 301 is fixedly connected to the side wall of the front leg tube 30. After the trolley is folded, the hook head of the trolley hook arm 203 hooks onto the front leg limiting rod 301.

[0061] The implementation principle of the linkage unlocking structure of a folding trolley in this application embodiment is as follows: When folding the trolley, firstly, the operator presses button 43 and pulls the first cable 42, thereby driving the top wheel 41 to rotate at a small angle. When the top wheel 41 rotates, with the cooperation of the ejector wedge groove 44 and the ejector wedge block 112, the top wheel 41 slides along its own axis toward the joint seat 12 of the main body, thereby driving the locking wheel 31 to slide along the first joint axis 13, so that the locking protrusion 33 on the locking wheel 31 disengages from the first tooth groove 113 and is completely released. The second tooth groove 122 is embedded to unlock the sub-joint 1. Then the operator applies force to the upper end of the handle tube 10, causing the handle tube 10 to fold forward and downward toward the main body tube 20. After the handle tube 10 is folded at a large angle, the linkage protrusion 114 on the inner wall of the handle joint seat 11 abuts against the touch block 124. After the handle tube 10 continues to rotate at a small angle (the handle tube 10 is folded in place and the handle tube 10 abuts against the back support body 801), the linkage piece 123 is driven to rotate at a small angle around the first joint axis 13. During the rotation of the linkage plate 123, the linkage cam 52 is driven to rotate by the second cable 53. The linkage cam 52 pushes the linkage sleeve 51 to slide through the linkage key 55, thereby driving the locking pin 201 from the locking groove 28 of the main joint 2 into the unlocking arc groove 29, realizing the unlocking of the main joint 2. This simultaneously unlocks the front leg tube 30, the rear leg tube 40, and the main body tube 20. Then, the upper part of the main body tube 20 is rotated and folded around the axis of the second joint shaft 27 towards the rear leg tube 40. When the folding mechanism starts to rotate, it drives the lower joint seat 21, the second joint shaft 27, and the seat cam plate 62 to rotate together. At the same time, the back support body 801 follows the main tube 20 to rotate and fold around the axis of the back connecting tube 80. During the rotation of the seat cam plate 62, the diameter of the outer peripheral wall of the unlocking part 65 gradually increases, thereby forcing the locking tongue linkage block 61 to slide away from the second joint shaft 27, and thus forcing the seat locking tongue 253 to slide out of the seat locking groove 243, thereby unlocking the seat joint seat 25. As the main body tube 20 rotates and folds towards the rear leg tube 40, the locking pin 201 slides within the unlocking groove. During this process, the locking pin 201 first abuts against the end of the unlocking arc groove 29 of the rear leg joint seat 24. As the main body tube 20 continues to rotate and fold, the locking pin 201 drives the rear leg joint seat 24 to rotate, causing the rear leg tube 40 to rotate and fold towards the front leg tube 30. Just as the main body tube 20 is about to fold into place, the locking pin 201 abuts against the armrest unlocking guide surface 235 of the armrest anti-rotation claw 233. After the main body tube 20 continues to rotate a small angle (the main body tube 20 is folded into place), the locking pin 201 forces the free end of the armrest anti-rotation claw 233 to swing away from the rotating plate, thereby disengaging the armrest locking tongue 234 from the armrest locking groove 226, unlocking the armrest joint seat 22. Subsequently, the armrest tube 60, seat tube 50, and front leg tube 30 are folded and folded. (Refer to...) Figure 17 After the trolley is folded and stowed in place, rotate the folding hook seat 202 so that the folding hook arm 203 on the folding hook seat 202 can hook onto the front leg limit rod 301 of the front leg tube 30, which can fix the folded state of the trolley and prevent the trolley from being accidentally unfolded after folding.

[0062] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A linkage unlocking structure for a folding trolley, characterized in that: The system includes a handle tube (10), a main body tube (20), a front leg tube (30), and a rear leg tube (40). The handle tube (10) and the main body tube (20) are rotatably connected by a secondary joint (1), and the front leg tube (30), the rear leg tube (40), and the main body tube (20) are rotatably connected by a primary joint (2). The secondary joint (1) includes a handle joint seat (11) fixedly connected to the lower end of the handle tube (10) and a main body upper joint seat (12) fixedly connected to the upper end of the main body tube (20) and rotatably connected to the handle joint seat (11). A space is provided between the handle joint seat (11) and the main body upper joint seat (12). The locking mechanism (3) and unlocking mechanism (4) are provided. A first joint shaft (13) is coaxially mounted on the handle joint seat (11). The locking mechanism (3) includes a locking wheel (31) that is coaxially rotatably sleeved on the first joint shaft (13) and can slide along the first joint shaft (13) axially, and a locking spring (32) that forces the locking wheel (31) to slide toward the handle joint seat (11) under normal conditions. The inner peripheral wall of the handle joint seat (11) has a first toothed groove (113). The outer wall of the locking wheel (31) has a locking protrusion (33) that is inserted into the first toothed groove (113). The unlocking mechanism (4) includes a locking wheel (31) that is coaxially rotatably sleeved on the handle joint seat (11). The top wheel (41) is located on the first joint axis (13) and can slide along the first joint axis (13) axially. A first cable (42) is built into the handle tube (10) and fixed at one end to the top wheel (41) to drive the top wheel (41) to rotate around its own axis. The end face of the handle joint seat (11) is provided with a protruding push-out wedge (112). The end face of the top wheel (41) is provided with a push-out wedge groove (44) that cooperates with the push-out wedge (112). The end face of the locking wheel (31) away from the top wheel (41) has an unlocking groove (35). The joint seat (12) on the main body is provided with a linkage that is rotatably sleeved on the first joint axis (13). The linkage plate (123) is inserted into the unlocking slot (35). The outer wall of the locking wheel (31) has a notch (34) communicating with the unlocking slot (35). The linkage plate (123) has a protruding and fixed a trigger block (124) that slides in the notch (34). After the locking tooth (33) of the locking wheel (31) is disengaged from the first tooth groove (113), the trigger block (124) protrudes from the end face of the locking wheel (31) away from the linkage plate (123). The inner wall of the handle joint seat (11) has a protruding and fixed a linkage protrusion (114) that abuts against the trigger block (124) to drive the linkage plate (123) to rotate.The main joint (2) includes a lower joint seat (21) fixedly connected to the lower end of the main body tube (20), a front leg joint seat (23) fixedly connected to the upper end of the front leg tube (30), and a rear leg joint seat (24) fixedly connected to the upper end of the rear leg tube (40). The lower joint seat (21) is coaxially fixed with a second joint shaft (27). The front leg joint seat (23) and the rear leg joint seat (24) are both coaxially rotatably sleeved on the second joint shaft (27). The front leg joint seat (23) and the rear leg joint seat (24) both have radially extending locking anti-slip features. The groove (28) and the unlocking arc groove (29) are connected at one end to the end of the locking slide groove (28). The axis of the unlocking arc groove (29) coincides with the axis of the second joint axis (27). The lower joint seat (21) of the main body is provided with a locking pin (201). The locking pin (201) is parallel to the second joint axis (27) and slides radially to the lower joint seat (21) of the main body. The linkage plate (123) is provided with a leg tube linkage unlocking assembly (5) that drives the locking pin (201) to slide from the locking slide groove (28) into the unlocking arc groove (29).

2. The linkage unlocking structure of a folding trolley according to claim 1, characterized in that: The leg tube linkage unlocking assembly (5) includes a linkage sleeve (51) slidably connected to the lower inner cavity of the main tube (20), a linkage cam (52) rotatably connected to the inner wall of the main tube (20), a second cable (53) passing through the inner cavity of the main tube (20) and fixedly connected between the linkage cam (52) and the linkage plate (123), and a sleeve return spring (54) set on the inner wall of the lower joint seat (21) of the main body to force the linkage sleeve (51) to slide and reset. The locking pin (201) is fixed to the linkage sleeve (51). One end of the linkage sleeve (51) is fixedly connected to a linkage key (55) abutting against the linkage cam (52). The abutting point of the key and the linkage cam (52) and the connection point of the linkage cam (52) and the second cable (53) are respectively located on both sides of the axis of the linkage cam (52).

3. The linkage unlocking structure of a folding trolley according to claim 1, characterized in that: It also includes a seat tube (50), and the main joint (2) also includes a seat joint seat (25) rotatably connected to the inside of the rear leg joint seat (24). The seat tube (50) is fixedly connected to the seat joint seat (25). The seat joint seat (25) is coaxially rotatably sleeved on the second joint shaft (27). The rear leg piece (242) is fixedly connected inside the rear leg joint seat (24). The outer wall of the rear leg piece (242) is radially provided with a seat lock groove (243). The seat joint seat (25) is radially slidably connected with a seat lock tongue (253) that is locked in the seat lock groove (243). A seat linkage unlocking component (6) that drives the seat lock tongue (253) to slide out of the seat lock groove (243) is provided between the second joint shaft (27) and the seat joint seat (25).

4. The linkage unlocking structure of a folding trolley according to claim 3, characterized in that: The seat linkage unlocking assembly (6) includes a latch linkage block (61) that is radially slidably connected to the seat joint seat (25) and fixedly connected to the seat latch (253), a seat cam disc (62) fixedly sleeved on the second joint shaft (27), and a seat lock spring (63) disposed between the seat joint seat (25) and the latch linkage block (61). The seat cam disc (62) has an unlocking part (65) and an anti-rotation part (64). Under normal conditions, the seat lock spring (63) forces the latch linkage block (61) to slide towards the second joint shaft (27) so that the latch linkage block (61) abuts against the outer peripheral wall of the unlocking part (65) of the seat cam disc (62). Under normal conditions, the side wall of the anti-rotation part (64) of the seat cam disc (62) abuts against the lower outer side wall of the latch linkage block (61) to restrict the rotation of the second joint shaft (27).

5. The linkage unlocking structure of a folding trolley according to claim 4, characterized in that: The seat joint seat (25) is rotatably connected to the backrest connecting tube (80), and the backrest connecting tube (80) is fixedly connected to the backrest support body (801).

6. The linkage unlocking structure of a folding trolley according to claim 1, characterized in that: It also includes a handrail tube (60), and the main joint (2) also includes a handrail joint seat (22) located between the lower joint seat (21) of the main body and the front leg joint seat (23). The handrail tube (60) is fixedly connected to the handrail joint seat (22). The handrail plate (222) is fixedly connected to the inner cavity of the handrail joint seat (22). The handrail plate (222) includes a handrail rotating plate (223) coaxially rotatably sleeved on the second joint shaft (27) and a handrail connecting plate (224) fixedly connected between the outer wall of the handrail rotating plate (223) and the handrail joint seat (22). The outer wall of the handrail connecting plate (224) has a handrail anti-rotation surface (225) that abuts against the outer peripheral wall of the locking pin (201). The outer peripheral wall of the handrail rotating plate (223) is provided with a handrail lock. The inner wall of the front leg joint seat (23) is hinged with a handrail anti-rotation pawl (233). The free end of the handrail anti-rotation pawl (233) protrudes and is fixed with a handrail locking tongue (234) that is locked in the handrail locking groove (226). The front leg joint seat (23) is provided with a handrail locking spring (236) that forces the free end of the handrail anti-rotation pawl (233) to swing toward the direction of the handrail rotating plate (223). The free end of the handrail anti-rotation pawl (233) is located on the sliding trajectory of the locking pin (201) in the unlocking arc groove (29). The free end of the handrail anti-rotation pawl (233) has a handrail unlocking guide surface (235) that allows the outer peripheral wall of the locking pin (201) to abut against so as to force the free end of the handrail anti-rotation pawl (233) to swing away from the rotating plate.

7. The linkage unlocking structure of a folding trolley according to claim 6, characterized in that: The inner wall of the front leg joint seat (23) is provided with a handrail spring groove. The middle part of the handrail anti-rotation claw (233) is hinged with a handrail swing piece (237). The other end of the handrail swing piece (237) protrudes and is fixed with a handrail sliding protrusion that is slidably connected to the handrail spring groove. The handrail locking spring (236) is built into the handrail spring groove. One end of the handrail locking spring (236) is fixed or abuts against the handrail spring groove, and the other end of the handrail locking spring (236) is fixed or abuts against the handrail sliding protrusion.

8. The linkage unlocking structure of a folding trolley according to claim 6, characterized in that: The front leg joint seat (23) is located between the rear leg joint seat (24) and the armrest joint seat (22). The arc length of the unlocking groove (29) of the rear leg joint seat (24) is smaller than that of the front leg joint seat (23). A front leg locking pin (232) is fixedly inserted through the inner wall of the front leg joint seat (23). The axial direction of the front leg locking pin (232) is parallel to the axial direction of the second joint axis (27). One end of the armrest anti-rotation claw (233) is rotatably sleeved on the front leg locking pin (232). The end of the front leg locking pin (232) extends into the rear leg joint seat (24). The inner cavity of the rear leg joint seat (24) has a rotating arc groove (244) on the end face for the front leg locking pin (232) to slide through. The axis of the rotating arc groove (244) coincides with the axis of the second joint axis (27). When the front leg locking pin (232) abuts against one end of the rotating arc groove (244), the locking groove (28) of the front leg joint seat (23) and the locking groove (28) of the rear leg joint seat (24) coincide and align. When the front leg locking pin (232) abuts against the other end of the rotating arc groove (244), the rear leg joint seat (24) shows that it has been folded and rotated into place.

9. The linkage unlocking structure of a folding trolley according to claim 1, characterized in that: The main tube (20) is rotatably connected to a trolley hook seat (202) on its side wall. A trolley hook arm (203) is fixedly protruding from the outer wall of the trolley hook seat (202). A front leg limiting rod (301) is fixedly connected to the side wall of the front leg tube (30). After the trolley is folded, the hook head of the trolley hook arm (203) is hooked onto the front leg limiting rod (301).

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