A cart frame

Abstract

The invention discloses a cart frame, wherein a guide slide bar extends downward and is fixedly connected to a front wheel connecting seat, a rear foot connecting seat is fixedly arranged at an upper end of the guide slide bar, a sliding seat is slidably connected to the guide slide bar, a push rod is slidably connected to the rear foot connecting seat, and a lower end of the push rod is fixedly connected to the sliding seat. Both sides of the sliding seat are respectively hinged with linkage rods between the rear foot rods, and a front support rod is hinged between the front part of the seat frame connecting seat and the sliding seat, and a rear part of the seat frame connecting seat is hinged with the rear foot connecting seat through a rear support rod, or is hinged with a sliding sleeve slidably arranged between the sliding seat and the rear foot connecting seat through the rear support rod. When the push rod is acted downward to make the sliding seat slide along the lower end of the guide slide bar, the rear foot rod can be linked together and folded forward and inward through a linkage part, the seat frame connecting seat is linked together and folded downward and forward, so the structural design is ingenious and reasonable, and it is convenient to use and fold.

Description

[Technical field]

[0001] The invention relates to a cart, in particular to a cart frame. [Background technology]

[0002] In the prior art, in order to improve the convenience of using the stroller, the stroller is designed to be a foldable structure. For example, Chinese utility model patent zl201720208916.5 discloses a lightweight stroller for children, including a push rod, two rear legs, a seat, a front wheel connected to the lower end of the push rod, and two rear wheels respectively connected to the lower ends of the two rear legs. The upper ends of the two rear legs are pivotally connected to the push rod, and a first limit device for limiting the relative rotation of the rear legs and the push rod is provided between the upper ends of the two rear legs and the push rod. The seat is connected to the push rod and can rotate relative to the push rod around the vertical Y axis, and a second limit device for limiting the relative rotation of the seat around the vertical Y axis is provided between the push rod and the seat. In this technical solution, the seat is connected to the push rod and can rotate up and down relative to the push rod, and a third limit device for limiting the relative rotation of the seat up and down is provided between the seat and the push rod. The push rod comprises an upper push rod and a lower push rod, the seat and the two rear foot tubes are connected to the lower push rod, the upper push rod is connected to the lower push rod and can slide up and down relative to the lower push rod, and a fourth limit device for limiting the upper push rod from sliding up and down is arranged between the upper push rod and the lower push rod.

[0003] With the above technical solution, the seat and the push rod, as well as the push rod and the rear leg tube, are connected by a rotating shaft. When folding, the user needs to act on the first, second, third and fourth limit devices respectively, and cannot perform linked folding, that is, the push rod, the seat and the rear leg tube are successively moved closer to the front wheels. After folding, the two rear wheels are correspondingly located on the outside of the two front wheels. Therefore, the lateral space occupied after folding is still relatively large.

[0004] The present invention is proposed to address the above-mentioned deficiencies in the prior art. [Summary of the invention]

[0005] The technical problem to be solved by the present invention is to provide a stroller frame, wherein a guide slide bar extends downward and is fixedly connected to a front wheel connecting seat, a rear foot connecting seat is fixedly arranged at an upper end of the guide slide bar, a sliding seat is slidably connected to the guide slide bar, a push rod is slidably connected to the rear foot connecting seat, and a lower end of the push rod is fixedly connected to the sliding seat, a linkage rod is hinged between the sliding seat and the rear foot rod, and a front support rod is hinged between the front part of the seat frame connecting seat and the sliding seat, and a rear part of the seat frame connecting seat and the rear foot connecting seat is hinged through a rear support rod. When the push rod is acted downward to make the sliding seat slide along the lower end of the guide slide bar, the rear foot rod and the seat frame connecting seat can be linked together and folded toward the lower end of the guide slide bar through a linkage part, the front support rod and the rear support rod. Therefore, it has the characteristics of ingenious and reasonable structural design and convenient folding and unfolding.

[0006] In order to solve the above technical problems, the present invention provides a cart frame, including a guide slide rod, a push rod and a seat frame connecting seat.

[0007] At least one guide slide bar is provided, the front end of the guide slide bar is inclined downward and is directly or indirectly connected to the front wheel assembly; the upper end of the guide slide bar is fixedly connected to the rear foot connecting seat, the rear foot connecting seat is rotatably connected to the rear foot rod, and the lower end of the rear foot rod is connected to the rear wheel assembly; the guide slide bar is slidably connected to the sliding seat, the sliding seat is hinged with a linkage rod, the other end of the linkage rod is directly or indirectly hinged to the rear foot rod, and when the sliding seat slides downward, the linkage rod acts on the rear foot rod and folds forward; The push rod can be connected to the rear foot connecting seat in a sliding manner toward the front wheel assembly, and the lower end of the push rod is relatively fixedly connected to the sliding seat, and the upper end of the push rod is connected to a handle; a front support rod and a rear support rod are respectively connected between the front part of the seat frame connecting seat and the sliding seat, and between the rear part of the seat frame connecting seat and the rear foot connecting seat to stably support the seat frame connecting seat when unfolded and drive the seat frame connecting seat to be folded when folded; the rear foot connecting seat is provided with a locking component for locking the push rod to prevent the push rod from sliding relative to the rear foot connecting seat when the cart frame is unfolded.

[0008] In the stroller frame as described above, the rear leg connecting seat is provided with a guide through hole / groove, and the push rod is slidably connected to the rear leg connecting seat through the guide through hole / groove.

[0009] In the cart frame as described above, the push rod is a telescopic adjustable rod group, including a sleeve and a telescopic rod that can telescopically slide relative to the sleeve, the sleeve is slidably connected to the rear leg connecting seat through a guide through hole / groove, and the lower end of the sleeve is fixedly connected to the sliding seat, and the upper end of the telescopic rod is connected to the handle.

[0010] As described above, in a cart frame, the upper end of the front support rod is hinged to the front part of the seat frame connecting seat, and the lower end of the front support rod is hinged to the sliding seat, the upper end of the rear support rod is hinged to the rear part of the seat frame connecting seat, and the lower end of the rear support rod is hinged to the rear leg connecting seat, and the upper ends of the front support rod and the rear support rod are relatively fixedly provided with a limiting structure for limiting the seat frame connecting seat from flipping and tilting forward or backward when the cart frame is unfolded.

[0011] As described above, in a cart frame, the upper end of the front support rod is hinged to the front part of the seat frame connecting seat, and the lower end of the front support rod is hinged to the sliding seat, the upper end of the rear support rod is relatively fixedly connected to the seat frame connecting seat, and the lower end of the rear support rod is hinged to the rear leg connecting seat.

[0012] In the above-mentioned stroller frame, the angle between the upper ends of the two rear leg rods and the pivot axis of the rear leg connecting seat is α, and 0<α<180°

[0013] In the stroller frame as described above, the two sides of the rear leg connecting seat 3 are respectively provided with guide connecting grooves with openings facing downward and inclined toward the outside, and the upper ends of the two rear leg rods are respectively pivotally connected to the two guide connecting grooves; or the upper ends of the two rear leg rods are directly pivotally connected to the corresponding sides of the rear leg connecting seat.

[0014] In the cart frame as described above, the lower end of the guide slide bar is connected to two front wheel assemblies, the distance between the two front wheel assemblies is A, the distance between the two rear wheel assemblies is B, and when the frame is folded, the two rear wheel assemblies are located between the inner sides of the two front wheel assemblies, satisfying: A>B; when the frame is unfolded, the two rear wheel assemblies are correspondingly located on both sides of the rear side of the two front wheel assemblies, satisfying A≤B.

[0015] In the cart frame as described above, a pedal is provided between the middle and upper parts of the two rear foot rods.

[0016] In the above-mentioned stroller frame, the front support rod is longer than the rear support rod, and when the frame is unfolded, the upper ends of the front support rod and the rear support rod are approximately on the same horizontal plane or on the same horizontal plane.

[0017] In the stroller frame as described above, the angle between the upper ends of the two rear leg rods and the pivot axis of the rear leg connecting seat is 180°.

[0018] In the cart frame as described above, a connecting rod is provided between the two rear foot rods, and the rear end of the linkage rod is hinged to the connecting rod.

[0019] In the cart frame as described above, the lower end of the guide slide bar is connected to two front wheel assemblies. When the frame is folded, the two front wheel assemblies are placed between the inner sides of the two rear wheel assemblies.

[0020] In the stroller frame as described above, the rear leg connecting seat is provided with a switch assembly for locking the movement of the rear leg rod relative to the rear leg connecting seat.

[0021] Compared with the prior art, the cart frame of the present invention has the following advantages:

[0022] 1. The sliding seat is hinged to the seat frame connecting seat and the rear foot rod respectively. When the sliding seat slides downward along the guide slide rod, the seat frame connecting seat and the rear foot rod can be linked to fold accordingly, which has the characteristics of convenient folding and unfolding.

[0023] 2. Since the angle between the upper ends of the two rear foot rods and the pivot axis of the rear foot connecting seat is α, and 0<α<180°, after folding, the distance B between the two rear wheel assemblies is smaller than the distance A between the two front wheel assemblies, and the two rear wheel assemblies are located between the inner sides of the two front wheel assemblies. After folding, the maximum lateral dimension of the frame is the distance between the two front wheel assemblies. Therefore, by adopting this technical solution, the volume of the folded shape is further minimized, so it is convenient to transport the whole vehicle, carry it outside, and store it.

[0024] 3. According to design requirements, when the present invention is folded, it can directly move closer to the front wheel assembly, and the front wheel assembly can be placed inside the two rear wheel assemblies, while the distance between the two rear wheel assemblies remains unchanged, thereby reducing the complexity and cost of the structural design.

Brief Description of the Drawings

[0025] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

[0026] Figure 1 It is a side view of a first embodiment of a stroller frame of the present invention.

[0027] Figure 2 This is one of the three-dimensional structural schematic diagrams of a first embodiment of a cart frame of the present invention.

[0028] Figure 3 This is the second schematic diagram of the three-dimensional structure of the first embodiment of a cart frame of the present invention.

[0029] Figure 4 This is one of the reference diagrams of the folded state of the first embodiment of a stroller frame of the present invention.

[0030] Figure 5 The second reference figure is a folded state of the first embodiment of a stroller frame of the present invention.

[0031] Figure 6 It is a schematic diagram of the three-dimensional structure of the connection between the push rod and the sliding seat in the first embodiment of a cart frame of the present invention.

[0032] Figure 7 It is a schematic diagram of the three-dimensional structure of the connection between the guide slide bar, the front wheel connecting seat and the rear leg connecting seat in the first embodiment of the stroller frame of the present invention.

[0033] Figure 8 It is a schematic diagram of the three-dimensional structure of the rear leg connecting seat in the first embodiment of a stroller frame of the present invention.

[0034] Fig. 9 This is a perspective view of a first embodiment of a stroller frame of the present invention connected to a seat when it is unfolded for use.

[0035] Fig.10 The present invention is a side view of a stroller frame in a folded state in which a first embodiment of the stroller frame is connected to a seat.

[0036] Fig.11 The figure is a side view of a second embodiment of a stroller frame of the present invention.

[0037] Fig.12 It is a schematic diagram of the three-dimensional structure of a first embodiment of a cart frame of the present invention.

[0038] Fig.13 It is a schematic diagram of the three-dimensional structure of the connection between the rear leg connecting seat, the push rod and the rear leg rod in the second embodiment of the stroller frame of the present invention.

[0039] Fig.14 An exploded view of a rear foot rod and a locking assembly in a second embodiment of a stroller frame of the present invention.

[0040] Fig.15 An exploded view of a push rod, a rear foot connecting seat and a locking assembly in a second embodiment of a stroller frame of the present invention. [Specific implementation method]

[0041] The following is combined with Figure 1-15 Embodiments of the present invention are described in detail.

[0042] The stroller frame of the present invention is not limited to being a child stroller or a shopping stroller, and for this purpose, the seat frame connecting seat can be connected to a child seat or a shopping basket accordingly as required.

[0043] As a first embodiment of a cart frame of the present invention, Figure 1-10 The invention comprises a guide slide bar 1, a push rod 5 and a seat frame connecting seat 8; the guide slide bar 1 is provided with at least one, and the front end of the guide slide bar 1 is tilted downward and connected to the front wheel connecting seat 2, and the front wheel connecting seat 2 is connected to the front wheel assembly 21; the upper end of the guide slide bar 1 is fixedly connected to the rear foot connecting seat 3, and the rear foot rods 6 are rotatably hinged on both sides of the rear foot connecting seat 3, and the lower end of each rear foot rod 6 is connected to the rear wheel assembly 61; the guide slide bar 1 is slidably connected to a sliding seat 4 between the front wheel connecting seat 2 and the rear foot connecting seat 3, and a linkage rod 7 is respectively hinged between the sliding seat 4 and the two rear foot rods 6 for folding forward when the sliding seat 4 slides downward; the push rod 5 is slidably connected to the rear foot connecting seat 3, and the lower end of the push rod 5 is fixedly connected to the sliding seat 4, and the upper end of the push rod 5 is connected to a handle 51, such as Figure 1 As shown, the upper end of the front support rod 81 is hinged to the front of the seat frame connecting seat 8, and the lower end of the front support rod 81 is hinged to the sliding seat 4, the upper end of the rear support rod 82 is hinged to the rear of the seat frame connecting seat 8, and the lower end of the rear support rod 82 is hinged to the rear foot connecting seat 3, and the upper ends of the front support rod 81 and the rear support rod 82 are relatively fixedly provided with a limiting structure 83 for limiting the seat frame connecting seat from flipping forward or backward when the cart frame is unfolded. When the cart frame is unfolded, the limiting structure 83 can limit the seat frame connecting seat from flipping forward or backward. The limiting structure 83 is a limiting rod / block, which is arranged on the pivot shafts at the upper ends of the front support rod and the rear support rod in opposite directions, and has the characteristics of simple structure.

[0044] The rear foot connection seat 3 is provided with a locking assembly 11 for locking the push rod 5 to prevent the push rod 5 from sliding relative to the rear foot connection seat 3 when the stroller frame is unfolded. In the first embodiment of the present invention, the locking assembly 11 can adopt the structure of the fourth limit device disclosed in Chinese utility model patent ZL2017202089165. When in use, the locking assembly 11 is used to release the locking state of the push rod 5, and then the push rod 5 is pushed downward, and the push rod 5 pushes the sliding seat 4 to slide along the lower end of the guide slide bar 1. During the sliding process of the sliding seat 4, the front support rod 81 pulls the seat frame connection seat 8 to gradually fold, and the two linkage rods 7 correspondingly pull the two rear foot rods 6 to gradually move closer to the front wheel assembly 21, until the bottom of the seat frame connection seat 4 contacts the guide slide bar 1, and the rear foot rods 6 are basically parallel to the guide slide bar 1, and the folding is completed.

[0045] When unfolded for use, since the rear foot connection seat 3 is fixed to the upper end of the guide slide bar 1, and the locking assembly 11 locks the sleeve 52 on the rear foot connection seat 3, the sliding seat 4 is also relatively locked on the guide slide bar 1. Therefore, the seat frame connection seat 8 is connected with the rear support rod 82, the rear foot connection seat 3, the front support rod 81, the sliding seat 4, the guide slide bar 1 and the limiting structure 83 to form a stable triangular structure. In addition, the sliding seat 4, the guide slide bar 1, the rear foot connection seat 3, the rear foot rod 6 and the linkage rod 7 also form a stable triangular structure. The limiting structure 83 is used to limit the seat frame connection seat 8 from leaning against the bottom, so that the seat frame connection seat will not tilt forward or backward, ensuring that the structure is stable and safe and reliable during use.

[0046] During the specific unfolding operation, the handle on the push rod is pulled upward, the push rod slides relative to the rear leg connecting seat, and the sliding seat is driven to slide upward along the guide slide rod, the front support rod pushes the seat frame connecting seat to move, and the linkage rod pushes the rear leg rod backward to unfold. When it is fully unfolded, the locking assembly elastically extends the locking pin to lock the push rod on the rear leg connecting seat.

[0047] When folding, the locking assembly 11 is used to release the locking state of the sleeve 52 so that it can slide relative to the rear foot connection seat 3, and the sliding seat 4 can also slide relative to the guide slide bar 1. At this time, the triangular structure formed by the seat frame connection seat 8, the rear support rod 82, the rear foot connection seat 3, the front support rod 81, the sliding seat 4 and the guide slide bar 1 is "destroyed" and becomes a foldable four-bar mechanism, which allows the seat frame connection seat to be folded accordingly. At the same time, the triangular structure formed by the sliding seat 4, the guide slide bar 1, the rear foot connection seat 3, the rear foot rod 6 and the linkage rod 7 is also "destroyed" and becomes a foldable four-bar mechanism, which allows the rear foot rod to move closer to the guide slide bar 1 and the front wheel assembly 21 and fold. Therefore, it has the characteristics of convenient folding and simple structure.

[0048] For the convenience of users, the push rod 5 is a telescopic adjustable rod group, including a sleeve 52 and a telescopic rod 53 that can telescopically slide relative to the sleeve 52. A guide through hole / groove 31 parallel to the guide slide rod 1 is provided in the middle of the rear foot connecting seat 3. The sleeve 52 is slidably connected to the sliding seat 4 through the guide through hole / groove 31. The lower end of the sleeve 52 is fixedly connected to the sliding seat 4. The upper end of the telescopic rod 53 is connected to the handle 51. The sleeve and the telescopic rod can be clamped and adjusted by a spring bean.

[0049] The angle between the upper ends of the two rear foot rods 6 and the pivot axis of the rear foot connecting seat 3 is α, and 0<α<180°. Therefore, by adopting the above design structure, the rear foot rods 6 can be folded forward and inward when being linked and folded.

[0050] In order to facilitate the hinge connection between the rear foot rod and the rear foot connecting seat, the two sides of the rear foot connecting seat 3 are respectively provided with guide connecting grooves 32 with openings facing downward and tilted toward the outside. The upper end of the rear foot rod is pivoted in the guide connecting groove, and the two sides in the guide connecting groove can guide the folding and unfolding of the rear foot rod. The left and right sides of the front wheel connecting seat 2 are respectively connected to the front wheel assembly 2.

[0051] In addition, the present invention can also directly pivotally connect the upper end of the rear foot rod and the rear foot connecting seat through a pin or a rivet. When folding or unfolding, the side surface of the upper end of the rear foot rod is used to abut against the side surface of the rear foot connecting seat for guidance. For this purpose, the side surface of the rear foot connecting seat is correspondingly set to an inclined slope, thereby ensuring that the rear foot rod is retracted forward and inward when folded.

[0052] The front wheel connecting seat 2 is connected to the front wheel assembly 21 on the left and right sides respectively, the distance between the two front wheel assemblies 21 is A, and the distance between the two rear wheel assemblies 61 is B. When the frame is folded, the two rear wheel assemblies 61 are located between the inner sides of the two front wheel assemblies 21, satisfying: A>B, then after the frame of the whole vehicle is folded, its maximum horizontal dimension is the distance between the two front wheel assemblies 21. Therefore, the space occupied by the appearance is reduced, which is convenient for people to carry out, transport and store; when the frame is unfolded, the two rear wheel assemblies 61 are correspondingly located on both sides of the rear side of the two front wheel assemblies 21, satisfying A≤B, so it is convenient for people to unfold and use.

[0053] The first embodiment of the present invention adopts the above technical solution, and preferably adopts the method that when the whole vehicle frame is folded, the two rear wheel assemblies can be folded between the inner sides of the two front wheel assemblies, so as to achieve the characteristic of minimizing the folded volume.

[0054] In order to improve the safety and stability of use, the guide slide rods 1 described in the present invention are two and are arranged in parallel. A pedal 62 is provided between the upper and middle parts of the two rear foot rods 6. The pedal 62 is made of a flexible and foldable material, and is either a retractable and foldable structure or a detachably connected structure. For the latter, a detachably connected structure is used. When folding, the pedal 62 needs to be removed first and then unlocked and folded.

[0055] like Figure 1 As shown, the front support rod 81 is longer than the rear support rod 82 and when the frame is unfolded, the upper ends of the front support rod 81 and the rear support rod 82 are approximately in the same horizontal plane or in the same horizontal plane, so that the seat frame connecting seat can be basically in a horizontal plane.

[0056] As a second embodiment of the present invention, Figure 11-15 As shown, the present embodiment is a cart frame, comprising a guide slide bar 1, a push rod 5 and a seat frame connecting seat 8; at least one guide slide bar 1 is provided, the front end of the guide slide bar 1 is inclined downward and is directly or indirectly connected to the front wheel assembly 21; the upper end of the guide slide bar 1 is fixedly connected to the rear foot connecting seat 3, and the rear foot connecting seat 3 is rotatably connected to the rear foot rod 6, and the angle between the upper ends of the two rear foot rods and the pivot axis of the rear foot connecting seat is 180°.

[0057] The lower end of the rear foot rod 6 is connected to a rear wheel assembly 61; the guide slide bar 1 is slidably connected to a sliding seat 4, the sliding seat 4 is hinged with a linkage rod 7, a connecting rod 62 is provided between the two rear foot rods 6, and the rear end of the linkage rod 7 is hinged with the connecting rod 62. When the sliding seat 4 slides downward, the linkage rod 7 acts on the rear foot rod 6 and folds forward; the push rod 5 is slidably connected to the rear foot connection seat 3 toward the front wheel assembly 21, and the lower end of the push rod 5 is relatively fixedly connected to the sliding seat 4, and the upper end of the push rod 5 is connected to a handle 51; the upper end of the front support rod 81 is hinged to the front of the seat frame connection seat 8, and the lower end of the front support rod 81 is hinged to the sliding seat 4, the upper end of the rear support rod 82 is relatively fixedly connected to the seat frame connection seat 8, and the lower end of the rear support rod 82 is hinged to the rear foot connection seat 3; the rear foot connection seat 3 is provided with a locking assembly 11 for locking the push rod 5 to prevent the push rod 5 from sliding relative to the rear foot connection seat 3 when the cart frame is unfolded. When in use, the push rod 5 is acted on and the push rod 5 can press the locking assembly 11 to force it to unlock, so that the push rod can slide relative to the rear foot connecting seat. During the downward sliding process of the push rod, the sliding seat pulls the rear foot rod to fold toward the front wheel assembly through the linkage rod and the connecting rod. Correspondingly, the lower end of the front support rod 81 also tilts as the sliding seat slides downward, and finally the bottom of the seat frame connecting seat 8 is close to or attached to the guide slide bar 1, and the guide slide bar and the front wheel assembly are both located on the inner side of the two rear foot rods and the rear wheel assembly.

[0058] In the second embodiment, the angle between the upper ends of the two rear foot rods 6 and the pivot axis of the rear foot connecting seat 3 is 180°, and the lower end of the guide slide bar 1 is connected to the two front wheel assemblies 21 through the front wheel connecting seat. When the frame is folded, the two front wheel assemblies 21 are placed between the inner sides of the two rear wheel assemblies 61.

[0059] In order to ensure safe and reliable use, the rear foot connection seat 3 is provided with a switch assembly 12 for locking the movement of the rear foot rod 6 relative to the rear foot connection seat 3. When it is necessary to fold, it is necessary to first release the locking state of the rear foot rod by the switch assembly 12, and then act downward on the push rod to force the locking assembly to release the locking state of the push rod.

[0060] For the switch assembly 12, as Fig.13 and Fig.14 As shown, the rear foot rod is rotatably connected to the rear foot connection seat, and an elastically retractable spline 121 is provided on the rear foot rod, and a key slot for the spline 121 to be inserted is correspondingly provided in the rear foot connection seat, so that the rear foot rod can be relatively fixedly locked on the rear foot connection seat. In order to release the locked state of the rear foot rod, an unlocking inclined surface 122 is provided on the side of the spline, and an unlocking wedge block 123 can be relatively movably provided on the rear foot connection seat, and a rear foot unlocking key 124 is also provided on the rear foot connection seat for elastically pressing the unlocking wedge block so that the unlocking wedge block is placed at a low position of the unlocking inclined surface. When the rear foot unlocking key 124 is pressed, the unlocking wedge block slides relative to the rear foot connection seat and slides along the unlocking inclined surface, pressing the spline out of the key slot, and then the rear foot rod can rotate relative to the rear foot connection seat. When the rear foot unlocking key 124 is released, the unlocking wedge 13 is automatically elastically reset, and when the rear foot rod is unfolded, the spline is automatically inserted into the key slot, thereby relatively fixing the rear foot rod to the rear foot connecting seat.

[0061] In the second embodiment, the push rod 5 is a telescopic adjustment rod group, including a sleeve 52 and a telescopic rod 53 that can telescopically slide relative to the sleeve 52. The middle part of the rear foot connecting seat 3 is provided with a guide hole / slot 31 parallel to the guide slide bar 1. The sleeve 52 is slidably connected to the sliding seat 4 through the guide hole / slot 31. The lower end of the sleeve 52 is fixedly connected to the sliding seat 4. The upper end of the telescopic rod 53 is connected to the handle 51. The sleeve and the telescopic rod can be clamped and adjusted by a spring bean. For the locking component 11, as shown in FIG. Fig.15 As shown, it includes a locking hole 112 arranged on the side of the sleeve 52, a mounting hole 111 arranged on the rear foot connection seat 3, the mounting hole 111 is connected to the guide through hole / slot 31, and a locking tongue 113 is arranged in the mounting hole 111. The locking tongue 113 can be elastically extended into the guide through hole / slot 31 and can be inserted into the locking hole 112 to relatively fix and lock the sleeve on the rear foot connection seat. In order to facilitate unlocking, the free end of the locking tongue 113 is provided with an inclined surface or an arc surface. When the telescopic rod slides downward relative to the sleeve, the lower end of the telescopic rod can press the locking tongue to elastically retract, thereby allowing the sleeve to slide relative to the rear foot connection seat.

[0062] For Example 2, similarly, in the unfolded state, since the rear foot connection seat 3 is fixed to the upper end of the guide slide bar 1, the locking assembly 11 locks the sleeve 52 on the rear foot connection seat 3, and the switch assembly 12 locks the rear foot rod 6 on the rear foot connection seat 3, the sliding seat 4 is also relatively locked on the guide slide bar 1. Therefore, the seat frame connection seat 8 and the rear support rod 82, the rear foot connection seat 3, the front support rod 81, the sliding seat 4 and the guide slide bar 1 form a stable triangular structure. In addition, the sliding seat 4, the guide slide bar 1, the rear foot connection seat 3, the rear foot rod 6 and the linkage rod 7 also form a stable triangular structure. It is ensured that the structure is stable and safe and reliable during use.

[0063] When folding, first release the locking state of the switch assembly 12 on the rear foot rod, and then act downward on the push rod to force the locking assembly to release the locking state of the push rod. When the locking state of the sleeve 52 is released and it slides relative to the rear foot connection seat 3, the sliding seat 4 can also slide relative to the guide slide bar 1. At this time, the triangular structure formed by the seat frame connection seat 8, the rear support rod 82, the rear foot connection seat 3, the front support rod 81, the sliding seat 4 and the guide slide bar 1 is "destroyed" and becomes a foldable four-bar mechanism, which makes the seat frame connection seat fold accordingly. At the same time, the triangular structure formed by the sliding seat 4, the guide slide bar 1, the rear foot connection seat 3, the rear foot rod 6 and the linkage rod 7 is also "destroyed" and becomes a foldable four-bar mechanism, which makes the rear foot rod close to the guide slide bar 1 and the front wheel assembly 21 and fold. Therefore, it has the characteristics of convenient folding and simple structure.

Claims

1. A cart frame, characterized in that It comprises a guide slide rod (1), a push rod (5) and a seat frame connecting seat (8); At least one guide slide bar (1) is provided, the front end of the guide slide bar (1) is tilted downward and is directly or indirectly connected to a front wheel assembly (21); The upper end of the guide slide bar (1) is fixedly connected to a rear foot connection seat (3), the rear foot connection seat (3) is rotatably connected to a rear foot rod (6), and the lower end of the rear foot rod (6) is connected to a rear wheel assembly (61); The guide slide bar (1) is slidably connected to a slide seat (4), the slide seat (4) is hinged to a linkage rod (7), the other end of the linkage rod (7) is directly or indirectly hinged to the rear foot rod (6), and when the slide seat (4) slides downward, the linkage rod (7) acts on the rear foot rod (6) and folds forward; The push rod (5) can be slidably connected to the rear foot connection seat (3) toward the front wheel assembly (21), and the lower end of the push rod (5) is relatively fixedly connected to the sliding seat (4), and the upper end of the push rod (5) is connected to a handle (51); A front support rod (81) and a rear support rod (82) are respectively connected between the front part of the seat frame connection seat (8) and the sliding seat (4) and between the rear part of the seat frame connection seat (8) and the rear foot connection seat (3) to stably support the seat frame connection seat when unfolded and drive the seat frame connection seat to fold when folded; The rear foot connection seat (3) is provided with a locking assembly (11) for locking the push rod (5) to prevent the push rod (5) from sliding relative to the rear foot connection seat (3) when the stroller frame is unfolded.

2. A cart frame according to claim 1, characterized in that The rear foot connection seat (3) is provided with a guide through hole / slot (31), and the push rod (5) is slidably connected to the rear foot connection seat (3) via the guide through hole / slot (31).

3. A cart frame according to claim 2, characterized in that The push rod (5) is a telescopic adjustment rod group, comprising a sleeve (52) and a telescopic rod (53) that can telescopically slide relative to the sleeve (52); the sleeve (52) is slidably connected to the rear foot connecting seat (3) through a guide through hole / slot (31), and the lower end of the sleeve (52) is fixedly connected to the sliding seat (4), and the upper end of the telescopic rod (53) is connected to the handle (51).

4. A cart frame according to claim 1, characterized in that The upper end of the front support rod (81) is hinged to the front of the seat frame connecting seat (8), and the lower end of the front support rod (81) is hinged to the sliding seat (4); the upper end of the rear support rod (82) is hinged to the rear of the seat frame connecting seat (8), and the lower end of the rear support rod (82) is hinged to the rear foot connecting seat (3); the upper ends of the front support rod (81) and the rear support rod (82) are relatively fixedly provided with a limiting structure (83) for limiting the seat frame connecting seat from flipping forward or backward when the stroller frame is unfolded.

5. A cart frame according to claim 1, characterized in that The upper end of the front support rod (81) is hinged to the front part of the seat frame connecting seat (8), and the lower end of the front support rod (81) is hinged to the sliding seat (4); the upper end of the rear support rod (82) is relatively fixedly connected to the seat frame connecting seat (8), and the lower end of the rear support rod (82) is hinged to the rear foot connecting seat (3).

6. A cart frame according to any one of claims 1 to 5, characterized in that The angle between the upper ends of the two rear foot rods (6) and the pivot axis of the rear foot connecting seat (3) is α, and 0<α<180°.

7. A cart frame according to claim 6, characterized in that The two sides of the rear foot connection seat (3) are respectively provided with guide connection grooves (32) with openings facing downward and tilted toward the outside, and the upper ends of the two rear foot rods (6) are respectively pivotally connected to the two guide connection grooves (32); or the upper ends of the two rear foot rods (6) are directly pivotally connected to the corresponding side surfaces of the rear foot connection seat (3).

8. A cart frame according to claim 6, characterized in that The lower end of the guide slide bar (1) is connected to two front wheel assemblies (21), the distance between the two front wheel assemblies (21) is A, and the distance between the two rear wheel assemblies (61) is B. When the frame is folded, the two rear wheel assemblies (61) are located between the inner sides of the two front wheel assemblies (21), satisfying: A>B; when the frame is unfolded, the two rear wheel assemblies (61) are correspondingly located on both sides of the rear side of the two front wheel assemblies (21), satisfying A≤B.

9. A cart frame according to claim 1, characterized in that A pedal (62) is provided between the middle and upper parts of the two rear foot rods (6).

10. A cart frame according to claim 1, characterized in that The front support rod (81) is longer than the rear support rod (82), and when the frame is unfolded, the upper ends of the front support rod (81) and the rear support rod (82) are approximately on the same horizontal plane or on the same horizontal plane.

11. A cart frame according to any one of claims 1 to 5, characterized in that The included angle between the upper ends of the two rear foot rods (6) and the pivot axis of the rear foot connecting seat (3) is 180 degrees.

12. A cart frame according to claim 11, characterized in that A connecting rod (62) is provided between the two rear foot rods (6), and the rear end of the linkage rod (7) is hinged to the connecting rod (62).

13. A cart frame according to claim 11, characterized in that The lower end of the guide slide bar (1) is connected to two front wheel assemblies (21). When the frame is folded, the two front wheel assemblies (21) are placed between the inner sides of the two rear wheel assemblies (61).

14. A cart frame according to claim 11, characterized in that The rear foot connection seat (3) is provided with a switch assembly (12) for locking the movement of the rear foot rod (6) relative to the rear foot connection seat (3).

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