CN212500619U

CN212500619U - Baby stroller convenient to fold quickly

Info

Publication number: CN212500619U
Application number: CN202020571706.4U
Authority: CN
Inventors: 刘长庆
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-04-17
Filing date: 2020-04-17
Publication date: 2021-02-09
Anticipated expiration: 2030-04-17

Abstract

The utility model provides a baby's shallow convenient to receive and close fast, include that receive and close the shallow body frame body that opens up and the seat support body that can receive and close through the link gear, the seat support body is detachable to be connected on the shallow body frame body, and the seat support body can rotate 360 degrees round the shallow body frame body level. The utility model provides a baby stroller convenient for quick folding, firstly, the stroller main frame body can be folded and unfolded in a linkage way, and the seat frame body can also be folded and unfolded, and the stroller main frame body and the seat frame body are detachably connected, thereby facilitating the folding and unfolding operations of the stroller body and providing convenience for the disassembly and assembly of the stroller body; moreover, the seat support body can rotate 360 degrees around the main frame body level of the stroller, so that the baby can sit on the seat support body facing and facing away from the stroller, a second choice is provided for the baby as the orientation, and the use experience of a user is improved.

Description

Baby stroller convenient to fold quickly

Technical Field

The utility model relates to a baby's shallow technical field especially relates to a baby's shallow convenient to receive fast and close.

Background

At present, in daily life of people, a baby carriage is often seen as a walking aid, so that an infant can sit or lie on the baby carriage. To facilitate portability, industry developers have developed strollers that can fold quickly.

However, in the current foldable baby carriage, the seat part and the frame part are integrally connected, and quick disassembly and independent folding cannot be realized.

Therefore, it is desirable to provide a stroller that is easy to fold quickly to solve the above-mentioned problems.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the main technical problem who solves provides a baby's shallow convenient to receive fast and close, and the shallow body frame body is received through linkage structure receipts and is closed and expand, and the seat support body is do not received and close yet, and the seat support body can wind 360 degrees rotations of shallow body frame body level for the baby can be in the face of and back to the person of pushing away the baby and sit on the seat support body, provides the second kind for infant's as the orientation and select.

In order to solve the technical problem, the utility model discloses a technical scheme provide a baby's shallow convenient to receive fast and close, include that receive and close the shallow body frame body 10 that opens up and the seat support body 20 that can receive through the link gear, seat support body 20 is detachable to be connected on shallow body frame body 10, and seat support body 20 can round on shallow body frame body 10 horizontal rotation 360 degrees.

In one embodiment: baby's shallow convenient to receive fast further includes quick detach formula roating seat 30, quick detach formula roating seat 30 includes: the trolley comprises a rotary chassis 31, a rotary surface hardware 32 screwed on the top surface of the rotary chassis 31, a chassis fixing middle shaft 33, a rotary upper cover 34, a rotary seat locking hardware 35 connected to the main trolley frame 10, an unlocking fixing piece 36, a seat fixing side seat 37 and a rotary fixing transverse pipe 38;

the rotating chassis 31 is fixed on the main cart frame 10, the seat fixing side seat 37 is integrally connected with the free end of the rotating fixing transverse pipe 38, and the seat frame body 20 is clamped with the seat fixing side seat 37;

the chassis fixing middle shaft 33 sequentially penetrates through the rotary upper cover 34, the rotary fixing transverse pipe 38 and the rotary surface hardware 32 from top to bottom to be connected with the rotary chassis 31 in a rotating mode, the unlocking fixing piece 36 is connected with the top of the rotary seat locking hardware 35, and two rail openings 341 for enabling the rotary seat locking hardware 35 to transversely advance and symmetrical to the chassis fixing middle shaft 33 are formed in the rotary surface hardware 32 and the rotary upper cover 34 respectively;

when the upper cover 34 is rotated to be aligned with the track opening 341 on the rotating surface hardware 32 up and down, the unlocking fixing piece 36 is pulled, the rotating seat locking hardware 35 realizes locking along the transverse movement of the corresponding track opening 341, and unlocking is realized when the rotating seat locking hardware 35 is withdrawn from the track opening 341.

In one embodiment: the quick release rotary base 30 further comprises two locking buttons 39;

the seat fixing side seat 37 extends upward, and the seat fixing side seat 37 is provided with the locking button 39;

the seat fixing side seat 37 is locked and connected to the bottom of the seat frame 20 by the locking button 39.

In one embodiment: the seat frame 20 includes a seat body 21, a footrest assembly 22 coupled to the seat body 21, an armrest assembly 23 coupled to an upper bottom surface of the seat body 21, a backrest tube 24, a ceiling support assembly 25 coupled to the backrest tube 24, a backrest lock assembly 26 coupled to the backrest tube 24 for adjusting an inclination angle of the backrest tube 24, a backrest joint 27 connecting the seat body 21 and the backrest tube 24, and a backrest connection flat iron 28 transversely connected to a lower end of the backrest tube 24.

In one embodiment: the foot support component 22 comprises a first bending joint 221, a foot support connecting pipe 222 and a foot supporting plate 223;

the first folding joint 221 is connected to the seat body 21, and the first folding joint 221 is connected to the leg plate 223 through the leg support connection tube 222.

In one embodiment:

the ceiling support assembly 25 comprises a lower ceiling seat 251, an upper ceiling seat 252, a front ceiling pipe 253, a rear ceiling pipe 254 and a third bending joint 255;

the lower ceiling seat 251 is fixed to the back rest tube 24, the upper ceiling seat 252 is connected to the lower ceiling seat 251 through a third bending joint 255, the front ceiling tube 253 is connected to the rear end of the upper ceiling seat 252, and the rear ceiling tube 254 is clamped to the back rest tube 24 by the lower ceiling seat 251.

In one embodiment:

the backrest lock assembly 26 comprises a backrest connecting and supporting flat iron 261 transversely connected with the backrest pipe 24, a backrest adjusting lock 262 and a backrest adjusting wrench 263 used for wrenching the backrest adjusting lock 262;

a backrest adjusting lock 262 is provided on the backrest connection support band 261, and a backrest adjusting wrench 263 is connected to the backrest adjusting lock 262.

In one embodiment:

the main cart frame 10 comprises a main joint 11, a rear transverse pipe 12 fixedly connected with the main joint 11, a front movable transverse pipe 13 connected with the main joint 11, a U-shaped folding handle 14 used for pulling the front movable transverse pipe 13 backwards to unlock the locking between the main joint 11 and the foot pipe assembly, a push handle assembly 15, the foot pipe assembly, four caster assemblies connected with the foot pipe assembly, and a transverse pipe fixing seat 18 fixed on the bottom surface of a rotating base 31;

the push handle assembly 15 and the foot tube assembly are axially connected with the main joint 11, the rear transverse tube 12 and the front movable transverse tube 13 are arranged on a transverse tube fixing seat 18 in a penetrating manner, the tail end of the U-shaped folding handle 14 is arranged on the front movable transverse tube 13 in a penetrating manner, and two side parts of the U-shaped folding handle 14 are connected with the transverse tube fixing seat 18 through folding fixing screws 19.

In one embodiment:

the push handle assembly 15 includes a push handle fixing base 151 connected to the outer side of the rear end of the main joint 11, a push handle pipe 152 connected to the push handle fixing base 151, and a one-hand switch button 153 connected to the push handle pipe 152 for controlling the locking state between the push handle pipe 152 and the push handle fixing base 151.

In one embodiment:

the foot tube assembly comprises a front foot tube 161, a rear foot tube 162, two sections of linkage flat irons 163, an underframe connecting tube 164, a front foot transverse tube 165 and a rear wheel brake transverse tube 166 which are connected with the main joint 11 through a shaft; the caster assembly includes a front wheel 171 and a rear wheel 172;

the front foot tube 161 is connected with the front wheel 171 through a front wheel seat, the rear foot tube 162 is connected with the rear wheel 172 through a rear wheel seat, the front foot transverse tube 165 is connected between the front wheel seats, and the rear wheel transverse brake tube 166 is connected between the rear wheel seats;

the tail end of the first section of the linkage flat iron 163 is rotatably connected with the inner side of the main joint 11, the middle part of the second section is rotatably connected with the rear foot tube 162, the tail part is rotatably connected with one end of the underframe connecting tube 164, and the other end of the underframe connecting tube 164 is rotatably connected with the front wheel seat.

The utility model has the advantages that:

(1) the seat frame body and the main cart body of the cart can be folded, the seat frame body is folded and unfolded through a linkage structure, and the seat frame body and the main cart body of the cart are detachably connected;

(2) the seat frame body can rotate 360 degrees relative to the main cart body of the cart, and an infant can face a pushchair to sit on the seat frame body;

(3) the back pipe of seat support body, the gradient of pushing away the subassembly of shallow main frame body can be adjusted, and the user can carry out appropriate adjustment gradient according to the demand of using.

Drawings

Fig. 1 and 2 are schematic structural views of a seat frame 20 of a stroller convenient for quick folding according to the present invention in a forward state;

fig. 3 and 4 are schematic structural views of a seat frame 20 of a stroller convenient for quick folding according to the present invention in a backward state;

fig. 5 is a schematic view illustrating a connection structure between the seat frame 20 and a portion of the quick release type rotary base 30;

fig. 6 is a schematic view of the connection structure of the quick release type rotary seat 30 and a part of the main frame 10 of the cart;

fig. 7 is a schematic view of a connection structure of a part of the quick release type rotary seat 30 and a part of the main frame 10 of the cart;

fig. 8 to 10 are schematic views showing three states of gradual folding of the stroller main frame 10 of the stroller convenient for quick folding according to the present invention.

Detailed Description

The technical solution of the present invention will be described in detail with reference to the drawings.

The utility model provides a baby's shallow convenient to receive fast closes, as shown in fig. 2, include that the shallow body frame body 10 that closes and expand and the seat support body 20 that can receive through the link gear receipts, seat support body 20 is detachable to be connected on shallow body frame body 10, and seat support body 20 can rotate 360 degrees round shallow body frame body 10 level. The baby stroller of the embodiment is convenient to disassemble and assemble, and can be conveniently folded in the using process, so that the baby stroller is convenient to store and carry. Furthermore, the stroller main frame 10 is folded and unfolded by the link mechanism, and the seat frame body can rotate 360 degrees around the stroller main frame, so that the orientation of the infant can be adjusted.

In order to facilitate the folding and unfolding of the stroller main frame 10 and the seat frame 20, as shown in fig. 2 and 3, the stroller further includes a quick-release rotary seat 30, as shown in fig. 6 and 7, the quick-release rotary seat 30 includes: the trolley comprises a rotary chassis 31, a rotary surface hardware 32 screwed on the top surface of the rotary chassis 31, a chassis fixing middle shaft 33, a rotary upper cover 34, a rotary seat locking hardware 35 connected to the main trolley frame 10, an unlocking fixing piece 36, a seat fixing side seat 37 and a rotary fixing transverse pipe 38;

the rotary chassis 31 is fixed on the main cart frame 10, the seat fixing side seats 37 are integrally connected with the free ends of the rotary fixing transverse pipes 38, and the seat frame body 20 is connected with the seat fixing side seats 37 in a clamping manner, so that the quick assembly and disassembly between the seat fixing side seats and the seat frame body are ensured;

the chassis fixing middle shaft 33 sequentially penetrates through the rotary upper cover 34, the rotary fixing transverse pipe 38 and the rotary surface hardware 32 from top to bottom to be connected with the rotary chassis 31 in a rotating mode, so that after the unlocking fixing piece 36 unlocks the rotary surface hardware 32 and the rotary upper cover 34, the rotary upper cover 34 and the rotary fixing transverse pipe 38 can be conveniently rotated on the rotary surface hardware 32 around the chassis fixing middle shaft 33, and therefore the facing direction of a person sitting on the seat frame body 20 can be changed to face forwards (shown in fig. 1 and 2) or backwards (shown in fig. 3 and 4). The convenience is brought to the user, and the user can change the direction according to the use requirement.

As shown in fig. 7, the unlocking fixing member 36 is connected to the top of the swivel lock hardware 35, and two rail openings 341 symmetrical with respect to the chassis fixing middle shaft 33 for the transverse travel of the swivel lock hardware 35 are respectively arranged on the swivel surface hardware 32 and the swivel upper cover 34;

referring to fig. 6 and 7, when the unlocking fixing member 36 is manually pulled, and the rail exit 341 is pulled away from the chassis fixing central axis 33, the unlocking can be realized, so that the rotary upper cover 34 and the rotary fixing transverse tube 38 can rotate around the chassis fixing central axis 33, when the corresponding rail exit 341 is aligned up and down, the unlocking fixing member 36 is pulled towards the chassis fixing central axis 33, so that the rotary seat locking hardware 35 enters the corresponding rail exit 341, and the rotary upper cover 34 and the rotary fixing transverse tube 38 are locked relative to the rotary surface hardware 32, thereby ensuring the stability of the seat frame 20 in the direction.

As shown in fig. 6, the quick-release swivel 30 further includes two locking buttons 39; the seat fixing side seat 37 extends upward, and the seat fixing side seat 37 is provided with the locking button 39; the seat fixing side seat 37 is locked and connected to the bottom of the seat frame 20 by the locking button 39. To remove the seat frame 20, the seat frame 20 can be easily removed by simply pressing the locking buttons 39 on both sides.

As shown in fig. 4, the seat frame 20 has a specific structure: the seat frame 20 includes a seat body 21, a footrest assembly 22 coupled to the seat body 21, an armrest assembly 23 coupled to an upper bottom surface of the seat body 21, a backrest tube 24, a ceiling support assembly 25 coupled to the backrest tube 24, a backrest lock assembly 26 coupled to the backrest tube 24 for adjusting an inclination angle of the backrest tube 24, a backrest joint 27 connecting the seat body 21 and the backrest tube 24, and a backrest connection flat iron 28 transversely connected to a lower end of the backrest tube 24. Thus, the back lock assembly 26 can control the inclination angle of the back pipe 24, and the back connection flat iron 28 ensures stable support of the back of the infant seated on the seat main body 21.

As shown in fig. 5, the foot rest assembly 22 includes a first bending joint 221, a foot rest connecting tube 222, and a foot support plate 223; the first bending joint 221 is connected with the seat body 21, the first bending joint 221 is connected with the foot supporting plate 223 through the foot supporting connecting pipe 222, the foot supporting connecting pipe 222 can rotate around the first bending joint 221, and then when an infant steps on the foot supporting plate 223, the rotating angle of the foot supporting connecting pipe 222 around the first bending joint 221 can be adjusted correspondingly, and the comfort is improved.

As shown in fig. 4, the ceiling support assembly 25 includes a ceiling lower seat 251, a ceiling upper seat 252, a ceiling front pipe 253, a ceiling rear pipe 254, a third bending joint 255;

the lower ceiling seat 251 is fixed on the backrest tube 24, the upper ceiling seat 252 is rotatably connected with the lower ceiling seat 251 through a third bending joint 255, so that the inclination angle of the front ceiling tube 253 can be adjusted, the front ceiling tube 253 is connected with the tail end of the upper ceiling seat 252, and the rear ceiling tube 254 is clamped on the backrest tube 24 by the lower ceiling seat 251.

As shown in fig. 4: the backrest lock assembly 26 comprises a backrest connecting and supporting flat iron 261 transversely connected with the backrest pipe 24, a backrest adjusting lock 262 and a backrest adjusting wrench 263 used for wrenching the backrest adjusting lock 262; the backrest adjusting lock 262 is provided on the backrest connection support band 261, the backrest adjusting wrench 263 is connected to the backrest adjusting lock 262, and when the user pulls the backrest adjusting lock 262, the inclination angle of the backrest tube 24 can be adjusted.

As shown in fig. 6: the main cart frame 10 comprises a main joint 11, a rear transverse pipe 12 fixedly connected with the main joint 11, a front movable transverse pipe 13 connected with the main joint 11, a U-shaped folding handle 14 used for pulling the front movable transverse pipe 13 backwards to unlock the locking between the main joint 11 and the foot pipe assembly, a push handle assembly 15, the foot pipe assembly, four caster assemblies connected with the foot pipe assembly, and a transverse pipe fixing seat 18 fixed on the bottom surface of a rotating base 31;

the push handle assembly 15 and the foot tube assembly are axially connected with the main joint 11, the rear transverse tube 12 and the front movable transverse tube 13 are arranged on a transverse tube fixing seat 18 in a penetrating way, the tail end of a U-shaped folding handle 14 is arranged on the front movable transverse tube 13 in a penetrating way, and two side parts of the U-shaped folding handle 14 are connected with the transverse tube fixing seat 18 through folding fixing screws 19;

when the frame body 10 needs to be folded, the U-shaped folding handle 14 is pulled towards the rear wheel side, so that the unlocking between the front movable transverse tube 13 and the main joint 11 is realized, after the frame body 10 is manually opened, the front movable transverse tube 13 and the main joint 11 are automatically locked, and the U-shaped folding handle 14 automatically restores to the initial position.

As shown in fig. 1: the push handle assembly 15 includes a push handle fixing base 151 connected to the outer side of the rear end of the main joint 11, a push handle pipe 152 connected to the push handle fixing base 151, and a one-hand switch button 153 connected to the push handle pipe 152 for controlling the locking state between the push handle pipe 152 and the push handle fixing base 151.

As shown in fig. 1: the foot tube assembly comprises a front foot tube 161, a rear foot tube 162, two sections of linkage flat irons 163, an underframe connecting tube 164, a front foot transverse tube 165 and a rear wheel brake transverse tube 166 which are connected with the main joint 11 through a shaft; the caster assembly includes a front wheel 167 and a rear wheel 168; the front foot tube 161 is connected with the front wheel 171 through a front wheel seat, the rear foot tube 162 is connected with the rear wheel 172 through a rear wheel seat, the front foot transverse tube 165 is connected between the front wheel seats, and the rear wheel transverse brake tube 166 is connected between the rear wheel seats; the tail end of the first section of the linkage flat iron 163 is rotatably connected with the inner side of the main joint 11, the middle part of the second section is rotatably connected with the rear foot tube 162, the tail part is rotatably connected with one end of the underframe connecting tube 164, and the other end of the underframe connecting tube 164 is rotatably connected with the front wheel seat. In the process of squeezing the front leg tube 161 and the rear leg tube 162 close to each other, the leg tube assembly is finally folded by two sections of linkage flat irons 163.

For the folding process of the main frame 10 of the stroller, fig. 8-10 can be seen, wherein fig. 8, 9 and 10 show the process of gradually folding.

The above only is the embodiment of the present invention, not limiting the scope of the present invention, all the equivalent structures made by the contents of the specification and the drawings, or directly or indirectly applied to other related technical fields, are included in the same principle as the protection scope of the present invention.

Claims

1. The utility model provides a baby's shallow convenient to receive fast closes which characterized in that: the foldable stroller frame comprises a stroller frame body (10) which is folded and unfolded through a linkage mechanism and a foldable seat frame body (20), wherein the seat frame body (20) is detachably connected to the stroller frame body (10), and the seat frame body (20) can horizontally rotate 360 degrees around the stroller frame body (10).

2. The stroller of claim 1, wherein: baby's shallow convenient to receive fast receipts further includes quick detach formula roating seat (30), quick detach formula roating seat (30) include: the trolley comprises a rotary chassis (31), a rotary surface hardware (32) screwed on the top surface of the rotary chassis (31), a chassis fixing middle shaft (33), a rotary upper cover (34), a rotary seat locking hardware (35) connected to a trolley main frame body (10), an unlocking fixing piece (36), a seat fixing side seat (37) and a rotary fixing transverse pipe (38);

the rotary chassis (31) is fixed on the main frame body (10) of the cart, the seat fixing side seat (37) is integrally connected with the free end of the rotary fixing transverse pipe (38), and the seat frame body (20) is clamped with the seat fixing side seat (37);

a chassis fixing middle shaft (33) sequentially penetrates through a rotary upper cover (34), a rotary fixing transverse pipe (38) and a rotary surface hardware (32) from top to bottom to be rotatably connected with a rotary chassis (31), an unlocking fixing piece (36) is connected with the top of a rotary seat locking hardware (35), and two rail openings (341) for the transverse traveling of the rotary seat locking hardware (35) and symmetrical about the chassis fixing middle shaft (33) are respectively arranged on the rotary surface hardware (32) and the rotary upper cover (34);

when the upper rotating cover (34) and the rail opening (341) on the rotating surface hardware (32) are aligned up and down, the unlocking fixing piece (36) is pulled, the rotating seat locking hardware (35) moves transversely along the corresponding rail opening (341) to realize locking, and the rotating seat locking hardware (35) is unlocked when being withdrawn from the rail opening (341).

3. The stroller of claim 2, wherein: the quick-release rotary base (30) further comprises two locking buttons (39);

the seat fixing side seat (37) extends upwards, and the seat fixing side seat (37) is provided with the locking button (39);

the seat fixing side seat (37) is connected to the bottom of the seat frame body (20) in a locking mode through the locking button (39).

4. The stroller of claim 3, wherein: the seat frame body (20) comprises a seat main body (21), a foot support assembly (22) connected with the seat main body (21) in a shaft mode, an armrest assembly (23) connected with the upper bottom surface of the seat main body (21) in a shaft mode, a backrest pipe (24), a ceiling supporting assembly (25) connected to the backrest pipe (24), a backrest lock assembly (26) connected to the backrest pipe (24) and used for adjusting the inclination angle of the backrest pipe (24), a backrest joint seat (27) connected with the seat main body (21) and the backrest pipe (24), and a backrest connecting flat iron (28) transversely connected with the lower end of the backrest pipe (24).

5. The stroller of claim 4, wherein: the foot support component (22) comprises a first bending joint (221), a foot support connecting pipe (222) and a foot supporting plate (223);

the first bending joint (221) is connected with the seat main body (21), and the first bending joint (221) is connected with the foot supporting plate (223) through the foot supporting connecting pipe (222).

6. The stroller of claim 4, wherein:

the ceiling supporting assembly (25) comprises a lower ceiling seat (251), an upper ceiling seat (252), a front ceiling pipe (253), a rear ceiling pipe (254) and a third bending joint (255);

the lower ceiling seat (251) is fixed on the backrest pipe (24), the upper ceiling seat (252) is connected with the lower ceiling seat (251) through a third bending joint (255), the front ceiling pipe (253) is connected with the tail end of the upper ceiling seat (252), and the rear ceiling pipe (254) is clamped on the backrest pipe (24) by the lower ceiling seat (251).

7. The stroller of claim 4, wherein:

the backrest lock assembly (26) comprises a backrest connecting and supporting flat iron (261) transversely connected with the backrest pipe (24), a backrest adjusting lock (262) and a backrest adjusting wrench (263) used for wrenching the backrest adjusting lock (262);

the backrest adjusting lock (262) is arranged on the backrest connecting and supporting flat iron (261), and the backrest adjusting wrench (263) is connected on the backrest adjusting lock (262).

8. The stroller of claim 3, wherein:

the cart main frame body (10) comprises a main joint (11), a rear transverse pipe (12) fixedly connected with the main joint (11), a front movable transverse pipe (13) connected with the main joint (11), a U-shaped folding handle (14) used for pulling the front movable transverse pipe (13) backwards to unlock the locking between the main joint (11) and the foot pipe assembly, a push handle assembly (15), the foot pipe assembly, four caster wheel assemblies connected with the foot pipe assembly, and a transverse pipe fixing seat (18) fixed on the bottom surface of the rotating chassis (31);

the push handle assembly (15) and the foot tube assembly are axially connected with the main joint (11), the rear transverse tube (12) and the front movable transverse tube (13) are arranged on a transverse tube fixing seat (18) in a penetrating mode, the tail end of the U-shaped folding handle (14) is arranged on the front movable transverse tube (13) in a penetrating mode, and two side portions of the U-shaped folding handle (14) are connected with the transverse tube fixing seat (18) through folding fixing screws (19).

9. The stroller of claim 8, wherein:

the push handle assembly (15) comprises a push handle fixing seat (151) connected to the outer side of the rear end of the main joint (11), a push handle pipe (152) connected with the push handle fixing seat (151), and a single-hand switch key (153) connected to the push handle pipe (152) and used for controlling the locking state between the push handle pipe (152) and the push handle fixing seat (151).

10. The stroller of claim 9, wherein:

the foot tube assembly comprises a front foot tube (161) which is connected with the main joint (11) through a shaft, a rear foot tube (162), two sections of linkage flat irons (163), an underframe connecting tube (164), a front foot transverse tube (165) and a rear wheel brake transverse tube (166); the caster assembly comprises a front wheel (171) and a rear wheel (172);

the front foot tubes (161) are connected with front wheels (171) through front wheel seats, the rear foot tubes (162) are connected with rear wheels (172) through rear wheel seats, the front foot transverse tubes (165) are connected between the front wheel seats, and the rear wheel transverse brake tubes (166) are connected between the rear wheel seats;

the tail end of a first section of the linkage flat iron (163) is rotatably connected with the inner side of the main joint (11), the middle part of a second section is rotatably connected with a rear foot tube (162), the tail part of the second section is rotatably connected with one end of an underframe connecting tube (164), and the other end of the underframe connecting tube (164) is rotatably connected with a front wheel seat.