CN213735149U

CN213735149U - Child's bike

Info

Publication number: CN213735149U
Application number: CN202022842104.0U
Authority: CN
Inventors: 赵丹丹
Original assignee: Zhongshan Youyou Baby Products Co ltd
Current assignee: Zhongshan Youyou Baby Products Co ltd
Priority date: 2020-11-30
Filing date: 2020-11-30
Publication date: 2021-07-20
Anticipated expiration: 2030-11-30

Abstract

The utility model discloses a perambulator, including preceding strut (1) that is connected with front wheel (1a) and back strut (2) that are connected with rear wheel (2a), preceding strut (1) rotationally connect on back strut (2) and be close to back strut (2) upper end position around first axis (A), back strut (2) upper end rotationally be connected with seat support frame (3) around second axis (B), seat support frame (3) front side rotationally be connected with transfer line (4) around third axis (C), transfer line (4) lower extreme and preceding strut (1) slidable connection, and, back strut (2) on still rotationally be connected with push rod frame (5) around fourth axis (D). The utility model discloses simple structure, convenient operation, folding back is small.

Description

Child's bike

[ technical field ] A method for producing a semiconductor device

The utility model relates to a child's bike.

[ background of the invention ]

The children's carriage has become an indispensable product in the growth process of the children. Current child vehicles are generally capable of being unfolded or folded for easy carrying or storage. But the connecting rod structure of traditional child's bike is more complicated, and it is inconvenient to fold, and the volume is great after folding.

Therefore, the present invention is based on the above disadvantages.

[ Utility model ] content

The utility model aims at overcoming the defects of the prior art and providing a child's bike which has simple structure, convenient operation and small volume after being folded.

The utility model discloses a realize through following technical scheme:

a child's vehicle that can move from an unfolded position to a folded position after a locking device is unlocked, characterized in that: including preceding strut 1 that is connected with front wheel 1a and the back strut 2 that is connected with rear wheel 2a, preceding strut 1 rotationally connect on back strut 2 and be close to back strut 2 upper end position around first axis A, back strut 2 upper end rotationally be connected with seat support frame 3 around second axis B, 3 front sides of seat support frame rotationally be connected with transfer line 4 around third axis C, 4 lower extremes of transfer line and preceding strut 1 sliding connection, and back strut 2 on still rotationally be connected with push rod frame 5 around fourth axis D.

The child vehicle is characterized in that: the front support frame 1 is provided with a sliding sleeve 6 capable of sliding along the front support frame, and the lower end of the transmission rod 4 is rotatably connected to the sliding sleeve 6 around a fifth axis E.

The child vehicle is characterized in that: the locking device comprises a first locking component 7 arranged between the front support frame 1, the push rod frame 5 and the rear support frame 2 and a second locking component 8 arranged between the sliding sleeve 6 and the front support frame 1 and driven by the push rod frame 5 to unlock when the push rod frame 5 rotates and draws close relative to the rear support frame 2.

The child vehicle is characterized in that: the locking arrangement further comprises a third locking assembly 9 provided between the seat support frame 3 and the back support frame 2.

The child vehicle is characterized in that: the first axis A and the fourth axis D are coaxial and collinear, the first locking assembly 7 comprises a first locking joint 71 arranged on the rear support frame 2, a second locking joint 72 arranged at the lower end of the push rod frame 5 and a third locking joint 73 arranged at the upper end of the front support frame 1, the first locking joint 71, the second locking joint 72 and the third locking joint 73 are connected through a connecting shaft 74, radial locking grooves 75 are formed in the first locking joint 71, the second locking joint 72 and the third locking joint 73, locking rods 76 capable of sliding in the locking grooves 75 are arranged in the locking grooves 75, arc-shaped grooves 77 which are communicated with the locking grooves 75 on the second locking joint 72 and can allow the locking rods 76 to move relatively in the locking grooves so that the push rod frame 5 and the front support frame 1 can rotate and approach to the rear support frame 2 are respectively arranged in the second locking joint 72, and pushing parts capable of pushing the locking rods 76 to slide from the locking grooves 75 to the arc-shaped grooves 77 are arranged in the second locking joint 72 And 78.

The child vehicle is characterized in that: the pushing component 78 comprises a pushing block 781 capable of sliding in the radial direction in the second locking joint 72, an inclined surface 782 is arranged on the pushing block 781, a driving rod 783 capable of sliding in the pushing block 781 and pressing against the inclined surface 782 to enable the pushing block 781 to slide in the radial direction is further arranged in the pushing rod frame 5, a first reset spring 784 is arranged between the pushing block 781 and the second locking joint 72, a second reset spring 785 is arranged between the pushing rod frame 5 and the driving rod 783, and a push rod 11 capable of stretching in the pushing rod frame and capable of pushing the driving rod 783 to slide when sliding is further arranged on the pushing rod frame 5.

The child vehicle is characterized in that: the second locking assembly 8 comprises a locking hole 81 arranged on the sliding sleeve 6, a locking pin 82 capable of transversely sliding in the front support frame 1 to be clamped with or separated from the locking hole 81 is arranged in the front support frame 1, a pushing piece 83 capable of longitudinally sliding in the front support frame 1 to push the locking pin 82 to be separated from the locking hole 81 is further arranged in the front support frame 1, a third return spring 84 capable of pushing the locking pin 82 to return is further arranged between the locking pin 82 and the front support frame 1, and a protruding portion 85 capable of pushing the pushing piece 83 to enable the pushing piece 83 to push the locking pin 82 to transversely move when the second locking joint 72 rotates relative to the rear support frame 2 is arranged on the second locking joint.

The child vehicle is characterized in that: the pushing part 83 comprises a pushing rod 831 exposed on the front support frame 1 and capable of being pushed by the protruding part 85 when the push rod frame 5 rotates relative to the rear support frame 2, the pushing rod 831 penetrates through the locking pin 82, an inclined hole 832 is formed in the pushing rod 831, a matching pin 833 which penetrates through the inclined hole 832 and can be matched with the hole wall of the inclined hole 832 is formed in the locking pin 82, and a fourth return spring 834 which can push the pushing rod 831 to return is further arranged in the front support frame 1.

The child vehicle is characterized in that: a rotating handle 10 which can unlock the third locking component 9 when the child car is lifted is rotatably connected on the seat supporting frame 3 around a sixth axis F.

The child vehicle is characterized in that: the third locking assembly 9 comprises an outer shell 91 arranged at the upper end of the back support frame 2 and an inner shell 92 arranged at the rear end of the seat support frame 3 and rotatably connected with the outer shell 91 around a second axis B, wherein clamping grooves 93 are formed in the outer shell 91 and the inner shell 92 along the circumferential direction, a gear 94 capable of transversely moving in the space defined by the outer shell 91 and the inner shell 92 and simultaneously clamped with the clamping grooves 93 on the outer shell 91 and the inner shell 92 is arranged in the space defined by the outer shell 91 and the inner shell 92, a driving member connected with the rotating handle 10 and capable of pushing the gear 94 to separate the gear 94 from the clamping grooves 93 on the inner shell 92 when the rotating handle 10 rotates is arranged between the gear 94 and the inner shell 92, the driving member comprises a rotating block 951 capable of rotating in the space defined by the outer shell 91 and the inner shell 92, and a pull cable 952 capable of pulling the rotating block 951 when the rotating handle 10 is arranged between the rotating block 951 and the rotating handle 10, the rotating block 951 is provided with a plurality of inclined protrusions 953 along the circumferential direction, a moving block 954 which is matched with the inclined protrusions 953 and can be pushed by the inclined protrusions 953 to move transversely when the rotating block 951 rotates is arranged between the gear 94 and the rotating block 951, and a fifth return spring 96 which can push the gear 94 to return is arranged between the gear 94 and the outer shell 91.

Compared with the prior art, the utility model discloses there is following advantage:

1. the utility model discloses locking device unblock when child's bike is folding, the relative back strut of push rod frame rotates downwards and draws close to the back strut, and at this in-process, the seat support frame rotates around the relative back strut of second axis, and strut downslide before the relative drive rod lower extreme realizes that the seat support frame draws close with the relative preceding strut of drive rod to preceding strut also rotates relatively with the back strut draws close, whole child's bike simple structure, it is folding convenient, folding back is small.

2. The utility model discloses a perambulator is equipped with first locking Assembly in the front between strut, push rod frame and the back strut to be equipped with second locking Assembly in the front between strut and sliding sleeve, consequently ensure that the perambulator is safe firm at the expansion state, and push rod frame pivoted in-process push rod frame can drive the unblock of second locking Assembly behind the unblock of first locking Assembly, realize the unblock of second locking Assembly at the folding in-process of push rod frame promptly, realize coordinated control, easy operation is swift.

3. The utility model discloses a still be equipped with third locking subassembly between seat support frame and the back strut, so when the unblock of first locking subassembly, the relative back strut of push rod frame rotates and draws close and drive second locking subassembly unblock after, the seat support frame is still locked by third locking subassembly, avoids folding forward suddenly because of the anterior weight of perambulator is great at push rod frame pivoted in-process, avoids operating push rod frame's wrist to receive the impact, ensures safety. When the push rod frame is close to the rear support frame, the rotating handle only needs to be lifted upwards, in the lifting process, the rotating handle rotates relative to the seat support frame to unlock the third locking assembly, the seat support frame rotates relative to the rear support frame under the action of gravity, and the lower end of the transmission rod slides downwards along with the sliding sleeve, so that the folding of the baby carriage is realized.

4. The utility model discloses simple structure, folding convenient operation, folding back is small, is fit for popularizing and applying.

[ description of the drawings ]

FIG. 1 is a perspective view of the present invention;

fig. 2 is one of the side views of the unfolded state of the present invention;

fig. 3 is a side view of the present invention during folding;

fig. 4 is a second side view of the present invention in the unfolded state;

fig. 5 is a partial cross-sectional view of the present invention;

fig. 6 is one of exploded views of components of the present invention;

fig. 7 is a second exploded view of the components of the present invention;

fig. 8 is a perspective view of a component of the present invention.

[ detailed description ] embodiments

The invention will be further described with reference to the accompanying drawings:

as shown in fig. 1 to 4, a child vehicle which can move from an unfolding position to a folding position after a locking device is unlocked comprises a front support frame 1 connected with front wheels 1a and a rear support frame 2 connected with rear wheels 2a, wherein the front support frame 1 is rotatably connected with the rear support frame 2 around a first axis a and is close to the upper end position of the rear support frame 2, the upper end of the rear support frame 2 is rotatably connected with a seat support frame 3 around a second axis B, the front side of the seat support frame 3 is rotatably connected with a transmission rod 4 around a third axis C, the lower end of the transmission rod 4 is slidably connected with the front support frame 1, and a push rod frame 5 is rotatably connected with the rear support frame 2 around a fourth axis D. Locking device unblock when child's bike is folding, push rod frame 5 rotates down and draws close to back strut 2 relatively back strut 2, at this in-process, seat support frame 3 rotates around the relative back strut 2 of second axis B, 4 lower extremes of transfer line slide down and realize that seat support frame 3 and transfer line 4 draw close to preceding strut 1 relatively before strut 1 relatively, and preceding strut 1 also rotates relatively with back strut 2 and draws close, whole child's bike simple structure, it is folding convenient, after folding small. The utility model discloses the perambulator can set up the shape structure of seat support frame 3 according to actual conditions, and children can directly take the seat support frame on, also can set up detachable seat subassembly 12 on seat support frame 3 certainly and supply children to take.

As shown in fig. 1 to 8, the front bracket 1 is provided with a sliding sleeve 6 capable of sliding along the front bracket, and the lower end of the transmission rod 4 is rotatably connected to the sliding sleeve 6 around a fifth axis E. When the child vehicle is folded, the transmission rod 4 and the sliding sleeve 6 rotate relatively, the sliding sleeve 6 drives the lower end of the transmission rod 4 to slide towards the lower end of the front support frame 1, and the whole movement process is stable and reliable.

The locking device comprises a first locking component 7 arranged between the front support frame 1, the push rod frame 5 and the rear support frame 2 and a second locking component 8 arranged between the sliding sleeve 6 and the front support frame 1 and driven by the push rod frame 5 to unlock when the push rod frame 5 rotates and draws close relative to the rear support frame 2. Consequently, ensure that the perambulator is safe firm at the expansion state to push rod frame 5 pivoted in-process push rod frame 5 can drive the unblock of second locking subassembly 8 after 7 unblocks of first locking subassemblies, realize the unblock of second locking subassembly 8 at push rod frame 5 folding in-process promptly, realize coordinated control, easy operation is swift.

As shown in fig. 5 to 8, the locking device further comprises a third locking assembly 9 provided between the seat support frame 3 and the rear support frame 2. Therefore, after the first locking component 7 and the second locking component 8 are unlocked, the seat support frame 8 is still in a locking state, so that the situation that the seat support frame 3 with heavier weight is folded forwards suddenly when the push rod frame 5 is folded relative to the rear support frame 2 to cause the wrist of a user to be impacted is avoided, the safety is ensured, and the operation of the user is comfortable.

As shown in fig. 5 to 8, the first axis a and the fourth axis D are coaxial and collinear, the first locking assembly 7 includes a first locking joint 71 disposed on the back support frame 2, a second locking joint 72 disposed at the lower end of the push rod frame 5, and a third locking joint 73 disposed at the upper end of the front support frame 1, the first locking joint 71, the second locking joint 72, and the third locking joint 73 are connected by a connecting shaft 74, the first locking joint 71, the second locking joint 72, and the third locking joint 73 are all provided with radial locking grooves 75, the locking grooves 75 are provided with locking rods 76 capable of sliding therein, the second locking joint 72, and the third locking joint 73 are further provided with arc-shaped grooves 77 respectively communicated with the locking grooves 75 thereon and capable of allowing the locking rods 76 to move relatively therein to enable the push rod frame 5 and the front support frame 1 to rotate and approach with respect to the back support frame 2, the second locking joint 72 is provided with a pushing component 78 capable of pushing the locking rod 76 to slide from the locking groove 75 to the arc groove 77. When the first locking assembly 7 is unlocked, the pushing component 78 is moved to withdraw the locking rod 76 from the locking groove 75, after the locking rod 76 is withdrawn from the locking grooves 75 on the first locking joint 71, the second locking joint 72 and the third locking joint 73, the locking rod 76 enters the arc-shaped grooves 77 on the second locking joint 72 and the third locking joint 73, and the arc-shaped grooves 77 provide a space for abdicating, so that the push rod frame 5 and the front support frame 1 can rotate relative to the back support frame 2 and approach the back support frame 2.

As shown in fig. 5 to 8, the pushing member 78 includes a pushing block 781 capable of sliding radially in the second locking joint 72, the pushing block 781 is provided with an inclined surface 782, the push rod frame 5 is further provided with a driving rod 783 capable of sliding therein and pressing against the inclined surface 782 to enable the pushing block 781 to slide radially, a first return spring 784 is disposed between the pushing block 781 and the second locking joint 72, a second return spring 785 is disposed between the push rod frame 5 and the driving rod 783, and the push rod frame 5 is further provided with a push rod 11 capable of extending therein and pushing the driving rod 783 to slide when sliding. When the perambulator need be folded, handspike 11 is to indentation in the push rod frame 5, and handspike 11 lower extreme promotes actuating lever 783, and the inclined plane 782 on the actuating lever 783 roof pressure promotion piece 781 for promote piece 781 and radially slide, promote the in-process of piece 781 and just release card locking lever 76 from the card locked groove 75, thereby realize the unblock of first locking subassembly 7, operate very simple swift.

As shown in fig. 5 to 8, the second locking assembly 8 includes a locking hole 81 provided on the sliding sleeve 6, a locking pin 82 capable of sliding transversely in the front bracket 1 to engage with or disengage from the locking hole 81 is provided in the front bracket 1, an ejector 83 capable of sliding longitudinally in the front bracket 1 to push the locking pin 82 to disengage from the locking hole 81 is further provided in the front bracket 1, a third return spring 84 capable of pushing the locking pin 82 to return is further provided between the locking pin 82 and the front bracket 1, and a protrusion 85 capable of pressing the ejector 83 to push the locking pin 82 to move transversely when the second locking joint 72 rotates relative to the rear bracket 2 is provided on the second locking joint 72. When the first locking component 7 is unlocked, the push rod frame 5 rotates relative to the rear support frame 2, in the rotating process, the protruding part 85 on the push rod frame 5 presses the pushing piece 83 in the front support frame 1, the pushing piece 83 slides longitudinally in the front support frame 1, and in the longitudinal sliding process, the locking pin 82 is pushed to be separated from the locking hole 81 on the sliding sleeve 6, so that the second locking component 8 is unlocked. Therefore, the unlocking of the second locking component 8 is realized in the rotating and folding process of the push rod frame 5, the linkage control is realized, and the operation is very convenient and fast.

As shown in fig. 5, the pushing member 83 includes a pushing rod 831 exposed to the front support frame 1 and capable of being pushed by the protrusion 85 when the push rod frame 5 rotates relative to the rear support frame 2, the pushing rod 831 is inserted into the locking pin 82, the pushing rod 831 is provided with an inclined hole 832, the locking pin 82 is provided with a matching pin 833 inserted into the inclined hole 832 and capable of matching with the hole wall of the inclined hole 832, and the front support frame 1 is further provided with a fourth return spring 834 capable of pushing the pushing rod 831 to return. When the push rod frame 5 rotates, the protrusion 85 presses the push rod 831, and when the push rod 831 slides longitudinally, the hole wall of the inclined hole 832 pushes the mating pin 833 on the locking pin 82, so that the locking pin 82 is separated from the locking hole 81, and the design is very ingenious.

As shown in fig. 1 to 7, a swing handle 10 for unlocking the third locking unit 9 when the child car is lifted is pivotally connected to the seat support frame 3 about a sixth axis F. After the first locking component 7 and the second locking component 8 are unlocked, the rotating handle 10 is lifted, the rotating handle drives the third locking component 9 to be unlocked in the process of lifting the baby carriage, and the seat support frame 3 can rotate relative to the back support frame 2 at the moment, so that the folding of the baby carriage is realized. Therefore, when the child car is folded, only the hand push rod 11 needs to be pushed downwards to unlock the first locking assembly 7, then the push rod frame 5 is rotated, the push rod frame 5 unlocks the second locking assembly 8 in the rotating process, then the rotating handle 10 is lifted upwards to enable the seat support frame 3, the front support frame 1 and the rear support frame 2 to be close to each other under the action of gravity, the folding of the whole child car is achieved, the whole child car is locked through multiple locking mechanisms, the safety is good, and the folding child car is very convenient and smooth.

As shown in fig. 6, the third locking assembly 9 includes an outer shell 91 disposed at the upper end of the rear support frame 2 and an inner shell 92 disposed at the rear end of the seat support frame 3 and rotatably connected to the outer shell 91 around the second axis B, the outer shell 91 and the inner shell 92 are both provided with a locking groove 93 along the circumferential direction, a gear 94 capable of moving transversely therein and being simultaneously locked to the locking groove 93 of the outer shell 91 and the inner shell 92 is disposed in a space enclosed by the outer shell 91 and the inner shell 92, a driving member connected to the rotating handle 10 and capable of pushing the gear 94 to disengage the gear 94 from the locking groove 93 of the inner shell 92 when the rotating handle 10 rotates is disposed between the gear 94 and the inner shell 92, the driving member includes a rotating block 951 capable of rotating in the space enclosed by the outer shell 91 and the inner shell 92, a cable 952 capable of pulling the rotating block 951 when the rotating handle 10 is disposed between the rotating block 951 and the rotating handle 10, the rotating block 951 is provided with a plurality of inclined protrusions 953 along the circumferential direction, a moving block 954 which is matched with the inclined protrusions 953 and can be pushed by the inclined protrusions 953 to move transversely when the rotating block 951 rotates is arranged between the gear 94 and the rotating block 951, and a fifth return spring 96 which can push the gear 94 to return is arranged between the gear 94 and the outer shell 91. When the rotating handle 10 is lifted, the rotating handle 10 pulls the cable 952, the cable 952 drives the rotating block 951 to rotate, the inclined protrusion 953 on the rotating block 951 pushes the moving block 954 to move transversely, the moving block 954 pushes the gear 94 to move transversely to be separated from the clamping groove 93 on the inner shell 92, and at the moment, the third locking assembly 9 is unlocked. Therefore, the third assembly 9 can be unlocked only by lifting the rotating handle 10, and the operation is very convenient and fast.

Claims

1. A child's vehicle that can move from an unfolded position to a folded position after a locking device is unlocked, characterized in that: including preceding strut (1) that is connected with front wheel (1a) and back strut (2) that are connected with rear wheel (2a), preceding strut (1) rotationally connect on back strut (2) and be close to back strut (2) upper end position around first axis (A), back strut (2) upper end rotationally be connected with seat support frame (3) around second axis (B), seat support frame (3) front side rotationally be connected with transfer line (4) around third axis (C), transfer line (4) lower extreme and preceding strut (1) slidable connection, and, back strut (2) on still rotationally be connected with push rod frame (5) around fourth axis (D).

2. The child's vehicle of claim 1, wherein: the front support frame (1) is provided with a sliding sleeve (6) capable of sliding along the front support frame, and the lower end of the transmission rod (4) is rotatably connected to the sliding sleeve (6) around a fifth axis (E).

3. Child's vehicle according to claim 2, characterized in that: the locking device comprises a first locking component (7) arranged between the front support frame (1), the push rod frame (5) and the rear support frame (2) and a second locking component (8) arranged between the sliding sleeve (6) and the front support frame (1) and capable of being unlocked by the push rod frame (5) in a driving mode when the push rod frame (5) rotates and draws close relative to the rear support frame (2).

4. The child's vehicle of claim 3, wherein: the locking device also comprises a third locking assembly (9) arranged between the seat support frame (3) and the rear support frame (2).

5. The child's vehicle of claim 3, wherein: first axis (A) and fourth axis (D) coaxial collineation, first locking Assembly (7) including establishing first locking joint (71) on back strut (2), establishing second locking joint (72) and the third locking joint (73) of establishing preceding strut (1) upper end at push rod frame (5) lower extreme, first locking joint (71), second locking joint (72) and third locking joint (73) connect through connecting axle (74), first locking joint (71), second locking joint (72) and third locking joint (73) on all be equipped with radial card locked groove (75), card locked groove (75) in be equipped with card locking lever (76) that can slide in it, second locking joint (72) and third locking joint (73) on still be equipped with respectively rather than last card locked groove (75) communicate with each other and can supply card locking lever (76) to move about and make push rod frame (5) and preceding strut (1) relative back strut (1) including (2) The second locking joint (72) is internally provided with a pushing component (78) which can push the locking rod (76) to slide into the arc-shaped groove (77) from the locking groove (75).

6. Child's vehicle according to claim 5, characterized in that: the push component (78) including can be in second locking joint (72) radial gliding promotion piece (781), promotion piece (781) on be equipped with inclined plane (782), push rod frame (5) in still be equipped with and can slide in it and can roof pressure inclined plane (782) and make the actuating lever (783) that promote piece (781) and radially slide, promotion piece (781) and second locking joint (72) between be equipped with first reset spring (784), push rod frame (5) and actuating lever (783) between be equipped with second reset spring (785), push rod frame (5) on still be equipped with and can stretch out and draw back and can promote the gliding handspike (11) of actuating lever (783) when sliding in it.

7. Child's vehicle according to claim 5 or 6, characterized in that: the second locking assembly (8) comprises a locking hole (81) arranged on the sliding sleeve (6), a locking pin (82) capable of transversely sliding in the front support frame (1) to be clamped or separated with the locking hole (81) is arranged in the front support frame (1), a pushing piece (83) capable of longitudinally sliding in the front support frame (1) to push the locking pin (82) to be separated from the locking hole (81), a third return spring (84) capable of pushing the locking pin (82) to be reset is further arranged between the locking pin (82) and the front support frame (1), and a protruding portion (85) capable of pushing the pushing piece (83) to enable the pushing piece (83) to push the locking pin (82) to transversely move when the second locking joint (72) rotates relative to the rear support frame (2) is arranged on the second locking joint.

8. The child's vehicle of claim 7, wherein: ejector member (83) including expose in preceding strut (1) and can be by ejector pin (831) that bulge (85) pushed away when push rod frame (5) back strut (2) relatively rotate, ejector pin (831) wear to establish in stop pin (82), ejector pin (831) on be equipped with inclined hole (832), stop pin (82) on be equipped with wear to establish in inclined hole (832) and can with inclined hole (832) pore wall complex cooperation round pin (833), preceding strut (1) in still be equipped with fourth reset spring (834) that can promote ejector pin (831) to reset.

9. Child's vehicle according to claim 4, characterized in that: and the seat support frame (3) is rotatably connected with a rotating handle (10) which can unlock the third locking assembly (9) when the child car is lifted.

10. The child's vehicle of claim 9, wherein: the third locking assembly (9) comprises an outer shell (91) arranged at the upper end of the rear support frame (2) and an inner shell (92) arranged at the rear end of the seat support frame (3) and rotatably connected with the outer shell (91) around a second axis (B), clamping grooves (93) are formed in the outer shell (91) and the inner shell (92) along the circumferential direction, a gear (94) capable of transversely moving in the space enclosed by the outer shell (91) and the inner shell (92) and simultaneously clamped with the clamping grooves (93) in the outer shell (91) and the inner shell (92) is arranged in the space enclosed by the outer shell (91) and the inner shell (92), a driving piece connected with the rotating handle (10) and capable of pushing the gear (94) to separate the gear (94) from the clamping grooves (93) in the inner shell (92) when the rotating handle (10) rotates is arranged between the gear (94) and the inner shell (92), and the driving piece comprises a rotating block (951) capable of rotating in the space enclosed by the outer shell (91) and the inner shell (92), the utility model discloses a gear wheel, including the turning block, be equipped with between turning block (951) and turning handle (10) and be equipped with between turning block (951) and can stimulate turning block (951) pivoted cable (952) when turning handle (10) rotate, turning block (951) go up and be equipped with a plurality of oblique archs (953) along the circumferencial direction, gear wheel (94) and turning block (951) between be equipped with oblique protruding (953) cooperation and can be pushed lateral shifting's movable block (954) by oblique protruding (953) when turning block (951) is rotatory, gear wheel (94) and shell body (91) between be equipped with fifth reset spring (96) that can promote gear wheel (94) and reset.