CN112107159B

CN112107159B - Integrated folding student desk and chair

Info

Publication number: CN112107159B
Application number: CN202011196751.7A
Authority: CN
Inventors: 修水华
Original assignee: 河北富都华创家具制造有限公司
Current assignee: Hebei Fu Douhuachuan Furniture Manufactures Co ltd
Priority date: 2020-10-31
Filing date: 2020-10-31
Publication date: 2022-04-22
Anticipated expiration: 2040-10-31
Also published as: CN112107159A

Abstract

The invention relates to a student desk and chair, in particular to an integrated folding student desk and chair. The invention provides an integrated folding student desk and chair which is adjustable in seat and convenient to use. An integral folding student desk and chair, comprising: the support frame is rotatably provided with two table plates; the chair plate is arranged on the supporting frame; the height adjusting component is arranged on the supporting frame and is connected with the chair plate; the self-locking assembly is arranged on the supporting frame and matched with the height adjusting assembly. The desk and chair assembly has the advantages that the effect of helping students to learn in a comfortable posture is achieved, the height of the chair and the distance between the desk and the chair can be adjusted through the matching of the height adjusting assembly, the self-locking assembly and the distance adjusting assembly, the chair can be placed in the desk through the matching of the folding assembly, the overturning assembly and the anti-falling assembly, and therefore the desk and chair can be folded.

Description

Integrated folding student desk and chair

Technical Field

The invention relates to a student desk and chair, in particular to an integrated folding student desk and chair.

Background

When the students use the desk and chair, the common desk and chair are difficult to adjust according to self conditions because of different body types of each student.

The publication number is CN201624293U, and discloses an assembled foldable table and chair, which comprises a central bottom plate, a first supporting bottom plate, a second supporting bottom plate, a front box plate and a rear box plate, wherein the first supporting bottom plate, the second supporting bottom plate, the front box plate and the rear box plate are movably connected with four sides of the central bottom plate; folding chairs are respectively arranged on the first supporting bottom plate and the second supporting bottom plate; the front box plate is movably connected with a first top plate; the foldable table and chair comprises a rear box plate, a first top plate, an assembled foldable table and chair body, wherein the rear box plate is movably connected with the rear box plate, the assembled foldable table and chair body moves between an unfolded state and a folded state, the assembled foldable table and chair body is a rectangular box body in the folded state, the foldable chair and the table plate are contained in the box body, the foldable table and chair body can be used for outdoor leisure when being unfolded, when the foldable table and chair body is not used, the foldable table and chair body can be folded to form the rectangular box body, the foldable table and chair body are contained in the rectangular box body, the foldable table and chair body is small in occupied space after being folded and more convenient to carry, and the device needs to be assembled when being used every time and is time-consuming.

Therefore, it is urgently needed to develop an integrated folding student desk and chair which can be adjusted according to self conditions, can be folded and is more convenient to use.

Disclosure of Invention

In order to overcome the defects that the seat cannot be adjusted and is inconvenient to use, the invention has the technical problems that: the integrated folding student desk and chair is adjustable in seat and convenient to use.

The technical scheme is as follows: an integral folding student desk and chair, comprising:

the support frame is rotatably provided with two table plates;

the chair plate is arranged on the supporting frame;

the height adjusting component is arranged on the supporting frame and is connected with the chair plate;

the self-locking assembly is arranged on the supporting frame and matched with the height adjusting assembly.

Preferably, the height adjusting assembly comprises:

the support frame is rotatably provided with a first rotating shaft;

the first rotating shaft is provided with a straight gear;

the chair plate is provided with a first rack which is meshed with the straight gear;

the chair plate is provided with a special-shaped supporting rod which is connected with the first rack;

the first rotating shaft is provided with a hand wheel.

Preferably, the self-locking assembly comprises:

the first limiting block is arranged on the supporting frame;

the first limiting block is provided with a first limiting block;

the pull rod is provided with a self-locking block which is matched with the hand wheel;

the first compression spring is wound on the pull rod and connected with the first limiting block and the self-locking block.

Preferably, the method further comprises the following steps:

the folding component is arranged on the support frame and matched with the other support frame;

the folding subassembly includes:

the upper part of the support frame is provided with two fixed blocks;

the second rotating shaft is rotatably arranged between the two fixed blocks;

the connecting rod is equipped with two connecting rods in the second pivot, and the connecting rod cooperates with the support frame.

Preferably, the method further comprises the following steps:

the spacing adjusting component is arranged on the supporting frame and matched with the folding component;

the interval adjustment subassembly including:

the connecting rod is provided with a sliding chute, two first sliding blocks are arranged in the sliding chute in a sliding mode, and the first sliding blocks are connected with the supporting frame;

the supporting frame is provided with two clamping plates in a sliding manner, and the clamping plates are matched with the connecting rod;

the two clamping plates are provided with bolts in a sliding manner;

the butterfly nut is rotationally arranged on the bolt and matched with the clamping plate.

Preferably, the method further comprises the following steps:

the turnover component is arranged on the table plate and connected with the folding component and the supporting frame.

Preferably, the opening assembly comprises:

the table plate is rotatably provided with a third rotating shaft;

the third rotating shaft is wound with a torsion spring, and the torsion spring is connected with the table plate and the third rotating shaft;

the deflector rod is arranged on the third rotating shaft;

the support frame is provided with two connecting rods in a sliding manner;

the connecting rod is provided with a second sliding block which is matched with the deflector rod;

the connecting rod is wound with a second compression spring, and the second compression spring is connected with the second sliding block and the supporting frame;

the connecting rod is provided with a first wedge block;

the table plate is provided with a supporting plate;

the connecting rod is provided with an L-shaped rod;

and the L-shaped rod is provided with a second wedge block which is matched with the first wedge block.

Preferably, the method further comprises the following steps:

the anti-drop subassembly is equipped with the anti-drop subassembly on the support frame, and the anti-drop subassembly is connected with folding assembly.

Preferably, the fall-off prevention means comprises:

the second rotating shaft is provided with a one-way gear;

the support frame is provided with two second limiting blocks;

the second limiting block is provided with a limiting pin in a sliding manner;

the third compression spring is wound on the limit pin and connected with the second limit block and the limit pin;

the two limit pins are connected with the T-shaped rods;

and a second rack is arranged on the T-shaped rod and meshed with the one-way gear.

Compared with the prior art, the invention has the following advantages:

1. the invention achieves the effect of helping students to study in a comfortable posture, and the height of the chair and the distance between the desk and the chair can be adjusted through the matching of the height adjusting assembly, the self-locking assembly and the spacing adjusting assembly.

2. The folding desk and chair achieves the effect of saving classroom space, and the chair can be placed in the desk through the matching of the folding component, the unfolding component and the anti-falling component, so that the desk and chair can be folded, and besides the convenience in movement, the space can be saved, and the cleaning is facilitated.

Drawings

Fig. 1 is a schematic perspective view of the present invention.

Fig. 2 is a perspective view of the height adjustment assembly of the present invention.

Fig. 3 is a schematic perspective view of the self-locking assembly of the present invention.

Fig. 4 is a perspective view of the folding assembly of the present invention.

Fig. 5 is a schematic perspective view of the spacing adjustment assembly of the present invention.

FIG. 6 is a schematic view of a first partially assembled body of the flip assembly of the present invention.

FIG. 7 is a schematic view of a second partially assembled body of the flip assembly of the present invention.

Fig. 8 is a schematic perspective view of the anti-falling off assembly of the present invention.

Reference numerals: 1. the device comprises a support frame, 2, a table plate, 3, a chair plate, 4, a height adjusting assembly, 41, a first rotating shaft, 42, a straight gear, 43, a first rack, 44, a special-shaped support rod, 45, a hand wheel, 5, a self-locking assembly, 51, a first limiting block, 52, a pull rod, 53, a first compression spring, 54, a self-locking block, 6, a folding assembly, 61, a fixing block, 62, a second rotating shaft, 63, a connecting rod, 7, a spacing adjusting assembly, 71, a sliding chute, 72, a first sliding block, 73, a clamping plate, 74, a bolt, 75, a butterfly nut, 8, a turnover assembly, 81, a third rotating shaft, 82, a torsion spring, 83, a deflector rod, 84, a second sliding block, 85, a second compression spring, 86, a connecting rod, 87, a first wedge-shaped block, 88, a support plate, 89, an L-shaped rod, 810, a second wedge-shaped block, 9, an anti-falling-off assembly, 91, a one-way gear, 92, a second rack, 93, a second compression spring, 5, a self-locking assembly, a first wedge-locking assembly, a second wedge-shaped screw, a second sliding block, a third sliding block, a fourth sliding block, a third sliding block, a fourth sliding, T-shaped rod 94, limit pin 95, third compression spring 96 and second limit block.

Detailed Description

It is to be noted that, in the case of the different described embodiments, identical components are provided with the same reference numerals or the same component names, wherein the disclosure contained in the entire description can be transferred to identical components having the same reference numerals or the same component names in a meaningful manner. The positional references selected in the description, such as upper, lower, lateral, etc., refer also to the directly described and illustrated figures and are to be read into the new position in the sense of a change in position.

Example 1

The utility model provides a student's table chair is folded to integral type, as shown in figure 1, including support frame 1, table 2, chair 3, height adjusting component 4 and auto-

lock subassembly

5, 1 top rotary type of left support frame is equipped with two tables 2, 1 top of support frame on right side is equipped with

chair

3, 1 upper portion of support frame on right side is equipped with height adjusting component 4, height adjusting component 4 is connected with

chair

3, 1 upper portion rear side of support frame on right side is equipped with auto-lock subassembly 5, auto-lock subassembly 5 cooperates with height adjusting component 4.

When the student uses the desk and chair, the student can adjust the common desk and chair difficultly according to the self condition, the desk and chair can help the student study in a comfortable posture, when the student needs to adjust the height of the chair, after the self-locking assembly 5 is opened, the chair plate 3 can be adjusted to be suitable for the height of the student through the height adjusting assembly 4, after the height adjusting assembly 5 is adjusted, the self-locking assembly 5 is loosened, the self-locking assembly 5 is matched with the height adjusting assembly 4, the height adjusting assembly 4 cannot operate, and when the desk and chair is used again, the steps are repeated.

Example 2

Based on embodiment 1, as shown in fig. 2 and 3, the height adjusting assembly 4 includes a first rotating shaft 41, a straight gear 42, a first rack 43, a shaped support rod 44, and a hand wheel 45, the first rotating shaft 41 is rotatably disposed on the left side of the upper portion of the right support frame 1, the straight gear 42 is disposed on the rear portion of the first rotating shaft 41, the first rack 43 is disposed at the bottom of the chair plate 3, the first rack 43 is engaged with the straight gear 42, the shaped support rod 44 is disposed at the middle portion of the bottom side of the chair plate 3, the left side of the bottom of the shaped support rod 44 is connected with the first rack 43, and the hand wheel 45 is disposed on the rear side of the first rotating shaft 41.

When the height of the chair plate 3 needs to be adjusted, firstly, the hand wheel 45 is not matched with the self-locking assembly 5, the hand wheel 45 is rotated, the hand wheel 45 drives the first rotating shaft 41 to rotate, the first rotating shaft 41 drives the straight gear 42 to rotate, because the straight gear 42 is meshed with the first rack 43, the straight gear 42 drives the first rack 43 to move upwards, the first rack 43 drives the chair plate 3 to move upwards, the telescopic rod on the upper part of the supporting frame 1 on the right side is stretched, when the chair plate 3 needs to move downwards, the hand wheel 45 is reversed, so that the first rack 43 can move downwards, when the chair plate 3 is adjusted to the height suitable for the height of the user, the hand wheel 45 is stopped to rotate, the hand wheel 45 is matched with the self-locking assembly 5, when the device is used again, the steps are repeated.

The self-locking assembly 5 comprises a first limiting block 51, a pull rod 52, a first compression spring 53 and a self-locking block 54, the first limiting block 51 is arranged on the rear side of the upper portion of the supporting frame 1 on the right side, the pull rod 52 is arranged on the left side of the first limiting block 51 in a sliding mode, the self-locking block 54 is arranged on the front side of the pull rod 52, the self-locking block 54 is matched with the hand wheel 45, the first compression spring 53 is wound on the front portion of the pull rod 52, and the first compression spring 53 is connected with the first limiting block 51 and the self-locking block 54.

In an initial state, the self-locking block 54 is matched with the hand wheel 45, when the height of the chair plate 3 needs to be adjusted, the pull rod 52 is pulled backwards manually, the pull rod 52 drives the self-locking block 54 to move backwards, the first compression spring 53 is compressed, the hand wheel 45 is not matched with the self-locking block 54, the hand wheel 45 can rotate, after the height of the chair plate 3 is adjusted, the pull rod 52 is loosened, the first compression spring 53 is restored to the initial state, the first compression spring 53 drives the pull rod 52 and the self-locking block 54 to move forwards, the self-locking block 54 and the hand wheel 45 are matched again, the hand wheel 45 cannot continue to rotate, and the steps are repeated when the device is used again.

Example 3

On the basis of embodiment 2, as shown in fig. 1, 4, 5, 6, 7 and 8, the foldable support frame further includes a folding assembly 6, the folding assembly 6 is disposed on the support frame 1 on the left side, the folding assembly 6 is matched with the support frame 1 on the right side, the folding assembly 6 includes fixing blocks 61, a second rotating shaft 62 and connecting rods 63, two fixing blocks 61 are disposed on the upper portion of the support frame 1 on the left side, the second rotating shaft 62 is rotatably disposed between the two fixing blocks 61, two connecting rods 63 are disposed on the second rotating shaft 62, and the connecting rods 63 are matched with the support frame 1 on the right side.

Except that can adjust the 3 height of chair plate, this equipment can also be folded, when the student need not use this equipment, with chair plate 3 to 2 direction upsets of table, chair plate 3 drives the rotation of support frame 1 on right side, make connecting rod 63 rotate, thereby second pivot 62 rotates, after

chair plate

3 and 1 cooperation of left support frame, the stall chair plate 3 can, folding back seat except convenient removal, can also save space, be convenient for clean, when needing to use this equipment, with the reversion of chair plate 3, make second pivot 62 reversal can, when using this equipment once more, repeat above-mentioned step.

The folding type folding device is characterized by further comprising a spacing adjusting assembly 7, the spacing adjusting assembly 7 is arranged on the supporting frame 1 on the right side, the spacing adjusting assembly 7 is matched with the folding assembly 6, the spacing adjusting assembly 7 comprises a first sliding block 72, clamping plates 73, bolts 74 and butterfly nuts 75, a sliding groove 71 is formed in the right portion of the connecting rod 63, two first sliding blocks 72 are arranged in the sliding groove 71 in a sliding mode, the first sliding blocks 72 are connected with the supporting frame 1 on the right side, the two clamping plates 73 are arranged on the upper portion of the supporting frame 1 on the right side in a sliding mode, the clamping plates 73 are matched with the connecting rod 63, the bolts 74 are arranged in the middle of the two clamping plates 73 in a sliding mode, butterfly nuts 75 are arranged on the upper portions of the bolts 74 in a rotating mode, and the butterfly nuts 75 are matched with the clamping plates 73 on the upper side.

Apart from adjusting the height of the chair plate 3, the distance between the chair plate 3 and the table plate 2 can be adjusted, firstly, the butterfly nut 75 is loosened, the height of the two clamping plates 73 is adjusted up and down, so that the first sliding block 72 can slide left and right, the chair plate 3 is moved left and right by students according to self conditions, in the moving process, the chair plate 3 drives the first sliding block 72 and the clamping plates 73 to move left and right through the support frame 1 on the right side, after the distance between the chair plate 3 and the table plate 2 is adjusted, the chair plate 3 is stopped to move, the butterfly nut 75 is screwed, so that the clamping plates 73 on the upper side and the lower side clamp the connecting rod 63, the first sliding block 72 cannot slide left and right, and the steps are repeated when the device is used again.

The folding table further comprises an opening component 8, the table plate 2 is provided with the opening component 8, the opening component 8 is connected with the folding component 6 and the left support frame 1, the opening component 8 comprises a third rotating shaft 81, a torsion spring 82, a deflector rod 83, a second sliding block 84, a second compression spring 85, a connecting rod 86, a first wedge-shaped block 87, a support plate 88, an L-shaped rod 89 and a second wedge-shaped block 810, the outer side of the bottom of the table plate 2 is rotatably provided with the third rotating shaft 81, the left part of the third rotating shaft 81 is wound with the torsion spring 82, the torsion spring 82 is connected with the table plate 2 and the third rotating shaft 81, the right part of the third rotating shaft 81 is provided with the deflector rod 83, the upper part of the left support frame 1 is provided with the two connecting rods 86 in a sliding manner, the top of the connecting rod 86 is provided with the second sliding block 84, the second sliding block 84 is matched with the deflector rod 83, the upper part of the connecting rod 86 is wound with the second compression spring 85, the second compression spring 85 is connected with the second sliding block 84 and the left support frame 1, the outer side of the bottom of the connecting rod 86 is provided with a first wedge-shaped block 87, the bottom of the table plate 2 is provided with a supporting plate 88, the outer side of the right part of the connecting rod 63 is provided with an L-shaped rod 89, the top of the outer side of the L-shaped rod 89 is provided with a second wedge-shaped block 810, and the second wedge-shaped block 810 is matched with the first wedge-shaped block 87.

When the connecting rod 63 rotates leftwards, the connecting rod 63 drives the second wedge block 810 to rotate leftwards through the L-shaped rod 89, the second wedge block 810 is matched with the first wedge block 87 in the leftward rotation process, the second wedge block 810 drives the second wedge block 810 to move downwards, the second wedge block 810 drives the second sliding block 84 to move downwards through the connecting rod 86, the second sliding block 84 pulls the driving lever 83 downwards to enable the third rotating shaft 81 to rotate, the torsion spring 82 deforms, the third rotating shaft 81 drives the table board 2 to turn outwards, on one hand, matching of the chair board 3 and the left supporting frame 1 is facilitated, on the other hand, the table board 2 drives the supporting plate 88 to turn over, a student can place an object on the supporting plate 88, when the connecting rod 63 rotates reversely, the second wedge block 810 is not matched with the first wedge block 87, so that the second compression spring 85 restores to the initial state, and the second compression spring 85 drives the first wedge block 87, The connecting rod 86 and the second sliding block 84 both move upwards, the second sliding block 84 stops pulling the shift lever 83, the torsion spring 82 restores the initial state, and the torsion spring 82 drives the third rotating shaft 81 to rotate reversely, so that the table board 2 and the supporting plate 88 both restore the initial state, and when the device is used again, the steps are repeated.

Still including anti-drop subassembly 9, 1 middle part of left support frame is equipped with anti-drop subassembly 9, anti-drop subassembly 9 is connected with folding assembly 6, anti-drop subassembly 9 is including one-way gear 91, second rack 92, T shape pole 93, spacer pin 94, third compression spring 95 and second stopper 96, second pivot 62 middle part is equipped with one-

way gear

91, 1 middle part right side of left support frame is equipped with two second stoppers 96, second stopper 96 internal sliding type is equipped with spacer pin 94, spacer pin 94 upper portion is around having third compression spring 95, third compression spring 95 is connected with second stopper 96 and spacer pin 94, two spacer pin 94 sub-unit connections have T shape pole 93, T shape pole 93 bottom is equipped with second rack 92, second rack 92 and one-way gear 91 meshing.

When the second rotating shaft 62 rotates counterclockwise, the second rotating shaft 62 drives the one-way gear 91 to rotate, when the one-way gear 91 is engaged with the second rack 92, the one-way gear 91 drives the second rack 92 to move downward, the second rack 92 drives the limit pin 94 to move downward through the T-shaped rod 93, the third compression spring 95 compresses, when the chair plate 3 is matched with the left support frame 1, because the length of the second rack 92 is limited, the one-way gear 91 is not engaged with the second rack 92, the third compression spring 95 returns to the initial state, the third compression spring 95 drives the limit pin 94 to move upward to be matched with the clamping plate 73, the limit pin 94 blocks the clamping plate 73, at this time, the one-way gear 91 is engaged with the second rack 92 again, but the one-way gear 91 idles, when a student needs to put down the chair plate 3, the second rack 92 is manually pulled downward, the second rack 92 drives the one-way gear 91 to idle, so that the limit pin 94 is not matched with the clamping plate 73, the chair is lowered and the second rack 92 is released, and the steps are repeated when the apparatus is used again.

It should be understood by those skilled in the art that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by using equivalent alternatives or equivalent variations fall within the scope of the present invention.

Claims

1. The utility model provides a student's table chair is folded to integral type which characterized in that, including:

the table plate (2), two table plates (2) are rotatably arranged on the supporting frame (1);

the chair plate (3) is arranged on the supporting frame (1);

the height adjusting component (4) is arranged on the supporting frame (1), and the height adjusting component (4) is connected with the chair plate (3);

the self-locking assembly (5) is arranged on the support frame (1), and the self-locking assembly (5) is matched with the height adjusting assembly (4);

the height adjusting component (4) comprises:

the first rotating shaft (41) is rotatably arranged on the support frame (1);

a straight gear (42), wherein the first rotating shaft (41) is provided with the straight gear (42);

the first rack (43) is arranged on the chair plate (3), and the first rack (43) is meshed with the straight gear (42);

the chair plate (3) is provided with a special-shaped support rod (44), and the special-shaped support rod (44) is connected with the first rack (43);

a hand wheel (45) is arranged on the first rotating shaft (41);

the self-locking assembly (5) comprises:

the first limiting block (51) is arranged on the supporting frame (1);

the pull rod (52) is arranged on the first limiting block (51) in a sliding mode;

the pull rod (52) is provided with a self-locking block (54), and the self-locking block (54) is matched with the hand wheel (45);

the first compression spring (53) is wound on the pull rod (52), and the first compression spring (53) is connected with the first limiting block (51) and the self-locking block (54);

also includes:

the folding component (6) is arranged on the support frame (1), and the folding component (6) is matched with the other support frame (1);

the folding assembly (6) comprises:

two fixing blocks (61) are arranged at the upper part of the support frame (1);

a second rotating shaft (62), wherein the second rotating shaft (62) is rotatably arranged between the two fixed blocks (61);

the connecting rod (63) is arranged on the second rotating shaft (62), and the two connecting rods (63) are matched with the supporting frame (1).

2. An integrated folding student desk and chair according to claim 1 further comprising:

the spacing adjusting component (7) is arranged on the supporting frame (1), and the spacing adjusting component (7) is matched with the folding component (6);

the spacing adjustment assembly (7) comprises:

the connecting rod (63) is provided with a sliding groove (71), the sliding groove (71) is internally provided with two first sliding blocks (72) in a sliding manner, and the first sliding blocks (72) are connected with the support frame (1);

the supporting frame (1) is provided with two clamping plates (73) in a sliding mode, and the clamping plates (73) are matched with the connecting rod (63);

the bolts (74) are arranged on the two clamping plates (73) in a sliding mode;

the butterfly nut (75) is rotationally arranged on the bolt (74), and the butterfly nut (75) is matched with the clamping plate (73).

3. An integrated folding student desk and chair according to claim 2 further comprising:

the turnover component (8) is arranged on the table board (2), and the turnover component (8) is connected with the folding component (6) and the support frame (1).

4. An integrated folding student desk and chair according to claim 3 wherein the flip assembly (8) comprises:

a third rotating shaft (81), wherein the table plate (2) is rotatably provided with the third rotating shaft (81);

the torsion spring (82) is wound on the third rotating shaft (81), and the torsion spring (82) is connected with the table plate (2) and the third rotating shaft (81);

the deflector rod (83) is arranged on the third rotating shaft (81);

the connecting rod (86), the support frame (1) is provided with two connecting rods (86) in a sliding way;

a second sliding block (84), wherein the connecting rod (86) is provided with the second sliding block (84), and the second sliding block (84) is matched with the shifting rod (83);

the connecting rod (86) is wound with the second compression spring (85), and the second compression spring (85) is connected with the second sliding block (84) and the support frame (1);

the connecting rod (86) is provided with a first wedge-shaped block (87);

the supporting plate (88) is arranged on the table plate (2);

the L-shaped rod (89) is arranged on the connecting rod (63);

and the L-shaped rod (89) is provided with a second wedge block (810), and the second wedge block (810) is matched with the first wedge block (87).

5. An integrated folding student desk and chair according to claim 4 further comprising:

anti-drop subassembly (9), be equipped with anti-drop subassembly (9) on support frame (1), anti-drop subassembly (9) are connected with folding subassembly (6).

6. An integrated folding student desk and chair according to claim 5 wherein the fall off prevention means (9) comprises:

the second rotating shaft (62) is provided with a one-way gear (91);

two second limiting blocks (96) are arranged on the supporting frame (1);

the limiting pin (94) is arranged on the second limiting block (96) in a sliding mode;

the third compression spring (95) is wound on the limiting pin (94), and the third compression spring (95) is connected with the second limiting block (96) and the limiting pin (94);

the T-shaped rod (93) is connected to the two limiting pins (94);

and a second rack (92) is arranged on the T-shaped rod (93), and the second rack (92) is meshed with the one-way gear (91).