CN114098482A

CN114098482A - Structure of foldable movable bathing chair

Info

Publication number: CN114098482A
Application number: CN202010868466.9A
Authority: CN
Inventors: 林翰
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-08-26
Filing date: 2020-08-26
Publication date: 2022-03-01

Abstract

The invention provides a foldable displacement bath chair structure, which mainly comprises a chair unit and a chair supporting unit, wherein the chair unit comprises a movable cushion and at least two sliding elements arranged below the movable cushion, and the sliding elements are respectively provided with at least one roller and a chair positioning piece; the seat supporting unit comprises four folding units, four chair legs, two side tube bodies and two cushion tube bodies, each folding unit comprises a first connecting part connected with the chair legs, a second connecting part connected with the side tube bodies and a third connecting part connected with the cushion tube bodies, at least one seat positioning hole is arranged on each cushion tube body, a folding switch element is arranged on each side tube body, each cushion tube body is provided with the sliding element, and the roller of the sliding element drives the movable cushion to move on the cushion tube body; the folding switch element makes the chair legs connected with the folding units move relative to the cushion tube.

Description

Structure of foldable movable bathing chair

Technical Field

The present invention relates to a chair, and more particularly to a foldable and easily displaceable chair for bathing.

Background

In recent years, old people or people with mobility disabilities often take a bath or shower through the bath chair, but most of the existing designs adopt the pipe fitting assembly to be directly and tightly connected with the chair body with the backrest, and the bath chair with the design often occupies a certain volume and has the defect of difficult storage.

Meanwhile, when the position of the conventional bath chair is moved during the bath, it is a time-consuming and difficult task for a caregiver who cares for a disabled person to take a bath, and a danger is easily generated for the disabled person, so that it is an object of the present invention to improve how to improve the conventional bath chair so that the conventional bath chair is easily moved during the bath and is easily stored after the use is finished.

Disclosure of Invention

The invention aims to provide a foldable displacement bath chair structure, which is convenient for a user to move during the bath process and is convenient to store after use, thereby achieving the purposes of improving the convenience and the safety of operation and solving the problems of the existing bath chair.

To achieve the above objects, the present invention provides a foldable movable bathing chair structure, which mainly comprises a chair unit and a chair supporting unit, wherein the chair unit comprises a movable cushion and at least two sliding elements disposed under the movable cushion, wherein each of the sliding elements is provided with at least one roller, and at least one of the sliding elements is provided with a chair positioning member, two sliding connecting members pivotally connected to the chair positioning member, two connecting wires connected to one end of the sliding connecting members, and a sliding return spring pivotally connected to the chair positioning member; the seat supporting unit comprises four folding units, four chair legs, two side tube bodies and two cushion tube bodies, each folding unit comprises a first connecting part connected with the chair leg, a second connecting part connected with the side tube body and a third connecting part connected with the cushion tube body, at least one seat positioning hole is arranged on the cushion tube body, a folding switch element is arranged on the side tube body, each cushion tube body is provided with the sliding element, the roller of the sliding element drives the movable cushion to move on the cushion tube body, and the seat positioning hole is used for positioning and fixing the movable cushion by the seat positioning element; the folding switch element makes the chair legs connected with the first connecting parts of the folding units displace relative to the cushion tube.

Furthermore, the folding unit further includes a first pivot unit having the first connection portion and the second connection portion, and a second pivot unit having the third connection portion, wherein the first pivot unit has a first pivot hole at the other end opposite to the first connection portion, the second connection portion is located between the first connection portion and the first pivot hole and is protruded outward from the peripheral side of the first pivot unit to form a tubular body for accommodating the lateral tubular body, the second pivot unit has a second pivot hole corresponding to the first pivot hole, and the first pivot hole and the second pivot hole are penetrated by a pivot member, so that the first pivot unit rotates relative to the second pivot unit.

Furthermore, a fixed pin sliding groove, a fixed pin and a fixed pin reset spring are formed in the second connecting part of the two folding units, the fixed pin and the fixed pin reset spring are accommodated in the fixed pin sliding groove, the second pivoting unit is pivoted with a pivoting surface of the first pivoting unit relatively and is provided with at least one folding positioning hole, one end of the fixed pin penetrates through the first pivoting unit and is positioned at the at least one folding positioning hole, and the other end of the fixed pin is connected with a fixed pin linkage part and is connected with the folding switch element connected with the other end of the fixed pin linkage part.

Furthermore, the side tube is further provided with a side tube groove and a folding switch cover body covering the side tube groove, the folding switch element comprises a switch stopping portion which is accommodated in the side tube and penetrates through the folding switch cover body to be limited, and one end of the switch stopping portion is connected with the fixing pin linkage piece.

Further, one end of the cushion tube body connected to the third connecting portion is provided with a cushion tube body positioner, and the third connecting portion is provided with at least one cushion tube body positioning hole, wherein the cushion tube body positioning hole accommodates the cushion tube body positioner.

Furthermore, one end of the chair leg connected with the first connecting part is provided with at least one chair leg positioning hole, and the position of the chair leg positioning hole of the first connecting part, which is opposite to the chair leg positioning hole, is provided with a chair leg positioner, wherein one of the chair leg positioning holes can accommodate the chair leg positioner.

Furthermore, a sliding control switch is arranged on one side edge of the seat unit, and the sliding control switch is connected with the other end of a sliding connecting piece and controls the seat positioning piece pivoted with one end of the sliding connecting piece to be separated from the seat positioning hole.

Furthermore, the seat unit is pivotally provided with a bendable backrest element and two detachable auxiliary side handles, the bendable backrest element comprises a backrest and at least one backrest control switch, wherein the backrest control switch controls the backrest to bend relative to the movable seat cushion.

Furthermore, the backrest control switch comprises a first positioning backrest pivot part with two first limiting grooves, a backrest positioning part with two backrest limiting blocks, a second positioning backrest pivot part with at least three second limiting grooves and a backrest control switch pivot part, wherein the backrest positioning part is also provided with a backrest positioning containing chamber for containing a backrest return spring, and the backrest limiting blocks are contained in the corresponding first limiting grooves and the at least two second limiting grooves.

Further, a seat rotation unit is disposed between the movable seat cushion and the sliding members, the seat rotation unit comprising: a first plate body, a locator arranged on the first plate body, a pivot shaft arranged on the first plate body and positioned in the locator, a limit fixer arranged on the first plate body and positioned at the peripheral side of the locator, wherein the pivot shaft is pivoted between the movable cushion and the first plate body, and the positioner is provided with a plurality of accommodating grooves, a plurality of balls and a plurality of rotating positioning holes, the containing groove contains a ball, the ball is connected with the movable cushion, the rotating positioning hole is arranged on the positioner, the limit fixer is provided with a limit rod, a group of reset springs arranged on the limit rod, a group of limit rod connecting pieces arranged on the limit rod and sleeved in the reset springs, and a limit fixing piece, the limiting fixing piece can contain the limiting rod, the reset spring and the limiting rod connecting piece, and the limiting rod connecting piece can be inserted into the rotary positioning hole.

The present invention provides a foldable movable bath chair structure to achieve the above and other objects, and the technical means, elements and effects thereof are described in the following description of a preferred embodiment.

Drawings

FIG. 1 is a perspective assembly view of the foldable movable bath seat structure of the present invention;

FIG. 2 is a schematic view of the foldable movable bath seat according to the present invention in a folded state;

FIG. 3 is a schematic view of the foldable movable bath seat of the present invention in a folded state from another perspective;

FIG. 4 is a partially exploded view of the folding unit of the foldable movable bath seat structure of the present invention;

FIGS. 5 to 7 are schematic views illustrating the folding operation of the folding unit of the foldable movable bath chair structure according to the present invention;

FIG. 8 is an exploded view of the slide member of the present foldable displaceable bath seat structure;

FIGS. 9 to 14 are schematic views showing the operation of displacing the seat unit of the foldable displaceable bath seat structure according to the present invention;

FIG. 15 is a partially exploded view of the seat unit of the structure of the foldable displaced bath seat of the present invention;

FIGS. 16 to 18 are schematic sectional views of the backrest control switch of the foldable type movable bath seat structure according to the present invention;

FIGS. 19 to 21 are schematic side views of the backrest control switch of the foldable type movable bath seat structure according to the present invention;

FIG. 22 is a partially exploded view of a seat rotation unit of a displaced foldable bath seat structure according to another embodiment of the present invention;

fig. 23 to 25 are schematic views illustrating the rotation and fixing actions of a seat rotation unit according to another embodiment of the present invention.

[ notation ] to show

Seat unit 10

Movable seat cushion 11

Bendable backrest element 12

Back support 121

Backrest control switch 122

1221 the first limiting groove

First positioning backrest pivot 1222

1223 backrest stop blocks

Backrest positioning member 1224

1225 second limiting groove

1226 second positioning backrest hinge

Back control switch pivot 1227

1228 backrest positioning Chamber

Back rest return spring 1229

Detachable auxiliary side handle 13

Sliding element 14

Roller 141

Seat positioning piece, 142

Sliding connector 143

Connecting wire body 144

Sliding return spring 145

Slide control switch 15

Seat support unit.20

Folding unit.21

First pivoting unit 211

2111 first connecting part

2112 of the second connection part

2113 first pivot hole

2114 fixed pin chute

Fixing pin 2115

2116 fixed pin reset spring

Chair leg positioner 2117

Second pivot unit 212

Third connecting part 2121

A second pivot hole 2122

Pivot surface 2123

Folding positioning hole 2124

Tube positioning hole of cushion 2125

Pivot connection piece 213

Chair leg 22

Chair leg positioning hole 221

Side tube body.23

Side tube body groove 231

Folding switch cover 232

Cushion tube 24

Seat positioning hole 241

Seat cushion tube positioner 242

Folding switch element, 30

Fixed pin linkage 31

Switch stop portion 32

Seat swivel unit 40

First plate 41

Locator, 42

Container 421

Ball bearing 422

Rotating positioning hole 423

Pivot shaft 43

Position limiting fixer 44

Limiting rod 441

Return spring 442

Position limiting rod connector 443

Spacing fixture 444

Detailed Description

Referring to fig. 1 to 21, the present invention provides a foldable movable bath chair structure, mainly comprising a seat unit 10 and a seat supporting unit 20, wherein:

referring to fig. 1, 2, 3 and 15, the seat unit 10 includes a movable seat cushion 11, a foldable backrest 12, two detachable auxiliary side grips 13 and three sliding members 14 disposed under the movable seat cushion 11, as shown in fig. 8, wherein each of the sliding elements 14 is provided with a sliding upper cover (not numbered), a sliding lower cover (not numbered), four screws (not numbered) for fixing the sliding upper cover and the sliding lower cover, and two rollers 141, at least one of the sliding elements 14 has a seat positioning member 142, two sliding connecting members 143 pivotally connected to the seat positioning member 142, and two connecting wires 144, and one end of the seat positioning member 142 is pivotally connected to a sliding return spring 145, the sliding return spring 145 is at least abutted against one of the sliding upper cover or the sliding lower cover, and one end of each connecting wire body 144 is connected with a corresponding sliding connecting piece 143; referring to fig. 9 to 14, the seat unit 10 is provided with a detachable auxiliary side handle 13 and a sliding control switch 15 at two sides of the seat unit 10, the sliding control switches 15 are respectively connected to the other end of the corresponding sliding connecting member 143, so that the sliding control switch 15 controls the sliding connecting member 143 and drives the seat positioning member 142 pivotally connected to one end to actuate, and the seat positioning member 142 is separated from the seat positioning hole 241, as shown in fig. 9 to 12, thereby controlling the seat unit 10 to be in a movable unlocking state and to be movable to the left and right sides, as shown in fig. 13 to 14, or controlling the seat unit 10 to be in an immovable fixed state; referring to fig. 15 to 21, the seat unit 10 is pivotally provided with the bendable backrest 12, the bendable backrest 12 includes a backrest 121 and a backrest control switch 122, wherein the backrest control switch 122 controls the backrest 121 to bend relative to the movable seat 11; the backrest control switch 122 includes a first positioning backrest pivot 1222 having two first limiting grooves 1221, a backrest positioning member 1224 having two backrest limiting blocks 1223, a second positioning backrest pivot 1226 having three second limiting grooves 1225, and a backrest control switch pivot 1227; referring to fig. 16 to 21, the backrest positioning member 1224 further includes a backrest positioning chamber 1228 for accommodating a backrest return spring 1229, and the backrest limiting blocks 1223 are accommodated in the corresponding first limiting grooves 1221 and two corresponding second limiting grooves 1225, when the user presses the backrest control switch 122, the first positioning backrest pivot 1222 bends the backrest 121 toward the movable seat 11, and the backrest return spring 1229 is reset after the backrest is bent to a predetermined position.

The seat supporting unit 20 includes four folding units 21, four legs 22, two side tubes 23 and two cushion tubes 24, please refer to fig. 1 to 4, each folding unit 21 includes a first pivoting unit 211 and a second pivoting unit 212 pivoted thereto, please refer to fig. 4, wherein the first pivoting unit 211 has a first connecting portion 2111 connected to one of the legs 22, a second connecting portion 2112 connected to the side tube 23 and a first pivoting hole 2113 provided at the other end opposite to the first connecting portion 2111, the second connecting portion 2112 is located between the first connecting portion 2111 and the first pivoting hole 2113 and is protruded outwardly from the peripheral side of the first pivoting unit 211 to form a tube shape for accommodating the side tube 23, the second pivoting unit 212 has a third connecting portion 2121 provided at the end connected to the cushion tube 24, and the second pivoting unit 212 has a second pivoting hole 2122 provided at the position corresponding to the first pivoting hole 2113, the first pivot hole 2113 and the second pivot hole 2122 are penetrated by a pivot member 213, so that the first pivot unit 211 rotates relative to the second pivot unit 212, wherein the cushion tube 24 is provided with at least one seat positioning hole 241, the side tube 23 is provided with a folding switch element 30, the folding unit 21 is provided with two folding units 21, the second connecting portion 2112 is formed with a fixed pin chute 2114, a fixed pin 2115 accommodated in the fixed pin chute 2114 and a fixed pin return spring 2116 abutting against one end of the fixed pin 2115, the second pivot unit 212 is pivoted with two folding positioning holes 2124 relative to a pivot surface 2123 of the first pivot unit 211, wherein one end of the fixed pin 2115 penetrates through the first pivot unit 211 and is positioned at one of the folding positioning holes 2124, and the other end is connected with a fixed pin linkage member 31, and is connected to the folding switch element 30 connected to the other end of the fixing pin linkage 31. in this embodiment, only one folding unit 21 of the folding units 21 at both ends of the same side tube 23 is provided with the fixing pin 2115, but not limited thereto;

in addition, the side tube 23 is further provided with a side tube recess 231 and a folding switch cover 232 covering the side tube recess 231, and the folding switch element 30 includes a switch stopping portion 32 accommodated in the side tube 23 and passing through and limited by the folding switch cover 232, and one end of the switch stopping portion 32 is connected to the fixing pin linkage 31;

as shown in fig. 4, one end of the cushion tube 24 connected to the third connecting portion 2121 is provided with two cushion tube positioners 242, and the third connecting portion 2121 is provided with two cushion tube positioning holes 2125, wherein the cushion tube positioning hole 2125 receives a corresponding cushion tube positioner 242;

furthermore, one end of the leg 22 connected to the first connection portion 2111 is provided with a plurality of leg positioning holes 221, and a leg positioner 2117 is disposed at a position opposite to the leg positioning holes 211 of the first connection portion 2111, wherein one of the leg positioning holes 221 can receive the leg positioner 2117.

Wherein, each cushion tube 24 is provided with the sliding element 14, please refer to fig. 9 to 14, the sliding control switch 15 controls the seat positioning element 142 at the other end of the sliding connecting piece 143 to disengage from the seat positioning hole 241, so that the roller 141 of the sliding element 14 drives the movable cushion 11 to move on the cushion tube 24 to the position of the seat positioning hole 241, and then the seat positioning element 142 automatically resets to be positioned and fixed in the seat positioning hole 241, thereby fixing the movable cushion 11;

as shown in fig. 5 to 7, the folding switch element 30 displaces the chair legs 22 connected to the first connecting portions 2111 of the folding units 21 relative to the seat cushion tube 23, as shown in fig. 2 to 3, when the user slides the folding switch element 30, the switch stop portion 32 drives the fixing pin linkage 31 to drive the fixing pin 2115, so that the fixing pin 2115 compresses the fixing pin return spring 2116 in the fixing pin sliding slot 2114 and the fixing pin 2115 is separated from the positioning hole folding 2124, so that the user can fold the chair legs 22 or unfold the chair legs 22 as desired, and when the user releases the folding switch element 30, the fixing pin return spring 2116 repositions the fixing pin 2115 in the positioning hole 2114.

Referring to fig. 22 again, the main structural features of the foldable bath seat structure according to another embodiment of the present invention are the same as those of the above-mentioned embodiments and are not repeated, and the main difference between the two embodiments is that a seat rotating unit 40 is disposed between the movable seat cushion 11 and the sliding elements 14, the seat rotating unit 40 includes: a first plate 41, a positioning device 42 disposed on the first plate 41, a pivot shaft 43 disposed on the first plate 41 and located in the positioning device 42, and a position-limiting fixer 44 disposed on the first plate 41 and located on the outer periphery of the positioning device 42, wherein the pivot shaft 43 is pivoted between the movable cushion 11 and the first plate 41 to make the movable cushion 11 rotate around the pivot shaft 43, the positioning device 42 has a plurality of receiving slots 421, a plurality of balls 422 and a plurality of rotation positioning holes 423, the receiving slots 421 respectively contain one of the balls 422, the balls 422 abut against the movable cushion 11 to assist the movable cushion 11 to rotate in the direction, the rotation positioning holes 423 are substantially uniformly disposed on the positioning device 42, and the position-limiting fixer 44 has a position-limiting rod 441, a set of return springs 442, a set of the position-limiting rod 441, A set of position-limiting rod connecting pieces 443 and a position-limiting fixing piece 444 disposed on the position-limiting rod 441 and sleeved in the return spring 442, wherein the position-limiting fixing piece 444 receives and limits the position-limiting rod 441, the return spring 442 and the position-limiting rod connecting piece 443, whereby one end of the position-limiting rod connecting piece 443 can be inserted into one of the rotation positioning holes 423 to position and fix the movable cushion 11 in a predetermined direction, the other end of the position-limiting rod connecting piece 443 can provide a user to move in the direction of the other end of the rotation positioning hole 423 to move the position-limiting rod connecting piece 443 away from the rotation positioning hole 423, so that the movable cushion 11 can be rotated to a predetermined direction, and the user releases the position-limiting rod 441 and then inserts the position-limiting rod connecting piece 443 into the rotation positioning hole 423 by the return spring 442.

Therefore, referring to fig. 23 and fig. 25, when the limiting rod 441 is pulled up, the limiting rod connecting piece 443 drives the return spring 442 and the limiting rod connecting piece 443 to separate the limiting rod connecting piece 443 from the rotation positioning hole 423 of the positioning device 42, so that the movable cushion 11 can rotate in a desired direction, that is, the movable cushion 11 rotates relative to the positioning device 42 by the pivot shaft 43, when the movable cushion rotates to a proper position, the limiting rod connecting piece 443 is fixed and limited in the rotation positioning hole 423 of the positioning device 44 by the elastic force of the return spring 442, so that the movable cushion 11 is fixed in one direction and does not rotate any more, wherein the positioning device 42 of the present embodiment is provided with four rotation positioning holes 423, and the rotation positioning holes 423 are equally arranged in four directions of the positioning device 42, but not limited thereto.

In summary, the present invention can make the movable seat 11 move on the seat tube 24 easily and effortlessly through the rollers 141 of the sliding element 14, so as to solve the problem that the user is not easy to move when sitting on the movable seat 11, and at the same time, the seat tube 24 is not deformed; meanwhile, when the user wants to fold or unfold the chair leg 22, the folding switch element 30 can be slid, and the fixing pin 2115 is controlled to be disengaged from the folding positioning hole 2124 by using the switch element 30, which is easy to operate.

Although the present invention has been described in detail, it should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Claims

1. A foldable movable bathing chair structure is characterized in that the foldable movable bathing chair structure comprises:

a seat unit, comprising a movable cushion and at least two sliding elements arranged below the movable cushion, wherein the sliding elements are respectively provided with at least one roller, and at least one sliding element is provided with a seat positioning piece, two sliding connecting pieces pivoted on the seat positioning piece, two connecting lines connected with one end of the sliding connecting pieces and a sliding reset spring pivoted on the seat positioning piece;

a seat supporting unit, which comprises four folding units, four chair legs, two side tube bodies and two cushion tube bodies, wherein each folding unit comprises a first connecting part connected with the chair leg, a second connecting part connected with the side tube body and a third connecting part connected with the cushion tube body, wherein the cushion tube bodies are provided with at least one seat positioning hole, and the side tube bodies are provided with a folding switch element;

wherein, each cushion tube body is provided with the sliding element, the roller of the sliding element drives the movable cushion to move on the cushion tube body, and the seat positioning hole is used for the seat positioning piece to position and fix the movable cushion;

wherein the folding switch element makes the chair legs connected with the first connecting parts of the folding units displace relative to the cushion tube.

2. The foldable movable bath chair structure as claimed in claim 1, wherein the foldable unit further comprises a first pivotal unit having the first connecting portion and the second connecting portion, and a second pivotal unit having the third connecting portion, wherein the first pivotal unit has a first pivotal hole at the other end opposite to the first connecting portion, the second connecting portion is disposed between the first connecting portion and the first pivotal hole and is protruded outwardly from the peripheral side of the first pivotal unit to form a tubular body for accommodating the side tubular body, and the second pivotal unit has a second pivotal hole corresponding to the first pivotal hole, and a pivotal member is inserted through the first pivotal hole and the second pivotal hole to allow the first pivotal unit to rotate relative to the second pivotal unit.

3. The structure of foldable displacement bath chair as claimed in claim 2, wherein a fixed pin sliding slot, a fixed pin accommodated in the fixed pin sliding slot and a fixed pin return spring are formed in the second connecting portion of the two folding units, and the second pivoting unit is provided with at least one folding positioning hole corresponding to a pivoting surface pivotally connecting the first pivoting unit, wherein one end of the fixed pin penetrates through the first pivoting unit and is positioned at least one folding positioning hole, and the other end is connected to a fixed pin linkage and is connected to the folding switch element connected to the other end of the fixed pin linkage.

4. The foldable movable bath chair structure as claimed in claim 3, wherein the side tube further comprises a side tube recess and a foldable switch cover covering the side tube recess, and the foldable switch element comprises a switch stopping portion received in the side tube and passing through the foldable switch cover, and one end of the switch stopping portion is connected to the fixing pin linkage.

5. The foldable movable bath seat structure of claim 1, wherein the end of the cushion tube connected to the third connecting portion is provided with a cushion tube positioning device, and the third connecting portion is provided with at least one cushion tube positioning hole, wherein the cushion tube positioning hole receives the cushion tube positioning device.

6. The foldable movable bath chair structure of claim 1, wherein one end of the leg connected to the first connecting portion has at least one leg positioning hole, and the other end of the first connecting portion opposite to the leg positioning hole has a leg positioning device, wherein one of the leg positioning holes is capable of receiving the leg positioning device.

7. The foldable movable bath chair structure according to claim 1, wherein the seat unit has a slide control switch disposed on one side thereof, the slide control switch is connected to the other end of a slide connection member and controls the seat positioning member pivoted to one end of the slide connection member to be disengaged from the seat positioning hole.

8. The foldable movable bath seat structure according to claim 1, wherein the seat unit is pivotally provided with a foldable backrest member and two detachable auxiliary side grips, the foldable backrest member comprises a backrest and at least one backrest control switch, wherein the backrest control switch controls the backrest to bend relative to the movable seat cushion.

9. The foldable movable bath chair structure of claim 1, wherein the backrest control switch comprises a first positioning backrest pivot with two first limiting grooves, a backrest positioning member with two backrest limiting blocks, a second positioning backrest pivot with at least three second limiting grooves, and a backrest control switch pivot, wherein the backrest positioning member further comprises a backrest positioning chamber for accommodating a backrest return spring, and the backrest limiting blocks are accommodated in the corresponding first limiting grooves and the at least two second limiting grooves.

10. The foldable, displaceable bath seat structure according to claim 1, characterized in that a seat rotation unit is provided between said movable cushion and said sliding members, said seat rotation unit comprising: a first plate, a locator arranged on the first plate, a pivot shaft arranged on the first plate and located in the locator, a limit fixer 44 arranged on the first plate and located at the outer periphery of the locator 42, wherein the pivot shaft is pivoted between the movable cushion and the first plate body, and the positioner is provided with a plurality of accommodating grooves, a plurality of balls and a plurality of rotating positioning holes, the containing groove contains a ball, the ball is connected with the movable cushion, the rotating positioning hole is arranged on the positioner, the limit fixer is provided with a limit rod, a group of reset springs arranged on the limit rod, a group of limit rod connecting pieces arranged on the limit rod and sleeved in the reset springs, and a limit fixing piece, the limiting fixing piece can contain the limiting rod, the reset spring and the limiting rod connecting piece, and the limiting rod connecting piece can be inserted into the rotary positioning hole.