CN110558760A

CN110558760A - Chair assembly structure

Info

Publication number: CN110558760A
Application number: CN201910890481.0A
Authority: CN
Inventors: 卜耀南
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-09-20
Filing date: 2019-09-20
Publication date: 2019-12-13
Anticipated expiration: 2039-09-20
Also published as: CN110558760B

Abstract

The invention discloses a chair composition structure, which at least comprises a base, a supporting frame, a chair back, a chair seat, an actuating frame and a first actuating rod, wherein the supporting frame is arranged above the base and is provided with a first guide groove, and the first guide groove is provided with a chute part and a lower groove part; the chair seat is pivoted with the chair back, at least one lower guide wheel is arranged at the rear part of the chair seat, and at least one front guide wheel is arranged at the front part of the chair seat; the actuating frame is provided with at least one actuating plate, the rear part and the front part of the actuating plate are respectively provided with a second guide slot and a third guide slot, and the lower guide wheel can move in the first guide slot and the second guide slot; the third guide groove can be jointed with the front guide wheel; two ends of the first actuating rod are respectively pivoted with the support frame and the seat, and when the first actuating rod is contracted, the lower guide wheel can be positioned at the rear positions of the first guide groove and the second guide groove, the front guide wheel is positioned at the rear position of the third guide groove, and the seat can move backwards and the front end of the seat can move upwards; therefore, the invention has better smooth and stable action and comfort.

Description

Chair assembly structure

Technical Field

the present invention relates to a chair assembly structure, and more particularly to a chair with better stability and comfort.

Background

The conventional chair has a backrest adjustable reclining design for improving the riding comfort, and as shown in fig. 8, the conventional chair mainly has a base 1 ', a seat 2', and a backrest 3 ', and the upper part and the center of the base 1' are respectively and fixedly provided with an armrest frame 11 'and a guide rod 12'; a sliding sleeve 21 ' capable of being sleeved with the guide rod 12 ' is arranged in front of the seat 2 ', and a pivoting part 22 ' is arranged at the rear end of the seat 2 '; the bottom of the chair back 3 ' is provided with a pivot part 31 ' pivoted with the pivot part 21 ' of the chair seat 2 ', and the center is provided with a pivot part 32 ' pivoted with the rear end of the armrest frame 11 ' above the base 1 ', so that the chair back 3 ' and the chair seat 2 ' can have a smaller sitting angle, the chair back 3 ' can be tilted backwards, the chair seat 2 ' can be driven to move forwards, and the sliding sleeve 21 ' can be displaced to the front position of the guide rod 12 ', so that the chair back 3 ' and the chair seat 2 ' can be adjusted to have a larger lying angle.

However, in the above structure, when lying or leaning on, the seat 2 ' is only driven by the backrest 3 ' to move forward, and the raising angle θ 1 of the front end of the seat 2 ' is small, so that most of the weight of the human body is still supported by the seat 2 ' when lying or leaning on, which is not comfortable enough, and the structure cannot independently control the angle of the backrest 3 ' and has the defect of poor applicability.

As shown in fig. 9, another conventional chair structure mainly includes a base 4 ', a seat 5 ', a backrest 6 ', and a leg rest 51 ' disposed in front of the seat 5 ', and a spring 52 ' disposed on the seat 5 ' to engage with the base 4 ', and the backrest 6 ', the seat 5 ' having a fixed engagement angle, and a pivot portion 61 ' pivotally connected to the base 4 ', so that when a user lies on the backrest 6 ', the seat 5 ' can rotate via the pivot portion 61 ' and stretch the spring 52 ' to limit the back-tilt angle of the backrest 6 ', and because the elevation angle θ 2 of the seat 5 ' corresponding to the ground parallel direction can be raised greatly, most of the lying weight of the user can act on the backrest 6 ', and the chair structure can have a better lying comfort similar to a gravity-free flip chair.

however, when the backrest 6 ' is tilted backward, the seat 5 ' correspondingly swings backward, which causes the center of gravity to shift to the rear position of the base 4 ' greatly, which may cause the unstable center of gravity of the whole chair to topple over, and the upward angle θ 2 of the seat 5 ' is much larger than the angle of lying down of a general person, which still causes the defect of unsatisfactory comfort, and the joint angle of the backrest 6 ' and the seat 5 ' is fixed, which cannot control the angle of the backrest 3 ' independently, thereby causing the defect of unsatisfactory applicability.

disclosure of Invention

The present invention is directed to at least one of the problems of the prior art, and provides a seat assembly structure with better stability and comfort.

According to an aspect of the present invention, there is provided a seat composition structure including:

A base;

A supporting frame, which is arranged above the base and is provided with at least one supporting plate vertical to the ground, the rear side of the supporting plate is provided with a first guide groove, and the first guide groove is provided with a chute part which is inclined downwards from the front to the rear;

A chair back;

The rear part of the chair seat is pivoted with the chair back, the chair back can adjust the backward tilt angle, at least one lower guide wheel is arranged at the rear part of the chair seat corresponding to the first guide groove, and at least one front guide wheel is arranged at the front part of the chair seat;

The second guide groove is approximately corresponding to the inclined groove part of the first guide groove and is arranged at one side of the first guide groove, and the lower guide wheel can move in the first guide groove and the second guide groove; the third guide groove can be jointed with the front guide wheel;

And the two ends of the first actuating rod are respectively pivoted with the support frame and the seat, the lower guide wheel can be positioned in front of the first guide wheel and the second guide wheel when the first actuating rod extends, the front guide wheel can be positioned in front of the third guide groove, the lower guide wheel can be positioned in rear of the first guide groove and the second guide groove when the first actuating rod contracts, the front guide wheel is positioned in rear of the third guide groove, the seat can move backwards while the rear end moves downwards, and the front end of the seat can move upwards and upwards.

Preferably, a lower slot portion is downwardly disposed behind the chute portion of the first guide slot, and the actuating frame is pivotally connected to the supporting frame, so that when the first actuating rod drives the lower guide wheel of the seat to move to the lower slot portion, the rear end of the seat can move downward and the actuating frame can pivot, and the front end of the seat can move upward.

Preferably, the chair further comprises a second actuating rod, the bottom end of the chair back is pivoted with the rear part of the chair seat, two ends of the second actuating rod are respectively pivoted with the chair back and the chair seat, and the back tilting angle of the chair back can be adjusted by the second actuating rod.

Preferably, the chair further comprises a foot pad having a link mechanism pivotally connected to the seat and capable of folding when the seat moves forward and unfolding when the seat moves backward.

Preferably, the device further comprises at least one spring, and the spring is connected with the support frame and the movable frame.

Preferably, the chair seat has two side rods, the front and rear sides of the two side rods are respectively provided with a front rod and a rear rod connected, the rear rod is provided with at least one rear guide post corresponding to the supporting plate of the supporting frame, each rear guide post has two parallel plate bodies, the space between the two plate bodies can clamp the supporting plate and the actuating rod plate, and the lower guide wheel is arranged at the lower position of the two plate bodies.

Preferably, the top edge of the first guide groove is parallel to the top edge of the support plate, the lower guide wheel is arranged between the two plate bodies of the rear guide post, an upper guide wheel is arranged between the two plate bodies and corresponds to the upper position of the lower guide wheel, and the upper guide wheel can move along the top edge of the support plate.

Preferably, the supporting frame has a horizontal column corresponding to the horizontal direction of the ground, a first pivot part is arranged above the horizontal column, two supporting plates are arranged at two sides of the horizontal column corresponding to the vertical direction of the ground, and a lower groove part is arranged at the rear end of the inclined groove part of the first guide groove in a downward bending way; a second pivoting part is arranged below the front side of the supporting plate; the chair seat has two side rods, the front and rear sides of the two side rods are respectively provided with a front rod and a rear rod which are connected, the rear rod is provided with two rear guide posts corresponding to the two support plates of the support frame, each rear guide post has two parallel plate bodies which can clamp the support plate and the action plate, and the lower position between the two plate bodies is provided with the lower guide wheel; two front guide plates which can be respectively jointed with a front guide wheel are arranged downwards on the front rod, and a ninth pivoting part is arranged behind the front rod; the actuating frame is provided with two actuating plates which are parallel and respectively arranged at the sides of the two supporting plates, the two actuating plates are connected by a connecting rod, and a tenth pivoting part is arranged below each actuating plate and is pivoted with the second pivoting part of the supporting plate; the first actuating rod has a fifteenth pivot portion and a sixteenth pivot portion at two ends thereof, which are pivotally connected to the first pivot portion of the supporting frame and the ninth pivot portion of the seat respectively.

Preferably, the chair further comprises a second actuating rod, wherein the lower parts of the two sides of the chair back are respectively provided with a third pivoting part, and the lower parts of the two sides of the chair back are provided with a fourth pivoting part; the rear ends of the two side rods of the chair seat are respectively provided with a fifth pivoting part which is pivoted with the third pivoting part of the chair back; an eighth pivoting part is arranged on the side lever towards the center of the chair seat; the second actuating rod has a seventeenth pivot part and an eighteenth pivot part at its two ends, which are respectively pivoted to the eighth pivot part of the chair seat and the fourth pivot part of the chair back, the top edge of the first guide slot is parallel to the top edge of the supporting plate, and an upper guide wheel is disposed above the rear guide post and can move along the edge of the supporting plate.

preferably, the chair further comprises a foot pad, wherein the seat is provided with two sixth pivoting portions and a seventh pivoting portion on the front rod, and the link mechanism of the foot pad has two twelfth pivoting portions pivotally connected to the two eleventh pivoting portions of the actuating plate, two thirteenth pivoting portions pivotally connected to the sixth pivoting portion of the seat, and a fourteenth pivoting portion pivotally connected to the seventh pivoting portion of the seat.

Any one of the technical schemes at least has the following beneficial effects: according to the technical scheme, the first actuating rod can be contracted to drive the seat to move backwards corresponding to the actuating frame, the connecting rod mechanism of the foot pad can be driven to move forwards, the inclined groove part of the first guide groove is arranged with the rear end lower than the front end, so that the back end of the seat moves downwards to the front end, the tilting angle is larger than the tilting angle of the seat which does not move backwards, the gravity center can be attached to the chair back backwards in the sitting process to reduce the stress of the buttocks, and the chair back can adjust the tilting angle backwards through the second actuating rod according to requirements so as to improve the sitting comfort and the applicability.

The first actuating rod can be contracted, the lower guide wheel can be moved to the lower groove part of the first guide groove, the actuating frame can be driven to pivot, the front end of the chair seat can be lifted to be positioned at a larger lifting angle than the lower guide wheel at the position of the inclined groove part, at the moment, the chair back can be lifted backwards to be positioned at a better lying and leaning angle through the second actuating rod, the pressure of the buttocks can be more evenly and backwards distributed to the back and the waist to improve the comfort, and the feet are lifted to promote the blood backflow circulation when lying and leaning, so that the better relaxing and comfortable effects can be improved.

drawings

The invention is further described below with reference to the accompanying drawings and examples;

FIG. 1 is an exploded view of an embodiment of the present invention;

FIG. 2 is an assembled view of the embodiment of the present invention showing the seat moved forward;

FIG. 3 is a top view of an embodiment of the present invention showing the seat in a forward position;

FIG. 4 is a side view of an embodiment of the present invention showing the seat in a forward position;

FIG. 5 is a side view of an embodiment of the present invention showing the seat moved backward and the front raised with the lower guide wheels at the rear end of the diagonal groove portion;

FIG. 6 is a perspective view of an embodiment of the present invention showing the seat moved backward and the seat moved forward with the lower guide wheels located in the lower groove;

FIG. 7 is a side view of an embodiment of the present invention showing the seat moved rearward with the rear end down and the front end up;

FIG. 8 is a schematic view of a conventional seat;

FIG. 9 is a schematic view of another conventional chair.

description of reference numerals:

1 base, 11 bottom frame, 12 support column, 2 support frame, 21 transverse column, 22 first pivot part, 23 support plate, 24 first guide slot, 241 oblique slot part, 242 lower slot part, 25 second pivot part, 26 lower convex column, 3 chair back, 31 third pivot part, 32 fourth pivot part, 4 chair seat, 40 side rod, 41 front rod, 42 rear rod, 43 fifth pivot part, 44 rear guide column, 441 plate body, 442 lower guide wheel, 443 upper guide wheel, 45 front guide plate, 451 front guide wheel, 46 sixth pivot part, 47 seventh pivot part, 48 eighth pivot part, 49 ninth pivot part, 5 actuating frame, 51 actuating plate, 52 connecting rod, 53 tenth pivot part, 54 second guide slot, 55 third guide slot, 56 upper convex column, 57 spring, 58 eleventh pivot part, 6 foot pad, 61 connecting rod mechanism, 62 twelfth pivot part, 63 thirteenth pivot part, 64 fourteenth pivot part, 7 first actuating rod, 71 fifteenth pivot part, a sixteenth pivot joint part 72, a second actuating rod 8, a seventeenth pivot joint part 81, and an eighteenth pivot joint part 82;

1 ' base, 11 ' handrail frame, 12 ' guide rod, 2 ' seat, 21 ' sliding sleeve, 22 ' pivot part, 3 ' back, 4 ' base, 5 ' seat, 51 ' leg rest, 52 ' spring, 6 ' back and 61 ' pivot part.

Detailed Description

Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

in the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and larger, smaller, larger, etc. are understood as excluding the number, and larger, smaller, inner, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.

Referring to fig. 1-4, the present embodiment includes a base 1, a support frame 2, a backrest 3, a seat 4, an actuating frame 5, a foot pad 6, a first actuating rod 7, and a second actuating rod 8, the base 1 has a bottom frame 11, and the bottom frame 11 has an upright post 12.

The supporting frame 2 is arranged above the pillar 12 of the base 1, and has a cross post 21 corresponding to the horizontal direction of the ground and the pillar 12 combination, the upper side of the cross post 21 is provided with a first pivot part 22, two sides of the cross post 21 are respectively provided with a supporting plate 23 corresponding to the vertical direction of the ground, the two supporting plates 23 are of a symmetrical structure, the rear side of each supporting plate 23 is provided with a first guide groove 24, the front side of the first guide groove 24 is provided with an inclined groove part 241, the inclined groove part 241 inclines downwards from the front to the rear, the rear end of the inclined groove part 241 is bent downwards to be provided with a lower groove part 242, and the top edge of the first guide groove 24 is parallel to the top edge of the supporting plate 23; a second pivot portion 25 is disposed under the front side of each support plate 23, and a lower protrusion 26 is disposed inside each support plate 23.

The chair back 3 is provided with a third pivot portion 31 at the lower side of the two sides, and a fourth pivot portion 32 at the lower side.

The chair seat 4 has two side rods 40, the front and rear sides of the two side rods 40 are respectively provided with a front rod 41 and a rear rod 42 for connection, the rear ends of the two side rods 40 are respectively provided with a fifth pivot joint part 43 for pivoting with the third pivot joint part 31 of the chair back 3, the rear rod 42 is provided with two rear guide posts 44 corresponding to the two support plates 23 of the support frame 2, each rear guide post 44 has two parallel plate bodies 441, the lower and upper positions between the two plate bodies 441 are respectively provided with a lower and upper guide wheel 442, 443 capable of displacing along the top edges of the first guide groove 24 and the support plate 23; two front guide plates 45 are arranged downwards on the front rod 41, a front guide wheel 451 is respectively arranged on the two front guide plates 45, two sixth pivoting parts 46 are arranged in front of the front rod 41, and a seventh pivoting part 47 is arranged behind the front rod 41; an eighth pivoting portion 48 is disposed on the side rod 40 toward the center of the seat 4; a ninth pivot portion 49 is disposed behind the front rod 41.

The action frame 5 is arranged under the chair seat 4, and has two action plates 51 which are parallel and respectively arranged at the side of the two support plates 23, the two action plates 51 are connected by a connecting rod 52, a tenth pivot joint part 53 is arranged under each action plate 51 and is pivoted with the second pivot joint part 25 of the support plate 23, a second guide slot 54 and a third guide slot 55 are respectively arranged at the back and the front of the action plate 51, the length of the second guide slot 54 approximately corresponds to the inclined slot part 241 of the first guide slot 24 and is arranged at one side of the first guide slot 24, the action plate 51 and the support plate 23 are clamped by the two plate bodies 441 of the back guide post 44, the lower guide wheel 442 can be simultaneously positioned and displaced in the first and the second guide slots 24, 54, the upper guide wheel 443 can be positioned and displaced at the top edge of the support plate 23, the third guide slot 55 is jointed with the front guide wheel 451 of the chair seat 4, the front guide wheel 451 can be displaced in the third guide slot 55, the inner side of the action plate 51 is provided with, the upper and lower studs 56, 26 are connected with a spring 57, and can prevent the actuating frame 5 from shaking by the tension of the spring 57 to improve the stability of the actuating frame 5, and an eleventh pivot part 58 is respectively arranged on the upper front side of the two actuating plates 51.

the foot pad 6 has a link mechanism 61 capable of folding and unfolding in accordance with the movement of the seat 4, the link mechanism 61 has two twelfth pivot portions 62 pivotally connected to the two eleventh pivot portions 58 of the actuating plate 51, two thirteenth pivot portions 63 pivotally connected to the sixth pivot portion 46 of the seat 4, and a fourteenth pivot portion 64 pivotally connected to the seventh pivot portion 47 of the seat 4.

the first actuating rod 7 can be an electric rod or other telescopic rod, and has fifteenth and sixteenth pivot portions 71 and 72 at two ends thereof, respectively, pivotally connected to the first pivot portion 22 of the supporting frame 2 and the ninth pivot portion 49 of the seat 4.

The second actuating rod 8 is an electric rod or other telescopic rod, and has seventeenth and eighteenth pivoting portions 81 and 82 at two ends thereof pivotally connected to the eighth pivoting portion 48 of the seat 4 and the fourth pivoting portion 32 of the backrest 3, respectively.

In this embodiment, when the first actuating rod 7 is extended, the seat 4 can be located at the position corresponding to the forward movement of the actuating frame 5, and the front guide wheel 451 is located at the front position of the third guide slot 55 of the actuating frame 5, the lower guide wheel 442 is located at the front positions of the first guide slot 24 of the supporting frame 2 and the second guide slot 54 of the actuating frame 5, the forward tilt angle of the seat 4 is θ 3, and the foot pad 6 is folded to provide a normal sitting, and the backrest 3 can be controlled by the second actuating rod 8 to adjust the proper tilt angle, the angle of the backrest 3 is not affected by the position of the seat 4, and the seat has better comfort and applicability.

referring to fig. 1 and 5, in the present embodiment, the first actuating rod 7 is contracted to drive the seat 4 to move backward corresponding to the actuating frame 5, and the front guide wheel 451 is movable to the rear end of the third guide slot 55, the lower guide wheel 442 is movable to the rear end of the inclined slot portion 241 of the first guide slot 24, the upper guide wheel 443 is movable to the rear end of the top of the supporting plate 23, and the seat 4 is moved backward to drive the link mechanism 61 of the foot pad 6 to expand forward, and because the inclined slot portion 241 of the first guide slot 24 is disposed at a lower rear end than the front end, the front end elevation angle θ 4 of the seat 4 is larger than the elevation angle θ 3 of the seat 4 that is not moved backward as shown in fig. 4, so as to provide a force that the center of gravity is laid back against the seat back 3 to reduce the hip force, and the seat back actuating rod 3 can adjust the inclination angle by the second rod 8 as required to improve the comfort and applicability of the seat, and the front guide slot 451 is engaged with the third guide slot 55 when the seat 4 is moved backward, the rear portion is engaged with the first and second guide grooves 24, 54 by the lower guide wheel 442, which provides better operation stability, and the lower and upper guide wheels 442, 443 can clamp the first guide groove 24 of the supporting plate 23 and the top edge of the supporting plate 23, which provides better supporting strength and operation stability.

Referring to fig. 6 and 7, in the present embodiment, the first actuating rod 7 is further contracted, the lower guide wheel 442 is moved to the position of the lower groove 242 of the first guide slot 24, and the actuating frame 5 is pivoted at the positions of the second and tenth pivoting portions 25, 53, so that the front end of the seat 4 can be raised to a higher raising angle θ 5 than the angle θ 4 of the lower guide wheel 442 in the position of the chute portion 241, and at this time, the back 3 can be tilted back to a better lying angle by the second actuating rod 8, so that the pressure of the buttocks can be more evenly distributed back to the back and the waist to improve the comfort, and the feet are raised to promote the blood circulation and better relaxation and comfort effects.

therefore, the present embodiment can improve the better lying comfort, and the chair back angle can be adjusted according to the requirement to improve the riding comfort, and the front of the chair seat of the present embodiment does not need to be provided with a foot pad.

Although specific embodiments have been described for illustration, many modifications and variations are possible without departing from the technical scope of the embodiments, which is defined in the appended claims.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.

Claims

1. seat component structure, its characterized in that includes:

A base;

a chair back;

2. The seat assembly as claimed in claim 1, wherein a lower slot is formed behind the slanted slot of the first guide slot, and the actuating frame is pivotally connected to the support frame, such that when the first actuating rod drives the lower guide wheel of the seat to move to the lower slot, the rear end of the seat can move downward and the actuating frame can pivot, and the front end of the seat can move upward.

3. the chair assembly as claimed in claim 1, further comprising a second actuating rod, wherein the bottom end of the backrest is pivotally connected to the rear of the seat, and two ends of the second actuating rod are pivotally connected to the backrest and the seat respectively, and the second actuating rod can adjust the tilting angle of the backrest.

4. The chair assembly of claim 1, further comprising a foot pad having a linkage pivotally connected to the seat and adapted to fold when the seat is moved forward and unfold when the seat is moved backward.

5. the seat assembly as claimed in claim 1, further comprising at least one spring coupled to the support frame and the movable frame.

6. The chair as claimed in claim 1, wherein the seat has two side bars, the front and rear sides of the two side bars are respectively provided with a front bar and a rear bar, the rear bar is provided with at least one rear guide post corresponding to the position of the supporting plate of the supporting frame, each rear guide post has two parallel plates, the distance between the two plates can clamp the supporting plate and the actuating bar plate, and the lower guide wheel is disposed at the position below the two plates.

7. the seat assembly as claimed in claim 6, wherein the top edge of the first guide groove is parallel to the top edge of the support plate, the lower guide wheel is disposed between two plates of the rear guide post, and an upper guide wheel is disposed between the two plates corresponding to an upper position of the lower guide wheel and capable of moving along the top edge of the support plate.

8. The seat assembly structure of claim 1, wherein the supporting frame has a cross-post corresponding to the horizontal direction of the ground, a first pivot portion is disposed above the cross-post, two supporting plates are disposed on two sides of the cross-post corresponding to the vertical direction of the ground, and a lower slot portion is disposed at the rear end of the inclined slot portion of the first guiding slot and bent downward; a second pivoting part is arranged below the front side of the supporting plate; the chair seat has two side rods, the front and rear sides of the two side rods are respectively provided with a front rod and a rear rod which are connected, the rear rod is provided with two rear guide posts corresponding to the two support plates of the support frame, each rear guide post has two parallel plate bodies which can clamp the support plate and the action plate, and the lower position between the two plate bodies is provided with the lower guide wheel; two front guide plates which can be respectively jointed with a front guide wheel are arranged downwards on the front rod, and a ninth pivoting part is arranged behind the front rod; the actuating frame is provided with two actuating plates which are parallel and respectively arranged at the sides of the two supporting plates, the two actuating plates are connected by a connecting rod, and a tenth pivoting part is arranged below each actuating plate and is pivoted with the second pivoting part of the supporting plate; the first actuating rod has a fifteenth pivot portion and a sixteenth pivot portion at two ends thereof, which are pivotally connected to the first pivot portion of the supporting frame and the ninth pivot portion of the seat respectively.

9. The seat assembly structure of claim 8, further comprising a second actuating rod, wherein the seat back is provided with a third pivot portion at the lower side of the two sides of the seat back, and a fourth pivot portion at the lower side of the seat back; the rear ends of the two side rods of the chair seat are respectively provided with a fifth pivoting part which is pivoted with the third pivoting part of the chair back; an eighth pivoting part is arranged on the side lever towards the center of the chair seat; the second actuating rod has a seventeenth pivot part and an eighteenth pivot part at its two ends, which are respectively pivoted to the eighth pivot part of the chair seat and the fourth pivot part of the chair back, the top edge of the first guide slot is parallel to the top edge of the supporting plate, and an upper guide wheel is disposed above the rear guide post and can move along the edge of the supporting plate.

10. The chair assembly structure of claim 8, further comprising a foot pad, wherein the seat is provided with two sixth pivot portions and a seventh pivot portion on the front rod, and the linkage mechanism of the foot pad has two twelfth pivot portions pivotally connected to the two eleventh pivot portions of the operating plate, two thirteenth pivot portions pivotally connected to the sixth pivot portion of the seat, and a fourteenth pivot portion pivotally connected to the seventh pivot portion of the seat.