CN214258640U

CN214258640U - Chair seat and chair back linkage device

Info

Publication number: CN214258640U
Application number: CN202120083679.0U
Authority: CN
Inventors: 戴龙飞
Original assignee: Anji Wanbao Smart Home Technology Co ltd
Current assignee: Anji Wanbao Smart Home Technology Co ltd
Priority date: 2021-01-13
Filing date: 2021-01-13
Publication date: 2021-09-24
Anticipated expiration: 2031-01-13

Abstract

The utility model discloses a chair seat and chair back linkage device, which comprises a back support piece, a seat support piece, a support frame and a transmission rod which enables the back support piece to be linked with the seat support piece when the back support piece tilts up; a connecting rod mechanism is arranged between the back support piece and the support frame, and the back support piece can tilt relative to the support frame through the connecting rod mechanism; a rotating support rod which enables the sitting support piece to be capable of being lifted upwards relative to the support frame is arranged between the rear end of the sitting support piece and the support frame; a sliding guide mechanism which can ensure that the front end of the sitting support piece can keep the same motion track with the rear end is correspondingly arranged between the front end of the sitting support piece and the support frame; and the seat supporting piece moves forwards while being lifted upwards; one end of the transmission rod is hinged on the back support piece or the connecting rod mechanism, and the other end of the transmission rod is hinged on the seat support piece or the rotating support rod; the back support piece tilts up to drive the transmission rod to move and then drive the seat support piece to synchronously lift up around the support frame; can eliminate the problems of waist running and back rubbing when the chair is used.

Description

Chair seat and chair back linkage device

Technical Field

The utility model relates to a thing to sit on field especially relates to a seat support back of chair aggregate unit.

Background

The chair is as living at home, the indispensable life instrument of office environment, not only living at home uses the chair to have the comfortable requirement that is higher and higher, even there is obvious promotion requirement to the travelling comfort and the operability of chair under work efficiency's prerequisite even for office environment, general chair is when the structural design limitation of user's back of the chair heels on in traditional chassis, can't accomplish the corresponding displacement of seat support simultaneously, because the back of the chair produces the change with the fore-and-aft distance of seat support when heeling on, under the unchangeable condition in seat support position, relative displacement and friction take place for the back of the chair and user back, lead to uncomfortable feeling, the function that the seat support displacement can be realized simultaneously to present just individuality current product, nevertheless also can't reach the linkage effect of engineering nature, cause the not enough of travelling comfort and the complexity of operability.

The patent number CN201520611537.1 of the chinese utility model discloses a "revolving chair seat back synchronous displacement system", the structure in this patent includes a seat cushion rubber shell, a chair back sliding connection frame, a chair back frame and a seat cushion base, the upper end of the chair back sliding connection frame is fixed with a chair back sliding rod, one end of the chair back sliding rod is connected with a chair back sliding ball, the lower end of the chair back sliding connection frame is connected with the seat cushion base; the inner side of the chair back frame is provided with a chair back frame sliding groove, a chair back sliding ball is embedded into the chair back frame sliding groove, the lower end of the chair back frame is sleeved with a chair back rotating shaft sleeve, a chair back rotating shaft fixer is sleeved on the chair back rotating shaft sleeve and is fixed at the lower end of the chair seat rubber shell; the lower end of the seat rubber shell is fixed with a pullback spring, the lower end of the pullback spring is connected with a seat base, the seat base is connected with a sliding connecting piece, and the sliding connecting piece is also connected with the seat rubber shell. The chair can conveniently realize the corresponding displacement of the seat cushion when the chair back tilts backwards.

However, the structure of this patent can only realize the horizontal displacement of seat support, and because only one end of slide bar is connected with back of the chair and slides the ball in this structure, probably lead to the linkage of back of the chair and cushion unstable, experience effect is poor.

Disclosure of Invention

The utility model aims to overcome the defects in the prior art and provide a chair seat and chair back linkage device which is more in accordance with human engineering mechanics; the back support piece linked with the chair seat and the chair back can synchronously drive the sitting support piece to lift upwards while inclining, and the sitting support piece moves forwards while lifting upwards; the chair has the advantages that the linkage between the chair back and the chair seat is realized, the phenomenon that a user rubs the back and runs the waist when using the chair is prevented, and the comfort of the chair is improved.

The technical scheme of the utility model is realized like this:

a chair seat and chair back linkage device comprises a back support piece, a seat support piece, a support frame and a transmission rod which enables the back support piece to be linked with the seat support piece when the back support piece tilts up; a connecting rod mechanism is arranged between the back support piece and the support frame, and the back support piece can tilt relative to the support frame through the connecting rod mechanism; a rotating support rod which enables the sitting support member to be capable of being lifted upwards relative to the support frame is arranged between the rear end of the sitting support member and the support frame, and two ends of the rotating support rod are respectively hinged with the sitting support member and the support frame; a sliding guide mechanism which can ensure that the front end and the rear end can keep the same motion track in the upward lifting process of the sitting support piece is correspondingly arranged between the front end of the sitting support piece and the support frame; and the seat supporting piece moves forwards while being lifted upwards; one end of the transmission rod is hinged on the back support piece or the connecting rod mechanism, and the other end of the transmission rod is hinged on the seat support piece or the rotating support rod; the back support member tilts up to drive the transmission rod to move and then drive the seat support member to synchronously lift up around the support frame.

Preferably, the supporting frame comprises supporting transverse plates which are positioned at two sides of the sitting supporting piece and are arranged in a mirror image mode, and supporting longitudinal plates which are positioned at two sides of the back supporting piece and are arranged in a mirror image mode; the supporting longitudinal plate is connected to the rear end of the supporting transverse plate; the connecting rod mechanism is arranged between the supporting longitudinal plate and the back supporting piece; the sliding guide mechanism and the rotating support rod are arranged between the seat support piece and the support transverse plate.

Preferably, the connecting rod mechanism comprises a first rocker and a second rocker, one end of the first rocker is hinged with the back supporting piece, and the other end of the first rocker is hinged with the supporting longitudinal plate; the second rocker is positioned below the first rocker, one end of the second rocker is hinged with the back support piece, and the other end of the second rocker is hinged with the supporting longitudinal plate; a four-bar linkage is formed among the first rocker, the second rocker, the supporting longitudinal plate and the back support; the link mechanism deforms and drives the back support member to move forward downward or backward upward. The four-bar mechanism enables the movement of the back support piece to be more stable and the tilting effect to be better.

Preferably, the back support member comprises a back support rod which is longitudinally arranged, a connecting seat is arranged at the lower end of the back support rod, and the first rocker and the second rocker are both hinged on the connecting seat. The back support rod is used for bearing back thrust of a user, and the back support rod can relatively support the longitudinal rod to lean backwards under the action of the first rocker and the second rocker.

Preferably, the rear end of the seat supporting piece is provided with a pin shaft which is transversely arranged, one end of the rotating supporting rod is hinged on the pin shaft, and the other end of the rotating supporting rod is hinged on the supporting transverse plate; and the hinged position of the rotating supporting rod on the supporting transverse plate is positioned at the front lower part of the pin shaft. The pin shaft is arranged, so that the rotating support rod can effectively drive the sitting support piece to move when rotating.

Preferably, the rotating support rod is an L-shaped rod. The L-shaped rod is arranged, so that the seat supporting piece can move forwards for a larger distance while being lifted upwards relative to the supporting transverse plate.

Preferably, one end of the transmission rod is hinged to the connecting rod mechanism, and the other end of the transmission rod is hinged to the seat support.

Preferably, the link mechanism comprises a first rocker and a second rocker, and the first rocker is positioned above the second rocker; the rear end of the seat supporting piece is provided with a pin shaft which is transversely arranged, and the rotating support rod is hinged on the pin shaft; one end of the transmission rod is hinged on the second rocker, and the other end of the transmission rod is hinged on the pin shaft. The linkage of the back support piece and the seat support piece can be realized only by respectively hinging two ends of the transmission rod on the second rocker and the pin shaft, and the structure is simple and reliable, and the design is ingenious.

Preferably, the transmission rod is a U-shaped rod and comprises a connecting cross rod, the front end of the connecting cross rod is provided with a longitudinal connecting short rod, and the rear end of the connecting cross rod is provided with a longitudinal connecting long rod; the connecting short rod is hinged on the pin shaft, and the connecting long rod is hinged on the second rocker. Through setting up the transfer line to "U" type, make back support piece when bending backward then, the transfer line can drive in more reasonable application of force direction and sit the support piece and make and sit the support and lift.

Preferably, the sliding guide mechanism comprises a gear and a gear track which are in sliding fit; the gear tracks are arranged on the two supporting transverse plates in a mirror image manner and extend obliquely to the front upper part; the gears are correspondingly arranged on two sides of the front end of the seat supporting piece. The sliding fit of the gear and the gear track is adopted, so that the movement of the seat supporting piece is more stable.

Preferably, a sliding seat is arranged on the inner side of the supporting transverse plate, and the gear track is formed in the sliding seat; two sides of the front end of the seat supporting piece are provided with rotating shafts protruding outwards, and gears are connected to the rotating shafts; the gear is located in the sliding seat and is in sliding fit with the gear rail, and the gear is limited between the sliding seat and the supporting transverse plate. The gear restriction is between slide and support diaphragm, rocks about between seat support piece and the support diaphragm when avoiding the seat to use, makes the structure more stable.

Adopted above-mentioned technical scheme the utility model discloses a design departure point, theory and beneficial effect are:

firstly, the linkage relation between the back support piece and the seat support piece is realized through the chair back and chair seat linkage device of the utility model, so that when the back support piece is tilted backwards, the seat support piece lifts the relative support frame upwards and moves forwards under the action of the transmission rod; the chair seat can always have the effect of supporting the waist of a human body, and the waist running condition is effectively avoided; in the process of backward leaning of the back support piece, the distance between the bottom of the back support piece and the rear part of the seat support piece is kept unchanged, the effect of zero displacement is achieved, and the back rubbing phenomenon of the back of a human body and the back of the chair is effectively avoided; the problem that the back of the chair in the prior art is rubbed and worn when the chair back tilts backwards is comprehensively solved, the health of a human body is facilitated, and the comfort of the chair is improved.

Secondly, be equipped with link mechanism between back support piece and the support vertical pole, and first rocker on the coupling mechanism, second rocker form four-bar linkage with support vertical pole and back support piece, stable in structure for the process of inclining of back support piece can the steady operation, and the effect of inclining of the back of the chair is better.

Furthermore, a rotating supporting rod is arranged between the rear end of the seat supporting piece and the supporting transverse plate, and a gear track which are in sliding fit are arranged between the front end of the seat supporting piece and the supporting transverse plate; the seat supporting piece can be lifted upwards and moved forwards relative to the supporting transverse plate under the combined action of the rotating supporting rod and the sliding guide mechanism; the gears and the gear tracks can enable the movement of the seat supporting piece to be more stable, and the user feels more comfortable when using the seat supporting piece.

Drawings

FIG. 1 is a schematic perspective view of the seat-back linkage of an embodiment of the present invention;

FIG. 2 is a schematic view of an internal three-dimensional structure of the chair seat-back linkage according to an embodiment of the present invention;

FIG. 3 is a schematic perspective view of the chair seat-back linkage of the present invention in an initial position;

FIG. 4 is a schematic perspective view of the back support member of the chair seat-back linkage assembly of the present invention in a reclined position;

fig. 5 is a schematic perspective view of the connection between the back support and the supporting vertical plate according to the embodiment of the present invention;

fig. 6 is a schematic perspective view of the connection between the seat supporting member and the supporting cross plate according to the embodiment of the present invention;

fig. 7 is a schematic perspective view of the slide guide mechanism according to the embodiment of the present invention.

The figures are numbered: a back support 1; a seat support 2; a support frame 3; supporting the cross plate 3 a; a supporting vertical plate 3 b; a back support bar 4; a connecting seat 5; connecting the vertical plate 5 a; a connecting side plate 5 b; a link mechanism 6; a first rocker 7; a second rocker 8; a seat plate 9; rotating the support rod 10; a pin 11; a housing 12; a rotating shaft 13; a slide guide mechanism A; a gear 14; a gear track 15; a slide 16; a sleeve 17; a movable slot 18; a transmission rod 19; a connecting stub 19 a; a long connecting rod 19 b; a connecting rail 19 c; a window 20.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail with reference to the accompanying drawings and detailed description. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

In the description of the present invention, the term "at least one" means one or more unless explicitly defined otherwise. The terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The specific implementation manner of the utility model is as follows:

as shown in fig. 1-7, the present invention provides a chair seat and backrest linkage device, which comprises a back support member 1, a seat support member 2, a support frame 3 for supporting the back support member 1 and the seat support member 2, and a transmission rod 19 for linking the back support member 1 with the seat support member 2 when the chair is tilted; the supporting frame 3 comprises supporting transverse plates 3a which are positioned on two sides of the sitting supporting piece 2 and are arranged in a mirror image mode, and supporting longitudinal plates 3b which are positioned on two sides of the back supporting piece 1 and are arranged in a mirror image mode, the supporting longitudinal plates 3b are perpendicular to the supporting transverse plates 3a, and the supporting longitudinal rods 3b are connected to the rear ends of the supporting transverse plates 3 a.

As shown in fig. 2-7, the back support member 1 includes a back support rod 4 disposed longitudinally, the back support rod 4 can bear the force applied by the user on the chair back, a connecting seat 5 is disposed below the back support rod 4, a link mechanism 6 is disposed between the connecting seat 5 and the vertical support plate 3b, the back support rod 4 can tilt relative to the vertical support plate 3b through the link mechanism 6, specifically: the connecting base 5 comprises a connecting vertical plate 5a and connecting side plates 5b positioned on two sides of the connecting vertical plate 5 a; the lower end of the back support rod 4 is fixedly connected with the connecting vertical plate 5a through a screw; the first linkage 6 comprises a first rocker 7 and a second rocker 8; under the initial position, the back support rod 4 is in a vertical state, the first rocker 7 is positioned above the second rocker 8, one end of the first rocker 7 is hinged on the support longitudinal plate 3b, and the other end of the first rocker 7 is hinged on the connecting side plate 5 b; two ends of the second rocker 8 are also hinged to the supporting longitudinal plate 3b and the supporting side plate 5b respectively; and the hinging position of the second rocker 8 on the supporting longitudinal plate 3b is positioned in front of the hinging position of the first rocker 7 on the supporting longitudinal plate 3b, and the hinging position of the first rocker 7 on the connecting side plate 5b is positioned behind the hinging position of the second rocker 8 on the connecting side plate 5 b. Then, a four-bar linkage mechanism is formed among the first rocker 7, the second rocker 8, the supporting longitudinal plate 3b and the connecting seat 5, as shown in fig. 3 and 4, through the deformation of the four-bar linkage mechanism, the back support rod 4 can tilt relative to the supporting longitudinal plate 3b, as shown in fig. 3, at the initial position, the back support rod 4 is in a vertical state, when a user leans on the chair back and applies back thrust to the back support rod 4, the four-bar linkage mechanism deforms, the first rocker 7 and the second rocker 8 both swing forward around the supporting longitudinal plate 3b, as shown in fig. 4, the back support rod 4 moves downward and forward, so that the back support rod 4 is in a backward tilting state to adapt to the backward tilting posture of the user.

Sit support piece 2 connect the cooperation between two support diaphragm 3a, and sit support piece 2 and can upwards lift and move forward simultaneously relatively support diaphragm 3a, specifically indicate: the height of the sitting support part 2 is higher than that of the supporting transverse plate 3a, the sitting support part 2 comprises a seat plate 9 which is horizontally arranged, the seat plate 9 is arranged along the length direction of the supporting transverse plate 3a, and the seat plate 9 is used for supporting a seat; a rotating support rod 10 is connected between each of the two sides of the rear end of the seat support member 2 and the support transverse plate 3a on the corresponding side; a pin shaft 11 which is transversely arranged is correspondingly arranged at the rear end of the seat supporting piece 2, the pin shaft 11 is a long shaft, and two ends of the pin shaft 11 protrude out of the seat plate 9; then one end of the rotating support rod 10 is hinged on the pin shaft 11, and the other end of the rotating support rod 10 is hinged on the supporting transverse plate 3 a; the hinged position of the rotating support rod 10 on the supporting transverse plate 3a is positioned at the front lower part of the pin shaft 11; the rear end of the seat supporting piece 2 can rotate around the supporting transverse plate 3a through the rotating supporting rod 10 so as to be lifted forwards relative to the supporting transverse plate 3 a; the pivot strut 10 is "L" shaped so that the seat strut 2 can also be moved forward a sufficient distance when raised to a certain height.

In addition, still be equipped with slide guide mechanism a between the front end of sitting support piece 2 and support diaphragm 3a, through this slide guide mechanism a for the front end can keep the same movement track with the rear end in the upward lift-up process of sitting support piece 2, makes then that sitting support piece 2 can be relatively to the steady forward lift-up of support horizontal pole 3a, specifically speaking: an outer cover 12 is arranged below the front end of the seat plate 9, and the outer cover 12 is a hollow shell; the outer cover 12 is fixedly connected with the seat plate 9 through screws; a rotating shaft 13 is arranged in the outer cover 12, and both ends of the rotating shaft 13 penetrate through both sides of the outer cover 12; the sliding guide mechanism A comprises a gear 14 arranged at the end part of the rotating shaft 13 and a gear track 15 correspondingly arranged on the supporting transverse plate 3 a; the method specifically comprises the following steps: as shown in fig. 7, a sliding base 16 is connected to the horizontal supporting plate 3a through a screw, a movable groove 18 is formed in the sliding base 16, and a gear track 15 is arranged in the movable groove 18 and is inclined forward and upward; the rotating shaft 13 is a four-corner rotating shaft, and the gear 14 is correspondingly provided with a sleeve 17 which is in inserted connection with the rotating shaft 13; when the device is installed, the gear 14 is placed in the movable groove 18, so that the gear 14 is in tooth joint fit with the gear track 15, the sleeve 17 on the gear 14 penetrates out of the sliding seat 16 towards the direction of the rotating shaft 13, the sliding seat 16 is correspondingly provided with a window 20 which is avoided from a moving track of the sleeve 17, and the sleeve 17 penetrates through the window 20 and then is sleeved and fixed on the rotating shaft 13; so that the gear 14 is circumferentially fixed with the rotary shaft 13; after the sleeve 17 is connected to the rotating shaft 13, the sleeve 17 penetrates through the outer cover 12, and the sleeve 17 is in rotating fit with the outer cover 12; then the sliding base 16 is fixed on the inner side of the supporting transverse plate 3a through screw connection, and the gear 14 is limited between the sliding base 16 and the supporting transverse plate 3 a; through the sliding fit between the gear 14 and the gear track 15, the front end of the seat support 2 can slide obliquely forward and upward or obliquely backward and downward relative to the support transverse plate 3 a; then under the combined action of the rotating support rod 10 and the sliding guide mechanism A, the whole seat support part 2 can be stably lifted upwards relative to the support transverse plate 3 a; in the process, the angle between the seat plate 9 and the horizontal plane is kept unchanged all the time, so that the seat is more comfortable and stable to use.

As shown in fig. 3-5, the transmission rod 19 is disposed between the seat support 2 and the back support 1, and the seat support 2 can be linked correspondingly during the tilting process of the back support 1 by the transmission rod 19; specifically, the method comprises the following steps: the transmission rod 19 is a U-shaped connecting rod, the transmission rod 19 comprises a connecting cross rod 19c, a connecting short rod 19a is longitudinally arranged at the front end of the connecting cross rod 19c, and a connecting long rod 19b is longitudinally arranged at the rear end of the connecting cross rod 19 c; under the initial position, the short connecting rod 19a and the long connecting rod 19b are both in a vertical state, the upper end of the short connecting rod 19a is hinged on the pin shaft 11, and the upper end of the long connecting rod 19b is hinged on the second rocker 8; then when the back support member 1 leans backwards to drive the link mechanism 6 to deform, the second rocker 8 will rotate forwards around the supporting longitudinal plate 3b, and then drive the transmission rod 19 to rotate forwards integrally; in the forward rotation process of the transmission rod 19, the hinge point of the connecting rod short rod 19a and the pin shaft 11 tends to move upwards and forwards, and then under the action of the transmission rod 19; the seat supporting piece 2 tends to be lifted forwards relative to the supporting transverse plate 3 a; the rotating support rod 10 correspondingly rotates forwards around the supporting transverse plate 3a, and the gear 14 slides forwards and upwards along the gear track 15; so that the seat support 2 is simultaneously lifted up and moved forward. Then when the user uses the chair to enable the chair back to lean backwards, the back support piece 1 tilts backwards, and meanwhile, the sitting support piece 2 synchronously lifts upwards and moves forwards, so that the linkage between the chair back and the chair seat is realized; the problem of the back of the chair with the back of the user produce the friction when leaning back is solved, prevent to use the problem that the back rubbing run the waist when using the seat, improve the travelling comfort of seat greatly.

Claims

1. A chair seat and chair back linkage device is characterized in that: comprises a back support piece, a seat support piece, a support frame and a transmission rod which enables the back support piece to be linked with the seat support piece when the back support piece tilts up; a connecting rod mechanism is arranged between the back support piece and the support frame, and the back support piece can tilt relative to the support frame through the connecting rod mechanism; a rotating support rod which enables the sitting support member to be capable of being lifted upwards relative to the support frame is arranged between the rear end of the sitting support member and the support frame, and two ends of the rotating support rod are respectively hinged with the sitting support member and the support frame; a sliding guide mechanism which can ensure that the front end and the rear end can keep the same motion track in the upward lifting process of the sitting support piece is correspondingly arranged between the front end of the sitting support piece and the support frame; and the seat supporting piece moves forwards while being lifted upwards; one end of the transmission rod is hinged on the back support piece or the connecting rod mechanism, and the other end of the transmission rod is hinged on the seat support piece or the rotating support rod; the back support member tilts up to drive the transmission rod to move and then drive the seat support member to synchronously lift up around the support frame.

2. The chair seat-back linkage of claim 1, wherein: the supporting frame comprises supporting transverse plates which are positioned on two sides of the sitting supporting piece and are arranged in a mirror image mode, and supporting longitudinal plates which are positioned on two sides of the back supporting piece and are arranged in a mirror image mode; the supporting longitudinal plate is connected to the rear end of the supporting transverse plate; the connecting rod mechanism is arranged between the supporting longitudinal plate and the back supporting piece; the sliding guide mechanism and the rotating support rod are arranged between the seat support piece and the support transverse plate.

3. The chair seat-back linkage assembly of claim 2, wherein: the connecting rod mechanism comprises a first rocker and a second rocker, one end of the first rocker is hinged with the back supporting piece, and the other end of the first rocker is hinged with the supporting longitudinal plate; the second rocker is positioned below the first rocker, one end of the second rocker is hinged with the back support piece, and the other end of the second rocker is hinged with the supporting longitudinal plate; a four-bar linkage is formed among the first rocker, the second rocker, the supporting longitudinal plate and the back support; the link mechanism deforms and drives the back support member to move forward downward or backward upward.

4. The chair seat-back linkage assembly of claim 3, wherein: the back support piece comprises a back support rod which is longitudinally arranged, a connecting seat is arranged at the lower end of the back support rod, and the first rocker and the second rocker are hinged on the connecting seat.

5. The chair seat-back linkage assembly of claim 2, wherein: the rear end of the seat supporting piece is provided with a pin shaft which is transversely arranged, one end of the rotating supporting rod is hinged on the pin shaft, and the other end of the rotating supporting rod is hinged on the supporting transverse plate; the rotating supporting rod is an L-shaped rod, and the hinged position of the rotating supporting rod on the supporting transverse plate is positioned in the front lower part of the pin shaft.

6. The chair seat-back linkage of claim 1, wherein: one end of the transmission rod is hinged on the connecting rod mechanism, and the other end of the transmission rod is hinged on the seat supporting piece.

7. The chair seat-back linkage assembly of claim 6, wherein: the connecting rod mechanism comprises a first rocker and a second rocker, and the first rocker is positioned above the second rocker; the rear end of the seat supporting piece is provided with a pin shaft which is transversely arranged, and the rotating support rod is hinged on the pin shaft; one end of the transmission rod is hinged on the second rocker, and the other end of the transmission rod is hinged on the pin shaft.

8. The chair seat-back linkage assembly of claim 7, wherein: the transmission rod is a U-shaped rod and comprises a connecting cross rod, the front end of the connecting cross rod is provided with a longitudinal connecting short rod, and the rear end of the connecting cross rod is provided with a longitudinal connecting long rod; the connecting short rod is hinged on the pin shaft, and the connecting long rod is hinged on the second rocker.

9. The chair seat-back linkage assembly of claim 2, wherein: the sliding guide mechanism comprises a gear and a gear track which are in sliding fit; the gear tracks are arranged on the two supporting transverse plates in a mirror image manner and extend obliquely to the front upper part; the gears are correspondingly arranged on two sides of the front end of the seat supporting piece.

10. The chair seat-back linkage assembly of claim 9, wherein: a sliding seat is arranged on the inner side of the supporting transverse plate, and the gear track is formed in the sliding seat; two sides of the front end of the seat supporting piece are provided with rotating shafts protruding outwards, and gears are connected to the rotating shafts; the gear is located in the sliding seat and is in sliding fit with the gear rail, and the gear is limited between the sliding seat and the supporting transverse plate.