CN111053386B

CN111053386B - Chair rack

Info

Publication number: CN111053386B
Application number: CN202010018830.2A
Authority: CN
Inventors: 王江林; 王郑兴; 鲍家华
Original assignee: Henglin Home Furnishings Co Ltd
Current assignee: Henglin Home Furnishings Co Ltd
Priority date: 2020-01-08
Filing date: 2020-01-08
Publication date: 2024-09-20
Anticipated expiration: 2040-01-08
Also published as: CN111053386A

Abstract

The invention discloses a chair frame, which comprises a foot, a fixed seat, a chair back frame, a chair seat frame, a first linkage frame and a second linkage frame, wherein the first linkage frame is fixedly connected with the bottom end of the chair back frame or integrally formed and rotatably arranged on the fixed seat; the second linkage frame is fixedly connected with the bottom surface of the seat frame or integrally formed and movably arranged on the fixed seat; the device also comprises a left set of first connecting rod mechanism, a right set of second connecting rod mechanism, a left set of second limiting long holes, a right set of second limiting long holes, at least one second linkage rod and an electric push rod; through this technical scheme can make the back of the chair frame backward topple over, and the seat frame upwards moves backward, and corresponding, at the in-process that the back of the chair frame was raised, the seat frame is forward down moved, and back of the chair frame bottom and seat frame rear portion keep the distance unchanged always, just so reached "zero displacement" effect, avoided the back of the body phenomenon of rubbing with the back of the chair promptly.

Description

Chair rack

Technical Field

The invention relates to the technical field of furniture, in particular to a chair frame.

Background

The comfort level of the chair is directly related to the quality of work and life of people. More and more enterprises are researching seat back linkage mechanisms to realize self-adaptive functions and improve the comfort level of seats.

The seat back linkage mechanism used by the existing seats in the market has a complex structure, high production and processing difficulty and high cost; as disclosed in chinese patent document CN104223821B, a swivel chair chassis is disclosed, wherein the chassis comprises a four-bar mechanism formed by a plurality of links, a bracket and a base, and when a rocker connected with a backrest rotates, the bracket connected with a seat moves upward and backward as a whole, and according to the weight of a human body, the tilting restoring force of the backrest is correspondingly matched, so that a person with light weight or heavy weight can easily tilt and restore to get up; the chassis mechanism is mainly suitable for office chairs; for leisure chairs, a large-angle backward leaning rest is usually needed, so that the front end of the chair seat can be tilted, and a seat back linkage mechanism which is simple in structure and easy to process and manufacture is needed to be researched to meet the market demands.

Accordingly, chinese patent publication No. CN109984499a discloses a seat back synchronization linkage and a seat, including a base for connecting an air bar, a bracket for connecting a seat, and a rocker for connecting a backrest; the base, the bracket and the wane are connected through a first connecting rod, a second connecting rod and a third connecting rod to form a four-bar mechanism; the two sides of the lower end of the seesaw extend forwards to form side plates, one end of the first connecting rod is hinged with the rear parts of the base and the bracket at the same time, and the other end of the first connecting rod is hinged with the lower end of the seesaw; one end of the third connecting rod is hinged with the front end of the base, and the other end of the third connecting rod is hinged with the front end of the side plate; one end of the second connecting rod is hinged with the bracket, and the other end of the second connecting rod is hinged with the middle part of the third connecting rod. When the rocker is driven to send and rotate by force, the front end of the bracket is driven to tilt under the action of the first connecting rod, the second connecting rod and the third connecting rod. The invention is assembled by adopting simple connecting rods, has simple structure, simple process and high stability, and greatly reduces the production cost.

However, when the backrest is at a relatively large reclining angle, the angle between the seat back and the horizontal plane is also relatively large, so that the force of the human body on the chair is concentrated on the backrest, resulting in the following problems:

1) The gravity centers of the human body and the chair are moved backwards, and the chair is easy to tilt backwards;

2) The backrest can bear larger acting force, so that the material and the structural stability of the backrest are required to be improved, and the production cost is increased;

3) Correspondingly, the chair mainly provides supporting force for the back of the human body through the backrest, and the back of the chair only has the function of fixing the position of the back of the chair to the buttocks of the human body, and does not accord with the stress condition of the human body when the human body is normally lying down, so that the human body is not in a comfortable state on the whole, and the human body is tired after lying on the back for a long time.

Disclosure of Invention

In order to solve the above-mentioned problems, an object of the present invention is to provide a chair frame in which a chair seat frame and a chair back frame are in back-to-back linkage, and the chair seat frame is not rotated backward or is rotated backward only by a small angle when the chair back frame is at a relatively large reclining angle.

In order to achieve the above object, the present invention adopts the following technical scheme:

The chair frame comprises a foot, a fixed seat, a chair back frame, a chair seat frame, a first linkage frame and a second linkage frame, wherein the fixed seat is fixedly connected with the foot, and the first linkage frame is fixedly connected with the bottom end of the chair back frame or integrally formed and rotatably arranged on the fixed seat; the second linkage frame is fixedly connected with the bottom surface of the seat frame or integrally formed and movably arranged on the fixed seat; further comprises:

The left and right sets of first link mechanisms are arranged on the fixed seat, the first link frame and the second link frame and comprise a first link, a second link and a third link which are sequentially hinged, the top end of the first link is rotatably arranged on the first link frame, the second link is inverted V-shaped and is rotatably arranged on the side surface of the fixed seat by taking the corner as the rotation center, and the top end of the third link is rotatably arranged on the side surface of the second link frame;

The left and right sets of second link mechanisms are arranged on the fixed seat and the second linkage frame and comprise a fifth link, a sixth link and a seventh link, the fifth link and the sixth link are rotatably arranged on the side surface of the fixed seat, the bottom end of the fifth link is hinged with one end of the seventh link, the bottom end of the sixth link is hinged with the middle section of the seventh link, and the other end of the seventh link is hinged with the side surface of the second linkage frame;

The left and right second limiting long holes are formed in the middle of the bottom of the first limiting long hole, and the top ends of the second limiting long holes are positioned behind the bottom ends of the second limiting long holes;

the second linkage rod is inserted into the second limiting long hole and is in clearance fit with the second limiting long hole;

the front end of the electric push rod is rotatably arranged on the fixed seat, and the other end of the electric push rod is rotatably arranged on the first linkage frame;

when the two second limiting long holes are symmetrically arranged on the two side faces of the fixed seat respectively, the second linkage rod is fixedly connected with the second linkage frame;

When the two second limiting long holes are symmetrically arranged on the two side faces of the second linkage frame respectively, the second linkage rod is fixedly connected with the fixed seat.

Preferably, the method further comprises:

The left and right arc-shaped concave first limiting long holes are positioned on the side surface of the fixed seat or the side surface of the second linkage frame;

At least two parallel first linkage rods, wherein the first linkage rods are inserted into the first limiting long holes and are in clearance fit with the first limiting long holes;

When the two first limiting long holes are symmetrically arranged on the two side surfaces of the fixed seat respectively, two ends of the two first linkage rods are fixedly connected with the two side surfaces of the first linkage frame respectively, and when the two first limiting long holes are symmetrically arranged on the two side surfaces of the first linkage frame respectively, the two first linkage rods are fixedly connected with the two side surfaces of the fixed seat.

Preferably, a horizontal first pipe is fixed at the front end of the fixing seat, a horizontal second pipe is fixed on the first linkage frame, two parallel vertical first mounting plates and two parallel vertical second mounting plates are further arranged, the bottom end of each first mounting plate is connected with the first pipe in a clamping mode, the top end of each first mounting plate is hinged to the front end of the corresponding electric push rod, and the top end of each second mounting plate is connected with the corresponding second pipe in a clamping mode, and the bottom end of each second mounting plate is hinged to the rear end of the corresponding electric push rod.

Preferably, the second limiting long hole is linear, and the top end of the second limiting long hole faces to the rear; the included angle between the second limiting long hole and the horizontal plane is 30-60 degrees.

Preferably, the second limiting long hole is in an arc shape, and the top end of the second limiting long hole is positioned behind the bottom end of the second limiting long hole; and the included angle between the straight line passing through the top end of the second limiting long hole and the bottom end of the second limiting long hole and the horizontal plane is 30-60 degrees.

Preferably, when the seat frame is at the lowest point, the top end of the sixth link is located forward of the bottom end of the sixth link, and the top end of the fifth link is located rearward of the bottom end of the fifth link.

Preferably, the first link mechanism further comprises an elastic member, wherein the top end of the elastic member is connected with the hinge member, the bottom end of the elastic member is connected with the fixing seat, the bottom end of the elastic member is located in front of the top end of the elastic member, and when the seat frame is at the lowest point, the elastic member is in a stretched state.

Further preferably, the first link includes at least a concave arcuate bend.

Preferably, the chair is further provided with a left hinge piece and a right hinge piece, the hinge pieces are fixedly connected with the chair seat frame or the second linkage frame, and the hinge pieces are hinged with the top ends of the third connecting rods.

Preferably, the back frame is rotatable through an angle in the range of 0 ° -60 °.

The invention has the technical effects that:

1) When the chair back frame is inclined backwards, the chair seat frame moves upwards and backwards, the distance between the bottom of the chair back frame and the rear part of the chair seat frame is kept unchanged all the time in the falling process of the chair back frame, and correspondingly, when the chair back frame is lifted, the chair seat frame moves forwards and downwards, the distance between the bottom of the chair back frame and the rear part of the chair seat frame is kept unchanged in the lifting process of the chair back frame, so that the zero displacement effect is achieved, namely, the back rubbing phenomenon of the back of a human body and the chair back is avoided, and further, the lying down and the rising of people are assisted through the electric push rod.

2) The lifting of the chair seat frame is controlled through the second connecting rod mechanism, the second linkage rod and the second limit groove, so that the rear half part of the chair seat frame reciprocates along the second limit long hole in the lifting process, the operation is stable and reliable, the rotation angle of the chair seat frame in the lifting process is small and even not rotating, when the chair back frame is at a relatively large back angle, the included angle between the chair seat frame and the horizontal plane still has a small difference from an initial state, the supporting force of the chair to the human body still concentrates on the buttocks of the human body, the stress condition of the human body when the human body normally lies down is met, the human body is in a comfortable state, the distance between the chair and the gravity center of the human body is reduced, and the stability of the chair is further improved.

Drawings

FIG. 1 is a schematic view of a chair frame according to an embodiment of the present invention;

FIG. 2 is a schematic view of a chair frame according to an embodiment of the present invention;

FIG. 3 is a schematic view of a chair frame according to an embodiment of the present invention (feet, chair frame, second linkage frame, and electric putter are omitted);

Fig. 4 is a schematic view of a chair frame according to an embodiment of the present invention (feet, chair seat and chair back frame are omitted).

Reference numerals illustrate: 1. a footing; 2. a fixing seat; 3. a chair back frame; 4. a chair seat frame; 5. a first linkage frame; 6. a second linkage frame; 7. a first limiting long hole; 8. a first linkage rod; 9. a second limiting slot; 10. a second linkage rod; 11. an electric push rod; 12. a first link; 13. a second link; 14. a third link; 15. a hinge; 17. a fifth link; 18. a sixth link; 19. a seventh link; 20. a first tube; 21. a second tube; 22. a first mounting plate; 23. and a second mounting plate.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more, unless otherwise clearly defined.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

Embodiment one:

As shown in fig. 1-4, a chair frame comprises a foot 1, a fixed seat 2, a chair back frame 3, a chair seat frame 4, a first linkage frame 5 and a second linkage frame 6, wherein the fixed seat 2 is fixedly connected with the foot 1, and the first linkage frame 5 is fixedly connected with the bottom end of the chair back frame 3 or integrally formed and rotatably arranged on the fixed seat 2; the second linkage frame 6 is fixedly connected with the bottom surface of the chair seat frame 4 or integrally formed and movably arranged on the fixed seat 2; further comprises:

The left and right sets of first connecting rod 12 mechanisms are arranged on the fixed seat 2, the first linkage frame 5 and the second linkage frame 6 and comprise a first connecting rod 12, a second connecting rod 13 and a third connecting rod 14 which are sequentially hinged, the top end of the first connecting rod 12 is rotatably arranged on the first linkage frame 5, the second connecting rod 13 is inverted V-shaped and is rotatably arranged on the side surface of the fixed seat 2 by taking a corner as a rotation center, and the top end of the third connecting rod 14 is rotatably arranged on the side surface of the second linkage frame 6;

The left and right sets of second connecting rod 13 mechanisms are arranged on the fixed seat 2 and the second linkage frame 6 and comprise a fifth connecting rod 17, a sixth connecting rod 18 and a seventh connecting rod 19, wherein the fifth connecting rod 17 and the sixth connecting rod 18 are rotatably arranged on the side surface of the fixed seat 2, the bottom end of the fifth connecting rod 17 is hinged with one end of the seventh connecting rod 19, the bottom end of the sixth connecting rod 18 is hinged with the middle section of the seventh connecting rod 19, and the other end of the seventh connecting rod 19 is hinged with the side surface of the second linkage frame 6;

The left and right second limiting long holes 9, the top ends of the second limiting long holes 9 are positioned behind the bottom ends of the second limiting long holes 9;

At least one second linkage rod 10, wherein the second linkage rod 10 is inserted into the second limiting long hole 9 and is in clearance fit with the second limiting long hole 9;

the front end of the electric push rod 11 is rotatably arranged on the fixed seat 2, and the other end of the electric push rod is rotatably arranged on the first linkage frame 5.

When the two second limiting long holes 9 are symmetrically arranged on the two side surfaces of the fixed seat 2 respectively, the second linkage rod 10 is fixedly connected with the second linkage frame 6;

when the two second limiting long holes 9 are symmetrically arranged on the two side surfaces of the second linkage frame 6 respectively, the second linkage rod 10 is fixedly connected with the fixed seat 2.

In the embodiment of the application, the method further comprises the following steps:

The left and right arc-shaped concave first limiting long holes 7, and the first limiting long holes 7 are positioned on the side surface of the fixed seat 2 or the side surface of the second linkage frame 6;

At least two parallel first linkage rods 8, wherein the first linkage rods 8 are inserted into the first limiting long holes 7 and are in clearance fit with the first limiting long holes 7;

When the two first limiting long holes 7 are symmetrically arranged on the two side surfaces of the fixed seat 2, two ends of the two first linkage rods 8 are fixedly connected with the two side surfaces of the first linkage frame 5 respectively, and when the two first limiting long holes 7 are symmetrically arranged on the two side surfaces of the first linkage frame 5 respectively, the two first linkage rods 8 are fixedly connected with the two side surfaces of the fixed seat 2.

In the embodiment of the present application, a horizontal first pipe 20 is fixed at the front end of the fixed seat 2, the first pipe 20 is a square pipe, a horizontal second pipe 21 is fixed on the first linkage frame 5, the second pipe 21 is a square pipe, two parallel vertical first mounting plates 22 and two parallel vertical second mounting plates 23 are further provided, the bottom ends of the first mounting plates 22 are fixedly connected with the first pipe 20, such as welding, and the top ends are hinged with the front end of the electric push rod 11, and the top ends of the second mounting plates 23 are fixedly connected with the second pipe 21, such as welding, and the bottom ends are hinged with the rear end of the electric push rod 11. Further preferably, the bottom end of the first mounting plate 22 is provided with a first rectangular notch, the first rectangular notch is fixed with the front side (rear side) and the upper surface of the first tube 20 by welding, the top end of the second mounting plate 23 is provided with a second rectangular notch, the second rectangular notch is fixed with the rear side (front side), the upper surface and the lower surface of the second tube 21 by welding, and then under the combined action of the first tube 20, the first mounting plate 22, the second tube 21, the second mounting plate 23 and the electric push rod 11, the electric push rod 11 is rotatably mounted on the chair frame; and the structure is stable, and the installation and the disassembly are convenient.

In the embodiment of the application, a left hinge member and a right hinge member 15 are further arranged, the hinge members 15 are fixedly connected with the seat frame 4 or the second linkage frame 6, and the hinge members 15 are hinged with the top end of the third connecting rod 14.

The seat back frame 3 is stably and rotatably arranged on the fixed seat 2 through the part, connected with the first connecting rod 12, of the second connecting rod 13, the first connecting rod 12, the first limiting long hole 7, the first linkage frame 5 and the linkage rod; the rotatable angle range of the chair back frame 3 is 0-60 degrees through the first limiting long hole 7;

The power for lifting or lowering the seat frame 4 is given to the seat frame 4 through the part of the second connecting rod 13 connected with the third connecting rod 14, the third connecting rod 14 and the hinge 15, and the moving track of the seat frame 4 is not restrained; so that the seat frame 4 can be lifted up and down along the second limiting long hole 9.

In the embodiment of the application, the second limiting long hole 9 is linear, and the top end of the second limiting long hole 9 faces to the rear; the included angle between the second limiting long hole 9 and the horizontal plane is 30-60 degrees, and more preferably, the included angle between the second limiting long hole 9 and the horizontal plane is 40-50 degrees.

It should be noted that the second limiting long hole 9 may also be an arc shape, and the top end of the second limiting long hole 9 is located at the rear of the bottom end of the second limiting long hole 9; and the included angle between the straight line passing through the top end of the second limiting long hole 9 and the bottom end of the second limiting long hole 9 and the horizontal plane is 30-60 degrees, and further preferably, the included angle between the straight line and the horizontal plane is 40-50 degrees.

In the embodiment of the application, during the ascending process of the seat frame 4, the ascending height of the end, hinged with the second linkage frame 6, of the seventh connecting rod 19 is larger than the descending height of the end, hinged with the second linkage frame 6, of the seventh connecting rod 19; further preferably, during the lifting of the seat frame 4, the end of the seventh link 19 hinged to the second linkage frame 6 is rotated upwards; that is, by adjusting the positions and sizes of the fifth link 17 and the sixth link 18, the movement trace of the end of the seven links hinged to the second link frame 6 can be adjusted.

In the embodiment of the present application, when the seat frame 4 is at the lowest point, the top end of the sixth link 18 is located forward of the bottom end of the sixth link 18, and the top end of the fifth link 17 is located rearward of the bottom end of the fifth link 17.

Further preferably, the first link 12 mechanism further includes an elastic member, wherein the top end of the elastic member is connected to the hinge 15, and the bottom end of the elastic member is connected to the fixed seat 2, and the bottom end of the elastic member is located in front of the top end of the elastic member, and when the seat frame 4 is at the lowest point, the elastic member is in a stretched state; further preferably, the elastic member is a spring, and the seat frame 4 is moved more smoothly by providing the spring.

Further preferably, the first link 12 includes at least a concave arcuate bend; in the linkage movement process of the chair back frame 3 and the chair seat frame 4, the first connecting rod 12 is a stress rod, and the structural strength of the first connecting rod 12 can be improved by arranging a concave arc-shaped bending part.

In the embodiment of the present application, the chair back frame 3 includes an upwardly convex arc-shaped bent portion, which is located at the middle section of the chair back frame 3; the arrangement accords with the back curve of the human body, and the upward-protruding arc-shaped bending part forms effective support for the waist of the human body, thereby being beneficial to slowing down the fatigue degree of the human body.

In the embodiment of the application, a telescopic rod is further arranged, the bottom end of the telescopic rod is fixedly connected with the foot 1, and the fixing seat 2 is fixed at the top end of the telescopic rod.

The specific movement process of the chair frame is as follows:

when the electric push rod 11 stretches, the first linkage rod 8 is driven to move from the front end to the rear end of the first limiting long hole 7, so that the chair back frame 3 rotates upwards, meanwhile, the first connecting rod 12 moves backwards, the second connecting rod 13 is pulled to rotate and the third connecting rod 14 is pulled to rotate, the third connecting rod 14 moves downwards in the rotating process, and the chair seat frame 4 is driven to move downwards;

In the process of downward movement of the seat frame 4, the seat frame 4 descends and moves forward along the second limiting long hole 9 under the combined action of the second connecting rod 13 mechanism, the second linkage rod 10 and the second limiting long hole 9;

When the electric push rod 11 is shortened, the first linkage rod 8 is driven to move from the rear end of the first limiting long hole 7 to the front end, so that the chair back frame 3 rotates downwards, meanwhile, the first connecting rod 12 moves forwards, the second connecting rod 13 is pushed to rotate and the third connecting rod 14 is pushed to rotate, the third connecting rod 14 rises in the rotating process, and the chair seat frame 4 is driven to rise;

During the lifting of the seat frame 4, the seat frame 4 can only lift and move backwards along the second limiting long hole 9 by the combined action of the second connecting rod 13 mechanism, the second linkage rod 10 and the second limiting long hole 9.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives, and variations may be made in the above embodiments by those skilled in the art without departing from the spirit and principles of the invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a chair frame, includes footing (1), fixing base (2), back of the chair frame (3), chair seat frame (4), first linkage frame (5) and second linkage frame (6), and wherein, fixing base (2) are installed on footing (1), and first linkage frame (5) and back of the chair frame (3) bottom fixed connection or integrated into one piece and rotatable install on fixing base (2); the second linkage frame (6) is fixedly connected with the bottom surface of the chair seat frame (4) or integrally formed and movably arranged on the fixed seat (2); characterized by further comprising:

The left and right sets of first link mechanisms are arranged on the fixed seat (2), the first link frame (5) and the second link frame (6) and comprise a first link (12), a second link (13) and a third link (14) which are hinged in sequence, the top end of the first link (12) is rotatably arranged on the first link frame (5), the second link (13) is inverted V-shaped and is rotatably arranged on the side surface of the fixed seat (2) by taking a corner as a rotation center, and the top end of the third link (14) is rotatably arranged on the side surface of the second link frame (6);

The left and right sets of second link mechanisms are arranged on the fixed seat (2) and the second linkage frame (6) and comprise a fifth link (17), a sixth link (18) and a seventh link (19), the fifth link (17) and the sixth link (18) are rotatably arranged on the side surface of the fixed seat (2), the bottom end of the fifth link (17) is hinged with one end of the seventh link (19), the bottom end of the sixth link (18) is hinged with the middle section of the seventh link (19), and the other end of the seventh link (19) is hinged with the side surface of the second linkage frame (6);

the left and right second limiting long holes (9), the top ends of the second limiting long holes (9) are positioned behind the bottom ends of the second limiting long holes (9);

At least one second linkage rod (10), wherein the second linkage rod (10) is inserted into the second limiting long hole (9) and is in clearance fit with the second limiting long hole (9);

the front end of the electric push rod (11) is rotatably arranged on the fixed seat (2), and the other end of the electric push rod is rotatably arranged on the first linkage frame (5);

when the two second limiting long holes (9) are symmetrically arranged on the two side surfaces of the fixed seat (2), the second linkage rod (10) is fixedly connected with the second linkage frame (6);

When the two second limiting long holes (9) are symmetrically arranged on the two side surfaces of the second linkage frame (6), the second linkage rod (10) is fixedly connected with the fixed seat (2);

The device is also provided with:

the left and right arc-shaped concave first limiting long holes (7), and the first limiting long holes (7) are positioned on the side surface of the fixed seat (2) or the side surface of the second linkage frame (6);

At least two parallel first linkage rods (8), wherein the first linkage rods (8) are inserted into the first limiting long holes (7) and are in clearance fit with the first limiting long holes (7);

When the two first limiting long holes (7) are symmetrically arranged on the two side surfaces of the fixed seat (2), the two ends of the two first linkage rods (8) are fixedly connected with the two side surfaces of the first linkage frame (5), and when the two first limiting long holes (7) are symmetrically arranged on the two side surfaces of the first linkage frame (5), the two first linkage rods (8) are fixedly connected with the two side surfaces of the fixed seat (2);

the front end of the fixed seat (2) is fixedly provided with a horizontal first pipe (20), the first linkage frame (5) is fixedly provided with a horizontal second pipe (21), the fixed seat is also provided with a first mounting plate (22) and a second mounting plate (23), the bottom end of the first mounting plate (22) is fixedly connected with the first pipe (20) and the top end of the first mounting plate is hinged with the front end of the electric push rod (11), and the top end of the second mounting plate (23) is fixedly connected with the second pipe (21) and the bottom end of the second mounting plate is hinged with the rear end of the electric push rod (11);

The two hinges (15) are arranged at the left and right sides, the hinges (15) are fixedly connected with the chair seat frame (4) or the second linkage frame (6), and the hinges (15) are hinged with the top end of the third connecting rod (14).

2. A chair frame according to claim 1, characterized in that the second limiting slot (9) is rectilinear, the top end of the second limiting slot (9) being directed backwards.

3. A chair frame according to claim 1, characterized in that the second limiting slot (9) is of an arc-shaped form, and the top end of the second limiting slot (9) is located behind the bottom end of the second limiting slot (9).

4. A chair frame according to claim 1, characterized in that the top end of the sixth link (18) is located in front of the bottom end of the sixth link (18) and the top end of the fifth link (17) is located behind the bottom end of the fifth link (17) when the chair frame (4) is at its lowest point.

5. A chair frame according to claim 1, characterized in that the first link mechanism further comprises an elastic member, the top end of which is connected to the hinge member (15) and the bottom end is connected to the fixed seat (2), the bottom end of which is located in front of the top end of the elastic member, which is in a stretched state when the chair frame (4) is at the lowest point.

6. A chair frame according to claim 1, characterized in that the first link (12) comprises at least a concave arcuate bend.

7. A chair frame according to claim 1, characterized in that the back frame (3) is rotatable through an angle in the range of 0 ° -60 °.