CN111096594B - Chair and footrest assembly thereof - Google Patents

Abstract

The invention discloses a chair and a footrest assembly thereof, the footrest assembly comprises a fixed seat, a chair seat frame arranged on the fixed seat, and a second driving mechanism arranged on the fixed seat and the chair seat frame, the second driving mechanism comprises a second electric push rod, a second linkage rod, a third linkage rod mechanism, a linkage assembly and a left set of second linkage rod mechanism and a right set of second linkage rod mechanism, wherein the second linkage rod mechanism acts on the lifting and the lowering of the footrest assembly, the third linkage rod mechanism is used for the extension and the shortening of the footrest assembly, the linkage assembly enables the footrest assembly to be shortened in the extension and the lowering of the footrest assembly in the lifting process, the footrest assembly is simple in structure, and the footrest assembly can be completely attached to the bottom of the chair frame when not lifted, so that the chair is simple, elegant and attractive.

Description

Chair and footrest assembly thereof

Technical Field

The invention relates to the technical field of furniture, in particular to a chair and a footrest assembly thereof.

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;

4) The legs of the human body still are in a bending state and cannot be unfolded, so that the human body cannot be relaxed in whole body and mind.

In order to solve the fourth technical problem, chinese patent document with publication No. CN109645726a discloses an electric coupling mechanism for a backrest footrest, comprising: the seat frame, the backrest, the foot rest assembly and the swing rod assembly are used for realizing a rotary swing mechanism of extending the foot rest assembly forwards and tilting the backrest backwards, the swing rod assembly is arranged below the seat frame, and a notch swing disc is arranged on the swing rod assembly; the foot rest connecting rod assembly is connected with the foot rest assembly and the seat frame respectively and used for realizing telescopic folding of the foot rest assembly; the foot rest connecting rod assembly is connected with a notch hinge; the backrest connecting rod assembly is respectively connected with the backrest and the swing rod assembly and is used for realizing tilting of the backrest; the driving piece is respectively connected with the swing rod assembly and the foot rest assembly and drives the swing rod assembly and the foot rest assembly to move relatively; the rolling assembly is matched with a notch swing disc on the swing rod assembly and a notch hinge on the foot rest connecting rod assembly to realize the forward extension and backward shrinkage of the foot rest assembly and the backward tilting and forward tilting of the backrest. This electronic disjunctor mechanism of back bracket can realize the lift of process of leaning on and bracket through a motor, and the duty cycle is few, and stability is good.

However, those skilled in the art have found that this chair has the following drawbacks during use:

1) The habit actions of people for lying down and getting up are not met; when the user needs to lie down, the chair is characterized in that the footrest is lifted firstly and then the chair back falls down, and when the user needs to lie down, the chair is characterized in that the chair back rises firstly and then the footrest falls down, and the movement process is opposite to the habit of people lying down and getting up;

2) The base in the chair is often a material with higher strength as the main stress piece, while other non-main stress pieces are often material with general strength for reducing the cost, but in the application, the base is except the base due to the motion mechanism; the foot rest component is also a main stress piece; therefore, the leg rest assembly also requires a stronger piece of material, which increases costs;

3) The foot rest assembly has a plurality of parts for lifting and descending and has a complex structure.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a chair and a footrest assembly thereof, wherein the footrest assembly has a simple structure and can be completely attached to the bottom of a chair frame when not lifted, so that the chair is simple, elegant and beautiful; and in the lifting process, the leg part of the human body can be completely placed on the footrest by gradually stretching, so that the comfort level of the human body is improved.

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

a footrest assembly comprising a fixed seat, a seat frame mounted on the fixed seat, a footrest assembly rotatably mounted on the seat frame, and a second drive mechanism mounted on the fixed seat, seat frame and footrest assembly for driving the footrest assembly to rotate to raise or lower and to extend or shorten the footrest assembly, the second drive mechanism comprising:

the left and right sets of second link mechanisms are arranged on the chair seat frame and the footrest assembly;

a third linkage mounted on the footrest assembly;

the end A of the linkage assembly is rotatably arranged on the seat frame, and the end B of the linkage assembly is in transmission connection with the third link mechanism;

the second linkage rod is fixedly connected with the second link mechanism or integrally formed;

The rear end of the second electric push rod is hinged with the seat frame, and the front end of the second electric push rod is hinged with the second linkage rod;

When the second electric push rod extends, the footrest assembly is lifted up through the second connecting rod mechanism, and in the process of lifting up the footrest assembly, the third connecting rod mechanism is driven to operate through the linkage assembly at the same time so that the footrest assembly extends; when the second electric push rod is shortened, the footrest assembly is put down through the second connecting rod mechanism, and in the process of putting down the footrest assembly, the third connecting rod mechanism is driven to operate through the linkage assembly simultaneously so that the footrest assembly is shortened.

Preferably, the chair is further provided with a first rotating shaft and second rotating shafts symmetrically fixed on the left side and the right side of the chair seat frame, the second rotating shafts are horizontally arranged, the footrest component is mounted on the chair seat frame through the second rotating shafts and rotates by taking the second rotating shafts as rotating central shafts, the first rotating shafts are fixedly connected with the chair seat frame, the included angle between the first rotating shafts and the horizontal plane is not more than 30 degrees, the A end of the linkage component is rotatably mounted on the first rotating shafts, and the A end of the linkage component is always located behind the second rotating shafts in the rotating process.

Preferably, the footrest assembly comprises a first footrest rotatably mounted on the seat frame and a second footrest slidably mounted on the first footrest;

The third link mechanism comprises an eighth link and a ninth link, the eighth link is rotatably mounted on the first footrest, the rear end of the eighth link is in transmission connection with the B end of the linkage assembly, the front end of the eighth link is hinged with the rear end of the ninth link, and the front end of the ninth link is rotatably mounted on the second footrest.

More preferably, the distance between the eighth link front end and the eighth link rotation center is greater than the distance between the eighth link rear end and the eighth link rotation center.

More preferably, a vertical third rotating shaft is further provided, and one end of the eighth connecting rod is mounted on the third rotating shaft; the novel clutch is characterized by further comprising a first ball body and a second ball body, wherein the first ball body is rotatably arranged on the first rotating shaft, the second ball body is rotatably arranged on the third rotating shaft, the end A of the linkage assembly is rotatably arranged on the outer surface of the first ball body, and the end B of the linkage assembly is rotatably arranged on the outer surface of the second ball body.

More preferably, the linkage assembly comprises a connecting rod and two linkage members rotatably sleeved at two ends of the connecting rod, wherein each linkage member comprises an integrally formed or fixedly connected ring body and a cylinder, the cylinder is provided with a connecting hole for the connecting rod to be inserted, and the ring bodies of the two linkage members are rotatably sleeved on the first sphere and the second sphere respectively.

More preferably, the first rotation axis is parallel to and behind the second rotation axis.

Preferably, the second link mechanism comprises a fifth link and a sixth link, the fifth link is rotatably mounted on the side surface of the seat frame, one end of the fifth link is hinged with one end of the sixth link, and the other end of the sixth link is rotatably mounted on the side surface of the footrest assembly; the two ends of the second linkage rod are fixedly connected with the left fifth connecting rod and the right fifth connecting rod or integrally formed.

More preferably, a concave arc-shaped bending part is arranged on the part, close to the footrest assembly, of the sixth connecting rod.

Preferably, two parallel vertical third mounting plates and two parallel vertical fourth mounting plates are further arranged, the second linkage rod is a square tube, the bottom end of the third mounting plate is connected with the third linkage rod in a clamping mode, the top end of the third mounting plate is hinged to the front end of the second electric push rod, the top end of the fourth mounting plate is fixedly connected with the seat frame, and the bottom end of the fourth mounting plate is hinged to the rear end of the second electric push rod.

A chair comprising a footrest assembly as described above.

The invention has the technical effects that:

1) When the second electric putter stretches, drive the fifth connecting rod and rotate and then make the sixth connecting rod rotate and move forward to drive first footrest and linkage subassembly simultaneously and rotate, at the rotation in-process, linkage subassembly's rotatory center pin is located first footrest rotatory center pin's rear all the time, the linkage subassembly is eccentric rotation for first footrest promptly, and the displacement difference that then produces is used for pulling eighth connecting rod and rotates, drive the ninth connecting rod simultaneously and rotate, make the second footrest roll-off for first footrest, when the second electric putter shortens, make the footrest subassembly put down and footrest subassembly shorten.

2) The footrest assembly is simple in structure and can be completely attached to the bottom of the chair frame when not lifted, so that the chair is concise, elegant and attractive.

Drawings

FIG. 1 is a schematic view of a chair according to an embodiment of the present invention (footrest assembly in lowered condition);

FIG. 2 is a schematic diagram of a first chair according to an embodiment of the present invention (the footrest assembly is in the lowered position and the feet and back rest are omitted);

FIG. 3 is a schematic view of a third embodiment of a chair according to the present invention (the footrest assembly in the lowered position and with the feet and back rest omitted);

FIG. 4 is a schematic view of a chair according to an embodiment of the present invention (footrest assembly in raised position);

FIG. 5 is a schematic view of a chair according to an embodiment of the present invention (footrest assembly in raised position);

FIG. 6 is an enlarged view of a portion of FIG. 5 in accordance with the present invention;

FIG. 7 is an exploded view of a linkage assembly mounting structure according to an embodiment of the present invention;

FIG. 8 is a schematic view of a third chair according to an embodiment of the present invention;

Fig. 9 is a second schematic structural view of a chair according to a third embodiment of the present invention (the feet and the back frame are omitted).

Reference numerals illustrate: 11. a footing; 12. a fixing seat; 13. a chair back frame; 14. a chair seat frame; 15. a footrest assembly; 16. a first linkage frame; 17. a second linkage frame; 18. a first electric push rod; 19. a first linkage rod; 20. a second electric push rod; 21. a second linkage rod; 22. a first link mechanism; 23. a fourth link mechanism; 24. a third link mechanism; 25. a linkage assembly; 26. a second link mechanism; 27. a first limiting long hole; 221. a first link; 222. a second link; 223. a third link; 28. a first mounting plate; 29. a fifth mounting plate; 30. a sixth mounting plate; 31. a second limiting slot; 32. a third linkage rod; 231. a fourth link; 261. a fifth link; 262. a sixth link; 33. a third mounting plate; 34. a fourth mounting plate; 151. a first footrest; 152. a second footrest; 241. an eighth link; 242. a ninth link; 35. a first rotation shaft; 36. a third rotation shaft; 37. a second rotation shaft; 38. a first sphere; 39. a second sphere; 251. a connecting rod; 252. a linkage member; 40. and (3) a spring.

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.

Example 1

1-5, A chair comprises a foot 11, a fixed seat 12, a chair back frame 13, a chair seat frame 14, a footrest assembly 15, a first linkage frame 16 and a second linkage frame 17, wherein the fixed seat 12 is fixedly connected with the foot 11, and the first linkage frame 16 is fixedly connected with the bottom end of the chair back frame 13 or integrally formed and rotatably arranged on the fixed seat 12; the second linkage frame 17 is fixedly connected with the bottom surface of the chair seat frame 14 or integrally formed and movably mounted on the fixed seat 12; the footrest assembly 15 is rotatably mounted on the second linkage frame 17 or the seat frame 14 and further includes:

The first driving mechanism comprises a first electric push rod 18, a first linkage rod 19, a left and a right sets of first linkage rod mechanisms 22 and a left and a right fourth linkage rod mechanisms 23, wherein the first linkage rod mechanisms 22 are arranged on the fixed seat 12, the first linkage frame 16 and the second linkage frame 17, the fourth linkage rod mechanisms 23 are arranged on the second linkage frame 17 and the fixed seat 12, two ends of the first linkage rod 19 are fixedly connected with or integrally formed with the rear half section of the first linkage rod mechanism 22, the front end of the first electric push rod 18 is hinged with the fixed seat 12, and the rear end of the first electric push rod 18 is hinged with the first linkage rod 19, so that when the first electric push rod 18 extends, the seat frame 13 is driven to rotate upwards and simultaneously drive the seat frame 14 to move forwards and downwards through the first linkage rod mechanisms 22 and the fourth linkage rod mechanisms 23, and when the first electric push rod 18 contracts, the seat frame 14 is driven to rotate downwards and simultaneously drive the seat frame 14 to move backwards and upwards through the first linkage rod mechanisms 23;

The second driving mechanism comprises a second electric push rod 20, a second linkage rod 21, a third linkage rod mechanism 24, a linkage assembly 25 and a left set and a right set of second linkage rod mechanisms 26, wherein the second linkage rod mechanisms 26 are arranged on the second linkage frame 17 and the footrest assembly 15, the third linkage rod mechanisms 24 are arranged on the footrest assembly 15, the linkage assembly 25 is rotatably arranged on the seat frame 14 and is connected with the third linkage rod mechanisms 24, the second linkage rod 21 is fixedly connected with the second linkage rod mechanisms 26 or integrally formed, the rear end of the second electric push rod 20 is hinged with the second linkage frame 17, the front end of the second electric push rod 20 is hinged with the second linkage rod 21, and when the second electric push rod 20 extends, the footrest assembly 15 is lifted through the second linkage rod mechanisms 26, and in the process of lifting the footrest assembly 15, the third linkage rod mechanisms 24 are simultaneously driven to operate through the linkage assembly 25 so as to extend the footrest assembly 15; when the second electric push rod 20 is shortened, the footrest assembly 15 is put down through the second link mechanism 26, and in the process of putting down the footrest assembly 15, the third link mechanism 24 is simultaneously driven to operate through the linkage assembly 25 so as to shorten the footrest assembly 15.

In the embodiment of the application, a left arc-shaped concave first limiting long hole 27 and a right arc-shaped concave first limiting long hole 27 are further arranged, the first limiting long hole 27 can be positioned on the side surface of the fixed seat 12 and the side surface of the second linkage frame 17, the two sides of the first linkage frame 16 are hinged with the fixed seat 12, so that the back frame 13 rotates by taking a straight line passing through two hinged points of the first linkage frame 16 and the fixed seat 12 as a rotation central shaft, and the rotatable angle range of the back frame 13 is 0-60 degrees through the first limiting long hole 27; further preferably, the back frame 13 is rotatable in an angle range of 0 degrees to 45 degrees.

As shown in fig. 2 and 3, the first link mechanism 22 includes a first link 221, a second link 222 and a third link 223 hinged in sequence, the top end of the first link 221 is rotatably mounted on the first link frame 16, the second link 222 is inverted V-shaped and is rotatably mounted on the side of the fixed seat 12 with the corner as the center of rotation, and the top end of the third link 223 is rotatably mounted on the side of the second link frame 17; the two ends of the first linkage rod 19 are fixedly connected with the left and right first connecting rods 221 or integrally formed; further preferably, a left first mounting plate 28 and a right first mounting plate 28 are arranged in parallel and vertical, a rectangular notch is arranged at the top end of the first mounting plate 28, the top end of the first mounting plate 28 is fixedly connected with the lower surface and the front side surface of the second linkage frame 17 through the rectangular notch, the first mounting plate is generally fixed through welding, and the bottom end of the first mounting plate 28 is hinged with the top end of the first connecting rod 221; so arranged, the chair back frame 13 can be rotated in a certain range and stably arranged on the fixed seat 12 through the part of the second connecting rod 222 connected with the first connecting rod 221, the first limiting groove and the first linkage frame 16; the power for ascending or descending the seat frame 14 is provided through the portion of the second link 222 connected to the third link 223 and the third link 223, and the moving track of the seat frame 14 is not restrained at all.

In the embodiment of the application, the main body of the first connecting rod 221 is in an L shape, the horizontal section of the first connecting rod 221 extends forwards and downwards to form a first extension part, the outer end of the first extension part is hinged with the second connecting rod 222, the top end of the vertical section of the second connecting rod 222 is hinged with the first mounting plate 28, and the two ends of the first connecting rod 19 are fixedly connected or integrally formed with the corners of the horizontal section and the vertical section in the first connecting rod 221; so arranged; the structure is simple and reasonable, and the transmission of the motion relationship between the chair back frame 13 and the chair seat frame 14 is facilitated.

In the embodiment of the present application, a horizontal first square tube is fixed at the front end of the fixed seat 12, the first linkage rod 19 is a square tube, two parallel vertical fifth mounting plates 29 and two parallel vertical sixth mounting plates 30 are further provided, the bottom end of the fifth mounting plate 29 is fixedly connected with the first square tube, the top end of the fifth mounting plate is hinged with the front end of the first electric push rod 18, the top end of the sixth mounting plate 30 is fixedly connected with the first linkage rod 19, and the bottom end of the sixth mounting plate is hinged with the rear end of the first electric push rod 18, so that the first electric push rod 18 is rotatably mounted on the chair frame; still preferably, the bottom end of the fifth mounting plate 29 is provided with a first rectangular notch, the first rectangular notch is welded with the front side (rear side) and the upper surface of the first square tube, the top end of the sixth mounting plate 30 is provided with a second rectangular notch, the second rectangular notch is welded with the rear side (front side), the upper surface and the lower surface of the second square tube, and then under the combined action of the first square tube, the fifth mounting plate 29, the second square tube, the sixth mounting plate 30 and the first electric push rod 18, the first electric push rod 18 is rotatably mounted on the chair frame; and the structure is stable, and the installation and the disassembly are convenient.

The left and right second limiting long holes 31 are further arranged, and the top ends of the second limiting long holes 31 are positioned behind the bottom ends of the second limiting long holes 31; the device is also provided with at least one third linkage rod 32 which is horizontally arranged, wherein the third linkage rod 32 is inserted into the second limiting long hole 31 and is in clearance fit with the second limiting long hole 31, when only one third linkage rod 32 is arranged, the two second limiting long holes 31 are respectively symmetrically arranged on two side surfaces of the fixed seat 12, two ends of the third linkage rod 32 are respectively fixedly connected with two side surfaces of the second linkage frame 17, or the two second limiting long holes 31 are respectively symmetrically arranged on two side surfaces of the second linkage frame 17, and two ends of the third linkage rod 32 are respectively fixedly connected with two side surfaces of the fixed seat 12; because the third linkage rod 32 may touch the first electric push rod 18 or the second electric push rod 20 or the first linkage mechanism 22 during movement, the middle section of the third linkage rod 32 may be cut off to form two separate third linkage rods 32.

In the embodiment of the present application, the second limiting long hole 31 is linear, and the top end of the second limiting long hole 31 faces to the rear; the included angle between the second limiting long hole 31 and the horizontal plane is 30-60 degrees, and more preferably, the included angle between the second limiting long hole 31 and the horizontal plane is 40-50 degrees.

It should be noted that the second limiting long hole 31 may be an arc shape, and the top end of the second limiting long hole 31 is located at the rear of the bottom end of the second limiting long hole 31; and the included angle between the straight line passing through the top end of the second limiting long hole 31 and the bottom end of the second limiting long hole 31 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.

The main function of the fourth link mechanism 23 is to limit the movement of the front end of the second linkage frame 17, in this embodiment, the fourth link mechanism 23 includes only the fourth link 231, the rear end of the fourth link 231 is hinged to the side of the fixed base 12, and the front end of the fourth link 231 is hinged to the side of the second linkage frame 17.

When the fourth link 231 rotates upward with the rear end thereof as the rotation center to be parallel to the second limiting slot 31 and the required rotation angle is not higher than 90 degrees, the movement process of the seat frame 14 is as follows: in the process that the seat back frame 13 rotates upwards to drive the seat frame 14 to move forwards and downwards, the front end of the seat frame 14 rotates upwards, and in the process that the seat back frame 13 rotates downwards to drive the seat frame 14 to move backwards and upwards, the front end of the seat frame 14 rotates downwards;

When the fourth link 231 rotates upward with the rear end thereof as the rotation center to be parallel to the second limiting slot 31 and the required rotation angle is higher than 90 degrees, the first movement process of the seat frame 14 is as follows: in the process that the back frame 13 rotates upwards to drive the seat frame 14 to move forwards and downwards, the front end of the seat frame 14 rotates downwards and then upwards, and in the process that the back frame 13 rotates downwards to drive the seat frame 14 to move backwards and upwards, the front end of the seat frame 14 rotates upwards and then downwards;

The second course of movement of the seat frame 14 is: in the process that the seat back frame 13 rotates upwards to drive the seat frame 14 to move forwards and downwards, the front end of the seat frame 14 rotates downwards, and in the process that the seat back frame 13 rotates downwards to drive the seat frame 14 to move backwards and upwards, the front end of the seat frame 14 rotates upwards;

therefore, in the embodiment of the present application, by adjusting the parameters related to the second limiting long hole 31 and the fourth link 231, the seat frame 14 can be rotated only by a small angle or not when the seat back frame 13 is rotated downward from the highest position to the lowest position.

In the embodiment of the present application, the second link mechanism 26 includes a fifth link 261 and a sixth link 262, the fifth link 261 is rotatably installed at the side of the second linkage 17, and one end of the fifth link 261 is hinged with one end of the sixth link 262, and the other end of the sixth link 262 is rotatably installed at the side of the footrest assembly 15; the second link 21 has both ends fixedly connected to or integrally formed with the left and right fifth links 261.

Further preferably, two parallel vertical third mounting plates 33 and two parallel vertical fourth mounting plates 34 are further provided, the second linkage rod 21 is a square tube, the bottom end of the third mounting plate 33 is fixedly connected with the second linkage rod 21, such as welded, and the top end of the third mounting plate is hinged with the front end of the second electric push rod 20, and the top end of the fourth mounting plate 34 is fixedly connected with the second linkage frame 17, such as welded, and the bottom end of the fourth mounting plate is hinged with the rear end of the second electric push rod 20; the third mounting plate 33 is then mounted on the second link 21 and the fourth mounting plate 34 is mounted on the second link 17 by the cooperation of the third mounting plate 33, the fourth mounting plate 34 and the second electric push rod 20.

As shown in fig. 4,5, 6 and 7, in an embodiment of the present application, the footrest assembly 15 includes a first footrest 151 rotatably mounted on the seat frame 14 and a second footrest 152 slidably mounted on the first footrest 151; further preferably, the first footrest 151 is mounted on the seat frame 14 through two second rotating shafts 37 that are symmetrically arranged in a horizontal direction, and rotates around the second rotating shafts 37 as a rotation center shaft, and the second rotating shafts 37 are fixedly connected with the second linkage frame 17;

more preferably, a concave arc-shaped bent portion is provided on the sixth link 262 near the footrest assembly 15; the arrangement is such that, firstly, the structural strength of the sixth link 262 is enhanced, and, secondly, the sixth link 262 is prevented from touching the second rotation shaft 37 during rotation.

The third link mechanism 24 includes an eighth link 241 and a ninth link 242, the eighth link 241 is rotatably installed on the first footrest 151, the rear end of the eighth link 241 is in driving connection with the B end of the linkage assembly 25 and the front end of the eighth link 241 is hinged with the rear end of the ninth link 242, the front end of the ninth link 242 is rotatably installed on the second footrest 152, and further preferably, the distance between the front end of the eighth link 241 and the rotation center of the eighth link 241 is greater than the distance between the rear end of the eighth link 241 and the rotation center of the eighth link 241; this arrangement amplifies the sliding stroke of the second footrest 152.

In the embodiment of the application, a first rotating shaft 35 and a vertical third rotating shaft 36 are further arranged, the first rotating shaft 35 is fixedly connected with the second linkage frame 17, the included angle between the first rotating shaft and the horizontal plane is not more than 30 degrees, the rear end of the eighth connecting rod 241 is arranged on the third rotating shaft 36, the A end of the third rotating shaft 36 linkage assembly 25 is rotatably arranged on the first rotating shaft 35, and the A end of the linkage assembly 25 is always positioned behind the second rotating shaft 37 in the rotating process; the end B of the linkage assembly 25 is rotatably mounted on a third rotary shaft 36; so configured, the eighth link 241 is pulled to rotate by the distance difference generated by the eccentric rotation, and the second footrest 152 is slid forward by the ninth link 242.

Further preferably, the first rotating shaft 35 and the second rotating shaft 37 are parallel and located behind the second rotating shaft 37.

Further preferably, there are also provided a first sphere 38 and a second sphere 39, wherein the first sphere 38 is rotatably mounted on the first rotation shaft 35, the second sphere 39 is rotatably mounted on the third rotation shaft 36, the a end of the linkage assembly 25 is rotatably mounted on the outer surface of the first sphere 38, and the B end of the linkage assembly 25 is rotatably mounted on the outer surface of the second sphere 39; this is provided to alleviate the difference in displacement between the a end of the linkage assembly 25 and the B end of the linkage assembly 25 in the up-down direction.

Still further preferably, the linkage assembly 25 includes a connecting rod 251 and two linkage members 252 rotatably sleeved at two ends of the connecting rod 251, the linkage members 252 include a ring body and a cylinder which are integrally formed or fixedly connected, the cylinder is provided with a connecting hole for inserting the connecting rod 251, and the ring bodies of the two linkage members 252 are respectively rotatably sleeved on the first sphere 38 and the second sphere 39; this is provided to alleviate the angular difference generated by the rotation of the two links 252 around the axis of the connecting rod 251 by different angles.

Example two

The difference between this embodiment and the first embodiment is that: the first electric push rod is not arranged.

In the embodiment of the application, an air rod and a left spring and a right spring are arranged, wherein the installation mode of the air rod is the same as the installation mode and the installation structure of the first electric push rod in the first embodiment, and the air rod is rotatably arranged on a first linkage frame and a fixed seat, the front end of the spring is arranged on the fixed seat, and the rear end of the spring is arranged on a first connecting rod or the first linkage frame; further preferably, the spring is not in tension;

It should be noted that, if the fixing seat is large enough, the rear end of the spring may be mounted on the fixing seat, and the front end of the spring is mounted on the first connecting rod or the first linkage frame; further preferably, the spring is not in a compressed state;

The seat back frame can be kept at any angle in the rotatable range and at any height in the liftable range through the air rod; the fallen chair back frame is pushed to rotate upwards by the elasticity of the spring so as to help people to get up.

Example III

As shown in fig. 8 and 9, the present embodiment is different from the second embodiment in that: the second drive mechanism and the footrest assembly are not provided in embodiments of the present application.

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 (8)

1. A footrest assembly comprising a fixed seat (12), and a seat frame (14) mounted on the fixed seat (12), and a second drive mechanism mounted on the fixed seat (12) and the seat frame (14) for driving the footrest assembly to rotate to raise or lower and to extend or shorten the footrest assembly, characterized in that the second drive mechanism comprises:

A left and a right set of second link mechanisms (26), wherein the second link mechanisms (26) are arranged on the chair seat frame (14) and the footrest assembly;

a third linkage (24), the third linkage (24) being mounted on the footrest assembly;

The linkage assembly (25), the A end of the linkage assembly (25) is rotatably installed on the chair seat frame (14), and the B end of the linkage assembly (25) is in transmission connection with the third link mechanism (24);

The second linkage rod (21), the second linkage rod (21) is fixedly connected with the second link mechanism (26) or integrally formed;

The rear end of the second electric push rod (20) is hinged with the chair seat frame (14), and the front end of the second electric push rod (20) is hinged with the second linkage rod (21);

When the second electric push rod (20) stretches, the footrest assembly is lifted up through the second connecting rod mechanism (26), and in the process of lifting up the footrest assembly, the third connecting rod mechanism (24) is driven to operate through the linkage assembly (25) at the same time so that the footrest assembly stretches; when the second electric push rod (20) is shortened, the footrest assembly is put down through the second connecting rod mechanism (26), and in the process of putting down the footrest assembly, the third connecting rod mechanism (24) is driven to operate through the linkage assembly (25) at the same time, so that the footrest assembly is shortened;

The footrest assembly includes a first footrest (151) rotatably mounted on the seat frame (14) and a second footrest (152) slidably mounted on the first footrest (151);

The third link mechanism (24) comprises an eighth link (241) and a ninth link (242), the eighth link (241) is rotatably mounted on the first footrest (151), the rear end of the eighth link (241) is in transmission connection with the B end of the linkage assembly (25), the front end of the eighth link (241) is hinged with the rear end of the ninth link (242), and the front end of the ninth link (242) is rotatably mounted on the second footrest (152);

The second link mechanism (26) comprises a fifth link (261) and a sixth link (262), the fifth link (261) is rotatably arranged on the side surface of the seat frame (14), one end of the fifth link (261) is hinged with one end of the sixth link (262), and the other end of the sixth link (262) is rotatably arranged on the side surface of the footrest assembly; the two ends of the second linkage rod (21) are fixedly connected with the left fifth connecting rod (261) and the right fifth connecting rod or integrally formed.

2. The footrest assembly of claim 1 wherein a distance between a forward end of the eighth link (241) and a center of rotation of the eighth link (241) is greater than a distance between a rearward end of the eighth link (241) and a center of rotation of the eighth link (241).

3. The footrest assembly as claimed in claim 1, further comprising two parallel vertical third mounting plates (33) and two parallel vertical fourth mounting plates (34), wherein the second linkage rod (21) is a square tube, the bottom end of the third mounting plate (33) is clamped with the third linkage rod (32) and the top end is hinged with the front end of the second electric push rod (20), and the top end of the fourth mounting plate (34) is fixedly connected with the seat frame (14) and the bottom end is hinged with the rear end of the second electric push rod (20).

4. The footrest assembly as claimed in claim 1, further comprising a first rotation shaft (35) and second rotation shafts (37) symmetrically fixed on the left and right sides of the seat frame (14), wherein the second rotation shafts (37) are horizontally arranged, the footrest assembly is mounted on the seat frame (14) through the second rotation shafts (37) and rotates by taking the second rotation shafts (37) as rotation center shafts, the first rotation shaft (35) is fixedly connected with the seat frame (14) and forms an included angle with the horizontal plane of not more than 30 degrees, and the end a of the linkage assembly (25) is rotatably mounted on the first rotation shaft (35) and is always located behind the second rotation shafts (37) in the rotation process.

5. A footrest assembly as claimed in claim 4, wherein said first axis of rotation (35) is parallel to and rearward of the second axis of rotation (37).

6. A footrest assembly as claimed in claim 4, further provided with a vertical third pivot axis (36), one end of the third linkage (24) being mounted on the third pivot axis (36); the novel clutch is further provided with a first ball body (38) and a second ball body (39), wherein the first ball body (38) is rotatably mounted on the first rotating shaft (35), the second ball body (39) is rotatably mounted on the third rotating shaft (36), the end A of the linkage assembly (25) is rotatably mounted on the outer surface of the first ball body (38), and the end B of the linkage assembly (25) is rotatably mounted on the outer surface of the second ball body (39).

7. The footrest assembly as claimed in claim 6, wherein the linkage assembly (25) includes a connecting rod (251) and two links (252) rotatably sleeved at both ends of the connecting rod (251), the links (252) include a ring body and a cylinder integrally formed or fixedly connected, the cylinder is provided with a connecting hole for inserting the connecting rod (251), and the ring bodies of the two links (252) are rotatably sleeved on the first sphere (38) and the second sphere (39), respectively.

8. A chair comprising a footrest assembly as claimed in any one of claims 1 to 7.