CN211933363U - Chair and footrest subassembly thereof - Google Patents

Abstract

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

Description

Chair and footrest subassembly 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 working and life quality of people. More and more enterprises are studying seat-back linkage mechanisms to realize self-adaptive functions and improve the comfort of the seat.

The seat back linkage mechanism used by the existing seat on the market is complex in structure and high in production and processing difficulty, so that the cost is high; for example, chinese patent publication No. CN104223821B discloses a swivel chair chassis, which comprises a four-bar mechanism consisting of a plurality of links, a bracket and a base, wherein when a rocker connected to a backrest rotates, the bracket connected to a seat moves upward and backward as a whole, and the backrest tilting restoring force is correspondingly matched according to the weight of a human body, so that a person with no matter light or heavy weight can easily tilt and return to lift up; the chassis mechanism is mainly suitable for office chairs; for a leisure chair, a large-angle backward leaning rest is usually required, so that the front end of a chair seat is required to be tilted, and a seat-back linkage mechanism which is simple in structure and easy to process and manufacture needs to be researched to meet the market requirement.

Thus, chinese patent publication No. CN109984499A discloses a seat-back synchronous linkage device and a seat, including a base for connecting an air rod, 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 linkage; two sides of the lower end of the rocker extend forwards to form side plates, one end of the first connecting rod is hinged with the base and the rear part of the bracket, and the other end of the first connecting rod is hinged with the lower end of the rocker; 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 by stress to send rotation, 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, in the process of using, those skilled in the art find that when the backrest is at a relatively large reclining angle, the included angle between the seat back and the horizontal plane is also at a relatively large state, so that the force of the human body on the chair is totally concentrated on the backrest, thereby causing the following problems:

1) the gravity centers of the human body and the chair move backwards, so that the chair is easy to tip backwards;

2) the backrest can bear larger acting force, so that the stability of the material and the structure of the backrest needs to be improved, and the production cost is improved;

3) correspondingly, the chair mainly provides supporting force for the back of the human body through the backrest, the seat back only has a function of fixing the position of the seat back on the buttocks of the human body and does not conform to the stress condition of the human body when the human body normally lies down, so that the human body is not in a comfortable state as a whole, and the human body feels tired after long-term lying on the back;

4) the legs of the human body are still in a bent 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 publication No. CN109645726A discloses an electric integrated mechanism for a backrest and a footrest, comprising: the seat frame, the back rest, the leg rest assembly, the swing rod assembly and the rotary swing mechanism are used for realizing the forward extension of the leg rest assembly and the backward inclination of the back rest, the swing rod assembly is installed below the seat frame, and a notch swing disc is arranged on the swing rod assembly; the foot rest connecting rod assembly is respectively connected with the foot rest assembly and the seat frame and is used for realizing the telescopic folding of the foot rest assembly; the bracket connecting rod component 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 the inclination of the backrest; the driving piece is respectively connected with the swing rod assembly and the leg rest assembly and drives the swing rod assembly and the leg rest assembly to move relatively; the rolling assembly is matched with a notch swinging disc on the swing rod assembly and a notch hinge on the leg rest connecting rod assembly to realize the forward extension and the backward contraction of the leg rest assembly and the backward tilting and the forward pitching of the backrest. This electronic disjunctor mechanism of back bracket can realize lifting of tilt up process and bracket through a motor, and it is less to fill a space, and stability is good.

However, the chair has the following defects found by the technicians in the field in the using process:

1) the device does not conform to the usual action of lying down and getting up; when people need to lie down, the footrest is firstly lifted and then the chair back falls down, when people need to lie down, the chair back is firstly lifted and then the footrest is descended, and the movement process is opposite to the usual action of people who lie down and get up;

2) the base in the chair is usually made of a material with higher strength as a main stress element, while other non-main stress elements are usually made of materials with ordinary strength for reducing the cost, but in the application, the motion mechanism of the base is not only the base; the leg rest component is also a main stressed component; therefore, the leg rest assembly also requires a stronger piece of material, thereby increasing costs;

3) the foot rest component has many 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 looks simple, elegant and beautiful; and in the process of lifting up, the leg support plate is gradually extended to enable the legs of the human body to be completely placed on the leg support plate, so that the comfort level of the human body is improved.

In order to achieve the purpose, the invention adopts the following technical scheme:

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

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

a third linkage mounted on the footrest assembly;

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

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

the rear end of the second electric push rod is hinged with the chair 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 component is lifted through the second connecting rod mechanism, and in the process of lifting the footrest component, the third connecting rod mechanism is driven to operate through the linkage component so as to extend the footrest component; when the second electric push rod shortens, make the footrest subassembly put down through second link mechanism to in-process that the footrest subassembly was put down drives the operation of third link mechanism simultaneously through the linkage subassembly and so that the footrest subassembly shortens.

Preferably, the chair seat 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 assembly is installed on the chair seat frame through the second rotating shafts and rotates by taking the second rotating shafts as rotating center 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, and the A ends of the linkage assemblies are rotatably installed on the first rotating shafts and are always positioned 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 connecting rod and a ninth connecting rod, the eighth connecting rod is rotatably installed on the first footrest, the rear end of the eighth connecting rod is in transmission connection with the end B of the linkage assembly, the front end of the eighth connecting rod is hinged to the rear end of the ninth connecting rod, and the front end of the ninth connecting rod is rotatably installed on the second footrest.

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

Preferably, the linkage assembly comprises a connecting rod and two linkage members rotatably sleeved at two ends of the connecting rod, each linkage member comprises a ring body and a cylinder which are integrally formed or fixedly connected, 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 respectively rotatably sleeved on the first ball body and the second ball body.

More preferably, the first rotation axis is parallel to and located 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; two ends of the second linkage rod are fixedly connected with the left fifth connecting rod and the right fifth connecting rod or are integrally formed.

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

As preferred, still be equipped with two vertical third mounting panels that parallel and two vertical fourth mounting panels that parallel, the second linkage pole is square pipe, third mounting panel bottom and third linkage pole joint and top are articulated with second electric putter front end, fourth mounting panel top and seat frame fixed connection and bottom are articulated with second electric putter rear end.

A chair comprising a footrest assembly as described above.

The invention has the technical effects that:

1) when the second electric push rod extends, the fifth connecting rod is driven to rotate, so that the sixth connecting rod rotates and moves forwards, and the first footrest and the linkage assembly are driven to rotate simultaneously, in the rotating process, the rotating central shaft of the linkage assembly is always positioned behind the rotating central shaft of the first footrest, namely, the linkage assembly rotates eccentrically relative to the first footrest, and then the generated displacement difference is used for pulling the eighth connecting rod to rotate, and meanwhile, the ninth connecting rod is driven to rotate, so that the second footrest slides out relative to the first footrest, when the second electric push rod shortens, so that the footrest assembly is put down and the footrest assembly is shortened.

2) The footrest component has simple structure, and can be completely attached to the bottom of the chair frame when not lifted, so that the chair looks simple, elegant and beautiful.

Drawings

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

FIG. 2 is a schematic structural view of a chair according to an embodiment of the present invention (the footrest assembly is in a lowered state and the feet and the backrest frame are omitted);

FIG. 3 is a schematic structural view of a chair according to an embodiment of the present invention (the footrest assembly is in a lowered state and the feet and the backrest frame are omitted);

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

FIG. 5 is a schematic structural view of a chair according to an embodiment of the present invention, showing the footrest assembly in a raised state;

FIG. 6 is an enlarged view of a portion of FIG. 5 of 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 first chair according to a third embodiment of the present invention;

fig. 9 is a second structural diagram of a third chair according to an embodiment of the invention (with feet and a backrest frame omitted).

Description of reference numerals: 11. footing; 12. a fixed seat; 13. a back of chair 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 limit 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 limit long hole; 32. a third link lever; 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 rotating shaft; 36. a third rotating shaft; 37. a second rotating shaft; 38. a first sphere; 39. a second sphere; 251. a connecting rod; 252. a linkage member; 40. a spring.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be considered as limiting the present invention.

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

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The first embodiment is as follows:

as shown in fig. 1-5, a chair includes a bottom 11, a fixed seat 12, a back frame 13, a 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 bottom 11, and the first linkage frame 16 is fixedly connected with the bottom end of the back frame 13 or integrally formed and rotatably mounted on the fixed seat 12; the second linkage frame 17 is fixedly connected with the bottom surface of the seat frame 14 or integrally formed and movably arranged 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:

a first driving mechanism, including a first electric push rod 18, a first linkage rod 19, a left set of first link mechanism 22 and a right set of first link mechanism 22, and a left set of fourth link mechanism 23 and a right set of fourth link mechanism 23, the first link mechanism 22 is installed on the fixed seat 12, the first linkage frame 16 and the second linkage frame 17, the fourth link mechanism 23 is installed 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 link mechanism 22, the front end of the first electric push rod 18 is hinged with the fixed seat 12, the rear end of the first electric push rod 18 is hinged with the first linkage rod 19, and further when the first electric push rod 18 extends, the first link mechanism 22 and the fourth link mechanism 23 drive the backrest frame 13 to rotate upwards and drive the seat frame 14 to move forwards and downwards, and when the first electric push rod 18 shortens, the first link mechanism 22 and the fourth link mechanism 23 drive the backrest frame 13 to rotate downwards and drive the seat frame 14 to move backwards and upwards (ii) a

The second driving mechanism comprises a second electric push rod 20, a second linkage rod 21, a third link mechanism 24, a linkage assembly 25 and a left set and a right set of second link mechanisms 26, the second link mechanisms 26 are arranged on the second linkage frame 17 and the footrest assembly 15, the third link mechanism 24 is arranged on the footrest assembly 15, the linkage assembly 25 is rotatably arranged on the chair seat frame 14 and is connected with the third link mechanism 24, the second linkage rod 21 is fixedly connected with the second link mechanism 26 or is 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, when the second electric push rod 20 is extended, the footrest assembly 15 is lifted by the second link mechanism 26, and during the process of lifting the footrest assembly 15, the linkage assembly 25 simultaneously drives the third link mechanism 24 to operate so as to extend the footrest assembly 15; when the second electric push rod 20 is shortened, the footrest assembly 15 is lowered through the second link mechanism 26, and in the process of lowering the footrest assembly 15, the linkage assembly 25 simultaneously drives the third link mechanism 24 to operate so as to shorten the footrest assembly 15.

In the embodiment of the application, a left concave first limiting long hole 27 and a right concave first limiting long hole 27 are further arranged, the first limiting long holes 27 can be positioned on the side surface of the fixed seat 12 and also can be positioned on the side surface of the second linkage frame 17, 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 axis, and the rotatable angle range of the back frame 13 is 0-60 degrees through the first limiting long holes 27; further preferably, the back frame 13 is rotatable at an angle ranging from 0 degree 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 linkage frame 16, the second link 222 is in an inverted V shape and rotatably mounted on the side surface of the fixed base 12 with the corner as a rotation center, and the top end of the third link 223 is rotatably mounted on the side surface of the second linkage frame 17; two ends of the first linkage rod 19 are fixedly connected with the left first connecting rod 221 and the right first connecting rod 221 or integrally formed; further preferably, a left first mounting plate 28 and a right first mounting plate 28 which are parallel and vertical are further arranged, a rectangular notch is formed in the top end of each first mounting plate 28, the top end of each 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 plates are generally fixed through welding, and the bottom ends of the first mounting plates 28 are hinged to the top ends of the first connecting rods 221; with such an arrangement, the backrest frame 13 can be rotatably and stably mounted on the fixing base 12 within a certain range through the portion of the second link 222 connected to the first link 221, the first limit groove, and the first linking frame 16; the power for ascending or descending the seat frame 14 is given by the portion of the second link 222 connected to the third link 223 and the third link 223, and no restriction is made to the moving locus of the seat frame 14.

In the embodiment of the present application, the main body of the first link 221 is L-shaped, the horizontal section of the first link 221 extends forward and downward to form a first extension portion, the outer end of the first extension portion is hinged to the second link 222, the top end of the vertical section of the second link 222 is hinged to the first mounting plate 28, and two ends of the first linkage rod 19 are fixedly connected to or integrally formed with the corners of the horizontal section and the vertical section of the first link 221; so as to set; the structure is simple and reasonable, and the transmission of the motion relation between the chair back frame 13 and the chair seat frame 14 is facilitated.

In the embodiment of the 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, and two parallel vertical fifth mounting plates 29 and two parallel vertical sixth mounting plates 30 are further arranged, the bottom end of each fifth mounting plate 29 is fixedly connected with the first square tube, the top end of each fifth mounting plate is hinged to the front end of the first electric push rod 18, the top end of each sixth mounting plate 30 is fixedly connected with the first linkage rod 19, the bottom end of each sixth mounting plate is hinged to the rear end of the first electric push rod 18, and the first electric push rod 18 is rotatably mounted on the chair frame; preferably, a first rectangular notch is formed in the bottom end of the fifth mounting plate 29 and is welded to the front side (rear side) and the upper surface of the first square tube, a second rectangular notch is formed in the top end of the sixth mounting plate 30 and is welded to the rear side (front side), the upper surface and the lower surface of the second square tube, and the first electric push rod 18 is rotatably mounted on the chair frame 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; 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 further provided with at least one third linkage rod 32 which is horizontally arranged, the third linkage rod 32 is inserted into the second limiting long holes 31 and is in clearance fit with the second limiting long holes 31, when only one third linkage rod 32 is arranged, the two second limiting long holes 31 are symmetrically arranged on two side faces of the fixed seat 12 respectively, two ends of the third linkage rod 32 are fixedly connected with two side faces of the second linkage frame 17 respectively, or the two second limiting long holes 31 are symmetrically arranged on two side faces of the second linkage frame 17 respectively, and two ends of the third linkage rod 32 are fixedly connected with two side faces of the fixed seat 12 respectively; considering that the third link 32 touches the first electric push rod 18, the second electric push rod 20 or the first link mechanism 22 during the movement, the middle section of the third link 32 can be cut off to form two separated third links 32.

In the embodiment of the present application, the second long limiting hole 31 is linear, and the top end of the second long limiting hole 31 faces rearward; the included angle range between the second limiting long hole 31 and the horizontal plane is 30-60 degrees, and further preferably, the included angle range 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 also be an arc line, and the top end of the second limiting long hole 31 is located behind 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 limit long hole 31 and the bottom end of the second limit long hole 31 and the horizontal plane ranges from 30 degrees to 60 degrees, and further preferably, the included angle between the straight line and the horizontal plane ranges from 40 degrees to 50 degrees.

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

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

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

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

In the embodiment of the present application, the second linkage 26 includes a fifth link 261 and a sixth link 262, the fifth link 261 is rotatably installed on the side of the second linkage frame 17, 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 on the side of the footrest assembly 15; both ends of the second linkage rod 21 are fixedly connected with the left and right fifth links 261 or integrally formed.

Preferably, the electric power tool is further provided with two parallel vertical third mounting plates 33 and two parallel vertical fourth mounting plates 34, 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 to the front end of the second electric push rod 20, 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 to the rear end of the second electric push rod 20; the third mounting plate 33 is mounted on the second linkage rod 21 and the fourth mounting plate 34 is mounted on the second linkage frame 17 by the cooperation of the third mounting plate 33, the fourth mounting plate 34 and the second electric putter 20.

As shown in fig. 4, 5, 6 and 7, in the present embodiment, the footrest assembly 15 includes a first footrest 151 and a second footrest 152, the first footrest 151 is rotatably mounted on the seat frame 14, and the second footrest 152 is slidably mounted on the first footrest 151; more preferably, the first footrest 151 is mounted on the seat frame 14 through two second rotating shafts 37 which are bilaterally symmetrical and horizontally disposed, and rotates with the second rotating shafts 37 as a rotating center shaft, and the second rotating shafts 37 are fixedly connected with the second linkage frame 17;

more preferably, a concave arc-shaped bending part is arranged on the part of the sixth connecting rod 262 close to the footrest assembly 15; this is provided to enhance the structural strength of the sixth link 262 and to prevent the sixth link 262 from touching the second rotation shaft 37 during the rotation.

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

In the embodiment of the present application, a first rotating shaft 35 and a vertical third rotating shaft 36 are further provided, the first rotating shaft 35 is fixedly connected with the second linkage frame 17, and an included angle with the horizontal plane is not more than 30 degrees, the rear end of the eighth connecting rod 241 is installed on the third rotating shaft 36, the end a of the linkage assembly 25 of the third rotating shaft 36 is rotatably installed on the first rotating shaft 35, and the end a of the linkage assembly 25 is always located behind the second rotating shaft 37 in the rotating process; the end B of the linkage assembly 25 is rotatably mounted on the third rotating shaft 36; with this arrangement, 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.

More preferably, the first rotating shaft 35 and the second rotating shaft 37 are parallel to each other and are located behind the second rotating shaft 37.

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

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 body which are integrally formed or fixedly connected, the cylinder body is provided with a connecting hole for the connecting rod 251 to be inserted, and the ring bodies of the two linkage members 252 are respectively rotatably sleeved on the first ball body 38 and the second ball body 39; this is provided to alleviate the angular difference generated by the two link members 252 rotating by different angles around the axis of the connecting rod 251.

Example two:

the difference between this embodiment and the first embodiment is: the first electric push rod is not arranged any more.

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 that and the installation structure of the first electric push rod in the first embodiment, the air rod and the first electric push rod are rotatably installed on a first linkage frame and a fixed seat, the front end of the spring is installed on the fixed seat, and the rear end of the spring is installed on a first connecting rod or the first linkage frame; further preferably, the spring is not in tension;

it is worth to be noted that, if the fixed seat is large enough, the rear end of the spring can be installed on the fixed seat, and the front end of the spring is installed on the first connecting rod or the first linkage frame; further preferably, the spring is not in a compressed state;

the arrangement is that the chair back frame can stay at any angle within a rotatable range and the chair seat frame can stay at any height within a liftable range through the air rod; the falling chair back frame is pushed to rotate upwards by the elasticity of the spring so as to help people get up.

Example three:

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

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean 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 invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. 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, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that changes, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the principles and spirit of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A footrest assembly comprising a holder (12), and a seat frame (14) mounted on the holder (12), and a second drive mechanism mounted on the holder (12) and the seat frame (14) for driving the footrest assembly in rotation to be raised or lowered and to be extended or shortened, characterized in that the second drive mechanism comprises:

the left and right sets of second link mechanisms (26), and the second link mechanisms (26) are arranged on the chair seat frame (14) and the footrest component;

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

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

the second linkage rod (21), the second linkage rod (21) and the second linkage mechanism (26) are fixedly connected 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) extends, the footrest component is lifted through the second link mechanism (26), and in the process of lifting the footrest component, the third link mechanism (24) is driven to operate through the linkage component (25) so as to extend the footrest component; when the second electric push rod (20) shortens, the footrest component is put down through the second link mechanism (26), and in the process of putting down the footrest component, the third link mechanism (24) is driven to operate through the linkage component (25) so as to shorten the footrest component.

2. A footrest assembly according to claim 1, characterized in that it comprises a first footrest (151) and a second footrest (152), the first footrest (151) being rotatably mounted on the seat frame (14), the second footrest (152) being 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 end B of the linkage assembly (25), the front end of the eighth link (241) is hinged to 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).

3. A footrest assembly according to claim 2 characterized in that the distance between the front end of the eighth link (241) and the rotation center of the eighth link (241) is larger than the distance between the rear end of the eighth link (241) and the rotation center of the eighth link (241).

4. The footrest assembly of claim 1 wherein the second linkage (26) comprises a fifth link (261) and a sixth link (262), the fifth link (261) being rotatably mounted on the side of the seat frame (14), and one end of the fifth link (261) being hinged to one end of the sixth link (262), the other end of the sixth link (262) being rotatably mounted on the side of the footrest assembly; two ends of the second linkage rod (21) are fixedly connected with the left fifth connecting rod (261) and the right fifth connecting rod (261) or are integrally formed.

5. The footrest assembly of claim 1, wherein two parallel vertical third mounting plates (33) and two parallel vertical fourth mounting plates (34) are provided, the second linkage rod (21) is a square tube, the bottom end of the third mounting plate (33) is connected with the third linkage rod (32) in a clamping manner, and the top end of the third mounting plate is hinged to 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 chair seat frame (14) and the bottom end of the fourth mounting plate is hinged to the rear end of the second electric push rod (20).

6. The footrest assembly of claim 1 further comprising a first rotation shaft (35) and a second rotation shaft (37) symmetrically fixed on the left and right sides of the seat frame (14), wherein the second rotation shaft (37) is horizontally disposed, the footrest assembly is mounted on the seat frame (14) through the second rotation shaft (37) and rotates with the second rotation shaft (37) as a rotation center shaft, the first rotation shaft (35) is fixedly connected with the seat frame (14) and forms an angle with the horizontal plane not exceeding 30 degrees, the a end of the linkage assembly (25) is rotatably mounted on the first rotation shaft (35) and the a end of the linkage assembly (25) is always located behind the second rotation shaft (37) during rotation.

7. Footrest assembly according to claim 6, characterized in that the first rotation axis (35) is parallel to the second rotation axis (37) and is located behind the second rotation axis (37).

8. Footrest assembly according to claim 6, characterized in that a vertical third rotation axis (36) is provided, on which third rotation axis (36) one end of the third linkage (24) is mounted; the ball-shaped linkage mechanism is further provided with a first ball body (38) and a second ball body (39), wherein the first ball body (38) is rotatably arranged on the first rotating shaft (35), the second ball body (39) is rotatably arranged on the third rotating shaft (36), the end A of the linkage assembly (25) is rotatably arranged on the outer surface of the first ball body (38), and the end B of the linkage assembly (25) is rotatably arranged on the outer surface of the second ball body (39).

9. The footrest assembly of claim 8, wherein the linkage assembly (25) comprises a connecting rod (251) and two linkage members (252) rotatably sleeved at two ends of the connecting rod (251), wherein the linkage members (252) comprise a ring body and a cylinder body which are integrally formed or fixedly connected, the cylinder body is provided with a connecting hole for the connecting rod (251) to be inserted, and the ring bodies of the two linkage members (252) are rotatably sleeved on the first spherical body (38) and the second spherical body (39), respectively.

10. A chair comprising a footrest assembly as claimed in any one of claims 1-9.

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