CN111616541A - Chair frame - Google Patents

Abstract

The invention discloses a chair frame, which comprises a chair seat frame, a lower chair back frame and an upper chair back frame, wherein the lower chair back frame is rotatably arranged on the chair seat frame and is also provided with a first connecting rod, a first fixing plate and a second connecting rod, the first fixing plate is fixedly arranged on one side of the chair seat frame, the lower chair back frame is hinged with the rear part of the first fixing plate, one end of the first connecting rod is hinged with the front part of the first fixing plate, the other end of the first connecting rod is hinged with one end of the second connecting rod, the other end of the second connecting rod is hinged with the upper chair back frame, the lower chair back frame is hinged with the upper chair back frame, the first connecting rod, the first fixing plate, the second connecting rod, the lower chair back frame and the upper chair back frame form a five-bar mechanism, and further when the lower chair back frame tilts backwards, a connecting rod device drives the upper chair back frame to; through this technical scheme lower back of the chair frame can be for seat frame backward tilt to in-process and the linkage of last back of the chair frame of leaning on, make and go up back of the chair frame and can be for lower back of the chair frame automatic lifting, and then bring more comfortable impression for the user.

Description

Chair frame

Technical Field

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

Background

The structural design of chairs generally attaches importance to ergonomics and comfort, but most of common chairs emphasize the structural design of back support, and neglect the structural design of head and neck support.

Generally, the back of a chair with a headrest can tilt backwards, but the backrest on the chair generally utilizes a bracket to fix the headrest on the chair back, so that a user can lean the head and neck backwards to relax the muscles of the shoulder and the neck when sitting; for example, chinese patent publication No. CN209694604U discloses a seat, comprising: a lower support part for supporting the buttocks of the human body; one end of the corner connector is connected with the lower supporting part; the back support part is arranged above the lower support part and is connected with the other end of the corner connector, the back support part rotates by taking the connecting position of the back support part and the corner connector as a rotating point, and the back support part is used for supporting the back of a human body; the counterforce part is connected with the corner brace and the back support part, and provides counterforce relative to the rotating direction of the back support part when the back support part rotates; the waist pillow part is arranged above the lower supporting part and is connected with the back supporting part, the waist pillow part is driven by the back supporting part to rotate, and the waist pillow part is used for supporting the waist of the human body; and the headrest part is arranged above the back support part and is connected with the other end of the corner brace, and the headrest part is used for supporting the head of a human body. The back supporting part of the chair can rotate around the rotating point, so that when a person leans upwards, the back supporting part can be well attached to the back of the human body, and the comfort is improved.

But those skilled in the art find during use: the requirement of a user for a headrest can change along with the change of the tilting angle, when the backrest does not tilt backwards, the requirement of the headrest on the headrest is smaller due to the fact that the head and neck of the user is supported by the back, at the moment, the headrest only needs to slightly protrude relative to the backrest, but along with the increase of the backward tilting angle of the backrest, the requirement of the user for the headrest is continuously increased, particularly when the tilting angle of the backrest reaches the maximum, the user needs to protrude the headrest enough relative to the backrest, and the existing headrest design is unfortunately not considered at all.

Disclosure of Invention

In order to solve the above problems, an object of the present invention is to provide a chair frame, which includes a chair seat frame, a lower back frame and an upper back frame, wherein the lower back frame can tilt backward relative to the chair seat frame and is linked with the upper back frame during tilting, so that the upper back frame can automatically lift relative to the lower back frame, thereby providing a more comfortable feeling to a user.

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

a chair frame comprises a chair seat frame, a chair back frame and a headrest frame, wherein the chair back frame is rotatably arranged on the chair seat frame to enable the chair back frame to tilt forwards and backwards relative to the chair seat frame, the headrest frame is arranged on the chair back frame,

the chair back frame comprises a lower chair back frame and an upper chair back frame, the lower chair back frame is hinged with the chair seat frame, and the lower chair back frame is hinged with the upper chair back frame; the headrest frame is arranged above the upper chair back frame,

the chair back frame comprises a chair seat frame, a lower chair back frame and an upper chair back frame, and is characterized in that a left connecting rod device and a right connecting rod device are further arranged, the connecting rod devices are installed on the chair seat frame, the lower chair back frame and the upper chair back frame, each connecting rod device comprises a first connecting rod, a first fixing plate and a second connecting rod, the first fixing plate is fixedly installed on one side of the chair seat frame, the lower chair back frame is hinged to the rear portion of the first fixing plate, one end of each first connecting rod is hinged to the front portion of the corresponding first fixing plate, the other end of each first connecting rod is hinged to one end of each second connecting rod, the other end of each second connecting rod is hinged to the upper chair back frame, and the first connecting rods, the first fixing plates, the second connecting rods, the lower chair back frame and the upper chair.

Preferably, the lower back frame rotates backward by an angle greater than that of the first link during the backward rotation of the lower back frame from the initial position to the maximum rotatable position.

Preferably, the angle of the backward rotation of the lower back frame is greater than the angle of the backward rotation of the upper back frame during the backward rotation of the lower back frame from the initial position to the maximum rotatable position.

Preferably, the device is further provided with a left first limiting part and a right first limiting part and a left second limiting part and a right second limiting part;

the first limiting piece is fixedly connected with the upper backrest frame or integrally formed with the upper backrest frame, and the second limiting piece is fixedly connected with the lower backrest frame or integrally formed with the lower backrest frame; or, the first limiting piece is fixedly connected with or integrally formed with the lower back-rest frame, and the second limiting piece is fixedly connected with or integrally formed with the upper back-rest frame;

the first limiting piece is matched with the second limiting piece to limit the upper chair back frame to rotate backwards.

Preferably, the first limiting member is a column structure integrally formed with the upper back frame, the second limiting member is a block structure formed by extending the upper end of the lower back frame upward, and when the first limiting member abuts against the second limiting member, the included angle between the upper back frame and the lower back frame is 100 degrees and 180 degrees.

Preferably, the first link includes a first section, a second section and a third section, wherein the first section, the second section and the third section are linearly and integrally formed, the first section is hinged to the first fixing plate, the third section is hinged to the second link, and the second section is connected to the first section and the third section such that the bottom of the third section is closer to the lower back frame.

Preferably, the lower back of the chair frame left and right sides all is equipped with first locating hole, and the upper back of the chair frame left and right sides all is equipped with the second locating hole, and when first locating hole and second locating hole coaxial line distributed, the contained angle between upper back of the chair frame and the lower back of the chair frame was 100 degrees plus one's worth.

Preferably, the chair is also provided with an air rod, one end of the air rod is hinged with the lower chair back frame, and the other end of the air rod is hinged with the chair seat frame;

or an electric push rod is further arranged, one end of the electric push rod is hinged with the lower chair back frame, and the other end of the electric push rod is hinged with the chair seat frame.

Preferably, the chair is further provided with a left third fixing plate, a right third fixing plate, a left sliding groove piece, a right sliding groove piece, a left buckling piece and a right buckling piece, wherein the third fixing plate is welded and fixed with the chair seat frame; the first fixing plate can be stably installed on the chair seat frame;

the sliding groove piece comprises two sliding grooves which are oppositely arranged, the two sliding grooves are gradually close to each other from top to bottom, and the third fixing plate is in a shape matched with the two sliding grooves.

Preferably, the chute member is inserted into the fastener, the fastener extends upward to form a V-shaped extension portion, the first fixing plate is provided with a third positioning hole, and the bottom of the extension portion extends into the third positioning hole.

The invention has the beneficial effects that: through this technical scheme can make lower back of the chair frame still can drive the upper back of the chair frame forward rotation at the in-process that leans back to face upward, when lower back of the chair frame did not lean back to face upward promptly, the upper back of the chair frame flushes or protrudes slightly in lower back of the chair frame with lower back of the chair frame, when lower back of the chair frame leaned on maximum angle, the upper back of the chair frame just rotated certain angle forward for lower back of the chair frame, and headrest frame fixed mounting just can enlarge headrest frame protrusion distance in lower back of the chair frame on the upper portion of upper back of the chair frame, and then satisfied the user when being in different angles of inclining to lower back of the chair frame different demands to headrest frame, bring more comfortable impression for the user.

Drawings

Fig. 1 is a schematic structural diagram of a chair frame according to an embodiment of the present invention 1 (the lower back frame is not tilted);

FIG. 2 is a side view of FIG. 1;

FIG. 3 is a schematic structural diagram of a chair frame according to an embodiment of the present invention 1 (the lower backrest frame is tilted to a maximum angle);

FIG. 4 is a side view of FIG. 2;

FIG. 5 is a schematic structural view of a second chair frame according to the embodiment of the present invention, which is shown in FIG. 1 (the lower back frame is not tilted);

FIG. 6 is a side view of FIG. 3;

FIG. 7 is a schematic structural view of a second chair frame according to an embodiment of the present invention, which is shown in FIG. 1 (the lower back frame is tilted to a maximum angle);

FIG. 8 is a side view of FIG. 4;

FIG. 9 is an enlarged view of a portion of FIG. 1 at I;

FIG. 10 is a schematic view of a second footrest assembly of an embodiment of the present invention (the footrest assembly is fully extended);

FIG. 11 is an exploded view of a linkage assembly in accordance with an embodiment of the present invention;

FIG. 12 is a schematic view of the construction of the linkage arrangement of the present invention;

FIG. 13 is a schematic view of the construction of a first link of the present invention;

fig. 14 is a schematic view of an installation structure of the first fixing plate of the present invention.

Description of reference numerals: 1. a chair leg frame; 5. a link means; 2. a chair seat frame; 3. a lower back-of-chair frame; 33. a second fixing plate; 4. an upper backrest frame; 11. a gas lever; 50. a first link; 51. a first fixing plate; 52. a second link; 41. a first limit piece; 31. A second limiting member; 12. a third limiting member; 501. a first stage; 502. a second stage; 503. a third stage; 32. a first positioning hole; 42. a second positioning hole; 53. a third fixing plate; 54. a fastener; 55. a chute member; 541. an extension portion; 510. a third positioning hole; 12. a first electric push rod; 6. a footrest assembly; 13. a second electric push rod; 62. a sixth link; 63. a first footrest; 64. a second footrest; 14. a second rotating shaft; 65. an eighth link; 66. a ninth link; 15. a first rotating shaft; 16. a third rotating shaft; 67. a first sphere; 68. a second sphere; 69. a connecting rod; 70. a linkage member.

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 or similar 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 illustrative and intended to be illustrative of the invention and are not to be construed as limiting the 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 used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to 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 meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

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 to 4, a chair frame includes a chair leg frame 1, a seat support rod, a chair seat frame 2, a back frame and a headrest frame, wherein the chair leg frame 1 is used for contacting the ground and supporting the whole chair frame, the seat support rod is mounted on the chair leg frame 1, the chair seat frame 2 is mounted on the seat support rod, the back frame is rotatably mounted on the chair seat frame 2 so that the back frame can tilt forward and backward relative to the chair seat frame 2, and the headrest frame is mounted on the back frame.

In the embodiment, the chair back frame comprises a lower chair back frame 3 and an upper chair back frame 4, the lower chair back frame 3 is hinged with the chair seat frame 2, and the lower chair back frame 3 is hinged with the upper chair back frame 4; the headrest frame is arranged above the upper backrest frame 4,

the chair back frame is characterized by further comprising an air rod 11, a left connecting rod device and a right connecting rod device 5, wherein one end of the air rod 11 is hinged to the chair seat frame 2, the other end of the air rod is hinged to the lower chair back frame 3, the connecting rod devices 5 are installed on the chair seat frame 2, the lower chair back frame 3 and the upper chair back frame 4, the lower chair back frame 3 is hinged to the upper chair back frame 4, the connecting rod devices 5, the lower chair back frame 3 and the upper chair back frame 4 form a five-connecting-rod mechanism, and therefore when the lower chair back frame 3 tilts backwards, the connecting rod devices 5 drive the upper chair back frame 4 to rotate forwards.

According to the arrangement, the lower back-rest frame 3 is rotatably mounted on the seat frame 2 through the connecting rod device 5 and the air rod 11, the tilting process of the lower back-rest frame 3 is smooth through the matching with the air rod 11, and the connecting rod device 5, the lower back-rest frame 3 and the upper back-rest frame 4 form a five-link mechanism, so that in the initial process of backward tilting of the lower back-rest frame 3, the upper back-rest frame 4 can rotate forwards under the driving of the connecting rod device 5 and simultaneously rotate to the maximum rotatable angle together with the lower back-rest frame 3;

in this embodiment, as shown in fig. 12, the link device 5 includes a first link 50, a first fixing plate 51 and a second link 52, the first fixing plate 51 is fixedly installed at one side of the seat frame 2, the lower back frame 3 is hinged to the rear half portion of the first fixing plate 51, one end of the first link 50 is hinged to the front half portion of the first fixing plate 51, the other end of the first link 50 is hinged to one end of the second link 52, and the other end of the second link 52 is hinged to the upper back frame 4.

In the present embodiment, in the process of rotating the lower back frame 3 backward from the initial position to the maximum rotatable position, the angle of rotation of the lower back frame 3 backward is greater than the angle of rotation of the first link 50 backward.

In this embodiment, in the process that the lower back-rest frame 3 rotates backwards from the initial position to the maximum rotatable state, the backward rotation angle of the lower back-rest frame 3 is greater than the backward rotation angle of the upper back-rest frame 4; that is, when the hinge point of the first connecting rod 50 and the first fixing plate 51, the hinge point of the first connecting rod 50 and the second connecting rod 52, and the hinge point of the second connecting rod 52 and the upper back frame 4 are located on the same straight line, the rearward translation distance of the hinge point of the second connecting rod 52 and the upper back frame 4 is less than the rearward translation distance of the hinge point of the upper back frame 4 and the lower back frame 3; this is so arranged that, when the lower back frame 3 is moved to the maximum turnable position, the upper back frame 4 is still turnable, but when the upper back frame 4 rotates backward until the hinge point of the first link 50 and the first fixing plate 51, the hinge point of the first link 50 and the second link 52, and the hinge point of the second link 52 and the upper back frame 4 are located on the same straight line, the link means 5, the upper back frame 4 and the lower back frame 3 form a four-bar linkage, and at this time, the lower back frame 3 and the first fixing plate 51 are all in a fixed state, namely, two rods in the four-bar linkage mechanism are fixed, so the whole four-bar linkage mechanism is in a fixed state, and at this time, the hinge point of the second link 52 and the upper back frame 4 is translated backward by a distance smaller than the hinge point of the upper back frame 4 and the lower back frame 3, that is, the upper back frame 4 is raised.

In this embodiment, two first limiting members 41 on the left and right and two second limiting members 31 on the left and right are further provided;

the first limiting member 41 is fixedly connected with or integrally formed with the upper back frame 4, and the second limiting member 31 is fixedly connected with or integrally formed with the lower back frame 3; or, the first limiting member 41 is fixedly connected to or integrally formed with the lower back frame 3, and the second limiting member 31 is fixedly connected to or integrally formed with the upper back frame 4;

the first limiting member 41 cooperates with the second limiting member 31 to limit the upper back frame 4 from rotating backwards.

As shown in fig. 9, the first position-limiting member 41 is a column-shaped structure integrally formed with the upper back-rest frame 4, the second position-limiting member 31 is a block-shaped structure formed by extending the upper end of the lower back-rest frame 3 upwards, and when the first position-limiting member 41 abuts against the second position-limiting member 31, the included angle between the upper back-rest frame 4 and the lower back-rest frame 3 is 100 degrees and 180 degrees; further preferably, when the first limiting member 41 abuts against the second limiting member 31, an included angle between the upper back frame 4 and the lower back frame 3 is 180 degrees.

As shown in fig. 13, the first link 50 includes a first section 501, a second section 502 and a third section 503 which are linear and integrally formed, wherein the first section 501 is hinged to the first fixing plate 51, the third section 503 is hinged to the second link 52, and the second section 502 is connected to the first section 501 and the third section 503 such that the bottom of the third section 503 is closer to the lower back frame 3. The arrangement is to prevent the first connecting rod 50 and the second connecting rod 52 from being locked when the hinge point of the first connecting rod 50 and the first fixing plate 51, the hinge point of the first connecting rod 50 and the second connecting rod 52, and the hinge point of the second connecting rod 52 and the upper back frame 4 are located on the same straight line, and to prevent the thickness of the chair back from being too large. In other embodiments, the first, second and third segments 501, 502, 503 may also be arc-shaped.

In this embodiment, as shown in fig. 9, the left and right sides of the lower back frame 3 are both provided with first positioning holes 32, the left and right sides of the upper back frame 4 are both provided with second positioning holes 42, and when the first positioning holes 32 and the second positioning holes 42 are coaxially distributed, the included angle between the upper back frame 4 and the lower back frame 3 is 100 degrees and 180 degrees; further preferably, when the first positioning hole 32 and the second positioning hole 42 are coaxially distributed, the included angle between the upper back frame 4 and the lower back frame 3 is 180 degrees; this is so arranged because when the lower back frame 3 is not rotated backward, the lower back frame 3 and the upper back frame 4 are generally parallel, and the first positioning hole 32 and the second positioning hole 42 are also coaxially distributed; then, the positioning pin is inserted into the first positioning hole 32 and the second positioning hole 42, so that the lower back frame 3 and the upper back frame 4 are not rotatable, at this time, a four-bar mechanism is formed among the link device 5, the lower back frame 3 and the upper back frame 4, the lower back frame 3 can still rotate backwards relative to the seat frame 2, but the rotatable range is small, namely, the seat frame is suitable for users in office state, when the positioning pin is taken out, the rotatable range of the lower back frame 3 is increased, and a deck chair can be formed, namely, the seat frame is suitable for users in rest state.

In this embodiment, as shown in fig. 14, a left third fixing plate 53 and a right third fixing plate 53, a left sliding groove part 55 and a right sliding groove part 54 are further provided, the third fixing plate 53 is welded and fixed to the seat frame 2, both the sliding groove parts 55 and the locking parts 54 are fixedly mounted on the third fixing plate 53, and the first fixing plate 51 is inserted and mounted in the sliding groove part 55 and cooperates with the locking parts 54 to form a locking structure; this arrangement allows the first fixing plate 53 to be stably mounted on the seat frame 2.

In this embodiment, the chute member 55 includes two opposite chutes, which gradually approach from top to bottom, and the third fixing plate 53 is shaped to match with the two chutes. The third fixing plate 53 is configured so as not to penetrate through the chute member 55 when inserted downward.

In the present embodiment, the chute element 55 is inserted into the locking element 54, the locking element 54 extends upward to form a V-shaped extending portion 541, the first fixing plate 51 is provided with a third positioning hole 510, and the bottom of the extending portion 541 extends into the third positioning hole 510. With such an arrangement, when the first fixing plate 51 moves from top to bottom on the sliding groove member 55, the first fixing plate 51 will first abut against the bottom of the extending portion 541 and lift the bottom of the extending portion 541, and when the first fixing plate 51 moves to the end, the bottom of the extending portion 541 is also located at the third positioning hole 510, and then extends into the third positioning hole 510 to form a fastening structure, so that the first fixing plate 53 can be stably installed on the seat frame 2.

Example two:

the difference between this embodiment and the first embodiment is: the chair frame in the embodiment is provided with a footrest, and the rotation between the lower back frame 3 and the seat frame 2 is completed by an electric push rod.

In this embodiment, as shown in fig. 5-8, a first electric push rod 12, a footrest assembly 6 and a second driving mechanism are further provided, the first electric push rod 12 has one end rotatably mounted on the lower back frame 3 and the other end rotatably mounted on the seat frame 2, the footrest assembly 6 is rotatably mounted on the seat frame 2, the second driving mechanism is mounted on the seat frame 2,

the first electric push rod 12 is used for driving the lower back frame 3 to tilt relative to the seat frame 2;

the second driving mechanism is used for driving the footrest assembly 6 to rotate so as to lift and put down the footrest assembly 6, and enabling the footrest assembly 6 to extend in the lifting process of the footrest assembly 6 and enabling the footrest assembly 6 to shorten in the putting down process of the footrest assembly 6.

In this embodiment, the second driving mechanism includes a second electric push rod 13, a second linkage rod, a third link mechanism, a linkage assembly and two sets of left and right second link mechanisms, the second link mechanism connects the chair seat frame 2 and the footrest assembly 6, the third link mechanism is installed on the footrest assembly 6, the linkage assembly is rotatably installed on the chair seat frame 2 and connected with the third link mechanism, the second linkage rod is fixedly connected with or integrally formed with the second link mechanism, the rear end of the second electric push rod 13 is hinged with the chair seat frame 2, the front end of the second electric push rod 13 is hinged with the second linkage rod, and when the second electric push rod 13 extends, the footrest assembly 6 is lifted through the second link mechanism, and in the process of lifting the footrest assembly 6, the third link mechanism is driven by the lifting assembly to operate so as to extend the footrest assembly 6; when second electric putter 13 shortens, make footrest subassembly 6 put down through second link mechanism to in-process that footrest subassembly 6 put down drives the third link mechanism function simultaneously through the linkage subassembly and so that footrest subassembly 6 shortens.

In the embodiment of the present application, the second link mechanism includes a fifth link and a sixth link 62, the fifth link is rotatably installed at the side of the seat frame 2, one end of the fifth link is hinged with one end of the sixth link 62, and the other end of the sixth link 62 is rotatably installed at the side of the footrest assembly 6; 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.

Preferably, the chair is further provided with two parallel vertical third mounting plates and two parallel vertical fourth mounting plates, the second linkage rod is a square tube, the bottom end of the third mounting plate is fixedly connected with the second linkage rod in a welding mode, the top end of the third mounting plate is hinged to the front end of the second electric push rod 13, the top end of the fourth mounting plate is fixedly connected with the chair seat frame 2 in a welding mode, and the bottom end of the fourth mounting plate is hinged to the rear end of the second electric push rod 13; and the third mounting plate is mounted on the second linkage rod and the fourth mounting plate is mounted on the seat frame 2 through the combined action of the third mounting plate, the fourth mounting plate and the second electric push rod 13.

As shown in fig. 10, in the present embodiment, the footrest assembly 6 includes a first footrest 63 and a second footrest 64, the first footrest 63 is rotatably mounted on the seat frame 2, and the second footrest 64 is slidably mounted on the first footrest 63; more preferably, the first footrest 63 is mounted on the seat frame 2 through two second rotation shafts 14 which are bilaterally symmetrical and horizontally disposed, and rotates with the second rotation shafts 14 as rotation center shafts, and the second rotation shafts 14 are fixedly connected with the seat frame 2;

more preferably, the sixth link 62 is provided with a concave arc-shaped bent part at a part close to the footrest assembly 6; this is provided to enhance the structural strength of the sixth link 62 and to prevent the sixth link 62 from touching the second rotating shaft 14 during the rotation.

The third link mechanism comprises an eighth link 65 and a ninth link 66, the eighth link 65 is rotatably mounted on the first footrest 63, the rear end of the eighth link 65 is in transmission connection with the other end of the linkage assembly, the front end of the eighth link 65 is hinged with the rear end of the ninth link 66, and the front end of the ninth link 66 is rotatably mounted on the second footrest 64, further preferably, the distance between the front end of the eighth link 65 and the rotation center of the eighth link 65 is greater than the distance between the rear end of the eighth link 65 and the rotation center of the eighth link 65; this arrangement enlarges the sliding stroke of the second footrest 64.

In the embodiment of the present application, as shown in fig. 11, a first rotating shaft 15 and a vertical third rotating shaft 16 are further provided, the first rotating shaft 15 is fixedly connected with the seat frame 2, and the included angle between the first rotating shaft 15 and the horizontal plane does not exceed 30 degrees, the rear end of the eighth connecting rod 65 is mounted on the third rotating shaft 16, one end of the linkage assembly is rotatably mounted on the first rotating shaft 15, and one end of the linkage assembly is always located behind the second rotating shaft 14 during the rotation process; the other end of the linkage assembly is rotatably mounted on a third rotating shaft 16; with this arrangement, the eighth link 65 is pulled to rotate by the distance difference generated by the eccentric rotation, and the second footrest 64 is slid forward by the ninth link 66.

Further preferably, the first turning shaft 15 and the second turning shaft 14 are parallel to each other and located behind the second turning shaft 14.

Further preferably, a first spherical body 67 and a second spherical body 68 are further provided, wherein the first spherical body 67 is rotatably mounted on the first rotating shaft 15, the second spherical body 68 is rotatably mounted on the third rotating shaft 16, one end of the linkage assembly is rotatably mounted on the outer surface of the first spherical body 67, and the other end of the linkage assembly is rotatably mounted on the outer surface of the second spherical body 68; this arrangement is to alleviate a difference in displacement between one end of the link assembly and the other end of the link assembly in the up-down direction.

Further preferably, the linkage assembly comprises a connecting rod 69 and two linkage members 70 rotatably sleeved at two ends of the connecting rod 69, each linkage member 70 comprises a ring body and a cylinder which are integrally formed or fixedly connected, a connecting hole for the connecting rod 69 to be inserted is formed in the cylinder, and the ring bodies of the two linkage members 70 are respectively rotatably sleeved on the first spherical body 67 and the second spherical body 68; this is provided to alleviate the difference in angle between the two link members 70 rotated by different angles about the axis of the connecting rod 69.

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 above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle 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 chair frame comprises a chair seat frame (2), a chair back frame and a headrest frame, wherein the chair back frame is rotatably arranged on the chair seat frame (2) to enable the chair back frame to tilt forwards and backwards relative to the chair seat frame (2), the headrest frame is arranged on the chair back frame,

the chair back frame comprises a lower chair back frame (3) and an upper chair back frame (4), the lower chair back frame (3) is hinged with the chair seat frame (2), and the lower chair back frame (3) is hinged with the upper chair back frame (4); the headrest frame is arranged on the upper chair back frame (4),

the chair back frame is characterized by further comprising a left connecting rod device and a right connecting rod device (5), wherein the connecting rod devices (5) comprise a first connecting rod (50), a first fixing plate (51) and a second connecting rod (52), the first fixing plate (51) is fixedly installed on one side of the chair seat frame (2), the lower chair back frame (3) is hinged to the rear portion of the first fixing plate (51), one end of the first connecting rod (50) is hinged to the front portion of the first fixing plate (51), the other end of the first connecting rod (50) is hinged to one end of the second connecting rod (52), the other end of the second connecting rod (52) is hinged to the upper chair back frame (4), the first connecting rod (50), the first fixing plate (51), the second connecting rod (52), the lower chair back frame (3) and the upper chair back frame (4) form a five-rod mechanism, when the lower back-rest frame (3) tilts backwards, the connecting rod device (5) drives the upper back-rest frame (4) to rotate forwards.

2. A chair frame according to claim 1, characterized in that the angle of rearward rotation of the lower back frame (3) is greater than the angle of rearward rotation of the first link (50) during rearward rotation of the lower back frame (3) from the initial position to the maximum rotatable position.

3. A chair frame according to claim 1, characterized in that the lower back frame (3) is rotated backwards by a greater angle than the upper back frame (4) during the backward rotation of the lower back frame (3) from the initial position to the maximum rotation.

4. A chair frame according to claim 1, characterized in that two first limit stop members (41) and two second limit stop members (31) are provided;

the first limiting piece (41) is fixedly connected with the upper backrest frame (4) or integrally formed, and the second limiting piece (31) is fixedly connected with the lower backrest frame (3) or integrally formed; or, the first limiting piece (41) is fixedly connected with or integrally formed with the lower back frame (3) and the second limiting piece (31) is fixedly connected with or integrally formed with the upper back frame (4);

the first limiting piece (41) is matched with the second limiting piece (31) so as to limit the upper chair back frame (4) to rotate backwards.

5. The chair frame according to claim 4, wherein the first position-limiting member (41) is a column-shaped structure integrally formed with the upper back frame (4), the second position-limiting member (31) is a block-shaped structure formed by extending the upper end of the lower back frame (3) upward, and when the first position-limiting member (41) abuts against the second position-limiting member (31), the angle between the upper back frame (4) and the lower back frame (3) is 100 degrees and 180 degrees.

6. A chair frame according to claim 1, characterized in that the first link (50) comprises a first section (501), a second section (502) and a third section (503) which are integrally formed, wherein the first section (501) is hinged with the first fixing plate (51), the third section (503) is hinged with the second link (52), and the second section (502) is connected with the first section (501) and the third section (503) so that the bottom of the third section (503) is closer to the lower back frame (3).

7. The chair frame according to claim 1, wherein the left and right sides of the lower back frame (3) are provided with first positioning holes (32), the left and right sides of the upper back frame (4) are provided with second positioning holes (42), and when the first positioning holes (32) and the second positioning holes (42) are coaxially distributed, the included angle between the upper back frame (4) and the lower back frame (3) is 100-180 degrees.

8. A chair frame according to claim 1, characterized in that an air rod (11) is provided, one end of the air rod (11) is hinged with the lower back frame (3) and the other end is hinged with the chair seat frame (2);

or an electric push rod is further arranged, one end of the electric push rod is hinged with the lower chair back frame (3) and the other end of the electric push rod is hinged with the chair seat frame (2).

9. The chair frame according to claim 1, characterized in that a left third fixing plate (53), a right third fixing plate (53), a left sliding groove member (55), a right sliding groove member (55), a left clamping member (54), a right clamping member (54), a left sliding groove member (53), a right sliding groove member (55), a left sliding groove member (54), a right sliding groove member (55), a left sliding groove member (55), a right sliding groove member (54), a right sliding groove member; the first fixing plate (51) can be stably installed on the chair seat frame (2) through the arrangement;

the sliding groove piece (55) comprises two sliding grooves which are oppositely arranged, the two sliding grooves are gradually close from top to bottom, and the third fixing plate (53) is in a shape matched with the two sliding grooves.

10. A chair frame according to claim 9, wherein the chute member (55) is inserted into the fastener (54), the fastener (54) extends upwardly to form a V-shaped extension (541), the first fixing plate (51) is provided with a third positioning hole (510), and the bottom of the extension (541) extends into the third positioning hole (510).

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