SEAT-BACKREST LINKAGE DEVICE

Abstract

A seat-backrest linkage device includes a base, a bracket plate, a swing bracket and a connecting member. The connecting member includes a crank and a connecting plate connected as a whole. The swing bracket is provided between the base and the bracket plate. Two ends of the crank are respectively hinged to the bracket plate and the swing bracket. An slide groove guide mechanism is provided between the bracket plate and the swing bracket. The swing bracket and the base are hinged in middles, such that the swing bracket, the connecting member, and the bracket plate are capable of together tilting and swinging left and right relative to the base. The support plate seat can be raised and lowered relative to the base, and the swing bracket hinged to the base is arranged between the base and the support plate seat.

Claims

1. A seat-backrest linkage device, comprising a base (1), a support plate seat (2) configured to support a chair seat, a swing bracket (3), and a connecting member (5) configured to connect a backrest, wherein the connecting member (5) comprises a crank (501) and a connecting plate (502) that are arranged in a front-rear direction of the base (1) and connected as a whole, the swing bracket (3) is arranged between the base (1) and the support plate seat (2), two ends of the crank (501) are respectively hinged to the support plate seat (2) and the swing bracket (3), and a slide groove guide mechanism (8) configured to guide raising/lowering of the support plate seat (2) is provided between the support plate seat (2) and the swing bracket (3); and the swing bracket (3) and the base (1) are hinged in middles, such that the swing bracket (3), the connecting member (5), and the support plate seat (2) are capable of together tilting and swinging left and right relative to the base (1).

2. The seat-backrest linkage device according to claim 1, wherein in a front-rear direction of the base, the swing bracket (3) is of a frame structure, the swing bracket (3) comprises a front portion I (301) and a rear portion I (302) that are connected as a whole, and the base (1) comprises a front portion II (101) and a rear portion II (102) that are connected as a whole; the front portion I (301) and the front portion II (101) are rotatably connected on a left-right symmetrical centerline of the base, and the rear portion I (302) and the rear portion II (102) are rotatably connected on the left-right symmetrical centerline of the base; and the slide groove guide mechanism (8) is arranged between the front portion I (301) and the support plate seat (2), or the slide groove guide mechanism (8) is arranged between the rear portion I (302) and the support plate seat (2).

3. The seat-backrest linkage device according to claim 2, wherein on the swing bracket (3), side wings (3011) symmetrically extend from left and right sides of the front portion I (301); on the base (1), side lugs (1011) symmetrically extend from left and right sides of the front portion II (101); and elastic mechanisms (4) configured to provide a reset force for the swing bracket (3) after swinging are symmetrically arranged on left and right sides of the chassis, and each elastic mechanism (4) is arranged between the side wing (3011) and the side lug (1011) on the same side.

4. The seat-backrest linkage device according to claim 3, wherein the side wing (3011) and the side lug (1011) are oppositely arranged up and down, the elastic mechanisms (4) each comprise a swing pressure spring (401), and when the side wing (3011) swings along with the swing bracket (3), the swing pressure spring (401) is compressed to generate a reset elastic force.

5. The seat-backrest linkage device according to claim 4, wherein the elastic mechanisms (4) each further comprise a bolt (402) and a nut (403); the bolt (402) oppositely passes through the side wing (3011) and the side lug (1011), and a passing part of the bolt (402) is threadedly connected to the nut (403); the swing pressure spring (401) is sleeved on a section of the bolt (402) located between the side wing (3011) and the side lug (1011), and a swing range of the swing bracket (3) is limited between the nut (403) and the side wing (3011).

6. The seat-backrest linkage device according to claim 3, wherein in a longitudinal direction, the side wing (3011) and the side lug (1011) are each internally provided with an accommodating cavity (103) having a depth, opposite sides of the side wing (3011) and the side lug (1011) are open for communication, and upper and lower portions of the elastic mechanism (4) are respectively located in the upper and lower accommodating cavities (103).

7. The seat-backrest linkage device according to claim 3, wherein the side lug (1011) and the side wing (3011) are oppositely arranged up and down, the elastic mechanisms (4) each comprise a tension spring, and when the side wing (3011) swings along with the swing bracket (3), the tension spring is stretched to generate a reset elastic force.

8. The seat-backrest linkage device according to claim 1, wherein the base (1) comprises a bottom plate, side plates (1021) extending upwards from left and right sides of the bottom plate, and vertical plates (1022) extending upwards from front and rear sides of the bottom plate; the side plates (1021) are each provided with a waist-shaped hole (10211), the crank (501) is hinged to the swing bracket (3) through a first pin shaft (304), the first pin shaft (304) simultaneously passes through the waist-shaped holes (10211), and when the swing bracket (3) swings left and right, the first pin shaft (304) moves up and down in the waist-shaped holes (10211).

9. The seat-backrest linkage device according to claim 1, wherein the swing bracket (3) is of a frame structure; the swing bracket (3) comprises left and right symmetric baffles (306), and a front surrounding plate (307) and a rear surrounding plate (309) that are connected to front and rear sides of the baffles (306); and the base (1) is located in a space enclosed by the baffles (306), the front surrounding plate (307), and the rear surrounding plate (309).

10. The seat-backrest linkage device according to claim 1, wherein the crank (501) is in an inclined state, an upper end of the crank (501) is hinged to the support plate seat (2) through a third pin shaft (308), and a lower end of the crank (501) is hinged to the swing bracket (3) through a first pin shaft (304); the support plate seat (2) comprises a support plate (201) and hanging plates (202) hanging down on left and right sides of the support plate (201); the slide groove guide mechanism (8) comprises a limiting slide groove (801) and a second pin shaft (802); the limiting slide groove (801) is formed in one of the hanging plate (202) and the swing bracket (3), the second pin shaft (802) is connected to the other one of the hanging plate (202) and the swing bracket (3), and the second pin shaft (802) is inserted into the limiting slide groove (801); and when the connecting plate (502) drives the crank (501) to rotate synchronously, the support plate seat (2) rises or falls, and the second pin shaft (802) and the limiting slide groove (801) slide relatively.

11. The seat-backrest linkage device according to claim 3, further comprising a swing locking mechanism (9) configured to limit the swing bracket (3) in a horizontal state.

12. The seat-backrest linkage device according to claim 11, wherein the side wings (3011) each comprise a horizontally arranged side wing body (30111) and a wing plate (30112) vertically bent from an edge of the side wing body (30111); the side lugs (1011) each comprise a side lug body (10111) and a lug plate (10112) vertically bent from an edge of the side lug body (10111); the swing locking mechanism (9) comprises a locking pin (901); the wing plate (30112) and the lug plate (10112) are partially staggered up and down, and a guide hole (30113) and a locking hole (10113) opposite to each other in a horizontal direction are formed in the up-down staggered part; the locking pin (901) is inserted in the guide hole (30113), and the locking pin (901) is controlled to move; when the locking pin (901) is synchronously inserted in the guide hole (30113) and the locking hole (10113), the swing bracket (3) is in a locked state; and when the locking pin (901) leaves the locking hole (10113) and is inserted only in the guide hole (30113), the swing bracket (3) is unlocked.

13. The seat-backrest linkage device according to claim 12, wherein the lug plate (10112) comprises a support lug (10114) perpendicular to left and right side walls of the base, the support lug (10114) continuously extends upwards to form a convex lug (10115), the convex lug (10115) and the wing plate (30112) adjacent thereto are staggered up and down, the convex lug (10115) is located on an outer side of the wing plate (30112) adjacent thereto, the locking hole (10113) is formed in the convex lug (10115), and the guide hole (30113) is formed in the wing plate (30112).

14. The seat-backrest linkage device according to claim 12, wherein the swing locking mechanism (9) comprises a locking pin control mechanism (902); the locking pin control mechanism (902) comprises a locking bracket (9021) fixed to a front wall of the swing bracket (3), and a wire control II (9022); the wire control II (9022) comprises an outer sleeve (90221), and a pull wire (90222) telescopically moving in the outer sleeve (90221); the outer sleeve (90221) is mounted on the locking bracket (9021); a part, exposed out of the outer sleeve (90221), of the pull wire (90222) is connected to a pull wire end (90223); a pressure spring (903) is further provided between the pull wire end (90223) and the locking bracket (9021); the pressure spring (903) is arranged along an extension direction of the pull wire (90222); torsion springs II (904) are symmetrically arranged on left and right sides of the pull wire end (90223); a collar in a middle of the torsion spring II (904) is sleeved on a fastening screw (905) connected to an upper portion of the swing bracket (3) such that the torsion spring II (904) rotates integrally around the fastening screw (905); the torsion springs II (904) are each provided with an elastic force arm I (9041) and an elastic force arm II (9042) that are respectively arranged on two sides of the fastening screw (905), a tail end of the elastic force arm I (9041) is rolled into a lantern ring (90411), the lantern ring (90411) passes through the pull wire (90222) to abut against the pull wire end (90223), and the elastic force arm II (9042) is bend and passes through a moving hole (3012) reserved in the wing plate (30112) to be connected to the locking pin (901); when the pull wire (90222) moves in a shortening direction, the pressure spring (903) is compressed to generate a reset elastic force while the pull wire end (90223) drives the elastic force arm I (9041) to rotate, and the locking pin (901) moves synchronously to enter or leave the locking hole (10113); and when the pull wire (90222) is released, that is, moving in a lengthening direction, the pressure spring (903) releases an elastic force to assist the pull wire end (90223), the torsion spring II (904), and the locking pin (901) in resetting.

15. The seat-backrest linkage device according to claim 8, further comprising a lifting locking mechanism (7) configured to keep the support plate seat (2) raised or lowered to a horizontal state.

16. The seat-backrest linkage device according to claim 15, wherein the lifting locking mechanism (7) comprises a locking plate (6); the locking plate (6) is located between a third pin shaft (308) and a second pin shaft (802), the locking plate (6) is movably connected to the second pin shaft (802), the locking plate (6) is fixedly connected to the third pin shaft (308), and a plurality of pin holes (601) are formed in a front end of the locking plate (6) exceeding the third pin shaft (308); the lifting locking mechanism (7) further comprises opposite side vertical plates (701); the side vertical plates (701) are fixed on a front wall of the swing bracket (3), the side vertical plates (701) are parallel to the locking plate (6), and guide holes (7011) are formed in the side vertical plates (701); the lifting locking mechanism (7) further comprises insertion pins (705); the insertion pins (705) are inserted in the guide holes (7011), and the insertion pins (705) are controlled to move; when the insertion pins (705) are synchronously inserted in the guide holes (7011) and the pin holes (601), the locking plate (6) is in a locked state; and when the insertion pins (705) leave the pin holes (601) and are inserted only in the guide holes (7011), the locking plate (6) is unlocked.

17. The seat-backrest linkage device according to claim 15, wherein the lifting locking mechanism (7) further comprises an insertion pin control mechanism (702); the insertion pin control mechanism (702) comprises a wire control bracket (7021) fixed to a periphery of the side vertical plates (701), and a wire control I (7022); the wire control I (7022) comprises an outer tube (70221), and a pull rope (70222) telescopically moving in the outer tube (70221); the outer tube (70221) is mounted on the wire control bracket (7021); a part, exposed out of the outer tube, of the pull rope (70222) is connected to a pull rope end (70223); a waist-shaped pressure spring (7023) is further provided between the pull rope end (70223) and the wire control bracket (7021); the waist-shaped pressure spring (7023) is arranged along an extension direction of the pull rope (70222); a torsion spring I (7024) is provided on a right side of the pull rope end; a collar in a middle of the torsion spring I (7024) is sleeved on a fastening screw (7025) at an upper portion of the wire control bracket (7021) such that the torsion spring I (7024) rotates integrally around the fastening screw (7025); the torsion spring I (7024) is provided with an elastic arm I (70241) and an elastic arm II (70242) that are respectively arranged on two sides of the fastening screw (7025), a tail end of the elastic arm I (70241) is rolled into a lantern ring (702411), the lantern ring (702411) passes through the pull rope (70222) to abut against the pull rope end (70223), and the elastic arm II (70242) is bend and inserted in a right side of the insertion pin (705); when the pull rope (70222) moves in a shortening direction, the waist-shaped pressure spring (7023) is compressed to generate a reset elastic force while the pull rope end (70223) drives the elastic arm I (70241) to rotate, and the insertion pins (705) move synchronously to enter the pin holes (601); and when the pull rope (70222) is released, that is, moving in a lengthening direction, the waist-shaped pressure spring (7023) releases an elastic force to assist the pull rope end (70223), the torsion spring I (7024), and the insertion pins (705) in resetting.

18. The seat-backrest linkage device according to claim 16, wherein limiting bosses (602) are provided at upper and lower parts of the front end of the locking plate (6) facing outwards, a fixing pin (603) is fixed to an upper end of the side vertical plate (701), an end of the fixing pin (603) facing the locking plate (6) protrudes from the side vertical plate (701) to form a limiting end (6031), and when the support plate seat (2) is hoisted or reset to a horizontal position, the fixing pin (603) is always located between the two bosses (602).

19. The seat-backrest linkage device according to claim 3, wherein the side wing (3011) and the side lug (1011) are oppositely arranged up and down, the elastic mechanisms (4) each comprise elastic rubber (404), and when the side wing (3011) swings along with the swing bracket (3), the elastic rubber (404) is compressed to generate a reset elastic force.

20. The seat-backrest linkage device according to claim 19, wherein mounting columns (4041) are provided at two ends of the elastic rubber (404), and the two mounting columns (4041) are fixedly inserted in preset holes in the side wing (3011) and the side lug (1011), respectively.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a schematic overall perspective view of an adaptive chassis for a chair seat according to the present disclosure;

[0013] FIG. 2 is an exploded view of an adaptive chassis according to the present disclosure;

[0014] FIG. 3 is a lateral view when a support plate seat of an adaptive chassis is horizontal according to the present disclosure;

[0015] FIG. 4 is a front view when a swing bracket of an adaptive chassis is horizontal according to the present disclosure;

[0016] FIG. 5 is a front view when a swing bracket of an adaptive chassis tilts leftwards according to the present disclosure;

[0017] FIG. 6 is a front view when a swing bracket of an adaptive chassis tilts rightwards according to the present disclosure;

[0018] FIG. 7 is a perspective view of connection of a swing bracket, a base, and an elastic mechanism of an adaptive chassis according to the present disclosure;

[0019] FIG. 8 is a partial sectional view of connection of a swing bracket, a base, and an elastic mechanism of an adaptive chassis according to the present disclosure;

[0020] FIG. 9 is an exploded view of connection of a swing bracket, a base, and an elastic mechanism of an adaptive chassis according to the present disclosure;

[0021] FIG. 10 is a lateral view when a support plate seat of an adaptive chassis is raised according to the present disclosure;

[0022] FIG. 11 is a lateral perspective view when a support plate seat of an adaptive chassis is raised according to the present disclosure;

[0023] FIG. 12 is another lateral perspective view when a support plate seat of an adaptive chassis is raised according to the present disclosure;

[0024] FIG. 13 is a perspective view of connection of a swing locking mechanism, a swing bracket, a base, and an elastic mechanism of an adaptive chassis according to the present disclosure;

[0025] FIG. 14 is a partial sectional view when a swing bracket of an adaptive chassis is in an unlocked state according to the present disclosure;

[0026] FIG. 15 is a partial sectional view when a swing bracket of an adaptive chassis is in a locked state according to the present disclosure;

[0027] FIG. 16 is a perspective view of a lifting locking mechanism of an adaptive chassis according to the present disclosure;

[0028] FIG. 17 is another perspective view of a lifting locking mechanism of an adaptive chassis according to the present disclosure; and

[0029] FIG. 18 illustrates a left-right swing elastic mechanism of an adaptive chassis according to the present disclosure.

[0030] Reference Numerals: 1base; 101front portion II; 1011side lug; 10111side lug body; 10112lug plate; 10113locking hole; 10114support lug; 10115convex lug; 102rear portion II; 1021side plate; 10211waistshaped hole; 103accommodating cavity; 2support plate seat; 201support plate; 202hanging plate; 3swing bracket; 301front portion I; 3011side wing; 30111side wing body; 30112wing plate; 3012moving hole; 302rear portion I; 304first pin shaft; 306baffle; 307front surrounding plate; 308third pin shaft; 309rear surrounding plate; 4elastic mechanism; 401swing pressure spring; 402bolt; 403nut; 404elastic rubber;

[0031] 5connecting member; 501crank; 502connecting plate; 6locking plate; 601pin hole; 602boss; 603fixing pin; 6031limiting end; 7lifting locking mechanism; 701side vertical plate; 7011guide hole; 702insertion pin control mechanism; 7021wire control bracket; 7022wire control I; 70221outer tube; 70222pull rope; 70223pull rope end; 7023waistshaped pressure spring; 7024torsion spring I; 70241elastic arm I; 702411collar; 70242elastic arm II; 7025fastening screw; 705insertion pin; 8slide groove guide mechanism; 801limiting slide groove; 802second pin shaft; 9swing locking mechanism; 901locking pin; 902locking pin control mechanism; 9021locking bracket; 9022wire control II; 90221outer sleeve; 90222pull wire; 90223pull wire end; 903pressure spring; 904torsion spring II; 9041elastic force arm I; 90411lantern ring; 9042elastic force arm II; and 905fastening screw.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The present disclosure will be further described below with specific embodiments. The invention patent with the application publication number of CN109419196A discloses a synchronous linkage device for a backrest of an office chair. This linkage mode adapts to the user's weight to drive a chair seat to move when a backrest reclines, but cannot adapt to the user's sitting posture of left or right leaning.

[0033] On the basis of the above reasons, the seat-backrest linkage device in this embodiment is shown in FIGS. 1-18:

[0034] As shown in FIGS. 1 and 2, an adaptive chassis for a chair seat includes a base 1, a support plate seat 2 configured to support a chair seat, and a connecting member 5 configured to connect a backrest. The connecting member 5 includes a crank 501 and a connecting plate 502 that are arranged in a front-rear direction of the base 1 and connected as a whole. In addition, the adaptive chassis further includes a swing bracket 3, where the swing bracket 3 is arranged between the base 1 and the support plate seat 2.

[0035] Specifically, as shown in FIGS. 3 and 10, two ends of the crank of the connecting member are respectively hinged to the support plate seat and the swing bracket. The crank 501 is in an inclined state, an upper end of the crank 501 is hinged to the support plate seat 2 through a third pin shaft 308, and a lower end of the crank 501 is hinged to the swing bracket 3 through a first pin shaft 304. A slide groove guide mechanism 8 configured to guide raising/lowering of the support plate seat 2 is provided between the support plate seat 2 and the swing bracket 3. The support plate seat can be guided by the slide groove guide mechanism, arranged between the support plate seat and the swing bracket, to be raised or lowered. The swing bracket and the base 1 are hinged in middles, such that the swing bracket, the connecting member, and the support plate seat are capable of together tilting and swinging left and right relative to the base 1. The support plate seat 2 includes a support plate 201 and hanging plates 202 hanging down on left and right sides of the support plate 201. The slide groove guide mechanism 8 includes a limiting slide groove 801 and a second pin shaft 802. The limiting slide groove 801 is formed in one of the hanging plate 202 and the swing bracket 3, the second pin shaft 802 is connected to the other one of the hanging plate 202 and the swing bracket 3, and the second pin shaft 802 is inserted into the limiting slide groove 801. The connecting plate 502 is connected to a seat back. When the connecting plate 502 drives the crank 501 to rotate synchronously, the support plate seat 2 rises or falls, and the second pin shaft 802 and the limiting slide groove 801 slide relatively. That is, when the user leans on or leaves the backrest, the chair seat can be raised or lowered adaptively according to the user's weight. When the connecting plate drives the crank to rotate relative to the swing bracket, the crank drives the support plate seat to be raised or lowered. Since the second pin shaft is connected to the hanging plate or the swing bracket, and the second pin shaft can only slide relatively in the limiting slide groove, the raising and lowering of the support plate seat are smooth and stable. FIG. 3 shows that the support plate seat 2 is in a horizontal state. FIG. 10 shows that the support plate seat 2 is in a raised state. This embodiment only describes the action that the support plate seat 2 can adapt to the user's weight and can be raised and lowered as the user leans against or leaves the backrest. For other specific details, please refer to the detailed description of the inventor in the invention patent with the application publication number of CN109419196A.

[0036] Furthermore, on the basis of the action that the support plate seat 2 can adapt to the user's weight and can be raised and lowered as the user leans against or leaves the backrest, the swing bracket 3 is arranged between the base 1 and the support plate seat 2. The swing bracket and the base 1 are hinged in the middle. The support plate seat and the swing bracket can tilt and swing left and right relative to the base 1. The support plate seat can also tilt and swing left and right as the user leans left or right. The user can change the sitting posture to relieve the discomfort caused by sitting for a long time. The swing bracket 3 is of a frame structure. In a front-rear direction of the chassis, the swing bracket 3 includes a front portion I 301 and a rear portion I 302 that are connected as a whole, and the base 1 includes a front portion II 101 and a rear portion II 102 that are connected as a whole. The front portion I 301 and the front portion II 101 are rotatably connected on a left-right symmetrical centerline of the base, and the rear portion I 302 and the rear portion II 102 are rotatably connected on the left-right symmetrical centerline of the base. As shown in FIGS. 5 and 6, the swing bracket 3 can tilt and swing left and right relative to the base as a whole. In addition, the slide groove guide mechanism 8 can be arranged between the rear portion I 302 and the support plate seat 2 as shown in FIG. 3, and can also be arranged between the front portion I 301 and the support plate seat 2. The front and rear portions of the swing bracket are rotatably connected to the front and rear portions of the base 1, respectively, such that the swing bracket can tilt and swing left and right relative to the base 1. The position of the slide groove guide structure can be set according to the requirements of the chassis structure and the inclination direction of the crank. The chassis further includes a swing locking mechanism configured to limit the swing bracket in a horizontal state. The swing locking mechanism is arranged such that when the user does not need the chair seat to swing left and right, the swing locking mechanism can be activated to fix the chair seat at a horizontal position.

[0037] Furthermore, as shown in FIGS. 8 and 9, on the swing bracket 3, side wings 3011 symmetrically extend from left and right sides of the front portion I 301. On the base 1, side lugs 1011 symmetrically extend from left and right sides of the front portion II 101. The side wing 3011 and the side lug 1011 are oppositely arranged up and down. In a longitudinal direction, the side wing 3011 and the side lug 1011 are each internally provided with an accommodating cavity 103 having a depth, opposite sides of the side wing 3011 and the side lug 1011 are open for communication. Spaces formed above and below the accommodating cavity can accommodate the elastic mechanisms, such that the elastic mechanisms operate stably. The elastic mechanisms 4 configured to provide a reset force for the swing bracket 3 after swinging are symmetrically arranged on left and right sides of the chassis, and each elastic mechanism 4 is arranged between the side wing 3011 and the side lug 1011 on the same side, and the upper and lower parts thereof are respectively located in the upper and lower accommodating cavities 103. On the one hand, the structure is simple and compact; on the other hand, when the swing bracket tilts to the left or right relative to the base 1, the elastic mechanisms buffer the swing action of the swing bracket, thereby increasing the comfort of the user in use.

[0038] Furthermore, as shown in FIG. 9, to make the structure of the chassis compact, the swing bracket 3 is set to be a frame structure. The swing bracket 3 includes left and right symmetric baffles 306, and a front surrounding plate 307 and a rear surrounding plate 309 that are connected to front and rear sides of the baffles 306. The base 1 is located in a space enclosed by the baffles 306, the front surrounding plate 307, and the rear surrounding plate 309. The base 1 is located in the space enclosed by the baffles, the front surrounding plate, and the rear surrounding plate, such that the structure of the whole chassis is compact.

[0039] Furthermore, as shown in FIGS. 8 and 9, the elastic mechanisms 4 each includes an elastic member capable of generating a reset elastic force, such as a swing pressure spring 401. When the side wing 3011 swings along with the swing bracket 3, the swing pressure spring 401 is compressed to generate a reset elastic force. The swing pressure spring of the elastic mechanism is an elastic member. When the swing bracket is inclined, the elastic member is compressed to generate a reset elastic force. When the user leaves or leans to the other side, the reset elastic force will work to make the chair seat return to be horizontal or help the chair seat tilt to the other side. In addition, the elastic member may also be a tension spring. When the side wing 3011 swings along with the swing bracket 3, the tension spring is tensioned to generate a reset elastic force. The elastic member of the elastic mechanism 4 can generate a reset elastic force to help the chair seat to reset or tilt, and can also provide a buffer force for the tilt of the chair seat, thereby improving the comfort of the user when sitting and leaning left or right.

[0040] Furthermore, as shown in FIGS. 8 and 9, when the elastic member of the elastic mechanism 4 is a swing pressure spring 401, the elastic mechanism 4 further includes a bolt 402 and a nut 403. The bolt 402 oppositely passes through the side wing 3011 and the side lug 1011, and a passing part of the bolt 402 is threadedly connected to the nut 403. The swing pressure spring 401 is sleeved on a section of the bolt 402 located between the side wing 3011 and the side lug 1011. In this way, the swing range of the swing bracket 3 is limited between the nut 403 and the side wing 3011. The swing pressure spring is sleeved on the bolt, and the part of the bolt passing through the side wing is threadedly connected to the nut. The swing range of the swing bracket is limited between the nut and the side wing. The swing range of the swing bracket is limited to prevent the swing bracket 3 from hitting the base 1 surrounded by the swing bracket 3 when tilting left or right, thereby causing abnormal noise or even damage.

[0041] Furthermore, as shown in FIG. 18, the elastic member of the elastic mechanism 4 may also be elastic rubber 404. Mounting columns 4041 are provided at two ends of the elastic rubber 404, and the two mounting columns 4041 are fixedly inserted in preset holes in the side wing 3011 and the side lug 1011, respectively. The mounting columns are directly inserted in the preset holes in the side wing and side lug, such that the structure is simple and mounting is convenient. The elastic rubber has elasticity and compression and stretching properties. On the one hand, the elastic rubber can provide a buffer force for the swing action to improve the user's comfort when swinging. On the other hand, the elastic rubber can also generate a reset elastic force to help the swing bracket reset and make the swing range of the swing seat within the stretching range of the rubber. When the side wings 3011 swing with the swing bracket 3, the side wing 3011 on one side compresses the elastic rubber 404 to generate a reset elastic force, and the side wing 3011 on the other side stretches the elastic rubber 404, such that the swing bracket 3 swings within the stretching range of the elastic rubber 404.

[0042] Furthermore, as shown in FIGS. 8 and 9, the base 1 includes a bottom plate, side plates 1021 extending upwards from left and right sides of the bottom plate, and vertical plates 1022 extending upwards from front and rear sides of the bottom plate. The side plates 1021 are each provided with a waist-shaped hole 10211, the crank 501 is hinged to the swing bracket 3 through a first pin shaft 304, and the first pin shaft 304 simultaneously passes through the waist-shaped holes 10211. When the swing bracket 3 swings left and right, the first pin shaft 304 moves up and down in the waist-shaped holes 10211. A waist-shaped hole is formed in the side plate, and the first pin shaft has a moving space in the waist-shaped hole, such that the rear portion of the swing bracket 3 swings left and right smoothly and the range is further limited to avoid the swing bracket 3 hitting the base 1 when swinging and generating abnormal noise.

[0043] However, when the user does not need to tilt the swing bracket 3 left and right, and needs to keep the swing bracket 3 in the horizontal state, the adaptive chassis is provided with a swing locking mechanism 9.

[0044] Furthermore, as shown in FIG. 13, the swing locking mechanism 9 includes a locking pin 901 and a locking pin control mechanism 902. The locking pin 901 is inserted in the guide hole 30113. Specifically, the side wings 3011 each include a horizontally arranged side wing body 30111 and a wing plate 30112 vertically bent from an edge of the side wing body 30111. The side lugs 1011 each include a side lug body 10111 and a lug plate 10112 vertically bent from an edge of the side lug body 10111. The wing plate and the lug plate are staggered up and down at some positions, and the staggered parts are provided with guide holes 30113 and locking holes 10113 corresponding to the horizontal position.

[0045] The lug plate 10112 includes a support lug 10114 perpendicular to left and right side walls of the base, the support lug 10114 continuously extends upwards to form a convex lug 10115, the convex lug 10115 and the wing plate 30112 adjacent thereto are staggered up and down, the convex lug 10115 is located on an outer side of the wing plate 30112 adjacent thereto, the locking hole 10113 is formed in the convex lug 10115, and the guide hole 30113 is formed in the wing plate 30112. The convex lug and the wing plate are staggered up and down, such that the swing bracket will not be interfered when swinging left and right. The convex lug is close to the wing plate, such that when the swing bracket switches between the locked and unlocked states, the movement distance of the locking pin is small, thereby reducing the switching error.

[0046] The locking pin is inserted in the guide hole, and the locking pin is controlled to move. When the locking pin is synchronously inserted in the guide hole and the locking hole, the swing bracket is in the locked state; and when the locking pin leaves the locking hole and is inserted only in the guide hole, the swing bracket is unlocked. The position of the base is fixed. When the swing bracket needs to be locked, the locking pins are synchronously inserted in the guide holes of the wing plates of the swing bracket and the locking holes of the lug plates of the base, the position of the swing bracket is fixed relative to the base. When the swing bracket needs to swing, and the locking pins leave the locking holes and are inserted only in the guide holes, the swing bracket can swing left and right relative to the base. The chair seat can be locked and unlocked by simply matching the pins and the holes, such that the structure is simple, and the cost is low. The pins and the holes are arranged on the side wings and the side lugs on the left and right sides of the swing bracket and the base, and a locking force arm for locking the swing of the swing bracket is added, thereby enhancing the swing locking effect.

[0047] The locking pin control mechanism 902 includes a locking bracket 9021 fixed to a front wall of the swing bracket 3, and a wire control II 9022. The wire control II 9022 includes an outer sleeve 90221, and a pull wire 90222 telescopically moving in the outer sleeve 90221. The outer sleeve 90221 is mounted on the locking bracket 9021. A part, exposed out of the outer sleeve 90221, of the pull wire 90222 is connected to a pull wire end 90223. A pressure spring 903 is further provided between the pull wire end 90223 and the locking bracket 9021. The pressure spring 903 is arranged along an extension direction of the pull wire 90222. Torsion springs II 904 are symmetrically arranged on left and right sides of the pull wire end 90223. A collar in a middle of the torsion spring II 904 is sleeved on a fastening screw 905 connected to an upper portion of the swing bracket 3 such that the torsion spring II 904 rotates integrally around the fastening screw 905. The torsion springs II 904 are each provided with an elastic force arm I 9041 and an elastic force arm II 9042 that are respectively arranged on two sides of the fastening screw 905, a tail end of the elastic force arm I 9041 is rolled into a lantern ring 90411, the lantern ring 90411 passes through the pull wire 90222 to abut against the pull wire end 90223, and the elastic force arm II 9042 is bend and passes through a moving hole 3012 reserved in the wing plate 30112 to be connected to the locking pin 901.

[0048] Furthermore, when the pull wire 90222 moves in a shortening direction, the pressure spring 903 is compressed to generate a reset elastic force while the pull wire end 90223 drives the elastic force arm I 9041 to rotate. As shown in FIG. 15, the locking pins 901 synchronously move and are synchronously inserted in the guide holes 30113 and the locking holes 10113, the swing bracket 3 is in the locked state. When the pull wire 90222 is released, that is, moving in a lengthening direction, the pressure spring 903 releases an elastic force to assist the pull wire end 90223, the torsion spring II 904, and the locking pin 901 in resetting. By shortening or lengthening the pull wire of the wire control, the torsion springs II at both ends of the swing bracket rotate simultaneously, and drive the locking pins to move, thereby locking and unlocking the swing bracket. This mode has a simple structure, is easy to operate, and is convenient to arrange. As shown in FIG. 14, when the locking pins 901 leave the locking holes 10113 and are inserted only in the guide holes 30113, the swing bracket 3 is unlocked.

[0049] In addition, unlike the locking mechanism in the invention patent with the application publication number of CN109419196A that keeps the support plate seat 2 raised or lowered to a horizontal state, the adaptive chassis for a chair seat of the present disclosure further includes a lifting locking mechanism 7 configured to keep the support plate seat raised or lowered to a horizontal state. The lifting locking mechanism is arranged such that when the user does not need the chair seat to be raised or lowered, the lifting locking mechanism can be activated to keep the chair seat at a required position.

[0050] Specifically, as shown in FIG. 16, the lifting locking mechanism 7 includes a locking plate 6. The locking plate 6 is located between the third pin shaft 308 and the second pin shaft 802, the locking plate 6 is movably connected to the second pin shaft 802, the locking plate 6 is fixedly connected to the third pin shaft 308, and a plurality of pin holes 601 are formed in a front end of the locking plate 6 exceeding the third pin shaft 308. The lifting locking mechanism 7 further includes opposite side vertical plates 701. The side vertical plates 701 are fixed on the front wall of the swing bracket 3, the side vertical plates 701 are parallel to the locking plate 6, and guide holes 7011 are formed in the side vertical plates 701. When insertion pins are synchronously inserted in the guide holes and the pin holes, since the side vertical plates are fixed to the front wall of the swing bracket, the position of the locking plate is fixed and the position of the third pin shaft fixedly connected thereto is also fixed, so the raising/lowering of the support plate seat is locked. When the insertion pins leave the pin holes and are only inserted in the guide holes, the locking plate is unlocked, and the position of the third pin shaft fixedly connected to the locking plate is also unlocked, so the raising/lowering of the support plate seat is unlocked. The locking plate is arranged between the third pin shaft and the second pin shaft, and the pin holes in the locking plate are combined with the insertion pins to achieve the purpose of locking and unlocking the support plate seat, thereby reasonably utilizing the structural space of the chassis, and making the structure of the chassis compact.

[0051] Furthermore, as shown in FIG. 16, the lifting locking mechanism 7 further includes insertion pins 705 and an insertion pin control mechanism 702. The insertion pins 705 are inserted in the guide holes 7011, and the insertion pins are controlled to move. The insertion pin control mechanism 702 includes a wire control bracket 7021 fixed to a periphery of the side vertical plates 701, and a wire control I 7022. The wire control I 7022 includes an outer tube 70221, and a pull rope 70222 telescopically moving in the outer tube 70221. The outer tube 70221 is mounted on the wire control bracket 7021. A part, exposed out of the outer tube, of the pull rope 70222 is connected to a pull rope end 70223. A waist-shaped pressure spring 7023 is further provided between the pull rope end 70223 and the wire control bracket 7021. The waist-shaped pressure spring 7023 is arranged along an extension direction of the pull rope 70222. A torsion spring I 7024 is provided on a right side of the pull rope end. A collar in a middle of the torsion spring I 7024 is sleeved on a fastening screw 7025 at an upper portion of the wire control bracket 7021 such that the torsion spring I 7024 rotates integrally around the fastening screw 7025. The torsion spring I 7024 is provided with an elastic arm I 70241 and an elastic arm II 70242 that are respectively arranged on two sides of the fastening screw 7025. A tail end of the elastic arm I 70241 is rolled into a lantern ring 702411, the lantern ring 702411 passes through the pull rope 70222 to abut against the pull rope end 70223, and the elastic arm II 70242 is bend and inserted in a right side of the insertion pin 705.

[0052] Furthermore, when the pull rope 70222 moves in a shortening direction, the waist-shaped pressure spring 7023 is compressed to generate a reset elastic force while the pull rope end 70223 drives the elastic arm I 70241 to rotate, the insertion pins 705 move synchronously and are synchronously inserted in the guide holes 7011 and the pin holes 601, and the locking plate 6 is in the locked state. When the pull rope 70222 is released, that is, moving in a lengthening direction, the waist-shaped pressure spring 7023 releases an elastic force to assist the pull rope end 70223, the torsion spring I 7024, and the insertion pins 705 in resetting. When the insertion pins 705 leave the pin holes 601 and are inserted only in the guide holes 7011, the locking plate 6 is unlocked.

[0053] Furthermore, both the swing locking mechanism 9 and the lifting locking mechanism 7 employ the wire control mode to control the lengths of the pull ropes and pull wires in the wire controls to twist the torsion springs, and at the same time drive the pins to move to enter or leave the locking holes, thereby achieving the purpose of locking or unlocking. This locking mode achieves a simple and compact structure. Since the wire controls are soft, the wire controls can be arranged flexibly, either front-to-back or left-to-right. The terminals of the wire controls are provided with switches for keeping the wire controls shortened or extended. The swing locking mechanism 9, the lifting locking mechanism 7, and even the switches of seat air springs can be concentrated at a certain place of the seat.

[0054] Furthermore, to further limit the raising/lowering range of the chair seat, as shown in FIG. 12, limiting bosses 602 are provided at upper and lower parts of the front end of the locking plate 6 facing outwards, a fixing pin 603 is fixed to an upper end of the side vertical plate 701, an end of the fixing pin 603 facing the locking plate 6 protrudes from the side vertical plate 701 to form a limiting end 6031, and when the support plate seat 2 is hoisted or reset to a horizontal position, the fixing pin 603 is always located between the two bosses 602. Therefore, the raising/lowering of the support plate seat is within the distance between the two bosses, such that the chair seat is raised/lowered within the range.