Adjustable waist support of seat and seat

Abstract

The utility model discloses an adjustable waist support of a seat and the seat, the adjustable waist support of the seat comprises a main waist support, a side wing waist support, a first connecting seat, a second connecting seat and an elastic piece; the first connecting base can rotate around an axis relative to the second connecting base so that the side wing waist support can have the freedom degree of rotation relative to the main waist support. The first connecting base is provided with a locking piece which can move in a plane perpendicular to the axis and can rotate relative to the second connecting base around the axis along with the first connecting base, the second connecting base is provided with a plurality of locking parts arranged around the axis, and the locking piece is provided with a clamping part. The elastic piece is used for providing elastic stress applied to the locking piece so that the locking piece can always have the trend of moving towards the direction close to the locking part along the plane. The waist support can be suitable for users of different body types, and meanwhile the waist support can be adjusted to the best posture according to different sitting postures so as to provide good support for the waist of the user.

Description

Technical Field

[0001] The utility model relates to the technical field of seats, in particular to an adjustable lumbar support for a seat and the seat. Background Art

[0002] Many existing gaming chairs and study chairs are equipped with lumbar supports to support the user's waist and prevent the user's waist from being suspended in the air and causing waist muscle fatigue. The lumbar supports of existing chairs are usually a single-piece structure. When the chair is in use, the single-piece lumbar support maintains a specific supporting posture to support the back of the user's waist, and both sides of the user's waist are suspended in the air and cannot get good support.

[0003] Some chairs also have lumbar supports that adopt a three-piece structure, with a main lumbar support set in the middle of the lumbar support, and a side lumbar support set on both sides of the main lumbar support. When the chair is in use, the main lumbar support supports the back of the waist, and the two side lumbar supports respectively support the two sides of the waist. The user's waist is wrapped with the main lumbar support and the two side lumbar supports. However, the side lumbar supports of the existing three-piece lumbar support are usually fixed to the sides of the main lumbar support, and they are fixed with the main lumbar support, that is, the angle between the side lumbar support and the main lumbar support is fixed. The side lumbar support can only provide support to the sides of the user's waist at a fixed angle, which makes it difficult to meet the individual needs of users with different body shapes and different sitting postures. Utility Model Content

[0004] The utility model aims to provide an adjustable lumbar support for a seat and a seat, which can be adjusted according to needs to provide better support for the waist of the user according to the different body shapes and sitting postures of the user.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An adjustable lumbar support of a seat, comprising a main lumbar support, a side lumbar support, a first connecting seat, a second connecting seat, and an elastic member;

[0007] The main lumbar support is connected to one of the first connection seat and the second connection seat, and the wing lumbar support is connected to the other of the first connection seat and the second connection seat; the first connection seat can rotate relative to the second connection seat around an axis so that the wing lumbar support has a degree of freedom to rotate relative to the main lumbar support;

[0008] The first connecting seat is provided with a locking member which can move in a plane perpendicular to the axis and can rotate relative to the second connecting seat around the axis as the first connecting seat; the second connecting seat is provided with a plurality of locking parts arranged around the axis; the locking member is provided with a latching part for combining with one of the locking parts; the elastic member is used to provide an elastic stress applied to the locking member so that the locking member always has a tendency to move along the plane in a direction close to the locking part.

[0009] Preferably, the second connecting seat is provided with a mounting groove which is recessed downward from its top surface, a plurality of locking portions are provided on the inner surface of the side wall of the mounting groove, and the locking member is located in the mounting groove.

[0010] Preferably, the multiple locking parts are divided into two groups, the two groups of locking parts are arranged opposite to each other, two opposite locking members are arranged on the first connecting seat, and the elastic member is placed between the two locking members to push the two locking members toward the two groups of locking parts respectively.

[0011] Preferably, the locking member includes a semicircular movable seat, the inner side of the movable seat forms a supporting plane, the outer side forms an arc surface, the locking portion is a locking boss protruding outward from the middle of the arc surface, and the locking portion is a locking groove arranged on the inner surface of the side wall of the installation groove and matching the shape of the locking boss.

[0012] Preferably, the elastic member is a spring or a spring sheet clamped between the supporting planes of the two movable seats.

[0013] Preferably, the first connecting seat and the second connecting seat are rotatably connected together by a rotating shaft running across the two, and an avoidance recess is provided in the middle of the supporting plane, and the avoidance recesses on the two supporting planes together form an avoidance hole for the rotating shaft to pass through; two elastic members are clamped between the two supporting planes, and the two elastic members are respectively placed on both sides of the rotating shaft.

[0014] Preferably, a mounting seat embedded in the mounting groove is provided on the first connecting seat, and a groove formed by an upward depression of the bottom surface thereof is provided on the mounting seat, and two through grooves penetrating from the inner surface to the outer surface thereof are provided on the side wall of the groove, and two locking members are located in the groove, and the locking bosses on the two locking members are respectively slidably embedded in the two through grooves so that the two locking members can rotate relative to the second connecting seat around the rotating axis with the first connecting seat, and the locking bosses of the locking members protrude from the outer surface of the mounting seat.

[0015] Preferably, a limiting groove extending along the circumferential direction of the rotating shaft is arranged on the inner surface of the side wall of the mounting groove, and a limiting block embedded in the limiting groove and capable of sliding between the two ends of the limiting groove is arranged on the outer surface of the mounting seat.

[0016] Preferably, the first connecting seat is provided with a clamping groove which is recessed upward from its bottom surface, and the mounting seat is provided with a boss which is clamped in the clamping groove so that the mounting seat and the first connecting seat cooperate synchronously. The mounting seat is provided with a through hole for the rotating shaft to pass through, and a threaded hole is provided on the top surface of the clamping groove. One end of the rotating shaft abuts against the second connecting seat, and the other end passes through the through hole of the mounting seat and is screwed in the threaded hole.

[0017] A seat including an adjustable lumbar support for the seat as described above.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] In the utility model, the side lumbar support is rotatably connected to the main lumbar support through the first connecting seat and the second connecting seat, and the relative rotation position of the first connecting seat and the second connecting seat can be locked by utilizing the engagement of the locking portion on the locking member with the plurality of locking portions, so as to realize the adjustment of the rotation angle of the side lumbar support, thereby enabling the side lumbar support to be relatively fixed with the main lumbar support at a plurality of different angles, so that the lumbar support can be suitable for users of different body shapes, and the lumbar support can also be adjusted to the best posture according to different sitting postures, thereby providing better support for the user's waist. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of an adjustable lumbar support for a seat of the utility model;

[0021] Figure 2 for Figure 1 a cutaway view of the adjustable lumbar support of the center seat;

[0022] Figure 3 for Figure 1 A schematic diagram of the cooperation between the first connecting seat and the mounting seat;

[0023] Figure 4 for Figure 1 A schematic diagram of the structure of the second connecting seat;

[0024] Figure 5 for Figure 1 A schematic diagram of the cooperation between the middle locking member and the mounting seat;

[0025] Figure 6 The utility model is a structural schematic diagram of an adjustable lumbar support of another seat.

[0026] Among them: 10, main lumbar support; 20, wing lumbar support; 30, first connecting seat; 31, snap-in groove; 32, threaded hole; 40, second connecting seat; 41, mounting groove; 411, limiting groove 411; 42, snap-in groove; 50, locking member; 51, movable seat; 511, supporting plane; 512, arc surface; 52, snap-in boss; 53, avoidance recess; 60, spring; 70, mounting seat; 71, groove; 72, through groove; 73, boss; 74, limiting block; 80, rotating shaft; 90, spring. DETAILED DESCRIPTION

[0027] Below, in conjunction with the accompanying drawings and specific implementation methods, the utility model is further described. It should be noted that, under the premise of no conflict, the various embodiments described below or the various technical features can be arbitrarily combined to form a new embodiment. Except for special instructions, the materials and equipment used in this embodiment can be purchased from the market. Examples of the embodiments are shown in the accompanying drawings, in which the same or similar numbers throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0028] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In the description of the present application, "plurality" means two or more, unless otherwise precisely and specifically specified.

[0029] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be connected through an intermediary medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0030] like Figure 1 , 2As shown in Figures 3, 4 and 5, an adjustable lumbar support for a seat of the utility model comprises a main lumbar support 10, two side lumbar supports 20, a first connecting seat 30, a second connecting seat 40 and a spring 60. The two side lumbar supports 20 are respectively located on both sides of the main lumbar support 10. The first connecting seat 30 and the second connecting seat 40 cooperate to connect the main lumbar support 10 and the side lumbar support 20 together, so that the side lumbar support 20 can rotate relative to the main lumbar support 10, and the rotation angle of the side lumbar support 20 relative to the main lumbar support 10 can be adjusted. The first connecting seat 30 and the second connecting seat 40 between the two side lumbar supports 20 and the main lumbar support 10 have the same matching structure; wherein, the first connecting seat 30 is fixed on the side lumbar support 20, and the second connecting seat 40 is fixed on the side of the main lumbar support 10 in an assembleable manner or is integrally formed on the side of the main lumbar support 10, and the first connecting seat 30 can rotate around an axis O relative to the second connecting seat 40, thereby enabling the side lumbar support 20 to have the freedom to rotate around the axis O relative to the main lumbar support 10. A locking member 50 is provided on the first connection seat 30. The locking member 50 is configured to be movable in a plane perpendicular to the axis O (i.e., the XY plane in the figure), and is synchronously matched with the first connection seat 30 so that the locking member 50 can rotate relative to the second connection seat 40 around the axis O along with the first connection seat 30. The second connection seat 40 is provided with a plurality of locking portions arranged around the axis O. The locking member 50 is provided with a locking portion matching the shape of the locking portion, and the locking portion can be combined with the locking portion. The spring 60 is used to provide an elastic stress applied to the locking member 50. The elastic stress is utilized to ensure that the locking member 50 always has a tendency to move along the XY plane toward the direction approaching the locking portion. Specifically, the locking member 50 can approach or move away from the locking portion on the XY plane. The elastic stress of the spring 60 pushes the locking member 50 toward the locking portion, so that the locking portion on the locking member 50 is combined with one of the locking portions. In this way, the locking member 50 is utilized to lock the first connecting seat 30 and the second connecting seat 40 in a relatively fixed state, thereby making a certain angle between the side lumbar support 20 and the main lumbar support 10 and keeping them relatively fixed.

[0031] When the adjustable lumbar support of the chair of the present invention is in use, the locking member 50 is used to lock the first connecting seat 30 and the second connecting seat 40, so that the first connecting seat 30 and the second connecting seat 40 remain in a relatively fixed state, the main lumbar support 10 supports the back of the user's waist, and the side lumbar support 20 supports the side of the user's waist. When the user adjusts the lumbar support according to his or her body shape and sitting posture, the side lumbar support 20 is rotated forward or backward, and the locking portion on the locking member 50 is disengaged from one of the locking portions, the spring 60 contracts, and the first connecting seat 30 drives the locking member 50 to rotate a certain angle, so that the locking portion on the locking member 50 is combined with the other locking portion, and the elastic stress of the spring 60 makes the locking portion of the locking member 50 stably combined with the other locking portion. In the present invention, the wing lumbar support 20 is rotatably connected to the main lumbar support 10 through the first connecting seat 30 and the second connecting seat 40. The locking portion on the locking member 50 cooperates with the plurality of locking portions to lock the relative rotational position of the first connecting seat 30 and the second connecting seat 40, thereby realizing the adjustment of the rotation angle of the wing lumbar support 20, so that the wing lumbar support 20 can be kept relatively fixed with the main lumbar support 10 at a plurality of different angles, so that the lumbar support can be suitable for users of different body shapes, and the lumbar support can also be adjusted to the best posture according to different sitting postures, thereby providing better support for the user's waist.

[0032] The first connecting seat 30 and the second connecting seat 40 are arranged up and down, and a mounting groove 41 which is recessed downward from the top surface thereof is provided on the second connecting seat 40, and a plurality of locking portions are provided on the inner surface of the side wall of the mounting groove 41, and the locking member 50 is located inside the mounting groove 41, so that the locking member 50 can move inside the mounting groove 41 in the XY plane to prevent the locking member 50 from detaching from the first connecting seat 30, and can enable the locking portion on the locking member 50 to be better combined with the locking portion on the second connecting seat 40. In order to ensure that the side lumbar support 20 can be stably matched with the main lumbar support 10 after being adjusted to an appropriate angle, to prevent the side lumbar support 20 from rotating abnormally, and to provide stable support for the side of the user's waist, the multiple locking parts arranged on the inner surface of the side wall of the installation groove 41 of the utility model are divided into two groups, and the two groups of locking parts are arranged opposite to each other. Two opposite locking members 50 are arranged on the first connecting seat 30, and the two locking members 50 correspond to the two groups of locking parts respectively. The spring 60 is placed between the two locking members 50, and the two ends of the spring 60 respectively press against the two locking members 50, so that the elastic stress provided by the spring 60 pushes the two locking members 50 toward the two groups of locking parts respectively. The locking portion is a slot 42 arranged on the inner surface of the side wall of the mounting slot 41, and the locking portion is a locking boss 52 arranged on the locking member 50. The shape of the locking boss 52 matches the shape of the slot 42. The elastic stress provided by the spring 60 enables the locking boss 52 to be embedded in the slot 42. When the locking member 50 rotates relative to the second connecting seat 40 as the first connecting seat 30 rotates, the locking member 50 rotates inside the mounting slot 41, so that the locking boss 52 can slide out of the slot 42. The convex structure formed between adjacent slots 42 squeezes the locking boss 52, causing the spring 60 to contract, so that the locking boss 52 can be disengaged from the slot 42, and then after the locking member 50 rotates a certain angle, the locking boss 52 can be re-engaged in other slots 42. The locking bosses 52 on the two locking members 50 are respectively locked in the two locking grooves 42 to provide relatively large resistance to the rotation of the locking members 50. After the side wing lumbar support 20 is adjusted to a suitable angle, it can withstand a large pressure from the side of the user's waist, preventing the side wing lumbar support 20 from rotating abnormally when squeezed, so that the side wing lumbar support 20 can provide stable support for the side of the user's waist.

[0033] In the present invention, the locking member 50 includes a semicircular movable seat 51, the inner side of the movable seat 51 forms a support plane 511, and the outer side forms a circular arc surface 512, so that the two locking members 50 are opposite to each other in a manner that the support planes 511 are opposite to each other, and the two locking members 50 can be placed in the installation groove 41, so that the structure of the first connecting seat 30 and the second connecting seat 40 cooperating with each other is more compact, and the locking boss 52 protrudes outward from the middle of the circular arc surface 512, and the locking groove 42 is located at the relative position of the locking boss 52. In order to enable the locking bosses 52 on the two locking members 50 to be stably combined with the respective corresponding locking grooves 42, in a preferred embodiment, two springs 60 are arranged between the two locking members 50, and the two springs 60 are respectively located on both sides of the space between the two supporting planes 511. The first connecting seat 30 and the second connecting seat 40 are connected together by a rotating shaft 80 that passes through the two. Specifically, one end of the rotating shaft 80 is abutted against the bottom surface of the second connecting seat 40, and the other end is fixed to the first connecting seat 30. The axis O is the central axis of the rotating shaft 80. The middle part of the supporting planes 511 on the two locking members 50 is provided with an avoidance recess 53. The avoidance recesses 53 on the two supporting planes 511 together form an avoidance hole for the rotating shaft 80 to pass through, thereby preventing the locking member 50 from interfering with the rotating shaft 80 when moving along the XY plane, thereby further improving the compactness of the structure of the first connecting seat 30 and the second connecting seat 40 cooperating with each other.

[0034] In order to install the locking member 50 on the first connecting seat 30, so that the locking member 50 can rotate with the first connecting seat 30 relative to the second connecting seat 40, and at the same time, the locking member 50 has the freedom of movement relative to the first connecting seat 30 on the XY plane, the utility model is provided with a mounting seat 70 on the first connecting seat 30, a part of the mounting seat 70 protrudes from the bottom surface of the first connecting seat 30, and the part of the mounting seat 70 protruding from the first connecting seat 30 is embedded in the mounting groove 41, and the mounting seat 70 is provided with a groove 71 formed by the bottom surface of the mounting seat 70 being recessed upward, and two through grooves 72 are provided on the side wall of the groove 71, which penetrate from the inner surface to the outer surface, and the two locking members 50 are embedded in the groove 71, and the two locking members 50 are embedded in the groove 71. The locking bosses 52 on the member 50 are respectively slidably embedded in the two through grooves 72. The locking bosses 52 cooperate with the through grooves 72 to limit the freedom of rotation of the locking member 50 relative to the mounting seat 70 in the circumferential direction of the rotating shaft 80, so that the two locking members 50 can rotate relative to the second connecting seat 40 around the rotating shaft 80 as the first connecting seat 30 rotates. The locking bosses 52 on the locking member 50 are slidably embedded in the through grooves 72, so that the locking member 50 has the freedom to move relative to the mounting seat 70 on the XY plane. The locking bosses 52 on the locking member 50 protrude from the outer surface of the mounting seat 70, so that the locking bosses 52 on the locking member 50 can be combined with or disengaged from the slots 42 when moving on the XY plane.

[0035] The above-mentioned mounting seat 70 of the utility model can be integrally formed and arranged on the first connecting seat 30, or connected to the first connecting seat 30 in an assembled manner so that the mounting seat 70 and the first connecting seat 30 can be synchronously matched. In a preferred embodiment, the mounting seat 70 is connected to the first connecting seat 30 in an assembled manner to facilitate the installation of the locking member 50 and the spring 60 into the groove 71 of the mounting seat 70, thereby facilitating the overall assembly of the waist support. A clamping groove 31 formed by an upward depression of its bottom surface is provided on the first connecting seat 30, and a boss 73 protruding upward is provided on the top of the mounting seat 70. The boss 73 is clamped in the clamping groove 31, and the cross-sectional shape of the boss 73 and the clamping groove 31 is set to a flat structure. The boss 73 and the clamping groove 31 are After the connecting groove 31 is engaged, the boss 73 cannot rotate relative to the first connecting seat 30, so that the mounting seat 70 and the first connecting seat 30 are synchronously engaged. A through hole for the rotating shaft 80 to pass through is provided on the mounting seat 70, and a threaded hole 32 is provided on the top surface of the clamping groove 31. The lower end of the rotating shaft 80 abuts against the bottom surface of the second connecting seat 40, and the upper end passes upward through the avoidance hole between the two locking members 50 and the through hole on the mounting seat 70 in sequence. After passing through the through hole of the mounting seat 70, the upper end of the rotating shaft 80 extends into the threaded hole 32 and is screwed into the threaded hole 32. Tighten the rotating shaft 80 to connect the first connecting seat 30 and the second connecting seat 40 together, and place the two locking members 50 and the spring 60 located in the groove 71 in the mounting groove 41.

[0036] A limiting groove 411 extending along the circumferential direction of the rotating shaft 80 is arranged on the inner surface of the side wall of the above-mentioned installation groove 41, and a limiting block 74 is arranged on the outer surface of the installation seat 70. The limiting block 74 is embedded in the limiting groove 411 and can slide between the two ends of the limiting groove 411. The limiting block 74 cooperates with the limiting groove 411 to limit the maximum rotation angle of the installation seat 70 relative to the second connecting seat 40, thereby limiting the maximum rotation angle of the side lumbar support 20 relative to the main lumbar support 10, thereby preventing excessive rotation during adjustment from causing damage to the locking member 50, the spring 60 and other components.

[0037] In other embodiments of the present invention, only one locking member 50 may be provided on the first connecting seat 30, and the spring 60 may be provided between the locking member 50 and the first connecting seat 30, or the spring 60 may be provided between the mounting seat 70 and the locking member 50, so that the elastic stress provided by the spring 60 can push the locking member 50 to move on the XY plane. Of course, the spring 60 may also be replaced by other elastic members, for example, Figure 6 In other embodiments shown, a V-shaped spring clip 90 may be provided between the two locking members 50, and the two locking members 50 and the two spring clips 90 may be embedded in the groove 71 of the mounting seat 70 to form an assembly, and then the assembly is assembled together with the first connecting seat 30 and the second connecting seat 40 through the rotating shaft 80.

[0038] In addition, the locking portion on the locking member 50 and the locking portion on the second connecting seat 40 are not necessarily the above-mentioned locking boss 52 and the locking groove 42. The locking portion and the locking portion can also be other structures that can be combined with each other, as long as they can prevent the locking member 50 from rotating relative to the second connecting seat 40 after the two are combined to limit the rotational freedom of the first connecting seat 30 relative to the second connecting seat 40.

[0039] In other embodiments, the first connecting seat 30 may be connected to the main lumbar support 10 , and the second connecting seat 40 may be connected to the wing lumbar support 20 .

[0040] The seat of the utility model includes the above-mentioned adjustable lumbar support of the seat, and other structures of the seat are the same as those in the prior art and will not be described in detail here.

[0041] Finally, it should be noted that the above-mentioned implementation modes are only optional embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. The adjustable lumbar support of the seat is characterized by: It includes a main waist support, a side waist support, a first connecting seat, a second connecting seat, and an elastic member; The main lumbar support is connected to one of the first connection seat and the second connection seat, and the wing lumbar support is connected to the other of the first connection seat and the second connection seat; the first connection seat can rotate relative to the second connection seat around an axis so that the wing lumbar support has a degree of freedom to rotate relative to the main lumbar support; The first connecting seat is provided with a locking member which can move in a plane perpendicular to the axis and can rotate relative to the second connecting seat around the axis as the first connecting seat; the second connecting seat is provided with a plurality of locking parts arranged around the axis; the locking member is provided with a latching part for combining with one of the locking parts; the elastic member is used to provide an elastic stress applied to the locking member so that the locking member always has a tendency to move along the plane in a direction close to the locking part.

2. The adjustable lumbar support for a chair as claimed in claim 1, characterized in that: The second connecting seat is provided with a mounting groove which is recessed downward from its top surface, a plurality of locking parts are arranged on the inner surface of the side wall of the mounting groove, and the locking piece is located in the mounting groove.

3. The adjustable lumbar support for a chair as claimed in claim 2, characterized in that: The multiple locking parts are divided into two groups, the two groups of locking parts are arranged opposite to each other, two opposite locking members are arranged on the first connecting seat, and the elastic member is arranged between the two locking members to push the two locking members toward the two groups of locking parts respectively.

4. The adjustable lumbar support for a chair as claimed in claim 3, characterized in that: The locking member includes a semicircular movable seat, the inner side of the movable seat forms a supporting plane, the outer side forms an arc surface, the locking portion is a locking boss protruding outward from the middle of the arc surface, and the locking portion is a locking groove arranged on the inner surface of the side wall of the installation groove and matching the shape of the locking boss.

5. The adjustable lumbar support for a chair as claimed in claim 4, characterized in that: The elastic member is a spring or a spring sheet clamped between the supporting planes of the two movable seats.

6. The adjustable lumbar support for a chair as claimed in claim 4, characterized in that: The first connecting seat and the second connecting seat are rotatably connected together by a rotating shaft that passes through the two. An avoidance recess is set in the middle of the supporting plane, and the avoidance recesses on the two supporting planes together form an avoidance hole for the rotating shaft to pass through; two elastic members are clamped between the two supporting planes, and the two elastic members are respectively placed on both sides of the rotating shaft.

7. The adjustable lumbar support for a chair as claimed in claim 6, characterized in that: The first connecting seat is provided with a mounting seat embedded in the mounting groove, and the mounting seat is provided with a groove formed by the bottom surface of the mounting seat being recessed upward, and the side wall of the groove is provided with two through grooves extending from the inner surface to the outer surface thereof, and the two locking members are located in the groove, and the positioning bosses on the two locking members are respectively slidably embedded in the two through grooves so that the two locking members can rotate relative to the second connecting seat around the rotating axis with the first connecting seat, and the positioning bosses of the locking members protrude from the outer surface of the mounting seat.

8. The adjustable lumbar support for a chair as claimed in claim 7, characterized in that: A limiting groove extending along the circumference of the rotating shaft is arranged on the inner surface of the side wall of the installation groove, and a limiting block embedded in the limiting groove and capable of sliding between the two ends of the limiting groove is arranged on the outer surface of the installation seat.

9. The adjustable lumbar support for a chair as claimed in claim 7, characterized in that: The first connecting seat is provided with a clamping groove which is recessed upward from its bottom surface, and the mounting seat is provided with a boss which is clamped in the clamping groove so that the mounting seat and the first connecting seat can cooperate synchronously. The mounting seat is provided with a through hole for the rotating shaft to pass through, and a threaded hole is provided on the top surface of the clamping groove. One end of the rotating shaft abuts against the second connecting seat, and the other end passes through the through hole of the mounting seat and is screwed in the threaded hole.

10. A seat, characterized in that: An adjustable lumbar support comprising a seat as claimed in any one of claims 1 to 9.

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