A lumbar support adjustment device for a chair and a chair

Abstract

The application provides a lumbar support adjusting device and a chair, comprising a lumbar support and a back support; the lumbar support has a first connecting arm and a second connecting arm; the first connecting arm is hinged to an upper rotating seat of the back support; the second connecting arm is hinged to a rotating support arm; a sliding adjusting part is slidably arranged in the back support; the rear end of the rotating support arm is hinged to the sliding adjusting part; a gear cycle assembly comprises a rotating gear, an elastic part and a toothed part; the rotating gear has outwardly extending reverse teeth, and the toothed part comprises reverse tooth grooves; the reverse teeth of the rotating gear are sequentially toothed with the reverse tooth grooves when the sliding adjusting part moves upward; a positioning tooth and a positioning gap are arranged between the sliding adjusting part and the rotating gear; the rotating gear is positioned in a reset state when the sliding adjusting part moves upward to tooth the positioning tooth with the positioning gap; the sliding fitting part is provided with a reset top tooth; the reset top tooth is pressed on the rotating gear when the sliding adjusting part moves downward to reset, so that the positioning tooth is separated from the positioning gap, and the rotating gear is deflected to reset.

Description

Technical Field

[0001] This invention relates to the field of seating, and particularly to a lumbar support adjustment device for a chair and a chair. Background Technology

[0002] The lumbar support of a chair is an important component that provides support and comfort when the human body is sitting. In order to effectively provide a wider range of adaptability, the lumbar support is often configured to be adjustable in depth to accommodate the back support needs of different people in different sitting positions; however, the lumbar support adjustment mechanisms on some existing chairs usually have drawbacks.

[0003] For example, the utility model disclosed in CN202122877140.5, "A Lumbar Support Adjustment Device for Office Chairs," includes a lumbar support and a mounting base. The lumbar support and the mounting base are connected by an adjustment device. The adjustment device includes a front-to-back adjustment mechanism for adjusting the lumbar support's front-to-back position and a vertical adjustment mechanism for adjusting the lumbar support's vertical position. The front-to-back adjustment mechanism is installed inside the mounting base. The moving end of the front-to-back adjustment mechanism is connected to the vertical adjustment mechanism, and the moving end of the vertical adjustment mechanism is connected to the lumbar support. An operating area is provided between the lumbar support and the mounting base for the user to reach into and operate the front-to-back adjustment mechanism to adjust the lumbar support's front-to-back position. The lumbar support has a simple structure and is easy to operate. Adjusting the lumbar support's front-to-back and vertical positions can be achieved simply by turning the adjustment knob and pushing the lumbar support up and down, making it suitable for people of different body types. However, this lumbar support adjustment device uses a rotating adjustment knob to adjust the lumbar support's front-to-back position, but the adjustment knob is located between the chair back and the lumbar support. When a person is sitting in the chair, their hand needs to reach back to the area between the lumbar support and the backrest to make adjustments, which limits hand movement and makes operation very inconvenient. For children, the elderly, and people with limited joint mobility, they may even need to get out of the seat to make adjustments.

[0004] Utility model patent CN201920198823.8 discloses a "lumbar support with front-to-back and height adjustment functions," comprising a back frame and a mounting post on the back frame. The mounting post has knob limiting holes on both sides. A mounting back plate is mounted in front of the mounting post. A movable functional plate is mounted in front of the mounting back plate. A lifting rack is provided on the rear side of the functional plate. A pull-wire end fixing plate is movably embedded in the functional plate. A lumbar support base plate is connected to the bottom of the pull-wire end fixing plate, and the upper end of the lumbar support base plate contacts the upper end of the functional plate. The lumbar support with front-to-back and height adjustment functions disclosed in this invention has a simple structure and is easy to operate, enabling front-to-back and height adjustment to suit different needs. While the lumbar support allows for convenient adjustment via a knob, its overly complex structure, employing cables, gears, and racks, results in numerous control components, consuming considerable space and significantly impacting the chair's aesthetics. Furthermore, the switches are prone to malfunction. While the chair may appear more high-end, it complicates a simple task, failing to consider user interaction during actual use and lacking ergonomic design.

[0005] Therefore, in order to address the above problems, this invention proposes to design a lumbar support that is easy for users to operate and can adjust the front and back positions without the need for a switch. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a simple and easy-to-operate lumbar support adjustment device for a chair. The lumbar support member can rotate back and forth to drive the sliding adjustment member to slide up and down. The sliding adjustment member can cyclically move up and down within the sliding mating part. This allows the lumbar support member to cyclically rotate forward around the rotating seat and then return to its original position. During the adjustment operation, the user only needs to grasp the lumbar support member and apply force to it, without any other switches. The adjustment is simpler, more convenient, and more sophisticated.

[0007] Furthermore, a chair that utilizes the aforementioned lumbar support adjustment device is also provided.

[0008] The technical solution of this invention is implemented as follows:

[0009] A lumbar support adjustment device for a chair includes: a lumbar support member disposed on a back support member; the rear end of the lumbar support member having a first connecting arm and a second connecting arm extending rearward; an upper rotating seat provided on the back support member, the first connecting arm being hinged to the upper rotating seat; a rotating support arm disposed between the second connecting arm and the back support member; the front end of the rotating support arm being hinged to the second connecting arm; a sliding engagement portion located below the upper rotating seat on the back support member, the rear end of the rotating support arm being connected to the sliding engagement portion; and a sliding adjustment member disposed within the sliding engagement portion; the sliding adjustment member being capable of sliding up and down along the back support member. The sliding adjustment member has a lower rotating seat, and the rear end of the rotating support arm is hinged to the lower rotating seat. The sliding adjustment member can slide up and down along the sliding mating part in response to the forward and backward rotation of the waist support member around the upper rotating seat via the rotating support arm. A gear circulation assembly is disposed between the sliding adjustment member and the sliding mating part. The gear circulation mechanism includes rotating gears mirror-image disposed on the sliding adjustment member, elastic members acting on the rotating gears, and longitudinal toothed portions mirror-image disposed on both sides of the sliding mating part. Each rotating gear has outwardly extending reverse teeth, and the toothed portion includes at least two longitudinal teeth. The sliding adjustment member has a recessed tooth groove; during the upward movement of the sliding adjustment member, the rotating tooth will deflect inward and move upward to disengage from the recessed tooth groove, and under the action of the elastic member, the rotating tooth will deflect outward again and engage with the recessed tooth groove at the corresponding position; the rotating tooth also has a reset state that allows the sliding adjustment member to move downward and reset; a telescopic protrusion capable of longitudinal elastic extension and retraction is provided at the upper end of each rotating tooth of the sliding adjustment member, a positioning tooth is provided on one of the telescopic protrusions and the rotating tooth, and a positioning notch is provided on the other of the telescopic protrusion and the rotating tooth; the upper end of the toothed part on each side has a protrusion towards the rotating tooth. The sliding adjustment member moves upward until the inner convex tooth acts on the rotating tooth, causing it to deflect inward and engage with the positioning notch. The lower ends of the two rotating teeth are then close together. The reverse teeth of each rotating tooth are offset from the inner convex tooth on the corresponding side. A reset top tooth is also provided at the middle position of the lower part of the sliding engagement. When the sliding adjustment member moves downward to reset, the reset top tooth can press upward and act on the two rotating teeth to cause them to move away from each other. Each rotating tooth deflects outward and causes the positioning tooth to disengage from the positioning notch. The elastic member presses on the rotating teeth to reset the reverse teeth to the bottom end of the toothed joint.

[0010] Preferably, the sliding adjustment member has a rectangular structure, and two movable slots for connecting the rotating gear are mirror-imagely provided at the middle position of the sliding adjustment member; each movable slot has a rotating shaft, and the rotating gear has a shaft hole; the rotating gear is embedded in the movable slot and the rotating shaft rotates through the shaft hole. This ensures that the rotating gear can only deflect inward and outward within the sliding adjustment member.

[0011] Preferably, the elastic element is a spring laterally disposed between the two rotating gears; both ends of the spring are respectively inserted into the rotating gears; the elastic element is configured such that each rotating gear always tends to rotate outward so that the reverse teeth engage with the reverse tooth grooves. This ensures that the spring can always act on the rotating gears to deflect them outward, so that the reverse teeth of the rotating gears can be stably engaged in the reverse tooth grooves.

[0012] Preferably, in the reset state, a concave groove is formed between the lower ends of the two rotating gears; the reset top tooth can press upward into this groove. This allows the reset top tooth to effectively push upward and disengage the two rotating gears from each other.

[0013] Preferably, a longitudinal clearance groove is recessed at the rear end of the sliding adjustment member to avoid the reset tooth, and the upper end of the clearance groove extends through the sliding adjustment member from front to back. In the reset state, the bottom junction of the two rotating teeth can be exposed at the upper end of the clearance groove. This allows the sliding adjustment member to retract downwards in the reset state, so that the reset tooth can just press against the rotating teeth, resulting in an ingenious structural design. During the upward movement of the sliding adjustment member, the reset tooth will move within the clearance groove, and there will be no interference between the structures.

[0014] Preferably, the end of the inner convex tooth approaches the side end of the sliding adjustment member; during the upward movement of the sliding adjustment member, the reverse tooth protrudes outward from the side end of the sliding adjustment member; in the reset state, the rotating gear retracts inward so that the end of the reverse tooth does not protrude from the side end of the sliding adjustment member. This allows the inner convex tooth to more effectively rotate the rotating gear during reset; and in the reset state, the end of the reverse tooth does not protrude from the side end of the sliding adjustment member, so the reverse tooth and the inner convex tooth will not interfere with each other, thereby allowing the sliding adjustment member to move downward and reset.

[0015] Preferably, the reverse tooth has an outwardly protruding triangular structure, and the shape of the reverse tooth groove matches the shape of the tip of the reverse tooth; and the reverse tooth has a beveled edge that presses against the groove wall of the reverse tooth groove and the inner convex tooth.

[0016] Preferably, the sliding mating part has a rectangular mounting groove recessed therein, and a fixing seat is embedded and fixedly mounted in the mounting groove; the fixing seat has a receiving groove in the middle for accommodating the sliding adjustment component; the sliding adjustment component slides and fits in the receiving groove; the toothed parts are mirror images of both sides of the fixing seat; the reset top tooth is located at the middle position of the lower part of the fixing seat. This allows for the installation groove to be provided only on the back support; the fixing seat and the sliding adjustment component are fitted and embedded in the mounting groove after mating; facilitating processing and assembly.

[0017] Preferably, a longitudinal guide groove is recessed at the back end of the sliding adjustment member, and a forward-protruding guide strip is correspondingly provided in the receiving groove; the sliding adjustment member is embedded in the receiving groove and the guide strip slides in cooperation with the guide groove. This allows the sliding adjustment member to slide stably up and down relative to the back support member.

[0018] Preferably, the sliding mating part further includes a cover plate disposed at the front end, and the lower rotating seat is disposed at the lower end of the sliding adjustment member, with the lower rotating seat protruding forward from the cover plate. A vertical groove is correspondingly provided on the cover plate to avoid the lower rotating seat. This conceals connection marks, making the structure aesthetically pleasing, and the forward protrusion of the lower rotating seat from the front end of the cover plate facilitates connection.

[0019] Preferably, each rotating tooth has an upwardly protruding arcuate portion at its upper end near the center of the sliding adjustment member, and the positioning notch is disposed on this arcuate portion; the positioning tooth is correspondingly disposed at the bottom end of the telescopic protrusion; the sliding adjustment member is provided with a longitudinal connecting spring for the elastic extension and retraction of the telescopic protrusion. The positioning tooth and the positioning notch cooperate to lock the rotating locking member in the reset state, and because the telescopic protrusion can extend and retract longitudinally, the rotating locking member can deflect under the action of external force to disengage the positioning tooth from the positioning notch.

[0020] Preferably, a limiting mechanism is provided between the rotating gear and the sliding adjustment member. The limiting mechanism includes a limiting protrusion provided on one of the rotating gear or the sliding adjustment member, and an arc-shaped limiting groove provided on the other of the rotating gear or the sliding adjustment member.

[0021] Preferably, when the sliding adjuster is in its lowest position, the rotating support arm and the second connecting arm tend to be in a straight line. This ensures good force transmission between the second connecting arm and the rotating support arm when the lumbar support rotates forward, making it easier to move the sliding adjuster upward.

[0022] Preferably, the lumbar support has a forward-protruding arc-shaped structure, with both the first and second connecting arms positioned at the middle of the upper rear end of the lumbar support. This allows the lumbar support to rotate around the upper rotating seat, enabling front-to-back depth adjustment.

[0023] A chair, including a lumbar support adjustment device as described above.

[0024] The design starting point, concept, and beneficial effects of the present invention, which adopts the above technical solution, are as follows:

[0025] 1. The lumbar support adjustment device of the chair of the present invention can adjust the front-to-back depth of the lumbar support member by rotating it back and forth around the upper rotating seat; and during the rotation of the lumbar support member, the rotating support arm can rotate adaptively, so that the sliding adjustment member can slide up and down along the sliding mating part accordingly. Furthermore, a gear circulation component is provided between the sliding adjustment member and the sliding mating part, which allows the sliding adjustment member to have multiple gear positions during its upward movement, thereby correspondingly giving the lumbar support member multiple front-to-back adjustment gears; and after the sliding adjustment member rises, it can also move down and reset again, that is, the sliding adjustment member can cyclically rise and fall and reset along the sliding mating part without the need for any switch; thus, the lumbar support member can be adjusted without any adjustment switch, and the user can directly apply a force to rotate the lumbar support member to make it rotate forward and then reset backward.

[0026] 2. By utilizing the interaction between the rotating gear and the countersunk tooth groove, the sliding adjustment component, during its ascent, is able to deflect back and forth under the action of the elastic element. This allows the countersunk tooth to sequentially engage with the countersunk tooth groove at different positions, enabling the sliding adjustment component to stop at different locations and the lumbar support component to remain at different rotation angles. When the sliding adjustment component needs to be reset, simply move it upwards again. The inner convex tooth will further compress the rotating gear, causing the positioning notch at the upper end of the rotating gear to engage with the positioning tooth of the telescopic protrusion, thereby locking the rotating gear in the reset state. The countersunk tooth and the inner convex tooth are then misaligned. Subsequently, the sliding adjustment component can be moved downwards to reset.

[0027] 3. A longitudinal clearance groove is recessed at the rear end of the sliding adjustment member to avoid the reset top tooth. The upper end of the clearance groove extends through the sliding adjustment member. When the rotating teeth are in the reset state, the bottom junction of the two rotating teeth can be exposed at the upper end of the clearance groove. This allows the reset top tooth to press upward on the two rotating teeth after the sliding adjustment member is reset downward, causing them to move away from each other. This causes each rotating tooth to deflect outward, disengaging the positioning tooth from the positioning notch. Then, the elastic member presses on the rotating teeth, causing the back tooth to reset to the bottom end of the tooth joint.

[0028] 4. Only a rectangular mounting groove needs to be recessed at the sliding mating part. The sliding adjustment part and the fixed seat are then installed together in the mounting groove. This makes it possible to set the mounting groove only on the back support. The fixed seat and the sliding adjustment part are then embedded in the mounting groove after mating. This facilitates processing and assembly. Attached Figure Description

[0029] Figure 1 This is a side view of the connection between the lumbar support and the back support in an embodiment of the present invention;

[0030] Figure 2This is a side view of the lumbar support member protruding forward in an embodiment of the present invention;

[0031] Figure 3 This is a three-dimensional structural diagram of the connection and cooperation between the lumbar support and the back support in an embodiment of the present invention;

[0032] Figure 4 This is a three-dimensional structural diagram of the sliding mating part in an embodiment of the present invention;

[0033] Figure 5 This is a three-dimensional structural diagram of the sliding adjustment member and the back support member cooperating in an embodiment of the present invention;

[0034] Figure 6 This is a three-dimensional structural diagram of the sliding adjustment member and the fixed base cooperating in an embodiment of the present invention;

[0035] Figure 7 This is a three-dimensional structural diagram of the cooperation between the rotating gear and the sliding adjustment component in an embodiment of the present invention;

[0036] Figure 8 This is a three-dimensional structural diagram of the engagement between the reverse teeth and the reverse tooth groove during the upward movement of the sliding adjustment member in an embodiment of the present invention;

[0037] Figure 9 This is a three-dimensional structural diagram of the toothed engagement between the reverse teeth and the reverse tooth groove in an embodiment of the present invention;

[0038] Figure 10 This is a three-dimensional structural diagram of the engagement of the reverse teeth and the internal convex teeth in an embodiment of the present invention;

[0039] Figure 11 This is a three-dimensional structural diagram of the sliding adjustment member during its descent and reset in an embodiment of the present invention;

[0040] Figure 12 This is a three-dimensional structural diagram of the rear end of the sliding adjustment member in an embodiment of the present invention;

[0041] Figure 13 This is a three-dimensional structural diagram of the rotating gear in the reset state in an embodiment of the present invention.

[0042] The reference numerals in the attached drawings are as follows: back support 1; waist support 2; first connecting arm 3; second connecting arm 4; upper rotating seat 5; sliding mating part 6; sliding adjusting part 7; guide groove 701; guide strip 702; lower rotating seat 8; rotating support arm 9; mounting groove 10; fixed seat 11; toothed part 1101; rotating tooth 12; receiving groove 13; rotating tooth 14; arc protrusion 14a; elastic element 15; reverse tooth 16; bevel 1601; reverse tooth groove 17; movable insert 18; rotating shaft 19; shaft hole 20; limiting protrusion 21; limiting groove 22; inner protruding tooth 23; telescopic protrusion 24; positioning tooth 25; positioning notch 26; connecting spring 27; slot 28; reset top tooth 29; clearance groove 30; cover plate 31; vertical groove 32. Detailed Implementation

[0043] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0044] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0045] In the description of this invention, the term "at least one" means one or more, unless otherwise expressly defined. The terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] This embodiment involves the reference orientation of each component, such as front and rear, and is described in the normal use state with the user seated behind the seat.

[0047] The specific embodiments of the present invention are as follows:

[0048] like Figure 1-13As shown, the lumbar support adjustment device for a chair provided by the present invention includes a back support member 1 and a lumbar support member 2; the rear end of the lumbar support member 2 has a first connecting arm 3 and a second connecting arm 4 extending rearward; the first connecting arm 3 tends to extend horizontally rearward, and an upper rotating seat 5 is provided on the back support member 1, with the first connecting arm 3 hinged to the upper rotating seat 5. A sliding engagement portion 6 is located below the upper rotating seat 5 on the back support member 1, and a sliding adjustment member 7 is slidably provided within the sliding engagement portion 6, the sliding adjustment member 7 being able to slide up and down along the back support member 1; a lower rotating seat 8 is provided on the sliding adjustment member 7, the second connecting arm 4 extends rearward and downward, and a rotating support arm 9 is connected between the second connecting arm 4 and the lower rotating seat 8, the front end of the rotating support arm 9 being hinged to the second connecting arm 4, and the rear end of the rotating support arm 9 being hinged to the lower rotating seat 8. Subsequently, the depth of the lumbar support 2 can be adjusted by rotating it back and forth around the upper rotating seat 5. During the rotation of the lumbar support 2, the rotating support arm 9 can adaptively rotate, allowing the sliding adjustment member 7 to slide up and down along the sliding mating part 6 accordingly. A gear circulation assembly is provided between the sliding adjustment member 7 and the sliding mating part 6. This gear circulation assembly is configured to provide multiple gear positions during the upward movement of the sliding adjustment member 7, thus providing multiple forward and backward adjustment gears for the lumbar support 2. Furthermore, after rising, the sliding adjustment member 7 can also move down and reset again. That is, the sliding adjustment member 7 can cyclically rise and fall back and reset along the sliding mating part 6 without the need for any switches. Therefore, the adjustment of the lumbar support 2 does not require any adjustment switches; the user can directly apply a force to rotate the lumbar support 2 to make it rotate forward and then reset backward.

[0049] Specifically: such as Figure 1-3 As shown, the lumbar support 2 has a forward-protruding arc-shaped structure. The first connecting arm 3 and the second connecting arm 4 are both located at the middle of the upper rear end of the lumbar support 2, allowing the lumbar support 2 to rotate around the upper rotating seat 5 to achieve front-to-back depth adjustment. The second connecting arm 4 extends obliquely downwards and backwards, and the lower rotating seat 8 protrudes forward from the back support 1, facilitating the connection and cooperation between the rotating support arm 9 and the sliding adjustment component 7; and as... Figure 1 As shown, when the sliding adjustment member 7 is in the lowest position, the rotating support arm 9 and the second connecting arm 4 tend to be in a straight line; this makes the force transmission effect between the second connecting arm 4 and the rotating support arm 9 better when the waist support member 2 rotates forward, and can more easily drive the sliding adjustment member 7 to move upward.

[0050] like Figure 3-7As shown, a rectangular mounting groove 10 is recessed at the sliding mating part 6, and a fixing seat 11 is embedded and fixed in the mounting groove 10; the fixing seat 11 has a receiving groove 13 in the middle for accommodating the sliding adjustment member 7; a longitudinal guide groove 701 is recessed at the back end of the sliding adjustment member 7, and a forward-protruding guide strip 702 is correspondingly provided in the receiving groove 13; the sliding adjustment member 7 is embedded in the receiving groove 13, and the guide strip 702 slides in cooperation with the guide groove 701; so that the sliding adjustment member 7 can slide up and down relative to the back support member 1.

[0051] like Figure 4-12 As shown, the gear shifting assembly includes rotating gears 14 mirror-imagely disposed on the sliding adjustment member 7, elastic members 15 acting on the rotating gears 14, and longitudinal toothed portions 1101 mirror-imagely disposed on both sides of the fixed seat 11; the lower rotating seat 8 is located below the rotating gears 14. Each rotating gear 14 has outwardly extending reverse teeth 16, and the toothed portions 1101 include several longitudinally spaced reverse tooth grooves 17, which can mesh with the reverse teeth 16. Specifically, the sliding adjustment member 7 has a rectangular structure, and two movable slots 18 mirror-imagely disposed at the middle position of the sliding adjustment member 7 for connecting the rotating gears 14 are provided; each movable slot 18 contains a rotating shaft 19, and the rotating gear 14 has a shaft hole 20; the rotating gear 14 is embedded in the movable slot 18 so that the rotating shaft 19 rotates through the shaft hole 20, allowing the rotating gear 14 to deflect inwards and outwards only within the sliding adjustment member 7. Furthermore, the reverse teeth 16 have an outwardly protruding triangular structure. The rotating gear 14 can rotate to make the reverse teeth 16 protrude outward beyond the outer side of the sliding adjustment member 7, or the rotating gear 14 can rotate inward to retract so that the end of the reverse teeth 16 does not protrude beyond the side end of the sliding adjustment member 7. A limiting mechanism is also provided between the rotating gear 12 and the sliding adjustment member 7. This limiting mechanism includes a limiting protrusion 21 at the rear end of the rotating gear 12 and a corresponding arc-shaped limiting groove 22 on the sliding adjustment member 7, so that the rotating gear 12 can only rotate within a certain range. Further, the elastic member 15 is a spring transversely disposed between the two rotating gears 14, with both ends of the elastic member 15 passing through the rotating gears 14. The elastic member 15 is configured such that each rotating gear 14 always has a tendency to rotate outward to engage the reverse teeth 16 with the reverse tooth groove 17.

[0052] The inverted tooth grooves 17 are arranged longitudinally at intervals, and the shape of the inverted tooth grooves 17 matches the tip shape of the inverted tooth 16; the inverted tooth 16 has a beveled edge 1601 for pressing and engaging with the inverted tooth grooves 17; then, when the actuating waist support member 2 rotates forward, the sliding adjustment member 7 moves upward to drive the rotating tooth member 14 to move upward; as Figure 8As shown, the inclined edge 1601 of the inverted tooth 16 will press against the groove wall of the inverted tooth groove 17, causing the rotating tooth 14 to deflect inward, so that the inverted tooth 16 can disengage upward from the inverted tooth groove 17 at its current position; and the elastic member 15 will correspondingly deform under pressure; as Figure 9 As shown, after the sliding adjustment member 7 rises a certain distance, the rotating gear 14 will deflect outward again under the elastic force of the elastic member 15, so that the reverse gear 16 engages with the upper reverse gear groove 17. The reverse gear 16 and the reverse gear groove 17 can restrict the downward movement of the sliding adjustment member 7, thus preventing it from moving backward; thereby locking the sliding adjustment member 7 in this position. Subsequently, as the lumbar support member 2 rotates forward, the sliding adjustment member 7 moves upward accordingly, allowing the reverse gear 16 to engage with the reverse gear grooves 17 at different heights in sequence; then the sliding adjustment member 7 can stop at multiple positions, giving the lumbar support member 2 multiple forward and backward adjustment positions. Moreover, the movements of the rotating gear 14 and the reverse gear groove 17 in the above process are all spontaneously performed following the rise of the sliding adjustment member 7, without the need for any switch control.

[0053] like Figure 5-12 As shown, when the reverse tooth 16 is engaged with the uppermost reverse tooth groove 17, the lumbar support 2 is in the maximum forward position. If it is necessary to rotate the lumbar support adjustment 2 backward to reset, even if the sliding adjustment 7 is lowered to reset again, it is only necessary to continue to rotate the lumbar support adjustment 2 forward so that the sliding adjustment 7 continues to rise. Specifically, the upper end of the toothed part 1101 on each side is also provided with an inwardly protruding tooth 23, the tip of which is close to the side end of the sliding adjustment 7. When it is necessary to move the sliding adjustment 7 down to reset, the sliding adjustment 7 is first moved up. The inwardly protruding tooth 23 will press and cooperate with the inclined side 1601 of the reverse tooth 16, and the inwardly protruding tooth 23 will act on the rotating tooth 14 to further deflect inward. Correspondingly, the sliding adjustment member 7 is provided with a telescopic protrusion 24 at the upper end of each rotating tooth 14, and a connecting spring 27 that allows the telescopic protrusion 24 to extend and retract longitudinally elastically; a downwardly protruding positioning tooth 25 is provided at the bottom end of the telescopic protrusion 24; and an upwardly protruding arcuate protrusion 14a is provided at the upper end of each rotating tooth 14 near the center of the sliding adjustment member 7, and a positioning notch 26 is provided on the arcuate protrusion 14a that can mesh with the positioning tooth 25. As the sliding adjustment member 7 continues to move upward, such as Figure 10 As shown, the inner protruding tooth 23 will act on the rotating tooth 14 to deflect inward, causing the positioning tooth 25 to press against the arcuate protrusion 14a, causing the telescopic protrusion 24 to elastically rise and have a tendency to move downward again; as Figure 11As shown, when the rotating gear 14 deflects inward until the end of the reverse tooth 16 is located inside the side of the sliding adjustment member 7, the positioning tooth 25 will engage with the positioning notch 26, thereby locking the rotating gear 14. At this time, the rotating gear 14 is in the reset state, and the reverse tooth 16 and the inner convex tooth 23 are offset to the left and right, allowing the sliding adjustment member 7 to move down and reset. The positioning tooth 25 and the positioning notch 26 cooperate to lock the rotating locking member 14 in the reset state, and because the telescopic protrusion 24 can extend and retract longitudinally, the rotating locking member 14 can deflect under the action of external force to disengage the positioning tooth 25 from the positioning notch 26.

[0054] like Figure 6 , 7 As shown in Figures 11-13, in the reset state, the lower ends of the two rotating gears 14 are abutted together, and a concave groove 28 is formed between the lower ends of the two rotating gears 14; a reset top tooth 29 is provided at the middle position of the lower part of the fixed base 11, and a longitudinal clearance groove 30 is provided at the back end of the sliding adjustment member 7 to avoid the reset top tooth 29. The upper end of the clearance groove 30 passes through the sliding adjustment member 7 from front to back, so that in the reset state, the bottom junction of the two rotating gears 14 can be just exposed. At the upper end of the clearance groove 30; then, after the sliding adjustment member 7 moves down and resets to the bottom end of the fixed seat 11, the reset top tooth 29 can just press against the groove 28 at the lower end of the two rotating teeth 14. The reset top tooth 29 can press upward on the two rotating teeth 14, causing each rotating tooth 14 to deflect outward, thereby causing the positioning tooth 25 to disengage from the positioning notch 26; subsequently, the rotating teeth 14 deflect outward under the action of the elastic member 15, causing the back tooth 16 to reset back to the bottom end of the toothed part 1101.

[0055] like Figure 3 As shown, a cover plate 31 is also connected to the front end of the fixed base 11. The cover plate 31 can prevent the sliding adjustment member 7 from disengaging from the fixed base 11 and can hide the connection marks, making the structure aesthetically pleasing. The lower rotating base 8 protrudes forward from the front end of the cover plate 31 for easy connection; the cover plate 31 is provided with a vertical groove 32 to avoid the lower rotating base 8 from moving up and down.

[0056] As can be seen from the above, the sliding adjustment member 7 can repeatedly move up and down within the sliding mating part 7; thus, the lumbar support member 2 can repeatedly rotate forward around the rotating seat 5 and then return to its original position; and during the adjustment operation, the user only needs to directly grasp the lumbar support member 2 and apply force to it, without any other switches; the adjustment is simpler and more convenient, and has a more sophisticated feel.

[0057] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A lumbar support adjustment device for a chair, characterised in that, The utility model relates to a backrest support, which is provided on a back support; the backrest support has a first connecting arm and a second connecting arm extending rearward at the rear end thereof; the back support is provided with an upper rotating seat; the first connecting arm is hingedly connected to the upper rotating seat; a rotating support arm is arranged between the second connecting arm and the back support; the front end of the rotating support arm is hingedly connected to the second connecting arm; the back support is provided with a sliding fitting part below the upper rotating seat; the rear end of the rotating support arm is connected to the sliding fitting part; a sliding adjusting part is arranged in the sliding fitting part; a rectangular mounting groove is formed in the sliding fitting part; a fixed seat is embedded in and fixed in the mounting groove; the middle part of the fixed seat is provided with an accommodating groove for accommodating the sliding adjusting part; the sliding adjusting part is slidingly fitted in the accommodating groove; the sliding adjusting part can slide up and down on the back support; the sliding adjusting part has a lower rotating seat; the rear end of the rotating support arm is hingedly connected to the lower rotating seat; the sliding adjusting part can slide up and down along the sliding fitting part in response to the forward and rearward rotation of the backrest support about the upper rotating seat through the rotating support arm; a gear cycle assembly is arranged between the sliding adjusting part and the sliding fitting part; the gear cycle assembly comprises rotating teeth arranged on the sliding adjusting part in mirror image, an elastic member acting on the rotating teeth, and longitudinal toothed parts arranged on both sides of the sliding fitting part in mirror image; the toothed parts are arranged in mirror image on both sides of the fixed seat; the elastic member is a spring arranged transversely between the two rotating teeth; the two ends of the spring are respectively arranged in the rotating teeth; each rotating tooth has an outwardly extending inverted tooth; the toothed part comprises at least two longitudinally spaced inverted tooth grooves; during the upward movement of the sliding adjusting part, the rotating teeth are deflected inward and upward to disengage from the inverted tooth grooves; the elastic member is configured to make each rotating tooth always have a tendency to rotate outward so that the inverted tooth is in toothed engagement with the inverted tooth groove; and the rotating teeth are deflected outward again under the action of the elastic member and are in toothed engagement with the corresponding position of the inverted tooth groove; The rotating teeth also have a reset state in which the sliding adjusting part can be moved downward and reset; a longitudinally elastically expandable expansion protrusion is arranged at the upper end of each rotating tooth; a positioning tooth is arranged on one of the expansion protrusion and the rotating tooth; a positioning notch is arranged on the other one of the expansion protrusion and the rotating tooth; the upper end of each toothed part on one side is provided with an inward protruding tooth; in the reset state, the sliding adjusting part moves upward to the inward protruding tooth to act on the rotating teeth to deflect inward so that the positioning tooth is in engagement with the positioning notch; the lower ends of the two rotating teeth are in abutment; and the inverted tooth of each rotating tooth is left-right staggered with the inward protruding tooth on the corresponding side; a reset tooth is further arranged at the middle position of the lower part of the sliding fitting part; the reset tooth is arranged at the middle position of the lower part of the fixed seat; when the sliding adjusting part is moved downward and reset, the reset tooth can press upward to act on the two rotating teeth to move away from each other; each rotating tooth is deflected outward so that the positioning tooth is disengaged from the positioning notch; the elastic member presses the rotating teeth to reset the inverted tooth to the bottom end of the toothed part. ​ ​ ​ ​ 2. The lumbar adjustment device of claim 1, wherein: The sliding adjusting member is in rectangular structure, and two movable slots for connecting the rotating teeth members are symmetrically arranged at the middle position of the sliding adjusting member; a rotating shaft is arranged in each movable slot, and a shaft hole is arranged on the rotating teeth member; the rotating teeth member is embedded in the movable slot and the rotating shaft is rotated and arranged in the shaft hole.

3. The lumbar adjustment device of claim 1, wherein: In the reset state, the lower ends of the two rotating teeth members form a concave notch; the reset top teeth can be upwardly abutted in the notch.

4. The lumbar adjustment device of claim 3, wherein: A longitudinal avoiding slot for avoiding the reset top teeth is concavely arranged at the rear end of the sliding adjusting member, and the upper end of the avoiding slot penetrates the sliding adjusting member; in the reset state, the bottom intersection of the two rotating teeth members can be exposed at the upper end of the avoiding slot.

5. The lumbar adjustment device of claim 1, wherein: The end of the inner convex tooth approaches the side end of the sliding adjusting member; during the upward movement of the sliding adjusting member, the inverted tooth protrudes outwardly from the side end of the sliding adjusting member; in the reset state, the inverted tooth is retracted by the inward rotation of the rotating teeth member, so that the end of the inverted tooth does not protrude from the side end of the sliding adjusting member.

6. The lumbar adjustment device of claim 1, wherein: The inverted tooth is in outwardly protruding triangular structure, the shape of the inverted tooth slot is matched with the shape of the tip of the inverted tooth; and the inverted tooth has an inclined edge matched with the slot wall of the inverted tooth slot and the inner convex tooth.

7. The lumbar adjustment device of claim 1, wherein: A longitudinal guide slot is concavely arranged at the back end of the sliding adjusting member, and a forwardly protruding guide strip is correspondingly arranged in the accommodating slot; the sliding adjusting member is embedded in the accommodating slot and the guide strip is slidably matched with the guide slot.

8. The lumbar adjustment device of claim 1, wherein: The sliding matching part further comprises a cover plate arranged at the front end, the lower rotating seat is arranged at the lower end of the sliding adjusting member, and the lower rotating seat protrudes forwardly from the cover plate, and a vertical slot for avoiding the lower rotating seat is correspondingly arranged on the cover plate.

9. The lumbar adjustment device of claim 1, wherein: Each rotating teeth member has an upwardly protruding arc convex part near the central position of the sliding adjusting member, and the positioning notch is arranged on the arc convex part; the positioning teeth are correspondingly arranged at the bottom end of the telescopic block; a longitudinal connecting spring for acting on the elastic extension of the telescopic block is arranged on the sliding adjusting member.

10. The lumbar adjustment device of claim 2, wherein: A limiting mechanism is arranged between the rotating teeth member and the sliding adjusting member, and the limiting mechanism comprises a limiting protrusion arranged on one of the rotating teeth member and the sliding adjusting member, and an arc-shaped limiting groove correspondingly arranged on the other of the rotating teeth member and the sliding adjusting member.

11. The lumbar adjustment device of claim 1, wherein: When the sliding adjusting member is located at the lowermost position, the rotating support arm and the second connecting arm tend to be in a straight line.

12. The lumbar adjustment device of claim 1, wherein: The lumbar support member is in forwardly protruding arc structure, and the first connecting arm and the second connecting arm are both arranged at the middle position of the upper rear end of the lumbar support member.

13. A chair, characterized in that The lumbar adjusting device of the chair according to any one of claims 1-12.

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