A chair back height adjustment device

Abstract

This invention discloses a chair backrest height adjustment device, including a support base, a sliding adjustment component, a limiting member, a first elastic member, and a second elastic member. The support base has a sliding groove, one side of which has a reverse tooth groove. The sliding adjustment component is disposed within the support base and includes a sliding plate and an adjustment member disposed within the sliding plate and capable of horizontal swaying. The adjustment member has a locking head that engages with the sliding groove and the reverse tooth groove. The limiting member has a clearance groove that avoids the locking head, and the bottom of the clearance groove also has a recessed notch. The side of the notch near the reverse tooth groove has an inclined limiting slope. The limiting member can move longitudinally relative to the support base. At least one side of the limiting member has an elastic locking strip that can elastically deflect in the horizontal direction. The elastic locking strip abuts against the side wall of the support base within the receiving groove. The sliding plate has a limiting support plate that engages with the limiting member. When the sliding plate slides upward along the support base, the limiting support plate causes the limiting member to move upward synchronously with the sliding plate.

Description

Technical Field

[0001] This invention relates to the field of seating, and in particular to a chair back height adjustment device. Background Technology

[0002] The chair back is a crucial component providing support and comfort when seated. To offer greater adaptability, chair backs are often height-adjustable to accommodate different upper body heights. Existing height adjustment mechanisms typically employ friction or snap-fit ​​mechanisms to provide adjustable backrest positions. These methods are usually initiated via knobs or switches; however, this type of operation is inconvenient, requiring one hand to operate the switch while the other simultaneously moves the backrest upwards. Furthermore, these adjustment mechanisms have complex components, are difficult to assemble, and suffer from short lifespans, difficulty in maintaining consistent functionality, and poor stability.

[0003] The above two gear adjustment methods are usually initiated through operating knobs or control switches. This type of structure is relatively inconvenient to operate, requiring one hand to operate the control switch and the other hand to move the chair back up at the same time. In addition, the parts of this type of adjustment structure are relatively complicated, the assembly is more troublesome, and there are problems such as short lifespan, difficulty in maintaining the function of repeated adjustment for a long time, and poor stability.

[0004] Furthermore, existing gear adjustment structures often only include an adjustment component and a gear matching component, focusing more on the fit between structures. This results in gaps between structures during actual assembly, causing wobbling and misalignment between components during adjustment, leading to instability in the adjustment mechanism. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a chair back lifting adjustment device. A sliding adjustment component is provided in the support seat, and the slide plate can slide longitudinally along the support seat. Furthermore, an adjustment component is provided in the slide plate that can engage with the slide groove stop on the support seat. In addition, a limiting component is provided to assist the slide plate in resetting. The components have clear division of labor and tight structural fit, and the device is very stable as a whole during adjustment.

[0006] The technical solution of this invention is implemented as follows:

[0007] A chair backrest height adjustment device includes: a support base having a longitudinally arranged, hollowed-out sliding groove, one side of which has longitudinally spaced counter-tooth grooves; the support base is hollow inside and forms a receiving groove, the receiving groove having openings on the left and right sides of the support base respectively; a sliding adjustment assembly disposed within the receiving groove; the sliding adjustment assembly includes a sliding plate that slides longitudinally with the support base, an adjustment member disposed within the sliding plate and capable of horizontally deflecting relative to the sliding plate, and a first elastic member acting on the adjustment member; the adjustment member and the sliding plate are longitudinally limited to allow the adjustment member to move longitudinally with the sliding plate; the adjustment... The component has a locking head protruding into the slide groove and capable of engaging with the reverse tooth groove; the first elastic member is configured to act on the adjusting member so that the locking head of the adjusting member always tends to engage into the reverse tooth groove; a limiting member is clamped between the slide plate and the support base; the limiting member has an avoidance groove for the locking head to engage into the slide groove; the bottom of the avoidance groove also has a recessed notch, the notch and the slide groove having a portion overlapping in the front-rear direction; the notch has an inclined limiting slope on the side near the reverse tooth groove; the limiting member can move longitudinally relative to the support base, and at least one side of the limiting member has an elastic locking strip capable of elastically deflecting in the horizontal direction, the elastic locking strip The sliding plate abuts against the side wall of the support seat within the receiving groove; the sliding plate is provided with a limiting plate that cooperates with the limiting member. When the sliding plate slides upward along the support seat, the limiting plate acts as a limiting member that moves upward synchronously with the sliding plate; a second elastic member is disposed between the sliding plate and the support seat; when the sliding plate slides upward from its initial lowest position, the second elastic member deforms to provide a spring force for the sliding plate to return to its downward position; a back connector is connected to the left and right sides of the sliding plate, and the back connector extends out of the support seat; when the sliding plate moves upward relative to the support seat from its initial lowest position, the locking head moves upward from the bottom of the groove, and the limiting member moves upward with the sliding plate under the action of the limiting plate; the... The locking head is longitudinally offset from the limiting inclined surface. Under the action of the first elastic element, the adjusting member causes the locking head to tend to sequentially engage with the reverse tooth grooves at different positions along the length of the slide groove. The engagement of the locking head with the reverse tooth groove restricts the downward movement of the slide plate. When the slide plate moves upward and the locking head moves to the uppermost end of the slide groove to reset downward, the slide plate resets downward relative to the limiting member under the action of the second elastic element. The locking head engages downward into the notch and abuts against the limiting inclined surface. The limiting inclined surface restricts the locking head from engaging with the reverse tooth groove. Under the action of the second elastic element, the slide plate continues to drive the locking head to move downward along the slide groove. The locking head acts downward on the limiting member, causing the limiting member and the slide plate to move downward together and reset to the bottom of the support base.

[0008] Preferably, the slide plate has a hollowed-out mounting groove in the middle for placing an adjustment component. The adjustment component includes an adjustment body and a connecting part located on the upper part of the adjustment body. The connecting part is movably connected to the slide plate so that the adjustment body can swing within the mounting groove. The adjustment component is set in the mounting groove of the slide plate, and the slide plate slides in conjunction with the support base; the components have clearly defined functions.

[0009] Preferably, a limiting groove is provided on one side of the connecting part; a horizontally extending limiting protrusion is provided at a corresponding position on the upper part of the mounting groove, the limiting protrusion extending into the limiting groove, and the size of the groove opening in the vertical direction is greater than the thickness of the limiting protrusion in the vertical direction. This allows the adjusting member to be hooked onto the limiting protrusion in a hook-like manner, thereby limiting the adjusting member and the sliding plate in the longitudinal direction; and the limiting groove has a margin to allow the adjusting member to swing within the mounting groove; thus, no screws or shafts are required between the adjusting member and the sliding plate to achieve longitudinal limiting between the adjusting member and the sliding plate, and to allow the adjusting member to move within the mounting groove.

[0010] Preferably, the adjusting body has a straight position and a tilted position. In the straight position, the locking head engages in the counter-tooth groove, the side wall of the adjusting body abuts against the groove wall of the mounting groove, and the groove walls at both ends of the limiting groove are parallel to the limiting protrusion. In the tilted position, the adjusting body tilts around the connection between the connecting part and the limiting protrusion until the limiting protrusion abuts against the groove wall of the limiting groove, causing the adjusting body to tilt to its maximum tilt state, and the locking head is in the sliding groove. The first elastic element acts on the adjusting body, giving it a tendency to always be in the straight position. The adjusting body can move freely between the straight and tilted positions.

[0011] Preferably, the maximum thickness of the portion of the slide plate within the receiving groove is not less than the groove diameter in the front-to-back direction. This allows the slide plate to be interference-fitted within the receiving groove. This is because the slide plate is made of plastic and the support base is made of sheet metal. The toughness of the plastic allows for an interference fit between the slide plate and the support base, resulting in a very tight front-to-back connection between them, eliminating wobbling and ensuring stable sliding of the slide plate.

[0012] Preferably, the locking head is located at the bottom of the adjustment body and protrudes from the adjustment body in both the front and rear directions.

[0013] Preferably, the limiting plate is disposed at the bottom of the slide plate, and the limiting plate is used to abut against the bottom wall of the limiting member. This allows the limiting member to move upward synchronously when the slide plate moves upward, and the limiting plate to disengage from the limiting member when the slide plate moves downward to reset.

[0014] Preferably, the limiting member includes a main body, and the elastic strip is disposed on the side end of the main body and extends longitudinally, with a gap between the elastic strip and the main body. This allows the elastic strip to effectively undergo elastic deformation in the horizontal direction.

[0015] Preferably, the support base has abutment walls on both sides of the accommodating groove and the limiting member, and the elastic retaining strip abuts against the abutment wall on the corresponding side. This can limit the swaying and displacement of the limiting member in the left and right directions, making the structure between components stable; and the static friction between the elastic retaining strip and the abutment wall limits the limiting member, allowing the limiting member to move up and down relative to the second base.

[0016] Preferably, the limiting inclined surface is configured such that the width of the notch gradually decreases from top to bottom. This allows the limiting inclined surface to limit the movement of the locking head, while also allowing the locking head to freely enter the notch downwards and exit the notch upwards.

[0017] Preferably, the width of the clearance groove in the horizontal direction is not less than the horizontal width between the countersunk groove and the sliding groove. This allows the chuck to move within the clearance groove to engage with the sliding groove or the countersunk groove.

[0018] Preferably, the support base is made of metal, while the slide plate and the limiting component are made of plastic. The metal support base provides a stable structure and stable support; the plastic material of the slide plate and limiting component prevents noise generation.

[0019] Preferably, the support base includes a first base and a second base that are joined at the front and rear, and the receiving groove is formed between the first base and the second base. This facilitates structural assembly.

[0020] Preferably, the slide plate is provided with the second elastic element on both its left and right sides; the second elastic element is a longitudinally arranged tension spring, the lower end of which is connected to the support base, and the upper end of which is connected to the slide plate. The use of a tension spring allows for effective slide plate repositioning.

[0021] Preferably, a sliding structure is provided between the skateboard and the support base. The sliding mechanism includes a slider disposed on one of the skateboard or the support base, and a guide groove disposed on the other of the skateboard or the support base. This allows the skateboard to slide smoothly, and the cooperation between the slider and the guide groove can further limit the lateral swaying of the skateboard and maintain structural stability.

[0022] The design starting point, concept, and beneficial effects of the present invention, which adopts the above technical solution, are as follows:

[0023] The chair backrest height adjustment device of the present invention features a sliding adjustment component within a support base. This component includes a sliding plate and an adjustment member disposed within the sliding plate. The sliding plate slides against the support base, and the adjustment member, disposed within the sliding plate, is capable of swaying to engage with a groove and a toothed groove on the support base. A first elastic element is provided, allowing the adjustment member, under the action of the first elastic element, to cause the locking head to sequentially engage with the toothed grooves at different positions along the length of the groove. This provides multiple adjustable positions for the sliding plate. The swaying motion of the adjustment member is spontaneous, guided by the elasticity of the first elastic element and the guidance of the toothed grooves. The user only needs to adjust the longitudinal movement of the sliding plate, making the adjustment operation very convenient. A limiting element is also provided, preventing the locking head from engaging with the toothed grooves when the sliding plate returns to its original position, allowing the sliding plate to quickly return to its original position. Each component has a clear function, and the structure is tightly integrated.

[0024] Secondly, the fit between the various components of the device of the present invention is very stable. The sliding plate is interference-fitted in the receiving groove, so that the front and back connection between the sliding plate and the support base is very tight, eliminating the swaying of the sliding plate in the front and back direction. Moreover, the adjusting member is set in the sliding plate, and the first elastic member is always elastically pressed against the adjusting member, so that the adjusting member will not wobble. The elastic strip on the limiting member abuts against the supporting wall of the support base, so that the limiting member will not wobble. It will only move relative to the support base when subjected to force. As a result, the sliding plate, adjusting member and limiting member will not shift or wobble in the support base, so that the device is very stable and smooth during adjustment, thereby making the chair back adjustment stable.

[0025] Furthermore, the support base is made of metal because the skateboard is made of plastic, which provides a stable structure and stable support. The skateboard and the limiting parts are also made of plastic to prevent noise during movement. In addition, the toughness of plastic allows the skateboard and the support base to be interference-fitted. Attached Figure Description

[0026] Figure 1 This is a three-dimensional structural diagram of the lifting device in an embodiment of the present invention;

[0027] Figure 2 This is an exploded view of the lifting device in an embodiment of the present invention;

[0028] Figure 3 This is a three-dimensional structural diagram of the present invention when the card head is at the bottom of the slide groove in an embodiment;

[0029] Figure 4 This is a three-dimensional structural diagram of the card head engaging the reverse tooth groove in an embodiment of the present invention;

[0030] Figure 5 This is a three-dimensional structural diagram of the adjusting member fitting inside the slide plate in an embodiment of the present invention;

[0031] Figure 6 This is a three-dimensional structural diagram of the cooperation between the limiting member and the support base in an embodiment of the present invention;

[0032] Figure 7 This is a schematic diagram of the card head being inserted into the tooth groove in an embodiment of the present invention, within the clearance groove;

[0033] Figure 8 This is a schematic diagram of the card head being located in the slide groove and in the clearance groove in an embodiment of the present invention;

[0034] Figure 9 This is a schematic diagram showing the card head rising to the top of the slide groove in an embodiment of the present invention;

[0035] Figure 10 This is a schematic diagram showing the locking action between the locking head and the limiting inclined surface during the sliding plate's downward repositioning in an embodiment of the present invention.

[0036] The reference numerals in the attached drawings are as follows: support base 1; first base 101; second base 102; slide groove 2; reverse tooth groove 3; receiving groove 4; slide plate 5; adjusting component 6; connecting part 6a; adjusting body 6b; locking head 7; limiting component 8; opening 9; slider 10; guide groove 11; side connecting plate 12; back connecting component 13; mounting groove 14; limiting groove 15; limiting protrusion 16; first elastic component 17; elastic locking strip 18; abutment wall 19; clearance groove 20; notch 21; limiting inclined surface 22; limiting support plate 23; second elastic component 24. Implementation

[0037] 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.

[0038] 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.

[0039] 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.

[0040] The specific embodiments of the present invention are as follows:

[0041] Please refer to Figures 1-10This invention provides a chair backrest height adjustment device, which includes a support base 1. The support base 1 has a longitudinal sliding groove 2, and longitudinally spaced reverse toothed grooves 3 are provided on one side of the sliding groove 2, the reverse toothed grooves 3 communicating with the sliding groove 2. The support base 1 is hollow inside and forms a receiving groove 4. A sliding adjustment assembly is provided in the receiving groove 4. The sliding adjustment assembly includes a sliding plate 5 that slides with the support base 1, and an adjustment member 6 that moves within the sliding plate 5 and can deflect horizontally relative to the sliding plate 5. The adjustment member 6 is provided with a locking head 7 that can engage with the reverse toothed grooves 3. A limiting member 8 is further provided between the sliding plate 5 and the support base 1.

[0042] refer to Figures 1-5 The support base 1 includes a first base 101 and a second base 102 joined together front to back. Both the first base 101 and the second base 102 are sheet metal parts, making the support base 1 structurally stable and providing stable support. The receiving groove 4 is formed between the first base 101 and the second base 102, and the receiving groove 4 has openings 9 on the left and right sides of the support base 1, respectively. The sliding groove 2 is arranged longitudinally at the middle position of the support base 1, and the sliding groove 2 passes through the first base 101 and the second base 102 from front to back.

[0043] A sliding structure is provided between the slide plate 5 and the support base 1. The sliding mechanism includes sliders 10 respectively disposed on the left and right sides of the slide plate 5, and guide grooves 11 respectively disposed on the support base 1. Each side of the slide plate 5 is provided with at least two spaced sliders 5, and the guide grooves 11 are specifically disposed on the first base 101, so that the slide plate 5 can slide stably up and down along the support base 1. The sliding cooperation between the sliders 10 and the guide grooves 11 can also limit the swaying and displacement of the slide plate 5 relative to the support base 1 in the left and right directions, so that the slide plate 5 can only slide longitudinally relative to the support base 1. Moreover, the slide plate 5 is made of plastic, so that no noise is generated when the slide plate 5 slides relative to the metal support base 1.

[0044] It also includes a back connector 13, which is configured to connect to the chair back. Specifically, there are side connecting plates 12 extending from the side openings 9 of the support seat 1 on the left and right sides of the slide plate 5, and the back connector 13 is connected to each of the side connecting plates 12. When the slide plate 5 slides longitudinally along the support seat 1, it can drive the back connector 13 to slide longitudinally, thereby driving the chair back to slide. In addition, the maximum thickness of the portion of the slide plate 5 inside the receiving groove 4 is not less than the groove diameter of the receiving groove 4, so that the slide plate 5 is interference-fitted in the receiving groove 4. This is because the slide plate 5 is made of plastic and the support seat 1 is made of sheet metal. The toughness of the plastic allows the side connecting plates 12 to be interference-fitted in the support seat 1, so that the front and rear connection between the slide plate 5 and the support seat 1 is very tight, preventing the slide plate 5 from wobbling or shifting in the front and rear direction, and allowing the slide plate 5 to slide longitudinally relative to the support seat 1 with very smooth movement. The sliding friction between the slide plate 5 and the support seat 1 is also configured to be of an appropriate magnitude so that the user does not have to exert force when sliding the slide plate 5.

[0045] refer to Figures 2-5 A mounting groove 14 with front and rear hollowing is provided at the middle position of the sliding plate 5. The adjusting member 6 is disposed in the mounting groove 14 and can move within the mounting groove 14. Specifically, the adjusting member 6 includes an adjusting body 6b and a connecting part 6a located on the upper part of the adjusting body 6b. A limiting groove 15 is provided on one side of the connecting part 6a. A horizontally extending limiting protrusion 16 is provided at a corresponding position on the upper part of the mounting groove 14. The limiting protrusion 16 extends into the limiting groove 15, so that the connecting part 6a is hooked onto the limiting protrusion 16 in a hook-like manner. The size of the groove opening in the vertical direction of the limiting groove 15 is larger than the thickness of the limiting protrusion 16 in the vertical direction, so that the limiting groove 15 has a margin to allow the adjusting member 6 to swing within the mounting groove 14. Figure 5 As shown, the adjusting body 6b has an upright position, in which the sidewall of the adjusting body 6b abuts against the groove wall of the mounting groove 14, and the groove walls at both ends of the limiting groove 15 are parallel to the limiting protrusion 16; as Figure 2 As shown, the adjusting body 6b also has a deflection position deflected from the upright position. In this deflection position, the adjusting body 6b deflects around the connection between the connecting part 6a and the limiting protrusion 16 until the limiting protrusion 16 abuts against the groove wall of the limiting groove 15, causing the adjusting body 6b to deflect to the maximum tilt state.

[0046] A horizontally arranged first elastic element 17 is also provided in the mounting groove 14. The first elastic element 17 is a spring. One end of the first elastic element 17 is connected to the groove wall of the mounting groove 14, and the other end of the first elastic element 17 is connected to the adjustment body 6b. The first elastic element 17 can act on the adjustment member 6. When the adjustment member 6 is in the sway position, the first elastic element 17 is in the compressed state. The first elastic element 17 will provide elastic force to make the adjustment member 6 tend to move to the straight position.

[0047] Furthermore, when the slide plate 5 slides longitudinally, the limiting protrusion 16 will abut against the wall of the limiting groove 15, causing the adjusting member 6 to move longitudinally along with the slide plate 5. This eliminates the need for screws or pivots between the adjusting member 6 and the slide plate 5, achieving longitudinal positioning between them and allowing the adjusting member 6 to move within the mounting groove 14. The design is ingenious and the structure is very simple, making assembly convenient.

[0048] like Figure 3-5 As shown, the card head 7 is disposed on the front and rear sides of the lower part of the adjusting body 6b, and when the adjusting body 6b is in the position as shown... Figure 2 , 3 When the device is in the indicated sway position, the locking head 7 will be positioned within the slide groove 2; at this time, the first elastic element 17 is in a compressed state, causing the adjusting body 6b to tend to move to the sway position; subsequently, as shown... Figure 3 , 4 As shown, when the sliding plate 5 moves upward relative to the support base 1 from its initial lowest position, the sliding plate 5 will drive the adjusting member 6 to move upward, and the locking head 7 will move upward along the slide groove 2. When the sliding plate 5 moves to the position where the locking head 7 coincides with the inverted tooth groove 3, under the action of the first elastic member 17, the adjusting member 6 will automatically swing to make the locking head 7 engage in the current inverted tooth groove 3, and the engagement of the locking head 7 with the inverted tooth groove 3 can restrict the downward movement of the sliding plate 5, so that the sliding plate 5 can stay in the current adjustment position. As the sliding plate 5 continues to move upward, the groove wall of the inverted tooth groove 3 will guide the locking head 7 to move the adjusting body 6b to the swing position again, and the locking head 7 will move again along the groove wall of the inverted tooth groove 3 into the slide groove 2. Then, as the sliding plate 5 moves upward relative to the support base 1, the locking head 7 will sequentially engage in the inverted tooth groove 3 at different positions along the length direction of the slide groove 2, so that the sliding plate 5 has multiple adjustment positions. Furthermore, the yaw motion of the main body 6b is spontaneously carried out under the elastic action of the first elastic element 17 and the guiding action of the inverted tooth groove 3. The user only needs to adjust the longitudinal sliding of the slide plate 5.

[0049] like Figure 2 , 6As shown in Figure -10, the limiting member 8 is a plate-shaped structure, clamped between the slide plate 5 and the support base 1. In this embodiment, specifically, the limiting member 8 is clamped between the second base 102 of the slide plate 5 to avoid interfering with the sliding structure between the slide plate 5 and the first base 101. Specifically: the limiting member 8 is made of plastic and includes a main body. At least one side of the main body is provided with an elastic strip 18 that can be elastically deflected in the horizontal direction. The elastic strip 18 extends longitudinally and is spaced apart from the main body. The second base 102 has abutment walls 19 on both sides of the limiting member 8. The limiting member 8 is located between the two abutment walls 19, and the elastic strip 18 abuts against the abutment wall 19 on the corresponding side, which can limit the swaying and displacement of the limiting member 8 in the left and right directions. The static friction between the elastic strip 18 and the abutment wall 19 limits the limiting member 8, so that the limiting member 8 can move up and down relative to the second base 102.

[0050] At the bottom end of the slide plate 5, there is also a limiting plate 23 that cooperates with the limiting member 8. The limiting plate 23 can abut against the bottom end of the limiting member 8. When the slide plate 5 slides upward along the support base 1, the limiting plate 23 can move upward synchronously with the limiting member 8.

[0051] Furthermore, the limiting member 8 is provided with a clearance groove 20, which is hollowed out front and back to avoid the locking head 7. The locking head 7 can pass through the clearance groove 20 to engage with the sliding groove 2. The width of the clearance groove 20 in the horizontal direction is not less than the horizontal width between the reverse tooth groove 3 and the sliding groove 2, so that the locking head 7 can move within the clearance groove 20 to cooperate with the sliding groove 2 or the reverse tooth groove 3. A recessed notch 21 is further provided at the bottom of the clearance groove 20. This notch 21 overlaps with the sliding groove 2 in the front-back direction. A slanted limiting slope 22 is provided on the side of the notch 21 near the reverse tooth groove 3. The width of the notch 21 gradually decreases from top to bottom. Figure 7-8 As shown, when the slide plate 5 moves upward along the support base 1, the bottom end of the limiting plate 23 abuts against the limiting member 8 so that the limiting member 8 and the slide plate 5 move upward at the same time. At this time, the locking head 7 will not enter the notch 21, that is, the locking head 7 and the limiting inclined surface 22 are longitudinally offset. Then, during the upward movement of the slide plate 5, the locking head 7 can move freely between the toothed groove 3 and the sliding groove 2, and the limiting member 8 will not interfere with the movement of the adjusting member 6.

[0052] A second elastic element 24 is provided between the slide plate 5 and the support base 1. The second elastic element 24 is a longitudinally arranged tension spring. The upper end of the tension spring is connected to the side connecting plate 12 of the slide plate 5, and the lower end of the tension spring is connected to the bottom of the support base 1. The second elastic element 24 is respectively arranged on the left and right sides of the slide plate 5. When the slide plate 5 moves upward along the support base 1 from the initial lowest position, the second elastic element 24 will undergo tensile deformation to provide the reset force for the slide plate 5 to move downward again, and make the slide plate 5 have a good damping feel when it moves upward. Then, when the slide plate 5 moves upward and the locking head 7 moves upward from the bottom of the slide groove 2, the second elastic element 24 will undergo tensile deformation to provide the spring force for the slide plate 5 to return downward.

[0053] like Figure 9-10 As shown, when the sliding plate 5 moves upward, causing the locking head 7 to move to the uppermost end of the slide groove 2 in preparation for downward reset, the action of the sliding plate 5 stops, and the second elastic element 24 will cause the sliding plate 5 to move downward along the support base 1 to reset; and as Figure 10 As shown, the slide plate 5 will move downwards relative to the limiting member 8 first, causing the locking head 7 to move down into the notch 21 and abut against the limiting inclined surface 22. At this time, there is a gap between the limiting support plate 23 and the bottom of the limiting member 8. Subsequently, as the slide plate 5 continues to move downwards, the locking head 7 will act downwards against the limiting member 8, causing the limiting member 8 to move down and reset as well. The limiting inclined surface 22 abuts against the locking head 7 from the left and right, so that during the downward movement, the limiting member 8 can prevent the locking head 7 from being locked into the toothed groove 3, so that the locking head 7 will move down directly along the slide groove 2 and reset to the bottom end of the slide groove 2; making the reset process quick and fast.

[0054] The chair backrest height adjustment device of this application is further described by setting a sliding plate 5, an adjusting member 6, and a limiting member 8 inside the support base 1; the adjusting member 6 can move and deflect within the sliding plate 5, and the locking head of the adjusting member 6 cooperates with the sliding groove 2 and the countertooth groove 3 on the support base 1; and the limiting member 8 can limit the downward movement of the adjusting member 6; so that the sliding plate 5 can be adjusted to multiple height levels along the support base 1, and the sliding plate 5 can also quickly move down to reset; the sliding plate 5 is provided with a back connector 13 connected to the chair back; and the support base 1 is used to connect to the seat; thus, by using this lifting device, the height adjustment of the chair back can be very convenient and quick, and the overall structure is very stable.

[0055] 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 chair backrest height adjustment device, characterized in that... include: The support base has a longitudinally arranged, hollowed-out sliding groove, and a longitudinally spaced reverse tooth groove on one side of the sliding groove; the support base is hollow inside and forms a receiving groove, and the receiving groove has openings on the left and right sides of the support base respectively. A sliding adjustment assembly is disposed within the receiving groove. The sliding adjustment assembly includes a sliding plate that slides longitudinally with the support base, an adjustment member disposed within the sliding plate and capable of tilting horizontally relative to the sliding plate, and a first elastic member acting on the adjustment member. The adjustment member is longitudinally limited to the sliding plate so that the adjustment member can move longitudinally with the sliding plate. The adjustment member has a locking head protruding from the sliding groove and capable of engaging with the reverse tooth groove. The first elastic member is configured to act on the adjustment member so that the locking head of the adjustment member always tends to engage with the reverse tooth groove. A limiting member is clamped between the slide plate and the support base; the limiting member is provided with an abutment head to engage with an abutment groove in the slide groove; the bottom of the abutment groove also has a recessed notch, the notch and the slide groove having a portion overlapping in the front-back direction; the notch has an inclined limiting slope on the side near the inverted tooth groove; the limiting member can move longitudinally relative to the support base; at least one side of the limiting member is provided with an elastic locking strip that can be elastically deflected in the horizontal direction, the elastic locking strip abutting against the side wall of the support base in the receiving groove; the slide plate is provided with a limiting support plate that cooperates with the limiting member; when the slide plate slides upward along the support base, the limiting support plate causes the limiting member to move upward synchronously with the slide plate. A second elastic element is disposed between the slide plate and the support base; when the slide plate slides upward from the initial lowest position, the second elastic element deforms to provide a spring force for the slide plate to return to its downward position; A back connector is attached to the left and right sides of the slide plate, and the back connector extends out of the support base; When the sliding plate moves upward relative to the support seat from its initial lowest position, the locking head moves upward from the bottom of the slide groove, and the limiting member moves upward with the sliding plate under the action of the limiting support plate; The locking head is longitudinally offset from the limiting inclined surface. Under the action of the first elastic element, the adjusting member causes the locking head to tend to sequentially engage with the reverse tooth grooves at different positions along the length of the slide groove. The engagement of the locking head with the reverse tooth groove restricts the downward movement of the slide plate. When the slide plate moves upward and the locking head moves to the uppermost end of the slide groove to reset downward, the slide plate resets downward relative to the limiting member under the action of the second elastic element. The locking head engages downward in the notch and abuts against the limiting inclined surface. The limiting inclined surface restricts the locking head from engaging with the reverse tooth groove. Under the action of the second elastic element, the slide plate continues to drive the locking head to move downward along the slide groove. The locking head acts downward on the limiting member, causing the limiting member and the slide plate to move downward together and reset to the bottom of the support base.

2. The chair backrest height adjustment device according to claim 1, characterized in that: The middle position of the slide plate is provided with a mounting groove with front and rear hollowed-out sections for placing the adjustment component. The adjustment component includes an adjustment body and a connecting part located on the upper part of the adjustment body. The connecting part is movably connected to the slide plate so that the adjustment body can swing within the mounting groove.

3. The chair backrest height adjustment device according to claim 2, characterized in that: A limiting groove is provided on one side of the connecting part; a horizontally extending limiting protrusion is provided at the corresponding position on the upper part of the mounting groove. The limiting protrusion extends into the limiting groove, and the size of the groove opening in the vertical direction is greater than the thickness of the limiting protrusion in the vertical direction.

4. The chair backrest height adjustment device according to claim 3, characterized in that: The adjusting body has a straight position and a tilted position. In the straight position, the locking head is engaged in the counter-tooth groove, the side wall of the adjusting body is against the groove wall of the mounting groove, and the groove walls at both ends of the limiting groove are parallel to the limiting protrusion. In the tilted position, the adjusting body deflects around the connection between the connecting part and the limiting protrusion until the limiting protrusion abuts against the groove wall of the limiting groove, causing the adjusting body to tilt to its maximum tilt state, and the locking head is in the sliding groove. The first elastic element acts on the adjusting body to make the adjusting body tend to always be in the straight position.

5. The chair backrest height adjustment device according to claim 1, characterized in that: The maximum thickness of the portion of the slide plate inside the receiving groove is not less than the diameter of the receiving groove in the front-to-back direction.

6. The chair backrest height adjustment device according to claim 2, characterized in that: The clip is located at the bottom of the adjustment body and protrudes from the adjustment body in both the front and back directions.

7. The chair backrest height adjustment device according to claim 1, characterized in that: The limiting plate is disposed at the bottom of the slide plate, and the limiting plate is used to abut against the bottom wall of the limiting member.

8. The chair backrest height adjustment device according to claim 1, characterized in that: The limiting member includes a main body, and the elastic clip is disposed on the side end of the main body and extends longitudinally, with a gap between the elastic clip and the main body.

9. The chair backrest height adjustment device according to claim 8, characterized in that: The support base has abutting walls on both sides of the receiving groove and the limiting member, and the elastic clip abuts against the abutting wall on the corresponding side.

10. The chair backrest height adjustment device according to claim 1, characterized in that: The limiting inclined surface is configured such that the width of the notch gradually decreases from top to bottom.

11. The chair backrest height adjustment device according to claim 1, characterized in that: The width of the clearance groove in the horizontal direction is not less than the horizontal width between the inverted tooth groove and the sliding groove.

12. The chair backrest height adjustment device according to claim 1, characterized in that: The support base is made of metal, while the slide plate and the limiting member are made of plastic.

13. The chair backrest height adjustment device according to claim 1, characterized in that: The support base includes a first base and a second base that are connected front to back, and the receiving groove is formed between the first base and the second base.

14. The chair backrest height adjustment device according to claim 1, characterized in that: The skateboard is provided with the second elastic element on both the left and right sides; the second elastic element is a longitudinally arranged tension spring, the lower end of the tension spring is connected to the support base, and the upper end of the tension spring is connected to the skateboard.

15. The chair backrest height adjustment device according to claim 1, characterized in that: A sliding structure is provided between the slide plate and the support base. The sliding mechanism includes a slider disposed on one of the slide plate or the support base, and a guide groove disposed on the other of the slide plate or the support base.

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