CN215686099U

CN215686099U - Waist rest adjusting device of chair

Info

Publication number: CN215686099U
Application number: CN202120923830.7U
Authority: CN
Inventors: 余夏聪; 郑捷
Original assignee: UE Furniture Co Ltd
Current assignee: UE Furniture Co Ltd
Priority date: 2021-04-29
Filing date: 2021-04-29
Publication date: 2022-02-01
Anticipated expiration: 2031-04-29

Abstract

The utility model discloses a lumbar support adjusting device of a chair, which comprises a chair back component and a lumbar support component arranged on the chair back component; the lumbar support component has elasticity and can be bent and deformed in the vertical direction; the upper end and the lower end of the lumbar support component are respectively connected to the chair back component, and at least one end of the lumbar support component can be adjusted to be lifted relative to the chair back component; the lower end of the waist support component moves upwards relative to the chair back component or the upper end of the waist support component moves downwards relative to the chair back component so that the waist support component is bent and deformed, and the waist support component pushes the chair back component forwards; the waist rest component can be elastically bent and deformed, so that the upper end or the lower end of the waist rest component is controlled to move and deform, and then the waist supporting effect can be realized; the bending degree of the waist rest is controlled, so that the ejection degree of the waist rest component can be controlled, and the waist rest component is matched with different users; simple and ingenious structure, convenient and fast adjustment.

Description

Waist rest adjusting device of chair

Technical Field

The utility model relates to the field of seats, in particular to a waist rest adjusting device of a chair.

Background

Sub-health is always a living problem concerned by people, wherein the lumbar vertebra problem brought to people by long-time sitting is particularly frequent, and the chair is used as daily furniture for office work and study of people, and under the long-time sitting and office work, the spine of the human body has natural bending, especially bending at the lumbar vertebra; the lumbar vertebra is easy to bend outwards when being in a sitting posture for a long time, and the isosceles lumbar disc herniation is easy to cause. As is well known, the spine of a human body is S-shaped, and therefore, a waist rest is additionally arranged at the backrest of part of office chairs so as to support the natural bending part of the lumbar vertebra, prevent the lumbar vertebra from bending outwards due to fatigue and ensure the health of the lumbar vertebra of office staff.

However, in practical application, because the body types of people are in diversified distribution of tall, short, fat and thin, the waist support with the fixed position is difficult to adapt to people with different body types, the front and back depth of the waist support cannot be adjusted to meet individual differences, and the application range and the health care effect of the waist support are limited. The existing chairs with the adjustable waist back front-back depth can provide proper support for the waist of a user by adjusting the waist back front-back depth. However, in order to realize the ejection function of the lumbar support, a complicated mechanism is often arranged between the lumbar support and the chair back of the existing lumbar support adjusting device on the market, and if the lumbar support is adjusted in a worm gear manner, the structure is complicated, the operation is time-consuming and labor-consuming, and the lumbar support can be adjusted back and forth by rotating for multiple turns; or the pull wire is adopted to control the ejection degree of the waist rest, so that the adjustment is more laborious; the two structures have the defects of complicated structure and inconvenient operation; the user is required to leave the sitting surface during adjustment.

CN 201721856841.8's chinese utility model discloses a "car seat with machinery top waist mechanism", including seat back iron platform and top waist mechanism assembly, top waist mechanism assembly sets up on the seat back iron platform, top waist mechanism assembly contains frame and backplate, the bottom and the frame fixed connection of backplate, the top and the frame sliding connection of backplate, the back middle part of backplate is provided with the pulley, and the head end of acting as go-between is fixed top one side of backplate, the end of acting as go-between passes the mounting hole who is located backplate top opposite side after walking around the pulley. The utility model has simple and reasonable structural design, convenient operation and high comfort, can randomly adjust the ejection degree according to different users with different heights and slimness, and has wide application prospect. The back plate has elasticity, and the middle part of the back plate is pushed out outwards by controlling the pull wire to drive the back plate to bend, so that the waist-pushing effect is achieved; but the structure is too complex and cumbersome; the linkage of the stay wire and the back plate is realized through the matching of a series of structures such as the stay wire, the regulator, the pulley and the like; installation and machining costs are prohibitive.

Disclosure of Invention

The utility model overcomes the defects in the prior art and provides the waist rest adjusting device of the chair, which has simple structure, quick operation and labor saving; the waist support component is arranged on the chair back component, and the waist support component has elasticity and can be bent and deformed; the lower end of the waist support component can be lifted and lowered relative to the chair back component, so that a user sits on the chair, the lower end of the waist support component directly acts on the chair back component to move upwards relative to the chair back component, the waist support component can be elastically bent, the waist support component is correspondingly pushed forwards, and the waist support effect is achieved; the deformation degree of the waist rest component is adjusted by adjusting the ascending distance of the lower end of the waist rest; so as to match users with different heights and weights; the use is more humanized, and convenient operation is swift.

The technical scheme of the utility model is realized as follows:

a lumbar support adjusting device of a chair comprises a chair back component and a lumbar support component arranged on the chair back component; the lumbar support component has elasticity and can be bent and deformed in the vertical direction; the upper end and the lower end of the lumbar support component are respectively connected to the chair back component, and at least one end of the lumbar support component can be adjusted to be lifted relative to the chair back component; the lower end of the waist support component moves upwards relative to the chair back component or the upper end of the waist support component moves downwards relative to the chair back component so that the waist support component is bent and deformed, and the waist support component is ejected forwards relative to the chair back component.

Preferably, the upper end of the lumbar support component is connected to the chair back component; a lifting adjusting mechanism is arranged between the lower end of the lumbar support component and the chair back component, and the lower end of the lumbar support component can move up and down relative to the chair back component and stay at a corresponding adjusting position. The lifting adjusting mechanism is arranged at the lower end of the chair back component, and can be operated by hands conveniently.

Preferably, the lifting adjusting mechanism comprises an installation seat arranged at the lower part of the chair back component, an adjusting rod in sliding fit with the installation seat and a connecting seat connected to the installation seat and used for limiting the adjusting rod; the adjusting rod is clamped between the connecting seat and the mounting seat and can slide up and down relative to the mounting seat, and the lower end of the waist rest assembly is connected to the adjusting rod. The lower end of the waist rest component can be driven to move by controlling the adjusting rod to move relative to the chair back component, the structure is simple, and the manual operation is more convenient.

Preferably, the adjusting rod comprises a sliding part positioned in the middle and control handles arranged on two sides of the sliding part in a mirror image mode, and the sliding part is clamped between the connecting seat and the mounting seat; a plurality of tooth grooves which are arranged at intervals in the longitudinal direction are arranged in the middle of the mounting seat, and a movable tooth which penetrates through the sliding part and can be clamped on the tooth grooves is correspondingly arranged on the sliding part; the front end of the movable gear is provided with a control switch which is rotationally connected with the control handle; the action control switch rotates relative to the control handle to drive the movable teeth to be clamped into or separated from the tooth grooves. The control handle is convenient for a user to carry out handheld operation, the matching of the movable teeth and the tooth grooves can be controlled by pressing the control switch, the lower end of the waist support component can be adjusted to move up and down relative to the chair back component at any time, and the waist support component can be quickly stopped at the adjusted position.

Preferably, a spring is arranged between the control switch and the control handle; the movable teeth are driven to move forwards and separate from the tooth grooves by pressing the control switch, and the springs correspondingly generate elastic deformation and provide restoring elasticity to enable the movable teeth to have the tendency of being clamped into the tooth grooves again. After the adjustment is finished, the control switch is loosened, and the movable teeth can be clamped into the tooth grooves to lock the lumbar support assembly.

Preferably, the back mirror image of back subassembly is equipped with the windowing that makes control handle expose. When a user sits on the chair, the control handle can be held by the two hands from the rear of the chair back component, so that the lumbar support component can be adjusted; the adjustment is very convenient, and the chair does not need to be separated.

Preferably, the connecting seat is of a hollow square-shaped structure, and the lower end of the lumbar support component is directly connected to the sliding part in a rotating mode.

Preferably, the upper end of the lumbar support assembly is pivotally connected to the seat back assembly. The upper end of the waist rest component is rotationally connected to the chair back component, and the lower end of the waist rest component is rotationally connected to the sliding part; when the waist support component is bent and deformed, the waist support component can be automatically rotated and adjusted, and the phenomenon that the joint is broken due to the fact that stress is concentrated in one direction is avoided.

Preferably, the waist leans on the subassembly to be the fishbone-shaped structure of rectangular shape, the main tributary fagging can take place elastic deformation in vertical direction, the floor can take place elastic deformation in the left and right directions. The waist rest component is of a fishbone-shaped structure and is similar to a human spine structure; and can be in vertical direction and left and right sides direction elastic deformation for when the user lies and leans on back of the chair subassembly, the back subassembly can laminate human waist and back more, accords with human engineering mechanics.

Preferably, the upper end and the lower end of the main supporting plate are close to each other, and the main supporting plate is bent forwards and ejected. The main supporting plate has high elasticity and can be repeatedly elastically bent and reset.

Preferably, the main supporting plate is in an S shape as a whole. The main supporting plate is designed into an S shape to simulate the spine of a human body;

preferably, at the connecting part of the main supporting plate and the ribbed plate, the main supporting plate is thickened correspondingly; the thickness of the main supporting plate is alternatively thick and thin along the length direction of the main supporting plate. The elastic deformation of the main supporting plate is more flexible, and the main supporting plate is more labor-saving when being driven to deform and bend.

The design starting point, the idea and the beneficial effects of the utility model adopting the technical scheme are as follows:

firstly, the structure is simple and ingenious, the lumbar support component has elasticity, the upper end of the lumbar support component is connected to the chair back component, and a lifting adjusting mechanism is arranged between the lower end of the lumbar support component and the chair back component; the lower end of the lumbar support component is controlled to move upwards relative to the chair back component, so that the lumbar support component is bent and deformed, and the lumbar support effect is achieved; the bending degree of the lumbar support component can be correspondingly adjusted by controlling the upward movement distance of the lower end of the lumbar support component, and the ejection degree of the lumbar support component is controlled; the chair can be adapted to user groups with different heights and weights, and the use comfort of the chair is improved. Simple and reliable structure, convenient and fast adjustment.

Secondly, the waist rest component is in a long strip fishbone structure, and the main support plate is designed into an S shape to simulate the spine of a human body; the main supporting plate can be elastically deformed in the vertical direction, and the rib plates can be elastically deformed in the left and right directions; when a user lies on the chair back component, the waist support component can be adjusted along with the dynamic sitting posture self-adaptive elasticity of the user, more comfortable support is provided, and the chair back component accords with human engineering mechanics. And at the junction of main backup pad and floor, the main backup pad is thickened correspondingly; the thickness of the main supporting plate is alternately thick and thin along the length direction of the main supporting plate; a plurality of bending nodes are formed, so that the bending deformation of the main supporting plate is more flexible, and the main supporting plate is not particularly stressed when being driven to deform and bend; the waist is more labor-saving when the waist is adjusted.

In addition, during adjustment, a user does not need to leave the chair, the user can directly hold the control handle with both hands from the windowing position at the back of the chair back component, and the adjusting rod can slide relative to the chair back component by pressing the control switch to enable the movable teeth to be separated from the tooth grooves; the control switch is loosened, the movable teeth are clamped with the tooth grooves, and the adjusting rod and the chair back component are relatively fixed. The operation is convenient and simple.

In addition, the upper end of the waist support component is rotationally connected with the upper end of the chair back component, and the lower end of the waist support component is rotationally connected with the adjusting rod; when the lumbar support component is bent and deformed, the lumbar support component can rotate and be adjusted automatically, and the phenomenon that the joint is broken due to the fact that stress is concentrated in one direction is avoided; the structural strength is improved.

Drawings

FIG. 1 is a front perspective view of a lumbar support assembly positioned on a seatback assembly in an embodiment of the present invention;

FIG. 2 is a rear view of the lumbar support assembly on the seatback assembly in an embodiment of the present invention;

figure 3 is a schematic perspective view of a lumbar support assembly in an embodiment of the present invention;

FIG. 4 is a perspective view of a chair back assembly according to an embodiment of the present invention;

FIG. 5 is a schematic perspective view of an embodiment of a lift adjustment mechanism of the present invention;

FIG. 6 is an enlarged view of portion A of FIG. 5;

FIG. 7 is an exploded view of the attachment of the riser adjustment mechanism to the seat back assembly in an embodiment of the present invention;

FIG. 8 is a schematic perspective view of an adjusting lever according to an embodiment of the present invention;

FIG. 9 is a schematic perspective view of the connection seat and the sliding portion of the present invention;

figure 10 is a schematic perspective view of the lumbar support assembly and the adjustment bar in accordance with an embodiment of the present invention.

The figures are numbered: a seat back assembly 1; a lumbar support assembly 2; a main supporting plate 3; a rib plate 4; a connecting plate 5; a first rotating base 6; a first rotating shaft 7; a mounting seat 8; an adjusting lever 9; a sliding portion 9 a; a control handle 9 b; a connecting seat 10; a slideway 11; a card strip 12; a chute 13; a gullet 14; a movable gear 15; a control switch 16; a spring 17; a second rotating shaft 18; a second rotary base 19; a window 20 is opened.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the utility model will be rendered by reference to the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

In the description of the present invention, the term "at least one" means one or more than one unless explicitly defined otherwise. The terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the present embodiment, the terms relating to the respective directions, such as front and rear, are described in the use state where the user is actually seated on the chair.

The specific embodiment of the utility model is as follows:

as shown in fig. 1-10, the utility model provides a lumbar support adjusting device for a chair, which comprises a chair back component 1 and a lumbar support component 2 arranged on the chair back component 1, wherein the lumbar support component 2 comprises a main support plate 3 arranged longitudinally and ribs 4 arranged on the main support plate 3 at intervals along the length direction of the main support plate 3; the lumbar support component 2 has elasticity and can be elastically bent; the upper end of the lumbar support component 2 is connected to the chair back component 1, and the lower end of the lumbar support component 1 can be adjusted to be lifted relative to the chair back component 1; then, the lower end of the lumbar support component 1 is adjusted to ascend relative to the chair back component 1, so that the lumbar support component 2 is elastically bent, and the lumbar support component 2 is ejected forwards relative to the chair back component 1, thereby achieving the effect of ejecting the waist; the bending degree of the lumbar support component 2 can be correspondingly adjusted by controlling the upward moving distance of the lower end of the lumbar support component 2, and the ejection degree of the lumbar support component 2 is controlled; the chair can be adapted to user groups with different heights and weights, and the use comfort of the chair is improved.

As shown in fig. 1-3, the lumbar support assembly 2 has a long-strip fishbone-shaped structure, similar to the shape of a human spine; when a user lies on the chair back component 1, the waist support component 2 can be more fit with the waist and the back of the human body, and the human engineering mechanics is met. The lumbar support component 2 is made of elastic plastic materials with high strength, wherein the main support plate 3 is S-shaped and simulates the spine of a human body, and the main support plate 3 can elastically deform in the vertical direction; the main supporting plate 3 has large elasticity, the upper end and the lower end of the main supporting plate can be close to each other to enable the main supporting plate to be bent and ejected forwards, the main supporting plate can be ejected repeatedly and reset without breaking, and the structural strength is high. The ribbed plate 4 is vertical to the main supporting plate 3, and the ribbed plate 4 is positioned at the left side and the right side of the main supporting plate 3 and is slightly bent forwards respectively, so that the waist and the back of a human body can be met; the rib 4 can be elastically deformed in the right-left direction. The waist rest component can generate elastic deformation to a certain degree in the vertical and horizontal directions; so that the lumbar assembly 2 can follow the dynamic sitting posture self-adaptive elastic adjustment of the user, providing a more comfortable support. Furthermore, at the junction of main tributary fagging 3 and floor 4, the corresponding thickening of main tributary fagging 3 is handled, then along the length direction of main tributary fagging 3, and the thickness of main tributary fagging 3 is thick, thin interval alternate form, and during elastic bending, the main tributary fagging can be very natural thick, thin linking department natural bending for the elastic deformation of main tributary fagging 3 is nimble light and handy more, can not eat power very much when ordering about its elastic deformation, and is more laborsaving during the regulation.

As shown in fig. 4, a connecting plate 5 protruding downward is disposed at the upper end of the seat back assembly 1, a first rotating seat 6 is disposed on the connecting plate 5, a first rotating shaft 7 capable of being matched with the first rotating seat 6 is correspondingly disposed at the upper end of the lumbar support assembly 2, and the first rotating shaft 7 is rotatably connected to the first rotating seat 6.

As shown in fig. 5-10, the lower end of the lumbar support assembly 2 is connected to the lower portion of the seat back assembly 1, and a lifting adjusting mechanism is arranged between the lower end of the lumbar support assembly 2 and the seat back assembly 1 to enable the lower end of the lumbar support assembly 2 to be lifted and adjusted relative to the seat back assembly 1, wherein the lifting adjusting mechanism comprises a mounting seat 8 arranged at the lower portion of the seat back assembly 1, an adjusting rod 9 slidably fitted on the mounting seat 8, and a connecting seat 10 connected to the mounting seat 8 and used for limiting the adjusting rod 9; specifically, the method comprises the following steps: the adjusting rod 9 comprises a sliding part 9a positioned in the middle and control handles 9b arranged on the left side and the right side of the sliding part 9a in a mirror image mode, the control handles 9b are transversely arranged, and the control handles 9b protrude forwards from the sliding part 9 a; during connection, the sliding part 9a is clamped between the connecting seat 10 and the mounting seat 8, the connecting seat 10 is fixed on the mounting seat 8 through screw connection, and a slide 11 for guiding the sliding part 9a to slide up and down is formed between the connecting seat 10 and the mounting seat 8, so that the adjusting rod 9 can slide up and down relative to the chair back component 1. The connecting seat 10 is of a hollow square-shaped structure, the length of the connecting seat 10 in the left-right direction is matched with that of the sliding part 8a, so that the left side and the right side of the connected connecting seat 10 are respectively abutted against the inner ends of the control handles 9b at the two sides, and the sliding part 9a can be limited from deviating in the left-right direction; a clamping strip 12 protruding towards the end (namely forward) of the connecting seat 10 is also arranged on the sliding part 9a, and a longitudinal sliding groove 13 is arranged at the corresponding position of the connecting seat 10; after the connection, the clamping strip 12 is embedded in the sliding groove 13, so that the sliding part 9a is further limited in the left-right direction, and the adjusting rod 9 is more stable in the up-down sliding process relative to the mounting base 8. Furthermore, a plurality of tooth sockets 14 which are arranged at intervals in the longitudinal direction are arranged at the middle position of the mounting seat 8, a movable tooth 15 which penetrates through the sliding part 9a and can be clamped on the tooth sockets 14 is correspondingly arranged at the middle position of the sliding part 9a, wherein the front end of the movable tooth 15 is connected with a control switch 16 which is transversely arranged, the control switch 16 is a handle which is convenient for a human hand to press, and the control switch 16 is rotationally connected on the control handle 9 b; then, the control switch 16 is pressed to enable the control switch 16 to rotate relative to the control handle 9b so as to drive the movable teeth 15 to move back and forth, and the movable teeth 15 are controlled to be clamped in or separated from the tooth grooves 14; a spring 17 is arranged between the control switch 16 and the control handle 9 b; pressing the control switch 16 causes the movable tooth 15 to move forward and disengage from the tooth socket 14, and the spring 17 deforms accordingly and provides restoring elasticity so that the movable tooth 15 tends to be locked into the tooth socket 14 again.

As shown in fig. 2, 3, 9 and 10, the sliding portion 9a is further provided with a second rotating shaft 18 protruding forward and penetrating through the connecting seat 10, a second rotating seat 19 is correspondingly provided at the lower end of the lumbar support assembly 2, and the second rotating seat 19 is rotatably connected with the second rotating shaft 18. And the rear end of the chair back component 1 is provided with the windowing 20, then a hand can act on the control handle 9b from the rear of the chair to drive the adjusting rod 9 to slide upwards relative to the mounting seat 8, so that the lower end of the lumbar support component 2 is driven to move upwards, the lumbar support component 2 deforms and bends, and the lumbar support component 2 is ejected forwards to achieve the effect of supporting the waist. In addition, the upper end of the lumbar support component 2 is rotationally connected with the chair back component 1, and the lower end of the lumbar support component 2 is rotationally connected with the adjusting rod 9; make the waist lean on subassembly 2 at deformation in-process, the upper and lower both ends that the waist leaned on subassembly 2 can corresponding rotation, and the atress is concentrated in a direction and is leaded to the junction to split easily when avoiding deformation, improves structural strength.

The specific use mode is as follows: when a user sits on the seat, the supporting function of the lumbar support component 2 is more obvious if needed, and the lumbar support component is pushed forwards; the control handle 9b is held by two hands from the rear of the chair back component 1 and the control switch 16 is pressed, and the movable teeth 15 are separated from the tooth grooves 14; the control handle 9b can be acted upwards, so that the adjusting rod 9 slides upwards along the mounting seat 8, the lower end of the lumbar support component 2 moves upwards, the whole lumbar support component 2 deforms and bends, and the lumbar support component 2 pushes the waist forwards; when the lumbar assembly 2 is pushed forward to a position satisfied by a user, the control switch 16 is released, and the movable teeth 15 automatically engage with the tooth grooves 14 at the corresponding height, so that the lumbar assembly 2 stays at the position. The waist rest adjusting device realizes the waist supporting function of the chair by controlling the elastic deformation of the waist rest component 2; the waist rest component 2 is fast and labor-saving to adjust, and a user can operate the chair without leaving the chair; the structure is simple, the lifting adjusting structure is hidden between the waist rest component 2 and the chair back component 1, and the self-modeling of the product cannot be damaged; the appearance is simple and beautiful, and the modern aesthetic requirement is met.

The present invention and its embodiments have been described above schematically, without limitation, and what is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if the person skilled in the art receives the teaching, without departing from the spirit of the utility model, the person skilled in the art shall not inventively design the similar structural modes and embodiments to the technical solution, but shall fall within the scope of the utility model.

Claims

1. A lumbar support adjusting device of a chair is characterized in that: comprises a chair back component and a lumbar support component arranged on the chair back component; the lumbar support component has elasticity and can be bent and deformed in the vertical direction; the upper end and the lower end of the lumbar support component are respectively connected to the chair back component, and at least one end of the lumbar support component can be adjusted to be lifted relative to the chair back component; the lower end of the waist support component moves upwards relative to the chair back component or the upper end of the waist support component moves downwards relative to the chair back component so that the waist support component is bent and deformed, and the waist support component is ejected forwards relative to the chair back component.

2. The lumbar support adjustment device for a chair according to claim 1, wherein: the upper end of the waist support component is connected to the chair back component; a lifting adjusting mechanism is arranged between the lower end of the lumbar support component and the chair back component, and the lower end of the lumbar support component can move up and down relative to the chair back component and stay at a corresponding adjusting position.

3. The lumbar support adjustment device for a chair according to claim 2, wherein: the lifting adjusting mechanism comprises a mounting seat arranged at the lower part of the chair back component, an adjusting rod in sliding fit with the mounting seat and a connecting seat connected to the mounting seat and used for limiting the adjusting rod; the adjusting rod is clamped between the connecting seat and the mounting seat and can slide up and down relative to the mounting seat, and the lower end of the waist rest assembly is connected to the adjusting rod.

4. A lumbar support adjustment device for a chair according to claim 3, wherein: the adjusting rod comprises a sliding part positioned in the middle and control handles arranged on two sides of the sliding part in a mirror image mode, and the sliding part is clamped between the connecting seat and the mounting seat; a plurality of tooth grooves which are arranged at intervals in the longitudinal direction are arranged in the middle of the mounting seat, and a movable tooth which penetrates through the sliding part and can be clamped on the tooth grooves is correspondingly arranged on the sliding part; the front end of the movable gear is provided with a control switch which is rotationally connected with the control handle; the action control switch rotates relative to the control handle to drive the movable teeth to be clamped into or separated from the tooth grooves.

5. The lumbar support adjustment device of a chair according to claim 4, wherein: a spring is arranged between the control switch and the control handle; the movable teeth are driven to move forwards and separate from the tooth grooves by pressing the control switch, and the springs correspondingly generate elastic deformation and provide restoring elasticity to enable the movable teeth to have the tendency of being clamped into the tooth grooves again.

6. The lumbar support adjustment device of a chair according to claim 4, wherein: the back mirror image of back of chair back subassembly is equipped with the windowing that makes control handle expose.

7. The lumbar support adjustment device of a chair according to claim 4, wherein: the connecting seat is of a hollow square-shaped structure, and the lower end of the waist rest component is directly connected to the sliding part in a rotating mode.

8. The lumbar support adjustment device for a chair according to claim 2, wherein: the upper end of the waist support component is rotatably connected to the chair back component.

9. The lumbar support adjustment device for a chair according to claim 1, wherein: the waist support component is of a long-strip fishbone structure and comprises a main support plate arranged longitudinally and ribbed plates arranged on the main support plate at intervals along the length direction of the main support plate; the main tributary fagging can take place elastic deformation in vertical direction, the floor can take place elastic deformation in the left and right sides direction.

10. The lumbar support adjustment device for chairs of claim 9, wherein: the upper end and the lower end of the main supporting plate are close to each other, and the main supporting plate is bent forwards and ejected out.

11. The lumbar support adjustment device for chairs of claim 9, wherein: the main supporting plate is S-shaped as a whole.

12. The lumbar support adjustment device for a chair according to claim 10, wherein: at the joint of the main supporting plate and the ribbed plate, the main supporting plate is thickened correspondingly; the thickness of the main supporting plate is alternatively thick and thin along the length direction of the main supporting plate.