Sliding telescopic connecting assembly for waist pillow and chair back and chair

Abstract

The utility model discloses a sliding telescopic connecting assembly for a waist pillow and a chair back and a chair, and the sliding telescopic connecting assembly comprises a first connecting shell, a second connecting shell, a third connecting shell and a fourth connecting shell, the second connecting shell is used for being connected with the waist pillow and is arranged in the slide way in a sliding manner; the locking mechanism is arranged between the first connecting shell and the second connecting shell and has a locking state and an unlocking state, the second connecting shell keeps fixed relative to the first connecting shell when the locking mechanism is in the locking state, and the second connecting shell can slide relative to the second connecting shell when the locking mechanism is in the unlocking state; the lining is arranged between the inner wall face of the sliding way and the outer wall face of the second connecting shell so as to separate the inner wall face of the sliding way from the outer wall face of the second connecting shell. By means of the waist pillow, friction resistance in the sliding process can be remarkably reduced, the waist pillow can be adjusted more smoothly, and meanwhile abnormal sound in the using process can be reduced.

Description

Technical Field

[0001] This utility model relates to the field of seating technology, specifically to a sliding telescopic connection component for a lumbar support and a chair back, and a chair. Background Technology

[0002] Lumbar support pillows in chairs provide effective support for the user's lower back, relieving lower back fatigue caused by prolonged sitting. To accommodate users of different body types, lumbar support pillows are typically designed to be adjustable relative to the chair back. Currently, a sliding telescopic connecting component is generally used to achieve this adjustment. However, existing sliding telescopic connecting components suffer from issues such as high sliding friction and rattling noises during use. Furthermore, these components generally use screws for locking, requiring users to first loosen the screws to unlock, then push or pull the pillow to the desired position, and finally tighten the screws to lock the pillow relative to the chair back. This process is cumbersome, and after repeated use, the screws may slip, preventing the pillow from locking properly.

[0003] In summary, how to provide a sliding telescopic connection component that can effectively reduce sliding friction and abnormal noise, while having reliable locking and smooth adjustment functions, has become a technical problem that urgently needs to be solved in this field. Utility Model Content

[0004] The purpose of this utility model is to provide a sliding telescopic connection component for a lumbar pillow and a chair back, and a seat, which can reduce the friction between the relatively sliding parts in the sliding telescopic adjustment component and reduce abnormal noise.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A sliding telescopic connection assembly for a lumbar support and a chair back, the sliding telescopic connection assembly comprising:

[0007] A first connecting shell is used to connect with the chair back and has a sliding track;

[0008] The second connecting shell is used to connect with the lumbar pillow and is slidably disposed within the slide rail;

[0009] A locking mechanism is disposed between a first connecting shell and a second connecting shell and has a locked state and an unlocked state. When the locking mechanism is in the locked state, the second connecting shell remains fixed relative to the first connecting shell; when the locking mechanism is in the unlocked state, the second connecting shell is slidable relative to the second connecting shell.

[0010] A bushing is disposed between the inner wall surface of the slide and the outer wall surface of the second connecting shell to separate the inner wall surface of the slide and the outer wall surface of the second connecting shell.

[0011] Preferably, the bushing is fixedly disposed on the first connecting shell, and the second connecting shell slides with the bushing when the locking mechanism is in the unlocked state.

[0012] Preferably, the first connecting shell includes a first top plate, a first bottom plate, and a first side plate disposed between the first top plate and the first bottom plate. The first top plate, the first bottom plate, and the first side plate cooperate to enclose and form the slide rail. The locking mechanism includes:

[0013] A connecting plate, which is fixedly disposed on the second connecting shell and has a connecting groove, wherein the inner wall of the connecting groove has a plurality of continuously distributed slots; and,

[0014] A locking element is disposed on the first base plate and has a locking portion that engages with the slot;

[0015] The first base plate has a mounting groove, the bottom wall of the mounting groove has a through hole and the side wall has a stop structure, the locking member is disposed in the mounting groove, and the locking part passes through the through hole and extends into the connecting groove.

[0016] The second connecting shell has an extension stroke that increases the total length of both relative to the first connecting shell and a shortening stroke that decreases the total length of both. The locking member is configured to remain separated from the slot by the stop structure during the shortening stroke, and the locking member is also configured to engage with the slot during the extension stroke.

[0017] Preferably, the locking mechanism further includes an elastic member disposed between the locking member and the first base plate, the elastic member applying pressure to the locking member such that the locking portion tends to engage with the slot.

[0018] Preferably, the second connecting shell includes a second top plate, second side plates disposed on both sides of the second top plate, and a second bottom plate disposed between the two second side plates. The second bottom plate and the second side plates cooperate to form a groove, and the bottom wall of the groove forms an installation opening. The connecting plate is fixedly disposed in the installation opening. The bushing includes a first liner and a second liner. Both the first liner and the second liner include a main body, a bent portion formed at the top of the main body, and a protruding edge formed at the bottom of the main body. The main body is located between the first side plate and the second side plate, the bent portion is located between the first top plate and the second top plate, and the protruding edge is located between the bottom of the first bottom plate and the second side plate.

[0019] Preferably, the first base plate has a protrusion extending into the groove, the outer surface of the connecting plate extends out of the mounting opening, and the outer surface of the connecting plate slides in contact with the protrusion to space the protrusion from the second base plate.

[0020] Preferably, both the bushing and the connecting plate are made of polyoxymethylene.

[0021] Preferably, the stop structure includes a limiting groove and a transition groove formed on the side wall of the mounting groove, and the locking member also has a movable part and a pressure-bearing part. The movable part is rotatably and movablely disposed in the transition groove, and the pressure-bearing part is engaged in the limiting groove during the shortening stroke and disengaged from the limiting groove during the extending stroke.

[0022] Preferably, the inner walls at both ends of the connecting groove are respectively formed with a first abutting part and a second abutting part. The first abutting part is used to drive the locking member to move by pushing the locking part and causing the pressure part to be inserted into the limiting groove. The second abutting part is used to drive the locking member to move by pushing the locking part and causing the pressure part to disengage from the limiting groove.

[0023] In addition, to achieve the above objectives, the present invention also adopts the following technical solution:

[0024] A seat includes a backrest and a lumbar support, and the seat further includes a sliding telescopic connection assembly as described in any of the above technical solutions, wherein the lumbar support is disposed on the backrest via the sliding telescopic connection assembly.

[0025] Compared to existing technologies, the advantages of this invention are as follows: by providing a bushing between the inner wall of the slide and the outer wall of the second connecting shell, the original direct contact between the two is transformed into indirect contact through the bushing. Since the bushing is typically made of a material with a low coefficient of friction, it significantly reduces frictional resistance during sliding, making the lumbar support adjustment smoother. Simultaneously, the bushing also acts as a buffer and shock absorber, reducing abnormal noises caused by rigid contact between components during sliding and improving quietness during use. Attached Figure Description

[0026] Figure 1 This application provides a sliding telescopic connection assembly for a lumbar support pillow and a chair back.

[0027] Figure 2 A schematic diagram illustrating the application of a sliding telescopic connection component;

[0028] Figure 3 This is a schematic diagram of the sliding telescopic connection component when it extends.

[0029] Figure 4 An exploded view of the sliding telescopic connection assembly;

[0030] Figure 5 A longitudinal sectional view of the sliding telescopic connection assembly;

[0031] Figure 6 This is a schematic diagram of the bushing structure;

[0032] Figure 7 An exploded view of the locking mechanism;

[0033] Figure 8 A schematic diagram of the locking element and the first connecting shell during the extension stroke;

[0034] Figure 9 This is a schematic diagram of the locking element and the first connecting shell during the shortened stroke.

[0035] The components include: 1. First connecting shell; 10. First top plate; 11. First bottom plate; 110. Mounting groove; 111. Perforation; 112. Adapter groove; 113. Limiting groove; 114. Protrusion; 12. First side plate; 13. Cover plate; 2. Second connecting shell; 20. Second top plate; 21. Second bottom plate; 210. Mounting port; 22. Second side plate; 23. Groove; 3. Bushing; 30. First liner plate; 31. Second liner plate; 32. Main body; 33. Bending part; 34. Protruding edge; 4. Connecting plate; 40. Connecting groove; 400. First abutment part; 401. Second abutment part; 41. Slot; 5. Locking element; 50. Locking part; 51. Movable part; 52. Pressure-bearing part; 6. Elastic element; 7. Lumbar pillow; 8. Connecting frame. Detailed Implementation

[0036] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. Unless otherwise specified, the materials and equipment used in this embodiment are all commercially available. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0037] In the description of this application, it should be understood that the terms "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In the description of this application, "a plurality of" means two or more, unless otherwise precisely specified.

[0038] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected," "linked," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a connection through an intermediary, or a connection within two elements or an interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0039] This embodiment provides a sliding and telescopic connection assembly for a lumbar support pillow and a chair back, such as... Figure 1 , Figure 3 and Figure 4 As shown, the sliding telescopic connection assembly includes a first connecting shell 1, a second connecting shell 2, a locking mechanism, and a bushing 3. The first connecting shell 1 has a slide rail, and the second connecting shell 2 is slidably disposed within the slide rail. Figure 2 As shown, the first connecting shell 1 is used to connect with the chair back, and the second connecting shell 2 is used to connect with the lumbar pillow 7. A locking mechanism is disposed between the first connecting shell 1 and the second connecting shell 2. The locking mechanism has a locked state and an unlocked state. When the locking mechanism is in the locked state, the second connecting shell 2 remains fixed relative to the first connecting shell 1. When the locking mechanism is in the unlocked state, the second connecting shell 2 can slide relative to the first connecting shell 1. A bushing 3 is disposed between the inner wall surface of the slide and the outer wall surface of the second connecting shell 2 to separate the inner wall surface of the slide and the outer wall surface of the second connecting shell 2.

[0040] The sliding telescopic connection assembly provided in this embodiment transforms the original direct contact between the inner wall of the slide and the outer wall of the second connecting shell 2 into indirect contact through the bushing 3. Since the bushing 3 is typically made of a material with a low coefficient of friction, it significantly reduces frictional resistance during sliding, making the adjustment of the lumbar pillow 7 smoother. Simultaneously, the bushing 3 also acts as a buffer and shock absorber, reducing abnormal noises caused by rigid contact between components during sliding and improving quietness during use.

[0041] In this embodiment, the bushing 3 is made of polyoxymethylene (POM). POM has high hardness and rigidity, and its mechanical strength is similar to that of metal, making it less prone to deformation and damage. At the same time, POM has excellent wear resistance and self-lubricating properties, and its low coefficient of friction can effectively reduce the sliding friction between components.

[0042] In this embodiment, the bushing 3 is fixedly mounted on the first connecting shell 1. Correspondingly, the second connecting shell 2 slides with the bushing 3 when the locking mechanism is in the unlocked state. Specifically, the bushing 3 can be fixed to the first connecting shell 1 by screw locking or adhesive fixing.

[0043] In this embodiment, the first connecting shell 1 includes a first top plate 10, a first bottom plate 11, and a first side plate 12 disposed between the first top plate 10 and the first bottom plate 11. The first top plate 10, the first bottom plate 11, and the first side plate 12 cooperate to form a slide. Correspondingly, in this embodiment, the second connecting shell 2 includes a second top plate 20, second side plates 22 disposed on both sides of the second top plate 20, and a second bottom plate 21 disposed between the two second side plates 22. In this embodiment, the second top plate 20 corresponds to the first top plate 10, the second side plate 22 corresponds to the first side plate 12, and the second bottom plate 21 corresponds to the first bottom plate 11. Figure 6 As shown, the bushing 3 in this embodiment includes a first bushing 30 and a second bushing 31. Both the first bushing 30 and the second bushing 31 include a main body 32, a bent portion 33 formed at the top of the main body 32, and a raised edge portion 34 formed at the bottom of the main body 32. The main body 32 is located between the first side plate 12 and the second side plate 22, the bent portion 33 is located between the first top plate 10 and the second top plate 20, and the raised edge portion 34 is located between the bottom of the first bottom plate 11 and the bottom of the second side plate 22. The second bottom plate 21 and the first bottom plate 11 are restricted from direct contact by other structures, which will be described in detail below.

[0044] It is readily understood that in this embodiment, the second connecting shell 2 has an extension stroke that increases the total length of both relative to the first connecting shell 1, and a shortening stroke that decreases the total length of both. When the second connecting shell 2 extends or retracts to a suitable position relative to the first connecting shell 1, the second connecting shell 2 can be locked relative to the first connecting shell 1 by a locking mechanism. Combined with... Figure 4 , Figure 7 , Figure 8 and Figure 9 As shown, the locking mechanism in this embodiment includes a connecting plate 4, a locking member 5, and an elastic member 6. The connecting plate 4 is fixedly disposed on the second connecting shell 2 and has a connecting groove 40. The inner wall of the connecting groove 40 has multiple continuously distributed slots 41. The locking member 5 is disposed on the first base plate 11 and has a locking portion 50 that engages with the slots 41. The elastic member 6 is disposed between the locking member 5 and the first base plate 11, and applies pressure to the locking member 5 such that the locking portion 50 tends to engage with the slots 41. The engagement described here means that the inner wall of the slot 41 has a guide slope. Under the interaction between the inner wall of the slot 41 and the locking portion 50, when the locking portion 50 and the slot 41 are engaged, the user can pull the second connecting shell 2 along the direction of extension, causing the connecting plate 4 to move relative to the locking member 5, so that the locking portion 50 can disengage from one slot 41 and engage with another adjacent slot 41. However, when the locking part 50 and the slot 41 are engaged, the user cannot push the second connecting shell 2 relative to the locking part 5 in the direction of shortening the stroke.

[0045] In this embodiment, the first base plate 11 forms a mounting groove 110. The bottom wall of the mounting groove 110 is provided with a through hole 111 and the side wall is provided with a stop structure. The locking member 5 is disposed in the mounting groove 110, and the locking part 50 passes through the through hole 111 and extends into the connecting groove 40. The locking member 5 is configured to remain separated from the slot 41 by the stop structure during the shortening stroke, and the locking member 5 is also configured to engage with the slot 41 during the extending stroke. It is easy to understand that, for ease of assembly, in this embodiment, a cover plate 13 is detachably provided on the second connecting shell 2 by screws. After the locking member 5 and the elastic member 6 are disposed in the mounting groove 110, the opening of the mounting groove 110 is sealed by the cover plate 13 to prevent the locking member 5 and the elastic member 6 from falling out of the mounting groove 110. In addition, the elastic element 6 in this embodiment is a compression spring. A rectangular groove for arranging the compression spring is provided in the mounting groove 110. The swaying of the compression spring can be limited by the inner wall of the rectangular groove and the cover plate 13. In other optional embodiments, a metal sheet can also be used as the elastic element 6.

[0046] The stopping structure in this embodiment includes a limiting groove 113 and a transition groove 112 formed on the side wall of the mounting groove 110. The locking member 5 also has a movable part 51 and a pressure-receiving part 52. The movable part 51 is rotatably and movablely disposed in the transition groove 112. The pressure-receiving part 52 engages with the limiting groove 113 during the shortening stroke and disengages from the limiting groove 113 during the extending stroke. It can be understood that the locking part 50 and the slot 41 are in a meshing state when the pressure-receiving part 52 disengages from the limiting groove 113, and the meshing state is released when the locking part 50 and the slot 41 engage with the limiting groove 113. Furthermore, in this embodiment, the inner walls of the two ends of the connecting groove 40 are respectively formed with a first abutting part 400 and a second abutting part 401. The first abutting part 400 is used to drive the locking member 5 to move by pushing the locking part 50 and causing the pressure part 52 to be inserted into the limiting groove 113. The second abutting part 401 is used to drive the locking member 5 to move by pushing the locking part 50 and causing the pressure part 52 to disengage from the limiting groove 113.

[0047] like Figure 8 and Figure 9 As shown, the movable part 51 has an arc-shaped structure and a flat structure. When the locking member 5 is pushed by the first abutting part 400 or the second abutting part 401, the movable part 51 can move relative to the transition groove 112 through the flat structure. After the pressure-bearing part 52 disengages from the limiting groove 113, and after the locking member 5 disengages from a slot 41, under the pressure of the elastic member 6, the movable part 51 can swing relative to the transition groove 112 through the arc-shaped structure.

[0048] With the above structural design, the operator can adjust the position of the second connecting shell 2 relative to the first connecting shell 1 and switch the state of the locking mechanism by pushing and pulling the second connecting shell 2 along the telescopic direction. Specific details are as follows:

[0049] When the user wants the lumbar support 7 to be further away from the chair back, the second connecting shell 2 needs to be pulled out relative to the first connecting shell 1, which means that the second connecting shell 2 extends its travel. It is easy to understand that at this time, the user can directly pull the second connecting shell 2 so that the locking part 50 on the locking member 5 switches between the corresponding slots 41 through the meshing relationship until the position of the second connecting shell 2 relative to the first connecting shell 1 is adjusted to the desired position, the locking part 50 is engaged in the corresponding slot 41, and the second connecting shell 2 remains stable relative to the first connecting shell 1.

[0050] When the user wants the lumbar support 7 to be closer to the chair back, the second connecting shell 2 needs to be retracted relative to the first connecting shell 1, which means the second connecting shell 2 needs to shorten its travel. Since the locking part 50 on the locking member 5 is engaged in the slot 41, the second connecting shell 2 cannot be directly pushed in the direction of shortening travel. At this time, the second connecting shell 2 needs to be pulled to extend its travel, which means the locking part 50 switches between slots 41 one by one until the locking member 5 moves to the point where the locking part 50 contacts the first abutment part 400. Continuing to pull the second connecting shell 2, the locking part 50 will be pressed by the first abutment part 400, thereby pushing the locking member 5 to shift and causing the pressure-bearing part 52 on the locking member 5 to engage in the limiting groove 113, resulting in... Figure 8 As shown in the diagram. Afterwards, since the locking portion 50 on the locking member 5 remains separated from the slot 41, the second connecting shell 2 can be pushed in the direction of shortening the stroke until the locking portion 50 contacts the second abutment portion 401. Continuing to push the second connecting shell 2 will apply pressure to the locking portion 50 through the second abutment portion 401, causing the locking member 5 to shift and the pressure-bearing portion 52 on the locking member 5 to disengage from the limiting groove 113, resulting in the state shown. Figure 9 The position shown is as follows. At this time, the lumbar pillow 7 is at its shortest distance relative to the chair back. Then, adjust the position of the lumbar pillow 7 according to the aforementioned adjustment method that makes the lumbar pillow 7 relatively farther away from the chair back.

[0051] As mentioned above, in this embodiment, the second base plate 21 and the first base plate 11 are restricted from direct contact by other structures. Specifically, the second base plate 21 and the second side plate 22 cooperate to form a groove 23, and the bottom wall of the groove 23 forms a mounting opening 210, in which the connecting plate 4 is fixedly disposed. That is, the second base plate 21 is not disposed at the end of the second side plate 22, thereby forming the groove 23 between the second base plate 21 and the second side plate 22. Figure 4 and Figure 5 As shown, in this embodiment, the first base plate 11 has a protrusion 114 extending into the groove 23. The outer surface of the connecting plate 4 extends out of the mounting opening 210, and the outer surface of the connecting plate 4 slides in contact with the protrusion 114 to separate the protrusion 114 from the second base plate 21. Specifically, the protrusion 114 and the second base plate 21 have a gap such that... Figure 5The gap H is shown. In this embodiment, the connecting plate 4 is also made of polyoxymethylene. In this way, the first base plate 11 slides in contact with the connecting plate 4 made of polyoxymethylene through the protrusion 114, which can reduce friction and reduce abnormal noise.

[0052] Combination Figure 2 As shown, the sliding telescopic connection assembly provided in this embodiment can be applied to a seat, which includes a backrest and a lumbar support 7. The lumbar support 7 is set on the backrest through the sliding telescopic connection assembly. Figure 2 The image shows a lumbar support 7 and a connecting bracket 8 for mounting to the chair back. A first connecting shell 1 of the sliding telescopic connecting assembly is mounted on the connecting bracket 8, allowing mounting to the chair back via the connecting bracket 8. A second connecting shell 2 of the sliding telescopic connecting assembly is mounted on the lumbar support 7. During use, the user can adjust the position of the lumbar support 7 relative to the chair back by pushing or pulling it.

[0053] Finally, it should be noted that the above embodiments are only optional embodiments of this utility model and should not be used to limit the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.

Claims

1. A sliding telescopic connecting assembly for a lumbar pillow and a backrest of a chair, characterized in that, The sliding telescopic connection component includes: A first connecting shell is used to connect with the chair back and has a sliding track; The second connecting shell is used to connect with the lumbar pillow and is slidably disposed within the slide rail; A locking mechanism is disposed between a first connecting shell and a second connecting shell and has a locked state and an unlocked state. When the locking mechanism is in the locked state, the second connecting shell remains fixed relative to the first connecting shell; when the locking mechanism is in the unlocked state, the second connecting shell is slidable relative to the second connecting shell. A bushing is disposed between the inner wall surface of the slide and the outer wall surface of the second connecting shell to separate the inner wall surface of the slide and the outer wall surface of the second connecting shell.

2. The sliding and telescopic connecting assembly for the lumbar support and the backrest of a chair according to claim 1, characterized in that, The bushing is fixedly mounted on the first connecting shell, and the second connecting shell slides with the bushing when the locking mechanism is in the unlocked state.

3. The sliding and telescopic connecting assembly for the backrest of a chair and a pillow as claimed in claim 1 or 2, wherein, The first connecting shell includes a first top plate, a first bottom plate, and a first side plate disposed between the first top plate and the first bottom plate. The first top plate, the first bottom plate, and the first side plate cooperate to enclose and form the slide rail. The locking mechanism includes: A connecting plate, which is fixedly disposed on the second connecting shell and has a connecting groove, wherein the inner wall of the connecting groove has a plurality of continuously distributed slots; and, A locking element is disposed on the first base plate and has a locking portion that engages with the slot; The first base plate has a mounting groove, the bottom wall of the mounting groove has a through hole and the side wall has a stop structure, the locking member is disposed in the mounting groove, and the locking part passes through the through hole and extends into the connecting groove. The second connecting shell has an extension stroke that increases the total length of both relative to the first connecting shell and a shortening stroke that decreases the total length of both. The locking member is configured to remain separated from the slot by the stop structure during the shortening stroke, and the locking member is also configured to engage with the slot during the extension stroke.

4. The sliding and telescopic connecting assembly for the lumbar support and the backrest of a chair as claimed in claim 3, wherein, The locking mechanism further includes an elastic member disposed between the locking member and the first base plate, the elastic member applying pressure to the locking member such that the locking portion tends to engage with the slot.

5. The sliding and telescopic connecting assembly for the lumbar support and the backrest of a chair as claimed in claim 3, wherein, The second connecting shell includes a second top plate, second side plates disposed on both sides of the second top plate, and a second bottom plate disposed between the two second side plates. The second bottom plate and the second side plates cooperate to form a groove, and the bottom wall of the groove forms an installation opening. The connecting plate is fixedly disposed in the installation opening. The bushing includes a first liner and a second liner. Both the first liner and the second liner include a main body, a bent portion formed at the top of the main body, and a raised edge formed at the bottom of the main body. The main body is located between the first side plate and the second side plate, the bent portion is located between the first top plate and the second top plate, and the raised edge is located between the bottom of the first bottom plate and the bottom of the second side plate.

6. The sliding and telescopic connecting assembly for the lumbar support and the backrest of a chair as claimed in claim 5, wherein, The first base plate has a protrusion that extends into the groove, the outer surface of the connecting plate extends out of the mounting opening, and the outer surface of the connecting plate slides in contact with the protrusion to space the protrusion from the second base plate.

7. The sliding and telescopic connecting assembly for the lumbar support and the backrest of a chair as claimed in claim 6, wherein, Both the bushing and the connecting plate are made of polyoxymethylene.

8. The sliding and telescopic connecting assembly for the backrest of a chair and a pillow as claimed in claim 3, wherein, The stop structure includes a limiting groove and a transition groove formed on the side wall of the mounting groove. The locking member also has a movable part and a pressure-bearing part. The movable part is rotatably and movablely disposed in the transition groove. The pressure-bearing part is engaged in the limiting groove during the shortening stroke and disengaged from the limiting groove during the extending stroke.

9. The sliding and telescopic connecting assembly for the lumbar support and the backrest of a chair according to claim 8, characterized in that, The inner walls at both ends of the connecting groove are respectively formed with a first abutting part and a second abutting part. The first abutting part is used to drive the locking member to move by pushing the locking part and cause the pressure part to be inserted into the limiting groove. The second abutting part is used to drive the locking member to move by pushing the locking part and cause the pressure part to be disengaged from the limiting groove.

10. A seat comprising a seat back and a lumbar support, characterized in that The seat further includes a sliding telescopic connection assembly for the lumbar support and the backrest as described in any one of claims 1 to 9, wherein the lumbar support is disposed on the backrest via the sliding telescopic connection assembly.

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