Backrest assembly of seat and seat

Abstract

The utility model discloses a backrest assembly of a seat, which comprises a backrest support, a backrest body and a lifting mechanism, the backrest body is fixedly connected with the lifting mechanism, and the lifting mechanism has an ascending stroke and a descending stroke relative to the backrest support; a guide groove is formed in the backrest support, ratchets are formed in the guide groove, the lifting mechanism comprises a gear piece with a pawl, and the pawl can be meshed with or separated from the ratchets; the gear piece is switched between a deflection state and an alignment state through swinging, a guide area used for driving the gear piece to be switched from the deflection state to the alignment state is arranged on the upper portion of the guide groove, under the condition that the gear piece is in the alignment state, the pawl is separated from the ratchet, and at the moment, the lifting mechanism can implement the descending stroke. The lower portion of the guide groove is provided with an inclined guiding area used for driving the gear piece to be switched from the alignment state to the inclined state, under the condition that the gear piece is in the inclined state, the pawl is meshed with the ratchet, and at the moment, the lifting mechanism can implement the ascending stroke. The backrest assembly is simple in lifting process.

Description

Technical Field

[0001] This utility model relates to the field of seating technology, specifically to a seat back assembly and a seat. Background Technology

[0002] In today's society, where comfort and personalization are highly valued, chair design increasingly focuses on adapting to the user experience of users of different heights and body types. Therefore, modern chair designs commonly incorporate height-adjustable backrests, allowing users to flexibly adjust the backrest height according to their needs to achieve optimal posture support.

[0003] However, existing height-adjustable backrests employ complex adjustment mechanisms, such as multi-stage gear transmission and complex linkage structures. This type of backrest structure is complex, and users need to adjust the backrest height according to specific steps and sequences. Therefore, the process of raising and lowering the backrest is cumbersome and inconvenient to operate. Utility Model Content

[0004] The purpose of this utility model is to provide a backrest assembly and a seat, wherein the backrest assembly is easy to operate during the lifting and lowering process.

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

[0006] A seat backrest assembly includes a backrest bracket, a backrest body, and a lifting mechanism. The backrest body is fixedly connected to the lifting mechanism, and the backrest bracket and the lifting mechanism are slidably engaged along the height direction of the backrest bracket, so that the lifting mechanism has an upward stroke and a downward stroke relative to the backrest bracket.

[0007] The backrest support is provided with a guide groove and the guide groove is formed with a plurality of ratchet teeth arranged and spaced apart along the height direction of the backrest support. The lifting mechanism includes a stop member with a pawl, which can engage or disengage with the ratchet teeth.

[0008] The shifting member switches between a tilted state and a aligned state by oscillating. The upper part of the guide groove is provided with a guide zone for driving the shifting member to switch from the tilted state to the aligned state. When the shifting member is in the aligned state, the pawl and the ratchet are separated, and the lifting mechanism can perform the downward stroke. The lower part of the guide groove is provided with a tilting zone for driving the shifting member to switch from the aligned state to the tilted state. When the shifting member is in the tilted state, the pawl and the ratchet are engaged, and the lifting mechanism can perform the upward stroke.

[0009] Preferably, the guide groove has an upper end and a lower end that are oppositely arranged along the height direction of the backrest bracket, and a first side and a second side that are opposite to the first side are connected between the upper end and the lower end, and the ratchet is formed on the first side;

[0010] The upper end, the portion of the first side near the upper end, and the portion of the second side near the upper end together form the guiding area adapted to the shape of the pawl, and the lower end constitutes the inclined area.

[0011] Preferably, the lifting mechanism further includes a connecting seat and an elastic element. The elastic element is used to keep the pawl of the stop member moving toward the ratchet. The connecting seat has an assembly groove for mounting the stop member and a receiving groove for mounting the elastic element. The receiving groove communicates with the assembly groove. One end of the elastic element abuts against the inner wall of the receiving groove, and the other end extends out of the receiving groove and abuts against the stop member.

[0012] Preferably, the mounting groove along the height direction of the backrest bracket has a locking part and a receiving part opposite to the locking part, the stop member has a locking end and a free end opposite to the locking end, the pawl is disposed between the locking end and the free end, the locking end can engage or disengage with the locking part, and the free end is rotatably disposed in the receiving part;

[0013] At the end of the upward stroke, the guide zone drives the locking end to engage with the locking part so that the stop member maintains the alignment state during the downward stroke. At the end of the downward stroke, the guide zone abuts against the pawl to drive the locking end to disengage from the locking part and keep the stop member in the deflection state during the upward stroke.

[0014] Preferably, the outer peripheral surface of the locking end is arc-shaped so that the stop member can swing relative to the connecting seat.

[0015] Preferably, the backrest bracket is further provided with a positioning groove that is adjacent to and parallel to the guide groove, and the connecting seat is provided with a positioning boss that cooperates with the positioning groove. The positioning boss moves within the positioning groove to restrict the connecting seat from sliding along the opening direction of the positioning groove.

[0016] Preferably, the backrest support is U-shaped, comprising two opposing support rods, each of which is provided with a guide groove and a lifting mechanism corresponding to the guide groove.

[0017] Preferably, the backrest assembly includes a mounting bracket and a cover plate engaged with the mounting bracket. The opposite ends of the mounting bracket on the side closer to the backrest body are respectively fixed to the backrest body by elastic torsion members. The opposite ends of the mounting bracket on the side away from the backrest body are respectively fixed to the lifting mechanisms on the two support rods. The cover plate is located between the two lifting mechanisms.

[0018] Preferably, the backrest body includes an inner backrest panel, an outer backrest panel, and a cushion, wherein the cushion is fixed to the side of the inner backrest panel away from the inner backrest panel, and the outer backrest panel is fixed to the side of the inner backrest panel away from the cushion.

[0019] In addition, to achieve the above objectives, the present invention also adopts the following technical solution:

[0020] A seat includes a backrest, and the seat further includes the aforementioned seat back assembly.

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0022] The lifting mechanism includes a stop with a pawl, and the backrest support has multiple ratchet teeth at different heights. The stop switches between a tilted and aligned state by swinging. When the stop is in the tilted state, the pawl engages with the ratchet teeth, locking the current height of the backrest and lifting mechanism, while allowing the lifting mechanism to rise with the user's push, easily adjusting the backrest to a higher position. When the stop is in the aligned state, the pawl and ratchet disengage, no longer providing resistance, allowing the lifting mechanism to smoothly descend under gravity or with user assistance until the desired height is reached. The upper part of the guide groove has a guide zone for switching the stop from the tilted to the aligned state; the stop automatically switches at the end of the upward stroke due to pressure from the guide zone. The lower part of the guide groove has a tilting zone for switching the stop from the aligned to the tilted state; the stop automatically switches at the end of the downward stroke due to pressure from the tilting zone. No user intervention is required for other components, making operation simple and quick. Users can switch the position of the backrest by simply pulling the lifting mechanism to the upper or lower part of the guide groove, thereby changing the height of the backrest body and simplifying the lifting process of the backrest assembly. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the backrest assembly provided in an embodiment of this application;

[0024] Figure 2 for Figure 1 An explosion diagram;

[0025] Figure 3aThis is a schematic diagram showing the fit between the stop and the guide groove during the upward stroke.

[0026] Figure 3b This is a schematic diagram showing the fit between the stop and the connecting seat during the upward stroke.

[0027] Figure 4a This is a schematic diagram showing the interaction between the stop and the guide groove during the descent stroke.

[0028] Figure 4b This is a schematic diagram showing the engagement between the stop and the connecting seat during the descent stroke.

[0029] Among them, 1. Backrest bracket; 11. Guide groove; 111. Ratchet; 112. Guiding area; 113. Inclining area; 114. First side; 115. Second side; 12. Positioning groove; 13. Support rod; 2. Backrest body; 21. Inner backrest panel; 22. Outer backrest panel; 23. Cushion; 3. Lifting mechanism; 31. Stop; 311. Pawl; 312. Free end; 313. Locking end; 32. Connecting seat; 321. Assembly groove; 321a. Locking part; 321b. Receiving part; 322. Receiving groove; 323. Positioning boss; 33. Elastic element; 4. Mounting bracket; 5. Cover plate; 6. Elastic torsion element. Detailed Implementation

[0030] 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.

[0031] 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.

[0032] 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.

[0033] like Figure 1 , Figure 2 , Figure 3a as well as Figure 4a As shown, this embodiment provides a seat backrest assembly, including a backrest bracket 1, a backrest body 2, and a lifting mechanism 3. The backrest body 2 is fixedly connected to the lifting mechanism 3, and the backrest bracket 1 and the lifting mechanism 3 are slidably engaged along the height direction of the backrest bracket 1, so that the lifting mechanism 3 has an upward stroke and a downward stroke relative to the backrest bracket 1. The backrest bracket 1 has a guide groove 11, and the guide groove 11 has a plurality of ratchet teeth 111 arranged and spaced apart along the height direction of the backrest bracket 1. The lifting mechanism 3 includes a stop member 31 with a pawl 311, which can engage or disengage with the ratchet teeth 111. The shifting member 31 switches between a tilted state and a aligned state by swinging. The upper part of the guide groove 11 is provided with a guide zone 112 for driving the shifting member 31 to switch from the tilted state to the aligned state. When the shifting member 31 is in the aligned state, the pawl 311 separates from the ratchet 111, and the lifting mechanism 3 can perform a downward stroke. The lower part of the guide groove 11 is provided with a tilting zone 113 for driving the shifting member 31 to switch from the aligned state to the tilted state. When the shifting member 31 is in the tilted state, the pawl 311 engages with the ratchet 111, and the lifting mechanism 3 can perform an upward stroke.

[0034] In this embodiment, the backrest body 2 is suitable for the user to lean back against, and the backrest bracket 1 provides support for the lifting mechanism 3 and the backrest body 2. The lifting mechanism 3 moves up and down along the backrest bracket 1 and is fixedly connected to the backrest body 2, so that the lifting mechanism 3 drives the backrest body 2 to move up and down along the backrest bracket 1. It can be understood that the lifting mechanism 3 has an upward stroke and a downward stroke relative to the backrest bracket 1, and the backrest body 2 also has an upward stroke and a downward stroke relative to the backrest bracket 1. Specifically, the ratchet teeth 111 in the guide groove 11 are arranged along the height direction of the backrest bracket 1 and are spaced apart, so that the pawl 311 of the stop member 31 can generate multiple stable support points when it engages with the ratchet teeth 111. The pawl 311 engages with the ratchet teeth 111 at different heights so that the stop member 31 can stop at different heights, thereby allowing the lifting mechanism 3 to stop at different heights. Then, the backrest body 2, which is fixedly connected to the lifting mechanism 3, can also stop at different heights, allowing the user to adjust the height of the backrest body 2 as needed and improve comfort. The stop component 31 has an oblique state where the pawl 311 is engaged with the ratchet 111, and an aligned state where the pawl 311 is disengaged from the ratchet 111. The upper part of the guide groove 11 is provided with a guide zone 112 for switching the stop component 31 from the oblique state to the aligned state. When the lifting mechanism 3 rises to the upper part of the guide groove 11 and needs to perform a downward stroke, the stop component 31 gradually swings to the aligned state under the action of the guide zone 112. In this state, the pawl 311 disengages from the ratchet 111, allowing the lifting mechanism 3 to descend freely. The lower part of the guide groove 11 is provided with a guide zone 113 for switching the stop component 31 from the aligned state to the oblique state. When the lifting mechanism 3 descends to the lower part of the guide groove 11 and needs to perform an upward stroke, the stop component 31 gradually swings to the oblique state under the action of the guide zone 113. In this state, the pawl 311 and ratchet 111 are tightly engaged, providing stable support and locking effect for the lifting mechanism 3.

[0035] Specifically, adjacent ratchet teeth 111 form a groove for the pawl 311 to engage. When the pawl 311 engages in the groove, along the downward direction of the lifting mechanism 3, the pawl 311 and the ratchet teeth 111 abut against each other, forming a limiting effect and restricting the descent of the lifting mechanism 3. However, along the upward direction of the lifting mechanism 3, the guide surface on the pawl 311 abuts against the ratchet teeth 111, and does not limit the lifting mechanism 3 in that direction. Therefore, the lifting mechanism 3 can rise. That is, the ratchet teeth 111 only limit the pawl 311 in one direction; the ratchet teeth 111 only allow the pawl 311 to rise, not to descend. The above-described engagement method of the pawl 311 and the ratchet teeth 111 is prior art and will not be described further here.

[0036] It should be noted that when the user wants to raise the height of the backrest body 2, the lifting mechanism 3 should first enter the upward stroke. At this time, the stop 31 is in an inclined state, and the pawl 311 is tightly engaged with the ratchet teeth 111 at different heights, providing stable support for the backrest body 2. As the lifting mechanism 3 rises, the backrest body 2 also rises until it reaches the height required by the user. However, the situation is different when the user needs to lower the height of the backrest body 2. Since the pawl 311 and the ratchet teeth 111 are in a disengaged state during the downward stroke, the lifting mechanism 3 cannot be suspended on the backrest bracket 1. Therefore, the lifting mechanism 3 needs to reach the end of the downward stroke first. At this time, the user can operate the lifting mechanism 3 again to enter the upward stroke, and then select a lower ratchet tooth 111 to engage with the pawl 311, thereby lowering the height of the lifting mechanism 3 and the backrest body 2.

[0037] In this embodiment, the lifting mechanism 3 includes a stop member 31 with a pawl 311, and the backrest support 1 has multiple ratchet teeth 111 at different heights. The stop member 31 switches between a tilted state and a aligned state by swinging. When the stop member 31 is in the tilted state, the pawl 311 can engage with the ratchet teeth 111, thereby locking the current height of the backrest body 2 and the lifting mechanism 3, while allowing the lifting mechanism 3 to perform an upward stroke under the push of the user, easily adjusting the backrest to a higher position. When the stop member 31 is in the aligned state, the pawl 311 disengages from the ratchet teeth 111, no longer forming resistance, thereby allowing the lifting mechanism 3 to smoothly perform a downward stroke under the action of gravity or with the assistance of the user, until the desired height is reached. The upper part of the guide groove 11 is provided with a guide zone 112 for switching the drive stop 31 from the tilted state to the aligned state. The stop 31 is automatically switched at the end of the upward stroke due to the pressure of the guide zone 112. The lower part of the guide groove 11 is provided with a tilting zone 113 for switching the drive stop 31 from the aligned state to the tilted state. The stop 31 is automatically switched at the end of the downward stroke due to the pressure of the tilting zone 113. No user operation of other components is required, making operation simple and quick. That is, the user only needs to pull the lifting mechanism 3 to the upper or lower part of the guide groove 11 to switch the state of the stop 31, thereby changing the height of the backrest body 2, simplifying the lifting process of the backrest assembly.

[0038] The guide groove 11 has an upper end and a lower end that are oppositely arranged along the height direction of the backrest bracket 1. A first side 114 and a second side 115 opposite to the first side 114 are connected between the upper end and the lower end. The ratchet 111 is formed on the first side 114. The upper end, the part of the first side 114 near the upper end and the part of the second side 115 near the upper end enclose and form a guide zone 112 that matches the shape of the pawl 311. The lower end forms a guide zone 113.

[0039] In this embodiment, along the height direction of the backrest bracket 1, the guide groove 11 has an upper end and a lower end that are oppositely arranged. The upper end and the lower end are connected by a first side 114 and a second side 115 to form a complete guide groove 11. The ratchet 111 is arranged on the first side 114 to provide a base for engagement with the pawl 311, and the second side 115 is constructed to be straight. The guide zone 112 is located in the upper part of the guide groove 11 and is enclosed by the upper end, the portion of the first side 114 near the upper end, and the portion of the second side 115 near the upper end. The pawl 311 is adapted to the shape of the guide zone 112, and the sidewalls of the guide zone 112 are all vertical structures. The sidewalls drive the pawl 311 to swing in the guide zone 112, thereby causing the stop member 31 to swing from the tilted state to the aligned state. The tilting zone 113 is located in the lower part of the guide groove 11 and is directly formed by the lower end of the guide groove 11. The tilting zone 113 is used to drive the shifting member 31 from the aligned state to the tilted state, so that the pawl 311 can be tightly engaged with the ratchet 111. When the lifting mechanism 3 performs its upward stroke, the shifting member 31 switches to the tilted state under the action of the tilting zone 113, and the pawl 311 also engages with the ratchet 111, providing stable support and locking effect for the lifting mechanism 3.

[0040] Combination Figure 1 , Figure 2 , Figure 3a , Figure 3b As shown, the lifting mechanism 3 also includes a connecting seat 32 and an elastic member 33. The elastic member 33 is used to keep the pawl 311 of the stop member 31 moving toward the ratchet 111. The connecting seat 32 has an assembly groove 321 for mounting the stop member 31 and a receiving groove 322 for mounting the elastic member 33. The receiving groove 322 communicates with the assembly groove 321. One end of the elastic member 33 abuts against the inner wall of the receiving groove 322, and the other end extends out of the receiving groove 322 and abuts against the stop member 31.

[0041] In this embodiment, the elastic element 33 ensures that the pawl 311 of the stop member 31 always tends to move towards the ratchet 111. That is, the elastic element 33 applies pressure to the stop member 31, ensuring that the pawl 311 can quickly and accurately engage with the ratchet 111 when the stop member 31 is tilted. This enhances the stability during engagement and prevents the pawl 311 from falling off or engaging poorly due to vibration or impact. The assembly groove 321 and receiving groove 322 formed in the connecting seat 32 provide positions for the installation of the stop member 31 and the elastic element 33, making the structure of the lifting mechanism 3 more compact and reducing manufacturing costs and assembly difficulty.

[0042] like Figure 2 , Figure 4a , Figure 4bAs shown, a locking part 321a and a receiving part 321b opposite to the locking part 321a are formed in the mounting groove 321 along the height direction of the backrest bracket 1. The stop member 31 is formed with a locking end 313 and a free end 312 opposite to the locking end 313. A pawl 311 is disposed between the locking end 313 and the free end 312. The locking end 313 can engage or disengage with the locking part 321a. The free end 312 is rotatably disposed in the receiving part 321b. At the end of the upward stroke, the guide zone 112 drives the locking end 313 to engage with the locking part 321a so that the stop member 31 remains aligned during the downward stroke. At the end of the downward stroke, the guide zone 113 abuts against the pawl 311 to drive the locking end 313 to disengage from the locking part 321a and keep the stop member 31 in an oblique state during the upward stroke.

[0043] In this embodiment, Figure 3a and Figure 3b The stop component 31 is in an skewed state. Figure 4a and Figure 4b The stop member 31 is in the aligned state. The locking part 321a in the assembly groove 321 and the locking end 313 of the stop member 31 constitute a locking mechanism that keeps the stop member 31 in the aligned state. Specifically, the locking part 321a is a recess. At the end of the upward stroke, the guide zone 112 drives the locking end 313 to engage with the locking part 321a, ensuring that the stop member 31 is stably kept in the aligned state during the downward stroke, keeping the ratchet 111 and the pawl 311 separated, that is, the backrest bracket 1 and the lifting mechanism 3 do not interfere with each other, and the lifting mechanism 3 can descend freely. The pawl 311 and the locking end 313 are arranged adjacent to each other. At the end of the downward stroke, the inclined area 113 abuts against the pawl 311, the pawl 311 moves upward and drives the locking end 313 to disengage from the locking part 321a. The free end 312 has an arc-shaped surface to facilitate rotation within the receiving part 321b. When the free end 312 rotates, the locking end 313 opposite to it rotates in the opposite direction. The elastic member 33 applies pressure to the stop member 31, causing the pawl 311 of the stop member 31 to move towards the ratchet 111. However, since the free end 312 cannot disengage from the receiving part 321b, only the locking end 313 moves towards the ratchet 111. Ultimately, the locking end 313 swings, the stop member 31 switches to the deflection state, and the stop member 31 automatically maintains the deflection state during the upward stroke.

[0044] The outer peripheral surface of the locking end 313 is arc-shaped so that the stop member 31 can swing relative to the connecting seat 32.

[0045] In this embodiment, the outer peripheral surface of the locking end 313 is arc-shaped, which allows the locking end 313 to naturally disengage from the locking part 321a when the stop member 31 moves up a small distance. This makes the stop member 31 more smoothly and naturally transition when swinging relative to the connecting seat 32, reducing friction and resistance during the swinging process. The stop member 31 can more easily switch from the locked state to the unlocked state, thereby improving the response speed and operating efficiency of the lifting mechanism 3.

[0046] The backrest bracket 1 is also provided with a positioning groove 12 that is adjacent to and parallel to the guide groove 11. The connecting seat 32 is provided with a positioning boss 323 that cooperates with the positioning groove 12. The positioning boss 323 moves in the positioning groove 12 to restrict the connecting seat 32 from sliding along the opening direction of the positioning groove 12.

[0047] In this embodiment, the positioning groove 12 and the positioning boss 323 cooperate to provide stable guidance and restriction for the movement of the connecting seat 32 on the backrest bracket 1, thereby enhancing the structural stability of the entire lifting mechanism 3. It can be understood that since the pawl 311 is located in the middle of the stop member 31, the length of the positioning groove 12 is set to be greater than the length of the guide groove 11 so that the movement range of the overall stop member 31 is greater than the movement range of the pawl 311.

[0048] The backrest support 1 has a U-shaped structure, which includes two opposing support rods 13. Each of the two support rods 13 is provided with a guide groove 11 and a lifting mechanism 3 corresponding to the guide groove 11.

[0049] In this embodiment, the backrest support 1 is U-shaped, comprising two opposing support rods 13 to support and bear the seat back. Guide grooves 11 and corresponding lifting mechanisms 3 are provided on these two support rods 13, enhancing the structural strength of the backrest support 1. The backrest support 1 can more evenly distribute the weight of the seat back, thereby improving overall stability and durability. Of course, in other embodiments, the backrest support 1 can also be constructed with one, three, or five support rods 13, etc.

[0050] The backrest assembly includes a mounting bracket 4 and a cover plate 5 connected to the mounting bracket 4. The opposite ends of the mounting bracket 4 on the side closer to the backrest body 2 are respectively fixed to the backrest body 2 by elastic torsion members 6. The opposite ends of the mounting bracket 4 on the side away from the backrest body 2 are respectively fixed to lifting mechanisms 3 on two support rods 13. The cover plate 5 is located between the two lifting mechanisms 3.

[0051] In this embodiment, the mounting bracket 4 is perpendicular to the backrest bracket 1. On the side of the mounting bracket 4 closest to the backrest body 2, its opposite ends are fixedly connected to the backrest body 2 via elastic torsion members 6. The elastic torsion members 6 allow the backrest body 2 to twist gently and in a controlled manner when subjected to pressure from the back of a person or tilting movements, thereby improving the comfort of the seat. At the same time, the elastic torsion members 6 can also effectively absorb and disperse impact forces, protecting the backrest body 2 from damage. On the side of the mounting bracket 4 furthest from the backrest body 2, its opposite ends are respectively fixedly connected to lifting mechanisms 3 on two support rods 13 to realize the height adjustment of the backrest body 2. The cover plate 5 is located between the two lifting mechanisms 3 to cover the internal structure of the lifting mechanisms 3 and the mounting bracket 4, making the entire backrest assembly look neater and more uniform.

[0052] The backrest body 2 includes an inner backrest panel 21, an outer backrest panel 22, and a cushion 23. The cushion 23 is fixed to the side of the inner backrest panel 21 away from the inner backrest panel 21, and the outer backrest panel 22 is fixed to the side of the inner backrest panel 21 away from the cushion 23.

[0053] In this embodiment, the backrest body 2 includes an inner backrest panel 21, an outer backrest panel 22, and a back cushion 23. The back cushion 23 is directly attached to the outer side of the inner backrest panel 21, providing the user with a soft and comfortable feel. The outer backrest panel 22 covers the outer sides of the inner backrest panel 21 and the back cushion 23, serving both protective and decorative purposes, while also ensuring overall aesthetics and harmony. The back cushion 23 can be made of high-density foam or memory foam, among other materials. The shape of the back cushion 23 can be designed to conform to the curve of the human back, providing all-around support.

[0054] The seat in this embodiment includes a backrest, on which the aforementioned adjustable backrest assembly 2 is installed. Of course, the seat may also include a seat, a base, or other structures. Since other structures of the seat are the same as those in the prior art, they will not be described in detail here.

[0055] 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 seat back assembly, characterized in that, It includes a backrest support, a backrest body, and a lifting mechanism. The backrest body is fixedly connected to the lifting mechanism, and the backrest support and the lifting mechanism are slidably engaged along the height direction of the backrest support, so that the lifting mechanism has an upward stroke and a downward stroke relative to the backrest support. The backrest support is provided with a guide groove and the guide groove is formed with a plurality of ratchet teeth arranged and spaced apart along the height direction of the backrest support. The lifting mechanism includes a stop member with a pawl, which can engage or disengage with the ratchet teeth. The shifting member switches between a tilted state and a aligned state by oscillating. The upper part of the guide groove is provided with a guide zone for driving the shifting member to switch from the tilted state to the aligned state. When the shifting member is in the aligned state, the pawl and the ratchet are separated, and the lifting mechanism can perform the downward stroke. The lower part of the guide groove is provided with a tilting zone for driving the shifting member to switch from the aligned state to the tilted state. When the shifting member is in the tilted state, the pawl and the ratchet are engaged, and the lifting mechanism can perform the upward stroke.

2. The seat back assembly according to claim 1, characterized in that, The guide groove has an upper end and a lower end that are oppositely arranged along the height direction of the backrest bracket. A first side and a second side opposite to the first side are connected between the upper end and the lower end. The ratchet is formed on the first side. The upper end, the portion of the first side near the upper end, and the portion of the second side near the upper end together form the guiding area adapted to the shape of the pawl, and the lower end constitutes the inclined area.

3. The seat back assembly according to claim 2, characterized in that, The lifting mechanism further includes a connecting seat and an elastic element. The elastic element is used to keep the pawl of the stop member moving toward the ratchet. The connecting seat has an assembly groove for installing the stop member and a receiving groove for installing the elastic element. The receiving groove communicates with the assembly groove. One end of the elastic element abuts against the inner wall of the receiving groove, and the other end extends out of the receiving groove and abuts against the stop member.

4. The seat back assembly according to claim 3, characterized in that, Along the height direction of the backrest bracket, the mounting groove has a locking part and a receiving part opposite to the locking part. The stop member has a locking end and a free end opposite to the locking end. The pawl is disposed between the locking end and the free end. The locking end can engage or disengage with the locking part, and the free end is rotatably disposed in the receiving part. At the end of the upward stroke, the guide zone drives the locking end to engage with the locking part so that the stop member maintains the alignment state during the downward stroke. At the end of the downward stroke, the guide zone abuts against the pawl to drive the locking end to disengage from the locking part and keep the stop member in the deflection state during the upward stroke.

5. The seat back assembly according to claim 4, characterized in that, The outer peripheral surface of the locking end is arc-shaped so that the stop member can swing relative to the connecting seat.

6. The seat back assembly according to claim 3, characterized in that, The backrest bracket is also provided with a positioning groove that is adjacent to and parallel to the guide groove. The connecting seat is provided with a positioning boss that cooperates with the positioning groove. The positioning boss moves within the positioning groove to restrict the connecting seat from sliding along the opening direction of the positioning groove.

7. The backrest assembly of the seat according to any one of claims 1-6, characterized in that, The backrest support is U-shaped and includes two opposing support rods. Each of the two support rods is provided with a guide groove and a lifting mechanism corresponding to the guide groove.

8. The seat back assembly according to claim 7, characterized in that, The backrest assembly includes a mounting bracket and a cover plate engaged with the mounting bracket. The opposite ends of the mounting bracket on the side closer to the backrest body are respectively fixed to the backrest body by elastic torsion members. The opposite ends of the mounting bracket on the side away from the backrest body are respectively fixed to the lifting mechanisms on the two support rods. The cover plate is located between the two lifting mechanisms.

9. The backrest assembly of the seat according to any one of claims 1-6, characterized in that, The backrest body includes an inner backrest panel, an outer backrest panel, and a back cushion. The back cushion is fixed to the side of the inner backrest panel away from the inner backrest panel, and the outer backrest panel is fixed to the side of the inner backrest panel away from the back cushion.

10. A seat, including a backrest, characterized in that, The seat also includes a backrest assembly as claimed in any one of claims 1 to 9.

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