Adjustable sofa backrest

Abstract

The present invention relates to a sofa or a chair with an adjustment function; specifically, an adjustable sofa backrest, comprising a balance board (3) and multifunctional brackets (4) respectively arranged on the left and right sides of the balance board (3), one end of a motor is connected to a motor fixing beam (2), and the other end of the motor is connected to the back of the balance board (3); the balance board (3) extends the multifunctional bracket (4) under the push of the motor (1) and makes the top of the multifunctional bracket (4) bend downward and the bottom bend upward; wherein the top of the multifunctional bracket (4) corresponds to the headrest part of the sofa backrest, the bottom of the multifunctional bracket (4) corresponds to the waist support of the sofa backrest, and the front of the balance board (3) corresponds to the backrest body of the sofa backrest. Compared with the traditional functional sofa backrest, the sofa backrest disclosed by the present invention provides a longer backrest body and more flexible and movable headrest and waist support functions, thereby improving the practical comfort of the sofa backrest.

Description

Technical Field

[0001] The invention relates to the field of living furniture or office furniture, and in particular to a functional sofa or chair with an adjustable function to change the user's body shape; specifically, a retractable sofa backrest with a movable headrest and waist support. Background Art

[0002] With the improvement of living standards, sofas with a single posture have been gradually marginalized by the market. Instead, they are replaced by functional sofas that have multiple different forms and can be combined and switched to change the user's sitting posture.

[0003] A functional sofa usually includes a backrest part, a seat cushion part and a footrest part; the three parts are sequentially linked and their angles are changed to enable the functional sofa to switch between three positions: sitting position, semi-reclining position and lying position.

[0004] Although the switching of the functional sofa between the above three forms can provide the user's back and legs with comfortable support at different angles to improve the user's body comfort, the user's head and waist often lack the ductility and comfort support that is compatible with the back and legs.

[0005] In order to solve the above problems, sofa manufacturers have developed auxiliary structures that are respectively provided with movable headrests and lumbar supports on the upper and lower parts of the backrest. These auxiliary structures realize autonomous or subordinate movement processes through one or more sets of actuators and a driving device, so that the headrest and lumbar support can change accordingly with the change of the angle of the backrest. The ultimate goal is to make the headrest and lumbar support provide the user's head and waist with ductile and comfortable support that is compatible with the back and legs.

[0006] However, current actuators used to move headrests and lumbar supports have several design flaws, such as:

[0007] 1. The actuator is too large:

[0008] The backrest already includes an iron frame and a wooden block for installing the sponge. After adding the above-mentioned actuator and drive device, the available space of the sponge will be occupied. The most direct impact is that the overall thickness of the backrest will increase, and the thickness of the sponge in direct contact with the user's back will decrease, thereby reducing the user's comfort experience.

[0009] 2. The actuator cannot change the length of the headrest or copy part:

[0010] The current actuator only moves the headrest and lumbar support of the backrest so that they move with the rotation of the backrest, but does not change the length of the headrest or the entire backrest. Therefore, when the user is tall or the sofa backrest is small, it cannot provide enough comfortable support for the user's head.

[0011] 3. The connection between the components is unreliable and the operating stability of the actuator is poor:

[0012] At present, the actuators are usually independently arranged on both sides of the iron frame of the backrest, and the actuators on both sides are not directly connected, and the actuators on both sides are only driven by the driving device. In this way, after long-term use, when the actuators on both sides are in motion, the motion will be asynchronous, and these phenomena will be converted into friction, abnormal noise and impact vibration and act on the user's back through the backrest sponge, which will eventually reduce the user's comfort experience. Summary of the invention

[0013] The purpose of the present invention is to overcome the above defects and to provide a sofa backrest with a compact actuator structure and stable and reliable operation. The length of the sofa backrest is adjustable, and the headrest and the waist support can move in a continuous manner.

[0014] In order to achieve the above object, the present invention is achieved in the following ways:

[0015] A retractable sofa backrest with a movable headrest and lumbar support comprises a driving motor, a motor fixing beam, a balance board and multifunctional brackets respectively arranged on the left and right sides of the balance board, one end of the motor is connected to the motor fixing beam, and the other end of the motor is connected to the back side of the balance board. The balance board, driven by the motor, extends the multifunctional bracket and makes the top of the multifunctional bracket bend downward and the bottom bend upward; wherein the top of the multifunctional bracket corresponds to the headrest part of the sofa backrest, the bottom of the multifunctional bracket corresponds to the lumbar support of the sofa backrest, and the front side of the balance board corresponds to the backrest body of the sofa backrest.

[0016] The adjustable sofa backrest and the multifunctional bracket realize the telescopic function through a pair of sliding friction components; the headrest part and the waist support of the sofa backrest realize continuous movement under the promotion of the multifunctional bracket.

[0017] The adjustable sofa backrest can realize the telescopic function through a group of rolling friction components; the headrest part and the waist support of the sofa backrest realize continuous movement under the promotion of the multifunctional bracket.

[0018] The above-mentioned retractable sofa backrest with movable headrest and lumbar support, the sliding friction component in the multifunctional bracket includes a mounting plate connected to the balance plate, and also includes a sliding piece slidably arranged relative to the mounting plate, and a headrest mounting plate, a lumbar support mounting plate, which are rotatably arranged at the top and bottom of the mounting plate, respectively, and a pull rod connecting the headrest mounting plate and the lumbar support mounting plate, wherein a pulley is arranged on one side of the lumbar support mounting plate, and an upper and lower baffles for limiting the moving distance of the pulley are arranged on the sliding piece, and one side of the headrest mounting plate is rotatably connected to the mounting plate; a positioning column is arranged on the sliding piece and a slide groove is arranged on the mounting plate, and the positioning column penetrates into the slide groove; in this way, when the motor pushes the balance plate, the mounting plate connected to the balance plate starts to move along the slide groove, and then the balance plate slides up and down along the track where the slide groove is located. In this process, the lumbar support mounting plate is limited by the baffle and can only rotate after sliding up and down a distance with the mounting plate, and at this time, it pulls the headrest mounting plate through the pull rod to make the headrest mounting plate bend downward.

[0019] The above-mentioned retractable sofa backrest with movable headrest and lumbar support, the rolling friction component in the multifunctional bracket includes a mounting plate for connecting with the balance plate, and also includes a slide plate, a slide rail assembly, a base plate, a headrest mounting plate, a lumbar support mounting plate and a pull rod; the slide rail assembly includes a slide rail bottom fixedly arranged on the base plate and a slide rail plate slidably connected to the slide rail bottom, the slide plate is connected to the slide rail plate, and the headrest mounting plate, the mounting plate and the lumbar support mounting plate are respectively arranged in sequence at the upper, middle and lower parts of the slide plate, and the headrest mounting plate and the lumbar support mounting plate are rotatably connected to the slide plate. The plate and the slide are fixedly connected, and the headrest mounting plate and the lumbar support mounting plate are also connected by a pull rod; wherein, an arc-shaped slide groove is provided on the lumbar support mounting plate, and a positioning column is provided on the slide, and the positioning column is inserted into the arc-shaped slide groove; in this way, when the motor pushes the balance board, the plate mounting member connected to the balance board drives the slide to slide up and down along the track of the slide rail assembly, and in this process, the lumbar support mounting plate is restricted by its arc-shaped slide groove and the positioning column on the slide and can only rotate upward, and it pulls the headrest mounting plate through the pull rod to make the headrest mounting plate bend downward.

[0020] The retractable sofa backrest with movable headrest and lumbar support has a nylon bushing on the positioning column, and the pulley arranged on the lumbar support mounting plate is also made of nylon. In this way, the mounting plate and the lumbar support mounting plate form a buffer layer during movement through the nylon bushing and the nylon pulley.

[0021] The retractable sofa backrest with movable headrest and lumbar support has a tension spring arranged between the base plate and the lumbar support mounting plate. The tension spring is respectively connected to the base plate and the lumbar support mounting plate through rivets, and the axis of the tension spring is parallel to the slide rail assembly.

[0022] The retractable sofa backrest with movable headrest and lumbar support is provided with upper and lower limit rivets on the base plate along the up and down sliding track of the lumbar support mounting plate, and the two limit rivets are used to limit the range of the up and down sliding of the lumbar support mounting plate along the sliding plate.

[0023] The above-mentioned retractable sofa backrest with movable headrest and lumbar support, when in the folded state, the highest points of the headrest mounting plate, the pull rod and the lumbar support mounting plate in the multifunctional bracket are in the same plane or the highest point of the pull rod does not exceed the headrest mounting plate.

[0024] The axis formed by the highest points of the mounting plate and the lumbar support mounting plate; that is, when in the folded state, the headrest mounting plate,

[0025] The front surfaces of the pull rod and the waist support mounting plate are located in the same plane or form an inner concave plane in the side projection.

[0026] Based on the above design, the present invention proposes a new structure that can make the length of the sofa backrest body adjustable and the headrest and waist support realize linkage. This sofa backrest has the following advantages:

[0027] 1. By arranging the multifunctional brackets on both sides of the sofa backrest, the part where the sofa backrest directly contacts the user's back is prevented from being occupied; in this way, when the sofa backrest is of the same thickness, the sofa backrest disclosed in the present invention can use a thicker backrest sponge, and with a large-area balance board, it can provide the user with a better back support experience.

[0028] 2. The multifunctional brackets on the left and right sides that were originally independent of each other are connected through a large-area balance board to form a sufficiently stable integrated actuator, which avoids the problem of asynchronous movement of independent actuators during operation. The integrated actuator also uses the slide rail as a guide mechanism during operation, making the entire sofa backrest stable and smooth when changing its shape, overcoming the friction noise and various vibrations of traditional functional sofas during the shape change process.

[0029] 3. By adopting a retractable multifunctional bracket in the form of friction or rolling with low resistance to realize the retractable function of the length of the sofa backrest body, the headrest and lumbar support in the sofa backrest assembly can be pushed out or flattened in a continuous manner by relying on the retractable stroke of the multifunctional bracket during the retraction process. Therefore, when the angle of the sofa backrest changes during the use of the sofa backrest, the headrest and lumbar support parts are changed at the same time, thereby providing additional support for the user's head and waist, thereby improving the user's comfort experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the sofa backrest disclosed in the present invention.

[0031] Figure 2 The structure of the multifunctional bracket in the present invention is shown in FIG. Figure 1 .

[0032] Figure 3 The structure of the multifunctional bracket in the present invention is shown in FIG. Figure 2 .

[0033] Figure 4 The structure of the multifunctional bracket in the present invention is shown in FIG. Figure 3 .

[0034] Figure 5 The structure of the multifunctional bracket in the present invention is shown in FIG. Figure 4 .

[0035] Figure 6 The action diagram of the sofa backrest in the present invention is shown in FIG. Figure 1 .

[0036] Figure 7 The action diagram of the sofa backrest in the present invention is shown in FIG. Figure 2 . DETAILED DESCRIPTION

[0037] The present invention is further described below by means of specific examples.

[0038] Embodiment 1

[0039] like Figure 1 , Figure 6 and Figure 7 As shown, a retractable sofa backrest with a movable headrest and lumbar support comprises a driving motor 1, a motor fixing beam 2, a balance board 3 and multifunctional brackets 4 respectively arranged on the left and right sides of the balance board 3, one end of the motor is connected to the motor fixing beam 2, and the other end of the motor is connected to the back of the balance board 3. Under the push of the motor 1, the balance board 3 extends the multifunctional bracket 4 and makes the top of the multifunctional bracket 4 bend down and the bottom rise up; wherein, the top of the multifunctional bracket 4 corresponds to the headrest part of the sofa backrest, the bottom of the multifunctional bracket 4 corresponds to the lumbar support of the sofa backrest, and the front of the balance board 3 corresponds to the backrest body of the sofa backrest.

[0040] In this embodiment, the multifunctional bracket has the functions of the bracket and the action execution mechanism of the sofa backrest, headrest and lumbar support. The multifunctional bracket is driven by a motor and realizes the stretching of the sofa backrest body and the bending of the headrest and the upward movement of the lumbar support, so that the sofa backrest disclosed by the present invention is more convenient than the traditional functional sofa backrest.

[0041] It provides a longer backrest body and more flexible headrest and lumbar support functions, thereby improving the practical comfort of the sofa backrest.

[0042] Embodiment 2

[0043] Embodiment 2 is an improvement of Embodiment 1, specifically, an improvement on the multifunctional bracket in Embodiment 1. Figure 5 As shown, the retractable sofa backrest with movable headrest and lumbar support, the multifunctional bracket 4 includes a mounting plate 5 for connecting with the balance board 3, and also includes a slide 14 slidably arranged relative to the mounting plate 5 and a headrest mounting plate 7 and a lumbar support mounting plate 8 rotatably arranged at the top and bottom of the mounting plate 5, and a pull rod 9 connecting the headrest mounting plate 7 and the lumbar support mounting plate 8, wherein a pulley 10 is arranged on one side of the lumbar support mounting plate 8, and upper and lower baffles 11 for limiting the moving distance of the pulley 10 are arranged on the slide 14, and one side of the headrest mounting plate 7 is connected to the lumbar support mounting plate 8. The mounting plate 5 is rotatably connected; a positioning column 12 is provided on the slide 14 and a slide groove 13 is provided on the mounting plate 5, and the positioning column 12 penetrates into the slide groove 13; in this way, when the motor 1 pushes the balance board 3, the mounting plate 5 connected to the balance board 3 starts to move along the slide groove 13, and then the balance board 3 slides up and down along the track of the slide groove 13. In this process, the lumbar support mounting plate 8 is restricted by the baffle 11 and can only rotate after sliding up and down with the mounting plate 5 for a distance. At this time, it pulls the headrest mounting plate 7 through the pull rod 9 and bends the headrest mounting plate 7 downward.

[0044] In this embodiment, a multifunctional bracket using a relatively slidable plate as a support is disclosed. In this type of multifunctional bracket, the extendable function of the sofa backrest body is realized by the relative sliding between the relatively fixed slide 14 and the slidable mounting plate 5. Secondly, a rotatable headrest mounting plate 7 and a lumbar support mounting plate 8 are arranged on the mounting plate 5 and the headrest mounting plate 7 and the lumbar support mounting plate 8 are linked to each other through a pull rod 9. When the lumbar support mounting plate 8 is restricted by the slide 14 and rotates upward, the headrest mounting plate 7 is rotated downward by the pulling force of the pull rod 9, thereby realizing the linkage function of the headrest and the lumbar support in the sofa backrest.

[0045] Embodiment 3

[0046] Embodiment 3 is an improvement on Embodiment 1 in parallel with Embodiment 2, and specifically is an improvement on the multifunctional bracket in Embodiment 1.

[0047] like Figure 2 , Figure 3 and Figure 4As shown, the retractable sofa backrest with movable headrest and lumbar support, the multifunctional bracket 4 includes a mounting plate 5' for connecting with the balance board 3, and also includes a slide 14, a slide rail assembly 15, a base plate 16, a headrest mounting plate 7, a lumbar support mounting plate 8 and a pull rod 9; the slide rail assembly 15 includes a slide rail bottom 151 fixedly arranged on the base plate 16 and a slide rail plate 152 slidably connected to the slide rail bottom 151, the slide 14 is connected to the slide rail plate 152, the headrest mounting plate 7, the mounting plate 5' and the lumbar support mounting plate 8 are arranged in sequence at the upper, middle and lower parts of the slide 14, and the headrest mounting plate 7 and the lumbar support mounting plate 8 are rotatably connected to the slide 14. The plate 5' is fixedly connected to the slide 14, and the headrest mounting plate 7 and the lumbar support mounting plate 8 are also connected by a pull rod 9; wherein, an arc-shaped slide groove 17 is provided on the lumbar support mounting plate 8, and a positioning column 18 is provided on the slide 14, and the positioning column 18 penetrates into the arc-shaped slide groove 17; thus, when the motor 1 pushes the balance board 3, the plate mounting member 5' connected to the balance board 3 drives the slide 15 to slide up and down along the track where the slide rail assembly 15 is located. During this process, the lumbar support mounting plate 8 is restricted by its arc-shaped slide groove 17 and the positioning column 18 on the slide 14 and can only rotate upward, and it pulls the headrest mounting plate 7 through the pull rod 9 to make the headrest mounting plate 7 bend downward.

[0048] It can be seen from the above-mentioned Embodiment 2 and Embodiment 3 that the sofa backrest proposed by the present invention has a multifunctional bracket that realizes the length extension function through the relatively displaceable component 2. Preferably, it can be a component form of direct friction between the two components, or by adding a third movable component, especially a sliding component, between the two components to realize the length extension function of the multifunctional bracket.

[0049] The retractable sofa backrest with movable headrest and lumbar support has a nylon bushing on the positioning column 12, and the pulley 10 arranged on the lumbar support mounting plate 8 is also made of nylon.

[0050] The plate 5 and the lumbar support mounting plate 8 form a buffer layer during movement.

[0051] The retractable sofa backrest with movable headrest and lumbar support has a tension spring 19 arranged between the base plate 16 and the lumbar support mounting plate 8. The tension spring 19 is connected to the base plate 16 and the lumbar support mounting plate 8 respectively by rivets, and the axis of the tension spring 19 is parallel to the slide rail assembly 15.

[0052] The retractable sofa backrest with movable headrest and lumbar support is provided with an upper limit rivet 20 and a lower limit rivet 21 on the base plate 16 along the up and down sliding track of the lumbar support mounting plate 8. The two limit rivets are used to limit the sliding range of the lumbar support mounting plate 8 along the up and down sliding of the sliding plate.

[0053] In this embodiment, the multifunctional bracket also serves as the bracket and action execution mechanism of the sofa backrest, headrest and lumbar support. The multifunctional bracket is driven by a motor and realizes the stretching of the sofa backrest body and the bending of the headrest and the upward movement of the lumbar support, so that the sofa backrest disclosed in the present invention provides a longer backrest body and more flexible and movable headrest and lumbar support functions compared with the traditional functional sofa backrest, thereby improving the practical comfort of the sofa backrest.

[0054] Furthermore, this embodiment has a better user experience than the second embodiment, because:

[0055] 1. The sliding guide is realized by the slide rail assembly, which avoids the problem that the guide slide and guide column are damaged due to the long-term squeezing of the sofa backrest by the back when the traditional guide slide is used as the sliding guide structure. The slide rail assembly can make the multi-functional bracket smoother when extending;

[0056] 2. By adding a tension spring, the lumbar support mounting plate can move in real time with the sliding action of the slide and the mounting plate, and the lumbar support adjustment range is more sensitive;

[0057] The advantages of the above-mentioned embodiment 1, embodiment 2, and embodiment 3 are as follows:

[0058] like Figure 3 , Figure 4 and Figure 5 As shown, the retractable sofa backrest with movable headrest and lumbar support, when in the folded state, the highest points of the headrest mounting plate 7, the pull rod 9, and the lumbar support mounting plate 8 in the multifunctional bracket are in the same plane or the highest point of the pull rod 9 does not exceed the axis formed by the highest points of the headrest mounting plate 7 and the lumbar support mounting plate 8; that is, when in the folded state, the front of the headrest mounting plate 7, the pull rod 9, and the lumbar support mounting plate 8 in the multifunctional bracket 4 are in the same plane in the side projection or form an inner concave plane. Based on the above design, the present invention proposes a new structure that can make the length of the sofa backrest body adjustable and the headrest and lumbar support realize linkage.

[0059] In view of the above embodiments and their advantages, the sofa backrest proposed by the present invention has the following advantages in general:

[0060] 1. By arranging the multifunctional brackets on both sides of the sofa backrest, the part where the sofa backrest directly contacts the user's back is prevented from being occupied; in this way, when the sofa backrest is of the same thickness, the sofa backrest disclosed in the present invention can use a thicker backrest sponge, and with a large-area balance board, it can provide the user with a better back support experience.

[0061] 2. The multifunctional brackets on the left and right sides that were originally independent of each other are connected through a large-area balance board to form a sufficiently stable integrated actuator, which avoids the problem of asynchronous movement of independent actuators during operation. The integrated actuator also uses the slide rail as a guide mechanism during operation, making the entire sofa backrest stable and smooth when changing its shape, overcoming the friction noise and various vibrations of traditional functional sofas during the shape change process.

[0062] 3. By adopting a retractable multifunctional bracket in the form of friction or rolling with low resistance to realize the retractable function of the length of the sofa backrest body, the headrest and lumbar support in the sofa backrest assembly can be pushed out or flattened in a continuous manner by relying on the retractable stroke of the multifunctional bracket during the retraction process. Therefore, when the angle of the sofa backrest changes during the use of the sofa backrest, the headrest and lumbar support parts are changed at the same time, thereby providing additional support for the user's head and waist, thereby improving the user's comfort experience.

Claims

1. An adjustable sofa backrest, comprising a drive motor (1), characterized in that: It also comprises a motor fixing beam (2), a balancing board (3) and multifunctional brackets (4) respectively arranged on the left and right sides of the balancing board (3); one end of the motor is connected to the motor fixing beam (2), and the other end of the motor is connected to the back side of the balancing board (3); the balancing board (3) extends the multifunctional bracket (4) under the push of the motor (1) and makes the top of the multifunctional bracket (4) bend downward and the bottom bend upward; wherein the top of the multifunctional bracket (4) corresponds to the headrest part of the sofa backrest, the bottom of the multifunctional bracket (4) corresponds to the lumbar support of the sofa backrest, and the front side of the balancing board (3) corresponds to the backrest body of the sofa backrest; the multifunctional bracket realizes the telescopic function through a pair of sliding friction components or a group of rolling friction components; the headrest part and the lumbar support of the sofa backrest realize continuous movement under the push of the multifunctional bracket; The sliding friction component in the multifunctional bracket (4) includes a mounting plate (5) for connecting with the balance plate (3), a slide plate (14) slidably arranged relative to the mounting plate (5), a headrest mounting plate (7) and a lumbar support mounting plate (8) rotatably arranged at the top and bottom of the mounting plate (5), respectively, and a pull rod (9) connecting the headrest mounting plate (7) and the lumbar support mounting plate (8), wherein a pulley (10) is arranged on one side of the lumbar support mounting plate (8), and upper and lower baffles (11) for limiting the moving distance of the pulley (10) are arranged on the slide plate (14), and one side of the headrest mounting plate (7) is rotatably connected with the mounting plate (5); a positioning column (12) is arranged on the slide plate (14) and a slide groove (13) is arranged on the mounting plate (5), and the positioning column (12) penetrates into the slide groove (13); The rolling friction assembly in the multifunctional bracket (4) comprises a mounting plate (5') for connecting with the balance plate (3), a slide plate (14), a slide rail assembly (15), a base plate (16), a headrest mounting plate (7), a lumbar support mounting plate (8) and a pull rod (9); the slide rail assembly (15) comprises a slide rail bottom (151) fixedly arranged on the base plate (16) and a slide rail plate (152) slidably connected to the slide rail bottom (151); the slide plate (14) is connected to the slide rail plate (152); a headrest mounting plate (7), a mounting plate (5') and a lumbar support mounting plate (8) are arranged in sequence at the upper part, the middle part and the lower part of the slide plate (14); the headrest mounting plate (7) and the lumbar support mounting plate (8) are rotatably connected to the slide plate (14), while the mounting plate (5') and the slide plate (14) are fixedly connected; the headrest mounting plate (7) and the lumbar support mounting plate (8) are also connected via a pull rod (9).

2. The adjustable sofa backrest according to claim 1, characterized in that: A nylon bushing is sleeved on the positioning column (12), and a pulley (10) arranged on the waist support mounting plate (8) is also made of nylon. Thus, the mounting plate (5) and the waist support mounting plate (8) form a buffer layer when in motion through the nylon bushing and the pulley (10) made of nylon.

3. The adjustable sofa backrest according to claim 1 is characterized in that: A tension spring (19) is arranged between the base plate (16) and the waist support mounting plate (8). The tension spring (19) is connected to the base plate (16) and the waist support mounting plate (8) respectively through rivets. The axis of the tension spring (19) is parallel to the slide rail assembly (15).

4. The adjustable sofa backrest according to claim 1 is characterized in that: An upper limit rivet (20) and a lower limit rivet (21) are arranged on the base plate (16) along the upward and downward sliding track of the waist support mounting plate (8), and the two limit rivets are used to limit the upward and downward sliding range of the waist support mounting plate (8) along with the sliding plate.

5. The adjustable sofa backrest according to claim 1, characterized in that: When in the folded state, the highest points of the headrest mounting plate (7), the pull rod (9), and the lumbar support mounting plate (8) in the multifunctional bracket are located in the same plane or the highest point of the pull rod (9) does not exceed the axis formed by the highest points of the headrest mounting plate (7) and the lumbar support mounting plate (8); that is, when in the folded state, the front faces of the headrest mounting plate (7), the pull rod (9), and the lumbar support mounting plate (8) in the multifunctional bracket (4) are located in the same plane in the side projection or form an inner concave plane.

6. The adjustable sofa backrest according to claim 1, characterized in that: When in the folded state, the highest points of the headrest mounting plate (7), the pull rod (9), and the lumbar support mounting plate (8) in the multifunctional bracket are located in the same plane or the highest point of the pull rod (9) does not exceed the axis formed by the highest points of the headrest mounting plate (7) and the lumbar support mounting plate (8); that is, when in the folded state, the front faces of the headrest mounting plate (7), the pull rod (9), and the lumbar support mounting plate (8) in the multifunctional bracket (4) are located in the same plane in the side projection or form an inner concave plane.

Images