Motorized backrest

Abstract

The utility model discloses electric backrest, include: frame body, sliding seat, up and down slidingly arranged in frame body, support plate for supporting the head / back of user, first connecting rod, first connecting rod's first end articulates in sliding seat, and first connecting rod's second end articulates in support plate, second connecting rod, be located below first connecting rod, and second connecting rod's first end articulates in sliding seat, and second connecting rod's second end articulates in support plate, third connecting rod, and the first end of third connecting rod is slidably arranged in frame body and can rotate relative to frame body, and the first end of third connecting rod is located above first connecting rod's first end, and the second end of third connecting rod articulates between the both ends of first connecting rod, drive assembly, with sliding seat transmission connection, when drive assembly drive sliding seat gradually slide upwards, under the guidance of first connecting rod, second connecting rod and third connecting rod, support plate gradually moves upwards and the inclination angle of relative frame body gradually becomes big. Thus, the flexible adjustment of support plate height and inclination angle has been realized.

Description

Technical Field

[0001] This utility model belongs to the field of electric furniture technology, specifically relating to electric backrests. Background Technology

[0002] In the field of seating, electric backrests are becoming increasingly widely used, providing users with comfortable support and meeting their needs for backrest angle and position in different usage scenarios.

[0003] Currently available electric backrests have certain limitations in their structural design. Most electric backrests can only operate within a fixed height range, unable to flexibly adjust height and tilt angle to meet the actual needs of users of different heights. Users of different heights, for example, have different requirements for the support height and tilt angle of the backrest. Taller users may need the backrest to provide support at a higher position and prefer a larger tilt angle for a more comfortable leaning experience; while shorter users may be more suited to a lower position and a relatively smaller tilt angle. However, existing electric backrests cannot adequately meet these diverse needs, resulting in some users not achieving optimal comfort during use. Structurally, existing electric backrests are usually quite complex, containing numerous parts and intricate transmission mechanisms. This not only increases the difficulty and cost of manufacturing the product but may also increase the probability of malfunctions during operation, affecting the smoothness of operation. The complex structure makes the coordination between various components more demanding. Problems in any part can affect the normal operation of the entire electric backrest. For example, wear or loosening of transmission components can cause the backrest to jam or make abnormal noises during adjustment, reducing the user experience. Utility Model Content

[0004] In order to overcome at least one of the defects described in the prior art, the present invention provides an electric backrest to solve the problem that existing electric backrests on the market can only operate at the same height and cannot meet the needs of people of different body sizes. At the same time, it simplifies the structure, increases the stability of operation, and optimizes costs.

[0005] The technical solution adopted by this utility model to solve its problem is: An electric backrest includes: a frame; a sliding seat slidably disposed on the frame; a support plate for supporting the user's head / back; a first link, the first end of which is hinged to the sliding seat, and the second end of which is hinged to the support plate; a second link located below the first link, the first end of which is hinged to the sliding seat, and the second end of which is hinged to the support plate; a third link, the first end of which is slidably disposed on the frame and rotatable relative to the frame, and the first end of which is located above the first end of the first link, and the second end of which is hinged between the two ends of the first link; and a drive assembly connected to the sliding seat; when the drive assembly drives the sliding seat to gradually slide upward, under the guidance of the first link, the second link, and the third link, the support plate gradually moves upward and the tilt angle relative to the frame gradually increases.

[0006] As an optional implementation, when the support plate is in its lowest position and at its minimum tilt angle, the first end of the first link and the first end of the third link are spaced apart from each other; when the support plate is in its highest position and at its maximum tilt angle, the first end of the first link and the first end of the third link abut against each other.

[0007] As an optional implementation, the frame is provided with a sliding groove extending in the vertical direction, the sliding seat is provided with a first sliding post, and the first end of the third connecting rod is provided with a second sliding post. The first sliding post is slidably disposed in the sliding groove, and the second sliding post is slidably disposed in the sliding groove and can rotate relative to the sliding groove.

[0008] As an optional implementation, the electric backrest further includes an elastic element connected between the sliding seat and the second link; when the drive assembly drives the sliding seat to move gradually downward, the elastic element is configured to elastically drive the first link and the second link to gradually retract so that the tilt angle of the support plate relative to the frame gradually decreases.

[0009] As an optional implementation, the sliding seat is provided with a limit post, and when the support plate moves to a preset minimum tilt angle, the limit post abuts against the second connecting rod.

[0010] As an optional implementation, an arc-shaped groove is provided on one side of the second connecting rod, the arc-shaped groove being used to engage with the limiting post.

[0011] As an alternative implementation, the portion of the third link relative to its first end is an arc shape that is away from the recess of the sliding seat.

[0012] As an optional implementation, the length of the second link is greater than the length of the first link.

[0013] As an optional implementation, the driving component includes a motor, a guide rail, and a slider. The motor is disposed in the frame, the guide rail is connected to the motor and extends in the vertical direction, the slider is slidably disposed on the guide rail, the slider and the sliding seat are connected in a transmission manner, and the motor drives the slider to move up and down.

[0014] As an optional implementation, the electric backrest further includes a linkage plate, two sliding seats are provided, and two support plates, two first connecting rods, two second connecting rods and two third connecting rods are provided respectively. The two sliding seats are respectively connected to the two ends of the linkage plate, and the slider is connected to the linkage plate.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: Firstly, by driving the sliding seat through the drive component, and coordinating with the first, second, and third links, the height and tilt angle of the support plate can be flexibly adjusted, meeting the personalized needs of users of different body types and improving user comfort. Secondly, compared to existing electric backrests, this invention has a simpler structure, reducing unnecessary parts and complex transmission mechanisms, lowering manufacturing difficulty and cost. Furthermore, the simplified structure makes the cooperation between various parts more stable, reducing the probability of malfunctions, improving the smoothness of the electric backrest during operation, avoiding problems such as jamming and abnormal noises, and enhancing the user experience. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a side view of the electric backrest (with the support plate at its highest position and maximum tilt angle) according to an embodiment of this application. Figure 2 This is a side view of the electric backrest (with the support plate at its lowest position and minimum tilt angle) according to an embodiment of this application. Figure 3 This is a three-dimensional structural diagram of the electric backrest (with the support plate at its highest position and maximum tilt angle) according to an embodiment of this application; Figure 4This is a three-dimensional structural diagram of the electric backrest (with the support plate at its lowest position and minimum tilt angle) according to an embodiment of this application. Figure 5 This is a diagram showing the engagement state of the first link, second link, third link, sliding seat, and support plate (with the support plate at its highest position and maximum tilt angle) according to an embodiment of this application. Figure 6 This is a diagram showing the engagement state of the first link, second link, third link, sliding seat, and support plate (with the support plate at its lowest position and minimum tilt angle) according to an embodiment of this application.

[0018] Explanation of key figure labels: 1. Frame; 11. Slide groove; 12. Upper fixed plate; 13. Lower fixed plate; 14. Track plate; 2. Sliding seat; 21. First sliding column; 22. Limiting column; 23. First connecting column; 3. First connecting rod; 4. Second connecting rod; 41. Arc groove; 42. Second connecting column; 5. Third connecting rod; 51. Second sliding column; 6. Drive assembly; 61. Motor; 62. Guide rail; 63. Slider; 7. Elastic element; 8. Linkage plate; 81. Connecting piece; 9. Support plate. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] In this invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this invention and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0021] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this utility model according to the specific circumstances.

[0022] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this utility model based on the specific circumstances.

[0023] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0024] The technical solution of this utility model will be further described below with reference to the embodiments and accompanying drawings.

[0025] Please see Figures 1 to 6 This application provides an electric backrest, including a frame 1, a sliding seat 2, a support plate 9, a first link 3, a second link 4, a third link 5, and a drive assembly 6. The frame 1 serves as the supporting frame for the entire electric backrest, providing an installation base and structural stability for other components. The sliding seat 2 slides up and down on the frame 1. The support plate 9 supports the user's head / back. The first end of the first connecting rod 3 is hinged to the sliding seat 2, and the second end of the first connecting rod 3 is hinged to the support plate 9. The second connecting rod 4 is located below the first connecting rod 3, with its first end hinged to the sliding seat 2 and its second end hinged to the support plate 9. The first end of the third connecting rod 5 is slidably mounted on the frame 1 and can rotate relative to the frame 1. The first end of the third connecting rod 5 is located above the first end of the first connecting rod 3, and the second end of the third connecting rod 5 is hinged between the two ends of the first connecting rod 3. The drive assembly 6 is connected to the sliding seat 2. When the drive assembly 6 drives the sliding seat 2 to gradually slide upward, under the guidance of the first connecting rod 3, the second connecting rod 4, and the third connecting rod 5, the support plate 9 gradually moves upward, and its tilt angle relative to the frame 1 gradually increases.

[0026] When the user needs to adjust the height and tilt angle of the backrest, the drive assembly 6 is activated. The drive assembly 6 drives the sliding seat 2 to slide upwards. During this sliding process, the first link 3, the second link 4, and the third link 5 move accordingly. The first link 3 and the second link 4 rotate as the sliding seat 2 rises, pushing the support plate 9 upwards. Simultaneously, the third link 5 slides and rotates on the frame 1, guiding and adjusting the movement of the first link 3, so that the tilt angle of the support plate 9 relative to the frame 1 gradually increases as it moves upwards. The user can adjust the backrest to a suitable height and tilt angle by controlling the start and stop of the drive assembly 6 according to their body size and comfort needs.

[0027] When it is necessary to lower the backrest height and reduce the tilt angle, the reverse operation drive component 6 is used to make the sliding seat 2 slide downward. Under the linkage of the connecting rod, the support plate 9 moves downward and the tilt angle gradually decreases.

[0028] The electric backrest provided in this application embodiment, in the first aspect, drives the sliding seat 2 to slide via the drive assembly 6, and in conjunction with the linkage of the first link 3, the second link 4, and the third link 5, achieves flexible adjustment of the height and tilt angle of the support plate 9, which can meet the personalized needs of users of different body sizes and improve the user's leaning comfort. In the second aspect, compared with existing electric backrests, the structure of this utility model is simpler, reducing unnecessary parts and complex transmission mechanisms, lowering manufacturing difficulty and cost. Furthermore, the simplified structure makes the cooperation between various parts more stable, reducing the probability of malfunctions, improving the smoothness of the electric backrest during operation, avoiding problems such as jamming and abnormal noises, and enhancing the user experience.

[0029] like Figure 2 , Figure 4 and Figure 6 As shown, in one embodiment, when the support plate 9 is at its lowest position and minimum tilt angle (at which point the support plate 9 is substantially parallel to the frame 1; in some other embodiments, a small included angle may also be formed between the support plate 9 and the frame 1), the first end of the first link 3 and the first end of the third link 5 are spaced apart from each other; as Figure 1 , Figure 3 and Figure 5As shown, when the support plate 9 is in its highest position and at its maximum tilt angle, the first end of the first link 3 and the first end of the third link 5 abut against each other. Thus, firstly, when the support plate 9 is in its lowest position and at its minimum tilt angle, the first ends of the first link 3 and the third link 5 are spaced apart, providing an initial stable layout for the entire electric backrest structure. This spaced-out state prevents unnecessary stress from mutual compression between the links in their initial positions, reducing wear on components in static conditions and extending the service life of the links and related parts. Secondly, when the support plate 9 is in its highest position and at its maximum tilt angle, the first ends of the first link 3 and the third link 5 abut against each other, forming a stable support point. This enhances the structural rigidity of the entire linkage system at its extreme positions. When the user leans against the backrest, placing it in its maximum adjustment state, this abutment point effectively distributes and bears the pressure applied by the user, preventing deformation of the links or loosening of the structure due to excessive force, thereby ensuring the structural stability of the electric backrest under various usage conditions. Thirdly, the process of the first ends of the first link 3 and the third link 5 changing from being spaced apart to touching each other precisely defines the movement trajectory of the support plate 9. During the process of the drive assembly 6 driving the sliding seat 2 to slide up and down, this specific link position relationship ensures that the support plate 9 can move smoothly and change its tilt angle according to the predetermined curve, avoiding problems such as offset, shaking or jamming of the support plate 9 during movement, so that users can obtain a smooth and precise backrest adjustment experience. For example, during the adjustment from the lowest position to the highest position, as the sliding seat 2 rises, the first end of the third link 5 gradually approaches the first end of the first link 3 until it touches each other. During this process, the third link 5 plays a precise guiding role in the movement of the first link 3, so that the support plate 9 can accurately achieve simultaneous changes in height and angle, meeting the precise needs of different users for backrest adjustment.

[0030] like Figure 3 and Figure 4As shown, in one embodiment, the frame 1 is provided with a slide groove 11 extending in the vertical direction, the sliding seat 2 is provided with a first slide post 21, and the first end of the third link 5 is provided with a second slide post 51. The first slide post 21 is slidably disposed in the slide groove 11, and the second slide post 51 is slidably disposed in the slide groove 11 and can rotate relative to the slide groove 11. Thus, the slide groove 11 extending in the vertical direction on the frame 1 provides basic guidance for the entire motion system. The first slide post 21 simply slides within the slide groove 11, allowing the sliding seat 2 to move linearly in the vertical direction, which is the key basic action for realizing backrest height adjustment. The second slide post 51 can not only slide up and down along the slide groove 11, but also rotate relative to the slide groove 11, a characteristic that introduces rotational freedom to the third link 5. During the electric backrest adjustment process, through the coordinated movement of the first slide post 21 and the second slide post 51, the third link 5 can perform complex compound movements. For example, when the sliding seat 2 moves up and down under the action of the drive component 6, the first sliding column 21 drives the sliding seat 2 to move linearly, while the second sliding column 51 rotates during the sliding process, thereby guiding the third link 5 to move at a specific angle and trajectory. This multi-dimensional movement allows the support plate 9 to achieve synchronous and precise adjustment of height and tilt angle, meeting the diverse needs of different users for backrest position and posture. Whether it is a slight adjustment of the backrest angle to obtain a more comfortable sitting posture, or a significant adjustment of the backrest height to adapt to different usage scenarios, it can be easily achieved. The characteristic that the second sliding column 51 can rotate relative to the slide groove 11 greatly enhances the flexibility of the entire motion system. During the backrest adjustment process, when encountering different load conditions or usage requirements, the rotation of the second sliding column 51 allows the third link 5 to automatically adjust its motion posture according to the actual situation, avoiding the problems of motion jamming or inability to adapt to complex situations caused by rigid connection.

[0031] like Figure 3 As shown ( Figure 4(Elastic element not shown). In one embodiment, the electric backrest further includes an elastic element 7 connected between the sliding seat 2 and the second link 4. When the drive assembly 6 drives the sliding seat 2 to move downwards gradually, the elastic element 7 is configured to elastically drive the first link 3 and the second link 4 to gradually retract, so that the tilt angle of the support plate 9 relative to the frame 1 gradually decreases. Thus, in the first aspect, the elastic element 7, connected between the sliding seat 2 and the second link 4, plays a key role in the process of the drive assembly 6 driving the sliding seat 2 to move downwards gradually. It uses its own elasticity to drive the first link 3 and the second link 4 to gradually retract in a gradual and smooth manner. This gradual adjustment method allows the tilt angle of the support plate 9 relative to the frame 1 to decrease slowly and evenly, avoiding abrupt changes in tilt angle adjustment. For example, when a user wants to adjust the backrest from a more tilted resting posture to a more upright sitting posture, there will be no discomfort caused by a sudden and large change in angle, providing the user with a more natural and comfortable adjustment experience and meeting the user's need for fine adjustment of the backrest tilt angle in different usage scenarios. Secondly, the elastic element 7 connects the sliding seat 2 and the second link 4 to form a stable mechanical balance system. During the backrest adjustment process, it can balance the forces between the components and prevent structural displacement or deformation caused by uneven forces. When the first link 3 and the second link 4 are retracted, the elastic force of the elastic element 7 can ensure the synchronicity and coordination of the link movement, making the tilt angle adjustment of the support plate 9 more stable and reliable. For example, during long-term use, the elastic element 7 can continuously maintain this balance state, ensuring that the electric backrest always maintains stable performance and reducing failures caused by structural instability.

[0032] like Figure 3As shown, in one embodiment, the elastic element 7 is a tension spring. The sliding seat 2 is provided with a first connecting post 23, and the second connecting rod 4 is provided with a second connecting post 42. One end of the tension spring is connected to the first connecting post 23, and the other end is connected to the second connecting post 42. Thus, the tension spring, as the elastic element 7, has one end connected to the first connecting post 23 of the sliding seat 2 and the other end connected to the second connecting post 42 of the second connecting rod 4. This connection method ensures that the tension can be stably and directly transmitted between the sliding seat 2 and the second connecting rod 4. When the driving assembly 6 drives the sliding seat 2 to move downward gradually, the elastic force of the tension spring will act evenly and continuously on the second connecting rod 4, so that the first connecting rod 3 and the second connecting rod 4 can gradually retract according to the preset trajectory and force, thereby achieving a precise reduction in the tilt angle of the support plate 9 relative to the frame 1. The elastic characteristics of the tension spring enable it to provide continuous and smooth tension during the movement of the sliding seat 2. When the sliding seat 2 moves downward, the tension spring gradually stretches, and its elastic force changes accordingly, but this change is gradual and continuous, without sudden changes in tension. This makes the retraction process of the first link 3 and the second link 4 smoother, and the reduction of the tilt angle of the support plate 9 is more natural, without causing any jamming or jumping.

[0033] It should be noted that in some other embodiments, the elastic element 7 may also be, but is not limited to, a torsion spring, elastic rubber, or elastic silicone, etc., and can be selected according to actual needs.

[0034] like Figure 2 , Figure 4 and Figure 6As shown, in one embodiment, the sliding seat 2 is provided with a limiting post 22. When the support plate 9 moves to a preset minimum tilt angle, the limiting post 22 abuts against the second connecting rod 4. Thus, the limiting post 22 is positioned on the sliding seat 2, and when the support plate 9 moves to the preset minimum tilt angle, the limiting post 22 abuts against the second connecting rod 4. This design sets a clear lower limit for the tilt angle adjustment of the support plate 9, precisely controlling the support plate 9 to prevent it from tilting further downwards. For example, in scenarios where basic user posture comfort and safety are required, such as office chair backrests, the limiting post 22 ensures that the backrest does not tilt excessively, preventing users from experiencing discomfort and health problems due to an excessively small backrest angle, such as leaning forward or excessive lumbar stress. Compared to software-set angle limits, this mechanical limiting method is more direct and reliable, unaffected by electronic component failures or program errors, and can always ensure that the minimum tilt angle of the support plate 9 is within a safe range. The mechanism of the limiting post 22 abutting against the second link 4 effectively prevents safety hazards caused by excessive tilting of the support plate 9 due to mechanical failure or misoperation. If the drive system of the electric backrest malfunctions, causing the sliding seat 2 to continue moving downwards, the limiting post 22 will promptly stop the second link 4 from moving further, thereby preventing the support plate 9 from tilting to a dangerous angle and preventing the user from falling and getting injured due to the backrest suddenly collapsing. For example, when children use furniture with electric backrests, the limiting post 22 can prevent children from tilting the backrest to an unsafe degree out of curiosity or by accidentally touching the adjustment buttons, providing additional protection for children's safety.

[0035] like Figure 2 , Figure 4 and Figure 6 As shown, in one embodiment, an arc-shaped groove 41 is provided on one side of the second connecting rod 4, which is used to engage with the limiting post 22. Thus, the arc-shaped groove 41 on one side of the second connecting rod 4 engages with the limiting post 22, making the positioning of the support plate 9 more precise when reaching the preset minimum tilt angle. The shape and size of the arc-shaped groove 41 can be precisely machined according to specific design requirements. When the limiting post 22 is engaged in a specific position in the arc-shaped groove 41, the tilt angle of the support plate 9 can be accurately determined. For example, in some medical devices or high-end office chairs where the backrest angle requires extreme precision, the cooperation between the arc-shaped groove 41 and the limiting post 22 ensures that the backrest can always stably remain at the preset minimum tilt angle, meeting the precise needs of different users for sitting posture. Compared with a simple point-contact limiting method, the arc-shaped groove 41 provides a larger contact area, allowing the limiting post 22 to be more stably fixed in the groove after engagement, reducing angle deviations caused by minor vibrations or external force interference, and improving the accuracy and stability of angle positioning.

[0036] like Figure 4 , Figure 5 and Figure 6 As shown, in one embodiment, the portion of the third link 5 closest to its first end is concave and curved away from the sliding seat 2. Firstly, this curved design of the third link 5 avoids interference with other components during movement. In the complex motion mechanism of an electric backrest, the spatial relationships between various links and components are very close. The curved structure allows the portion of the third link 5 closest to its first end to better adapt to the movement trajectory of surrounding components, reducing collisions and friction with other links, the sliding seat 2, or the support plate 9. Secondly, the concave and curved shape of the portion of the third link 5 closest to its first end alters the stress distribution of the link under load. During electric backrest adjustment, the link bears forces from the support plate 9, the sliding seat 2, and other linked components. The curved structure disperses the force concentrated at a single point on the link over a larger curved area, reducing localized stress concentration.

[0037] like Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, in one embodiment, the length of the second link 4 is greater than the length of the first link 3. Thus, firstly, in the linkage mechanism of the electric backrest, the first link 3 and the second link 4 are typically connected to components such as the sliding seat 2 and the support plate 9, forming a multi-link motion system; the greater length of the second link 4 than the first link 3 means that when the sliding seat 2 moves the same distance, the second link 4 can cause the support plate 9 to produce a larger angle change; when the user wants to adjust the backrest from an upright position to a near-reclined position, the longer second link 4 allows the support plate 9 (backrest) to achieve a larger tilt angle. Secondly, during movement, the displacement change of the endpoint of the longer second link 4 is more significant than that of the first link 3, which allows for more precise control of the angle change of the support plate 9 caused by the second link 4 by controlling the amount of movement of the sliding seat 2.

[0038] like Figure 3 and Figure 4As shown, in one embodiment, the drive assembly 6 includes a motor 61, a guide rail 62, and a slider 63. The motor 61 is mounted on the frame 1, the guide rail 62 is connected to the motor 61 and extends vertically, and the slider 63 is slidably mounted on the guide rail 62. The slider 63 is connected to the sliding seat 2, and the motor 61 drives the slider 63 to move up and down. Thus, firstly, the motor 61, mounted on the frame 1, provides a stable foundation for the entire drive system. The guide rail 62, connected to the motor 61, ensures a stable and reliable power transmission path from the motor 61 to the guide rail 62 and then to the slider 63. The sliding friction of the slider 63 on the guide rail 62 is relatively small and uniform, reducing energy loss and fluctuations during power transmission. This ensures stable power during the adjustment of the electric backrest, preventing problems such as backrest adjustment jamming, sudden acceleration, or deceleration caused by unstable power. Secondly, by placing the motor 61 on the frame 1, the internal space of the frame 1 is fully utilized. The guide rail 62 extends vertically, and this vertical layout occupies less space in the horizontal direction, allowing the entire drive assembly 6 to be installed reasonably within the limited product space. The slider 63 slides on the guide rail 62 without the need for additional complex structures to support its movement, further saving space. For some space-constrained products, this compact drive assembly 6 design can reduce the overall size of the product, making the product smaller and lighter, easier to install and use. At the same time, it also leaves more space for the layout of other components inside the product, which is beneficial to the overall design and functional integration of the product.

[0039] like Figure 3 and Figure 4As shown, in one embodiment, the electric backrest also includes a linkage plate 8, two sliding seats 2 are provided, and two support plates 9, two first connecting rods 3, two second connecting rods 4 and two third connecting rods 5 are provided respectively. The two sliding seats 2 are respectively connected to the two ends of the linkage plate 8, and the slider 63 is connected to the linkage plate 8. Thus, firstly, the two sliding seats 2 are respectively connected to the two ends of the linkage plate 8, and the slider 63 is connected to the linkage plate 8. When the slider 63 moves up and down under the drive of the motor 61, it will drive the linkage plate 8 to move synchronously, thereby causing the two sliding seats 2 to move simultaneously and with the same amplitude. The support plate 9 is connected to the sliding seats 2 through the first link 3, the second link 4, and the third link 5. The synchronous movement of the sliding seats 2 will keep the adjustment of the two support plates 9 at the same height. This allows the two support plates 9 to achieve precise synchronization during the electric backrest adjustment process, whether adjusting the tilt angle or the height of the backrest. When the user adjusts the two support plates 9 to a comfortable angle, there will be no situation where one side is high and the other side is low, avoiding backrest distortion or jamming caused by asynchronous movement, providing users with a more stable and smooth adjustment experience, and improving the comfort of use. Secondly, the linkage plate 8 provides a fixed connection between the two sliding seats 2, ensuring their relative position stability during movement. When the slider 63 drives the linkage plate 8, the two sliding seats 2 move along a preset trajectory, making the movement trajectories of the connected support plate 9, first link 3, second link 4, and third link 5 more stable. This stable movement trajectory ensures that the two support plates 9 maintain the correct posture during adjustment, without shifting or wobbling. In scenarios where backrest stability is critical, this ensures the user maintains the correct posture during use. Thirdly, the linkage plate 8 connects the two sliding seats 2 into a single unit, forming a stable frame structure. This structure effectively distributes the load on the backrest. When the user sits on the support plate 9, the force is transmitted to the sliding seats 2 through the support plate 9 and the link, and then evenly distributed by the linkage plate 8, reducing local stress concentration and improving the overall structural strength and load-bearing capacity of the electric backrest. For heavier users, the stable structure prevents the backrest from deforming or being damaged due to excessive force, extending the product's lifespan.

[0040] like Figure 3 and Figure 4 As shown, in one embodiment, the linkage plate 8 is provided with two connecting pieces 81, and the slider 63 is connected between the two connecting pieces 81. Thus, the two connecting pieces 81 on the linkage plate 8 provide a stable connection foundation for the slider 63. This design is equivalent to constructing a relatively closed and stable connection frame between the linkage plate 8 and the slider 63. The stable connection structure ensures that the slider 63 and the linkage plate 8 are always tightly connected and will not loosen or fall off due to long-term use.

[0041] like Figure 3 and Figure 4 As shown, in one embodiment, the frame 1 includes an upper fixed plate 12 and a lower fixed plate 13 arranged opposite to each other. The frame 1 also includes two vertical and oppositely arranged track plates 14, which are respectively connected between the upper fixed plate 12 and the lower fixed plate 13. The motor 61 is disposed on the upper fixed plate 12, and the end of the guide rail 62 away from the motor 61 is connected to the lower fixed plate 13. The two sliding seats 2 are slidably connected to the two track plates 14 respectively, and the two third rods are slidably disposed on the two track plates 14 respectively.

[0042] It should be noted that in some other embodiments, the motor 61 can be mounted on the lower fixed plate 13, and the end of the guide rail 62 away from the motor 61 can be connected to the upper fixed plate 12. The choice can be made according to actual needs.

[0043] It should be noted that in some other embodiments, the drive component 6 may also be, but is not limited to, a lead screw drive component 6 or a telescopic drive component 6, etc., and can be selected according to actual needs.

[0044] In summary, the electric backrest disclosed in this utility model can bring at least the following beneficial technical effects: (1) The sliding seat 2 is driven to slide by the drive component 6. With the linkage of the first link 3, the second link 4 and the third link 5, the height and tilt angle of the support plate 9 can be flexibly adjusted, which can meet the personalized needs of users of different body sizes and improve the user's leaning comfort.

[0045] (2) The structure is simpler, reducing unnecessary parts and complex transmission mechanisms, reducing manufacturing difficulty and cost. Furthermore, the simplified structure makes the cooperation between various parts more stable, reducing the probability of failure.

[0046] (3) When the support plate 9 is at its lowest position and minimum tilt angle, the first end of the first link 3 and the first end of the third link 5 are spaced apart. This design provides an initial stable layout for the entire electric backrest structure. The spaced state prevents unnecessary stress from mutual compression of the links in the initial position, reduces wear of parts in static state, and extends the service life of the links and related components.

[0047] (4) When the support plate 9 is at its highest position and maximum tilt angle, the first end of the first link 3 and the first end of the third link 5 abut against each other, forming a stable support point. This enhances the structural rigidity of the entire linkage system at its limit position, preventing the linkage from deforming or the structure from loosening due to excessive force, thereby ensuring the structural stability of the electric backrest under various usage conditions.

[0048] The technical means disclosed in this utility model are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications are also considered within the scope of protection of this utility model.

Claims

1. An electric backrest, characterized in that, include: Frame (1); The sliding seat (2) is slidably disposed on the frame (1) up and down; Support plate (9) for supporting the user's head / back; The first link (3) has its first end hinged to the sliding seat (2) and its second end hinged to the support plate (9). The second link (4) is located below the first link (3). The first end of the second link (4) is hinged to the sliding seat (2), and the second end of the second link (4) is hinged to the support plate (9). The third link (5) has its first end slidably disposed on the frame (1) and can rotate relative to the frame (1), and the first end of the third link (5) is located above the first end of the first link (3), and the second end of the third link (5) is hinged between the two ends of the first link (3). The drive assembly (6) is connected to the sliding seat (2) in a transmission manner; when the drive assembly (6) drives the sliding seat (2) to slide upward gradually, under the guidance of the first link (3), the second link (4) and the third link (5), the support plate (9) moves upward gradually and the tilt angle relative to the frame (1) gradually increases.

2. The electric backrest according to claim 1, characterized in that, When the support plate (9) is at its lowest position and minimum tilt angle, the first end of the first link (3) and the first end of the third link (5) are spaced apart from each other; when the support plate (9) is at its highest position and maximum tilt angle, the first end of the first link (3) and the first end of the third link (5) abut against each other.

3. The electric backrest according to claim 1, characterized in that, The frame (1) is provided with a slide groove (11) extending in the vertical direction, the sliding seat (2) is provided with a first slide post (21), and the first end of the third connecting rod (5) is provided with a second slide post (51). The first slide post (21) is slidably disposed in the slide groove (11), and the second slide post (51) is slidably disposed in the slide groove (11) and can rotate relative to the slide groove (11).

4. The electric backrest according to any one of claims 1-3, characterized in that, The electric backrest also includes an elastic element (7), which is connected between the sliding seat (2) and the second link (4); when the drive assembly (6) drives the sliding seat (2) to move downward gradually, the elastic element (7) is configured to elastically drive the first link (3) and the second link (4) to gradually retract so that the tilt angle of the support plate (9) relative to the frame (1) gradually decreases.

5. The electric backrest according to claim 4, characterized in that, The sliding seat (2) is provided with a limiting post (22). When the support plate (9) moves to the preset minimum tilt angle, the limiting post (22) abuts against the second connecting rod (4).

6. The electric backrest according to claim 5, characterized in that, The second connecting rod (4) has an arc-shaped groove (41) on one side, which is used to engage with the limiting post (22).

7. The electric backrest according to claim 1, characterized in that, The portion of the third link (5) that is relatively close to its first end is concave and arc-shaped, away from the sliding seat (2).

8. The electric backrest according to claim 1, characterized in that, The length of the second link (4) is greater than the length of the first link (3).

9. The electric backrest according to claim 1, characterized in that, The driving component (6) includes a motor (61), a guide rail (62), and a slider (63). The motor (61) is disposed on the frame (1). The guide rail (62) is connected to the motor (61) and extends in the vertical direction. The slider (63) is slidably disposed on the guide rail (62). The slider (63) and the sliding seat (2) are connected in a transmission manner. The motor (61) drives the slider (63) to move up and down.

10. The electric backrest according to claim 9, characterized in that, The electric backrest also includes a linkage plate (8), two sliding seats (2) are provided, and two support plates (9), two first connecting rods (3), two second connecting rods (4) and two third connecting rods (5) are provided respectively. The two sliding seats (2) are respectively connected to the two ends of the linkage plate (8), and the slider (63) is connected to the linkage plate (8).

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