Backrest mechanism and sofa

Abstract

The invention discloses a backrest mechanism and a sofa, the backrest mechanism comprises a supporting assembly, a backrest assembly and a locking transmission assembly, the backrest assembly is rotatably connected with the supporting assembly, and the basic requirement of backrest rotation adjustment is met; the locking transmission assembly is arranged between the supporting assembly and the backrest assembly and comprises a locking part, a transmission part and a reset piece. One end of the transmission part is fixedly connected with one side of the backrest assembly, and the other end is in transmission connection with the locking part; the locking part is matched with the supporting assembly to limit rotation of the backrest assembly relative to the supporting assembly, and the reset piece is matched with the locking part to drive the locking part to be clamped with the supporting assembly. The mechanism overcomes the defect that in the prior art, a backrest is temporarily positioned through friction force and is prone to deviation, and stable locking is achieved; a user only needs to apply acting force to one side of the backrest assembly to unlock, the reset piece drives the locking part to reset and clamp after adjustment, it is guaranteed that the backrest assembly does not deflect at the preset position due to external force, the leaning comfort is improved, and the situation that the user is unbalanced due to sudden deflection of the backrest is avoided.

Description

Technical Field

[0001] This invention relates to the field of furniture technology, specifically to a backrest mechanism and a sofa. Background Technology

[0002] In the furniture manufacturing industry, in order to improve the flexibility of sofa use, existing technologies have developed rotatable sofa backrest structures. These backrests can rotate horizontally relative to the sofa cushion body. However, the current rotatable sofa backrests generally have a core defect: the backrest can only achieve temporary positioning by relying on friction during rotation and cannot be stably locked in the user's preset rotation position. When the user leans against the backrest, the backrest is prone to deflection due to external force, which not only affects the comfort of leaning but may also cause the user to lose balance due to sudden deflection. Summary of the Invention

[0003] The embodiments of the present invention provide a backrest mechanism and a sofa, which solves the technical problem that the backrest of an existing rotatable sofa cannot stably stop and lock after rotating to different positions.

[0004] To address the aforementioned problems, according to one aspect of this application, an embodiment of the present invention provides a backrest mechanism, the backrest mechanism including a support assembly, a backrest assembly, and a locking transmission assembly, the backrest assembly and the support assembly being rotatably connected, and the locking transmission assembly being disposed between the support assembly and the backrest assembly; the locking transmission assembly includes a locking part, a transmission part, and a reset member, one end of the transmission part being fixedly connected to one side of the backrest assembly, and the other end being drively connected to the locking part, the locking part cooperating with the support assembly to restrict the rotation of the backrest assembly relative to the support assembly, and the reset member cooperating with the locking part to drive the locking part to engage with the support assembly.

[0005] In some embodiments, the support component includes a base and a positioning plate. The positioning plate is located inside the base. The positioning plate has multiple positioning slots along the circumferential direction. The included angle between adjacent positioning slots corresponds to a preset rotation angle of the backrest component. Different positioning slots correspond to different rotation positions of the backrest component. The locking part engages with the positioning slots to restrict the rotation of the backrest component.

[0006] In some embodiments, the locking part includes a locking body, the bottom of which has a plug-in portion, and the locking body is capable of rotating the plug-in portion to engage with different positioning slots.

[0007] In some embodiments, there are two plug-in portions, which are symmetrically arranged and engage with two positioning slots on the positioning disk in a one-to-one correspondence.

[0008] In some embodiments, the lower end of the plug-in portion is provided with an arc-shaped guide surface, the curvature of which is adapted to the curvature of the groove edge of the positioning slot, for guiding the plug-in portion to slide into the positioning slot at the corresponding angle.

[0009] In some embodiments, the number of positioning slots is 4-12, and they are evenly distributed along the circumference of the positioning disk.

[0010] In some embodiments, the reset member is a spring, which is sleeved on the top outer side of the locking body. One end of the spring abuts against the upper surface of the locking body, and the other end abuts against the lower part of the transmission part. The spring is in a pre-compressed state and can drive the plug part to engage with the positioning slot at the corresponding angle by relying on its own restoring force.

[0011] In some embodiments, the transmission part includes a traction rope, a guide pulley, and an auxiliary guide wheel. The guide pulley is fixedly disposed at the lower end of the backrest assembly, and the auxiliary guide wheel is disposed between the guide pulley and the locking part. One end of the traction rope is fixedly connected to one side of the backrest assembly, and the other end passes through the guide pulley and the auxiliary guide wheel in sequence before being connected to the locking body. The other end of the spring abuts against the lower part of the auxiliary guide wheel.

[0012] In some embodiments, the backrest assembly includes a backrest body and a rotating connecting seat. The rotating connecting seat is fixedly disposed on the lower end face of the backrest body. The lower part of the rotating connecting seat is rotatably engaged with the upper part of the positioning plate. The lower part of the positioning plate extends to the bottom of the rotating connecting seat. The locking transmission assembly is disposed inside the rotating connecting seat.

[0013] In some embodiments, the lower part of the rotary connector is provided with a mating groove, and the positioning disk is embedded in the mating groove to achieve a rotatable fit between the rotary connector and the positioning disk.

[0014] In some embodiments, one side of the backrest assembly is the end of the backrest body, which is fixedly connected to one end of the traction rope. When the end is lifted, a lever structure is formed to reduce the force exerted on the locking part.

[0015] According to another aspect of this application, an embodiment of the present invention provides a sofa, the sofa including a seat cushion assembly and the aforementioned backrest mechanism, wherein a support component of the backrest mechanism is connected to the seat cushion assembly, and the backrest assembly serves as the backrest of the sofa.

[0016] Compared with the prior art, the backrest mechanism of the present invention has the following advantages: The backrest mechanism provided by the present invention includes a support assembly, a backrest assembly, and a locking transmission assembly. The backrest assembly and the support assembly are rotatably connected, and the locking transmission assembly is disposed between the support assembly and the backrest assembly. The locking transmission assembly includes a locking part, a transmission part, and a reset member. One end of the transmission part is fixedly connected to one side of the backrest assembly, and the other end is drively connected to the locking part. The locking part cooperates with the support assembly to restrict the rotation of the backrest assembly relative to the support assembly, and the reset member cooperates with the locking part to drive the locking part to engage with the support assembly.

[0017] The backrest mechanism features a rotatable connection between the backrest assembly and the support assembly, fulfilling the basic requirement for backrest rotation adjustment. Simultaneously, a locking transmission component is installed between the support assembly and the backrest assembly, transforming the backrest assembly's positioning method from temporary frictional positioning to a stable locking mechanism where the locking part engages with the support assembly. Users only need to apply force to one side of the backrest assembly to unlock it. After adjustment, the reset component drives the locking part to reset and engage, ensuring the backrest assembly remains in its preset position without shifting due to external force. This completely solves the problem of easy backrest shifting in existing technologies, improving both comfort and preventing users from losing balance due to sudden backrest shifting.

[0018] The sofa provided by this invention is designed based on the aforementioned backrest mechanism. Its beneficial effects are described in the section on the beneficial effects of the backrest mechanism, and will not be repeated here.

[0019] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a cross-sectional view of the backrest structure when the backrest assembly is in a fixed state in a backrest mechanism provided in an embodiment of the present invention. Figure 2 This is a cross-sectional view of the backrest structure when the backrest assembly is in a rotating state in a backrest mechanism provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the structure of a backrest mechanism provided in an embodiment of the present invention, showing the positioning plate and the mating groove engaging. Figure 4This is a schematic diagram of the structure of a backrest mechanism in which a support component and a locking part cooperate, provided by an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the locking body in a backrest mechanism provided in an embodiment of the present invention; Figure 6 This is a structural diagram of a sofa in its initial state, provided by an embodiment of the present invention; Figure 7 A schematic diagram of the structure of a sofa after its backrest is rotated 180 degrees, provided in an embodiment of the present invention; Figure 8 A schematic diagram of the structure of a sofa provided in an embodiment of the present invention, showing the backrest rotated 30 degrees; Figure 9 This is a schematic diagram of the structure of a sofa with its backrest in a rotating state, provided by an embodiment of the present invention. Figure label explanation: 1. Support assembly; 11. Base; 12. Positioning plate; 121. Positioning slot; 2. Backrest assembly; 21. Backrest body; 22. Rotary connecting seat; 221. Mating groove; 3. Locking transmission assembly; 31. Locking part; 311. Locking body; 312. Insertion part; 3121. Arc-shaped guide surface; 32. Transmission part; 321. Traction rope; 322. Guide pulley; 323. Auxiliary guide wheel; 33. Reset component. Detailed Implementation

[0022] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific embodiments, structures, features, and effects according to the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "an embodiment" or "an embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0023] In the description of this invention, it should be clearly stated that the terms "first," "second," etc., in the specification, claims, and accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence; the terms "vertical," "lateral," "longitudinal," "front," "rear," "left," "right," "up," "down," "horizontal," etc., indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, and are merely for the convenience of describing this invention, and do not mean that the device or element referred to must have a specific orientation or position, and therefore should not be construed as a limitation of this invention.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0026] Example 1 This embodiment provides a backrest mechanism, such as Figures 1-5 As shown, the backrest mechanism includes a support assembly 1, a backrest assembly 2, and a locking transmission assembly 3. The backrest assembly 2 is rotatably connected to the support assembly 1, and the locking transmission assembly 3 is disposed between the support assembly 1 and the backrest assembly 2. The locking transmission assembly 3 includes a locking part 31, a transmission part 32, and a reset member 33. One end of the transmission part 32 is fixedly connected to one side of the backrest assembly 2, and the other end is drively connected to the locking part 31. The locking part 31 cooperates with the support assembly 1 to restrict the rotation of the backrest assembly 2 relative to the support assembly 1. The reset member 33 cooperates with the locking part 31 to drive the locking part 31 to engage with the support assembly 1.

[0027] Support component 1 is the load-bearing foundation of the entire backrest mechanism, providing stable installation support for backrest component 2 and locking transmission component 3. Backrest component 2 is the main component that the user leans against directly, and it is rotatably connected to support component 1 to meet the user's need to adjust the angle of backrest component 2 relative to support component 1. More specifically, the position of locking transmission component 3 allows it to better link support component 1 and backrest component 2, ensuring the accurate transmission of locking and unlocking actions. Furthermore, the locking transmission assembly 3 includes a locking part 31, which is the core component for locking the position of the backrest assembly 2. It can cooperate with the support assembly 1 to restrict the rotation of the backrest assembly 2 relative to the support assembly 1. The transmission part 32 transmits the force applied to the backrest assembly 2, thereby driving the locking part 31 to move. The reset part 33 cooperates with the locking part 31 and drives the locking part 31 to engage with the support assembly 1, thereby ensuring the stable maintenance of the locked state. The entire connection and positional relationship can not only meet the needs of the rotational adjustment of the backrest assembly 2, but also achieve reliable position locking through the setting of the locking transmission assembly 3.

[0028] When the user needs to adjust the angle of the backrest assembly 2, a force is first applied to one side of the backrest assembly 2. This force is transmitted to the locking part 31 through the transmission part 32, which is fixedly connected to that side of the backrest assembly 2. This causes the locking part 31 to move and disengage from the support assembly 1. At this time, the backrest assembly 2 is no longer restricted to rotation and can rotate freely relative to the support assembly 1. After the user adjusts the backrest assembly 2 to the appropriate position, the force applied to one side of the backrest assembly 2 is removed. The reset part 33, which cooperates with the locking part 31, then activates, driving the locking part 31 to re-engage with the support assembly 1, thereby restricting the rotation of the backrest assembly 2 and stably locking it in the current position. The entire engagement process requires no complicated operation; the angle adjustment and stable locking of the backrest assembly 2 can be achieved by the linkage of each component, ensuring ease of use and reliability.

[0029] Existing rotatable sofa backrests can only achieve temporary positioning through friction, and cannot be stably locked in a preset position. When users lean against them, the backrest is prone to deflection, which can even cause imbalance. The backrest mechanism in this embodiment effectively solves this technical problem by reasonably setting the connection method and cooperation relationship of the support component 1, the backrest component 2, and the locking transmission component 3. Specifically, the backrest component 2 and the support component 1 are rotatably connected to meet the basic requirements for backrest rotation adjustment. At the same time, a locking transmission component 3 is set between the support component 1 and the backrest component 2. Its locking part 31 can cooperate with the support component 1 to restrict the rotation of the backrest component 2. The reset part 33 can drive the locking part 31 to engage with the support component 1, so that the positioning method of the backrest component 2 changes from temporary positioning by friction to stable locking by the engagement of the locking part 31 with the support component 1. Furthermore, one end of the transmission part 32 is fixedly connected to one side of the backrest assembly 2, and the other end is connected to the locking part 31. The user only needs to apply force to one side of the backrest assembly 2 to unlock it. After adjustment, the reset part 33 drives the locking part 31 to reset and engage, ensuring that the backrest assembly 2 will not deflect due to external force in the preset position. This completely solves the defect of easy backrest deviation in the prior art, which not only improves the comfort of leaning but also avoids the user from losing balance due to sudden backrest deviation.

[0030] In a specific embodiment, such as Figure 4 As shown, the support component 1 includes a base 11 and a positioning disk 12. The positioning disk 12 is located inside the base 11. The positioning disk 12 has multiple positioning slots 121 along the circumferential direction. The included angle between adjacent positioning slots 121 corresponds to the preset rotation angle of the backrest component 2. Different positioning slots 121 correspond to different rotation positions of the backrest component 2. The locking part 31 engages with the positioning slots 121 to restrict the rotation of the backrest component 2.

[0031] The support component 1 mainly consists of a base 11 and a positioning plate 12. The base 11 serves as the foundation for the entire support component 1, firmly supporting and fixing the positioning plate 12 to ensure that the positioning plate 12 does not move or rotate within the base 11 and remains stable. The positioning plate 12 has multiple positioning slots 121. The angle between two adjacent positioning slots 121 is the preset rotation angle of the backrest component 2. When the user pushes the backrest component 2 to rotate, each preset angle causes a positioning slot 121 to precisely align with the locking part 31. Different positioning slots 121 correspond to different rotation positions of the backrest component 2, allowing the user to adjust the backrest component 2 to a suitable angle according to their needs. When the locking part 31 engages with the corresponding positioning slot 121, because the positioning plate 12 is fixed by the base 11, the locking part 31 is limited by the positioning slot 121 and cannot move further, thus restricting the rotation of the backrest component 2 and keeping it stably in the adjusted position, preventing displacement caused by external forces.

[0032] In a specific embodiment, such as Figures 2-5 As shown, the locking part 31 includes a locking body 311, and the bottom of the locking body 311 has a plug-in part 312. The locking body 311 can drive the plug-in part 312 to rotate so that it can cooperate with different positioning slots 121.

[0033] The insertion part 312 is located at the bottom of the locking body 311, and the two are tightly connected together. When the locking body 311 moves, the insertion part 312 moves synchronously. As the main body of the locking part 31, the locking body 311 can drive the insertion part 312 at the bottom to rotate. This rotation is not a rotation of the locking body 311 alone, but is synchronized with the rotation of the backrest assembly 2. Because the locking part 31 needs to cooperate with the support assembly 1 to restrict the rotation of the backrest assembly 2, when the user adjusts the angle of the backrest assembly 2 and drives the backrest assembly 2 to rotate, the locking body 311 will also rotate together, thereby causing the insertion part 312 at the bottom to rotate synchronously. More specifically, the positioning slots 121 on the positioning disk 12 are distributed along the circumference. Different positioning slots 121 correspond to different rotation positions of the backrest assembly 2. The locking body 311 drives the insertion part 312 to rotate, which essentially means that the insertion part 312 continuously changes its own position as the angle of the backrest assembly 2 is adjusted, so as to accurately align and adapt to the positioning slots 121 at different positions on the positioning disk 12. This enables the insertion part 312 to cooperate with different positioning slots 121, preparing for the subsequent angle locking of the backrest assembly 2. It ensures that after the backrest assembly 2 is adjusted to any preset angle, it can be stably fixed through this cooperation, avoiding positional deviation.

[0034] In a specific embodiment, such as Figure 4 and Figure 5As shown, there are two plug-in parts 312, which are symmetrically arranged and engage with the two positioning slots 121 on the positioning disk 12 in a one-to-one correspondence.

[0035] There are two insertion parts 312 at the bottom of the locking body 311. These two insertion parts 312 are not randomly placed, but are symmetrically arranged around the bottom center of the locking body 311. That is to say, the two insertion parts 312 are in corresponding positions at the bottom of the locking body 311 and are exactly the same distance from the center of the locking body 311. This symmetrical design allows the two insertion parts 312 to be subjected to more even force during subsequent engagement, and will not cause the engagement to loosen due to excessive force on one side. Correspondingly, the positioning slots 121 on the positioning disk 12 are also set in pairs. The two positioning slots 121 in each group are also symmetrically distributed along the center of the positioning disk 12. Their symmetrical positions are exactly matched with the symmetrical positions of the two plug-in parts 312. When the locking body 311 drives the two plug-in parts 312 to rotate to the preset angle, the two plug-in parts 312 will simultaneously align with the two positioning slots 121 of the same group on the positioning disk 12, realizing one-to-one corresponding engagement. That is, one plug-in part 312 is precisely engaged in one positioning slot 121, and the other plug-in part 312 is engaged in the other positioning slot 121 of the same group. This corresponding engagement method of double plug-in parts and double slots can greatly improve the stability of the engagement between the locking part 31 and the positioning disk 12, thereby more reliably restricting the rotation of the backrest assembly 2 and preventing the backrest assembly 2 from shifting or shaking due to external force after locking, making the locking effect of the entire backrest mechanism more reliable.

[0036] In a specific embodiment, such as Figure 5 As shown, the lower end of the insertion part 312 is provided with an arc-shaped guide surface 3121. The arc of the arc-shaped guide surface 3121 is adapted to the arc of the groove edge of the positioning slot 121, and is used to guide the insertion part 312 to slide into the positioning slot 121 at the corresponding angle.

[0037] During the process of the locking part 31 driving the insertion part 312 to approach the positioning slot 121 and complete the engagement, the arc-shaped guide surface 3121 provided at the lower end of the insertion part 312 plays a key guiding role. The curvature of the arc-shaped guide surface 3121 is precisely designed to perfectly match the curvature of the slot edge of the positioning slot 121. In this way, when the two come into contact, the arc-shaped guide surface 3121 can fit well against the slot edge of the positioning slot 121 without misalignment or scraping. When the locking body 311 moves the insertion part 312 toward the positioning slot 121, the arc-shaped guide surface 3121 will first contact the edge of the slot of the positioning slot 121, and then slide naturally along the arc of the slot edge, slowly guiding the insertion part 312 to adjust its posture and accurately align with the inside of the positioning slot 121, and finally smoothly slide into the positioning slot 121 at the corresponding angle. This guiding effect not only makes the locking action smoother and avoids the situation where the insertion part 312 gets stuck in the slot and cannot enter smoothly, but also ensures that the insertion part 312 can accurately lock into the corresponding positioning slot 121 every time, ensuring the accuracy of the locking position of the backrest assembly 2, thereby reliably limiting the rotation of the backrest assembly 2 and making the use of the backrest mechanism smoother and more convenient.

[0038] In a specific embodiment, the number of positioning slots 121 is 4-12, and they are evenly distributed along the circumference of the positioning disk 12.

[0039] The number of positioning slots 121 is set between 4 and 12. This range is reasonably designed to meet the user's different angle adjustment needs while ensuring the stability of the backrest assembly 2 after locking. These positioning slots 121 are evenly distributed along the circumference of the positioning disk 12. The included angle between two adjacent positioning slots 121 is fixed and equal, and there will be no angle deviation. Depending on the number of positioning slots 121, the included angle between adjacent slots will also change accordingly, thereby realizing rotation and locking at different angles. For example, when there are 6 positioning slots 121, the included angle between two adjacent slots is 60 degrees; when there are 8, the included angle is 45 degrees; and when there are 12, the included angle is 30 degrees. This allows the backrest assembly 2 to easily rotate at preset angles such as 30 degrees, 45 degrees, and 60 degrees. Moreover, each time it rotates to a preset angle, the insertion part 312 can accurately engage with the corresponding positioning slot 121 to achieve limit locking and hovering, allowing the backrest assembly 2 to stop steadily at the currently adjusted angle without any deviation. Meanwhile, since the positioning slots 121 are evenly distributed along the entire circumference of the positioning disk 12 without any gaps or breaks, during the adjustment process, the backrest assembly 2 can drive the locking part 31 to rotate 360 ​​degrees around the positioning disk 12. No matter where it rotates to on the circumference, as long as it rotates to the corresponding slot, it can be locked by the engagement of the insertion part 312 with the positioning slot 121. This ensures both the flexibility of angle adjustment and the reliability of locking, perfectly meeting the usage requirements.

[0040] In a specific embodiment, such as Figures 1-4 As shown, the reset member 33 is a spring, which is sleeved on the top outer side of the locking body 311. One end of the spring abuts against the upper surface of the locking body 311, and the other end abuts against the lower part of the transmission part 32. The spring is in a pre-compressed state and can drive the plug part 312 to engage with the positioning slot 121 at the corresponding angle by relying on its own restoring force.

[0041] The reset component 33 is a spring, which is sleeved on the top outer side of the locking body 311. This sleeve arrangement ensures that the spring's extension / retraction direction aligns with the vertical movement of the locking body 311, guaranteeing that the force generated by the spring is accurately transmitted to the locking body 311 and ensuring the stability of subsequent reset and engagement actions. One end of the spring abuts against the upper surface of the locking body 311, and the other end abuts against the lower part of the transmission part 32. This abutment structure provides stable force support for the spring, effectively preventing deviation or tilting during extension / retraction that could affect force transmission, further ensuring the smooth operation of the locking transmission assembly 3. After installation, the spring is in a pre-compressed state. In this pre-compressed state, the spring stores a certain amount of elastic potential energy, which is continuously converted into a downward restoring force, continuously acting on the locking body 311. This ensures that the insertion part 312 at the bottom of the locking body 311 always tends to move closer to the positioning slot 121, preparing for subsequent engagement and locking.

[0042] When the backrest assembly 2 is adjusted to a preset suitable angle and the insertion part 312 is precisely aligned with the corresponding positioning slot 121, the restoring force generated by the spring will directly drive the locking body 311 to move downward, thereby causing the insertion part 312 to smoothly engage in the positioning slot 121 at the corresponding angle, achieving stable locking of the backrest assembly 2; when the transmission part 32 pulls the locking body 311 upward, the spring will be further compressed, storing more elastic potential energy. After the external force is removed, the elastic potential energy can be quickly released to drive the locking body 311 to reset, ensuring that subsequent engagement actions can be completed in a timely and smooth manner.

[0043] In a specific embodiment, such as Figure 2 As shown, the transmission part 32 includes a traction rope 321, a guide pulley 322, and an auxiliary guide wheel 323. The guide pulley 322 is fixedly disposed at the lower end of the backrest assembly 2. The auxiliary guide wheel 323 is disposed between the guide pulley 322 and the locking part 31. One end of the traction rope 321 is fixedly connected to one side of the backrest assembly 2, and the other end passes through the guide pulley 322 and the auxiliary guide wheel 323 in sequence before being connected to the locking body 311. The other end of the spring abuts against the lower part of the auxiliary guide wheel 323.

[0044] The guide pulley 322 is fixedly installed at the lower end of the backrest assembly 2. Its installation position is precisely matched with the force point of the backrest assembly 2 and the direction of the traction rope 321. Its core function is to change the direction of the tension transmission of the traction rope 321, so that the force applied by the user to one side of the backrest assembly 2 can be transmitted to the locking part 31 in accordance with the direction of the mechanism layout. The auxiliary guide wheel 323 is correspondingly located between the guide pulley 322 and the locking part 31. Its installation height forms a line with the connection point of the guide pulley 322 and the locking body 311. The optimized force trajectory is primarily used to improve the transmission path of the traction rope 321 and reduce frictional resistance between the traction rope 321 and other components of the mechanism during pulling. The traction rope 321, as the core carrier of force transmission, has one end fixedly connected to one side of the backrest assembly 2. The connection is reinforced to ensure it does not loosen or detach under load. The other end is precisely wound along the grooves of the guide pulley 322 and the auxiliary guide wheel 323, ultimately connecting firmly to the locking body 311 to ensure complete force transmission. Furthermore, the other end of the spring rests against the underside of the auxiliary guide wheel 323. The fixed installation of the auxiliary guide wheel 323 provides a stable support point for the spring, ensuring that the normal rotation of the auxiliary guide wheel 323 is not affected while maintaining a stable pre-compression state, guaranteeing a continuous and stable output of the spring's restoring force.

[0045] When the user needs to adjust the angle of the backrest assembly 2 or apply force to one side of the backrest assembly 2, the force is directly transmitted to one end of the traction rope 321 fixedly connected to it, causing the traction rope 321 to generate tension. Under the action of tension, the traction rope 321 slides along the groove of the guide pulley 322, and the guide pulley 322 precisely changes the direction of the tension transmission, so that the tension can be transmitted towards the locking part 31 in accordance with the mechanism layout. Subsequently, the traction rope 321 continues to slide along the groove of the auxiliary guide wheel 323, and the auxiliary guide wheel 323 further organizes the tension. The direction of the guide rope 321 reduces frictional loss during the transmission of tension, ensuring that the tension can be transmitted smoothly and efficiently to the locking body 311 connected to the other end of the guide rope 321. Driven by the tension, the locking body 311 moves upward, causing the insertion part 312 to disengage from the positioning slot 121, thereby unlocking the backrest assembly 2. At this time, the auxiliary guide wheel 323 continuously provides stable support for the spring, ensuring that the spring is further compressed and stores elastic potential energy when the locking body 311 moves upward, making full preparation for the subsequent reset and locking action.

[0046] In a specific embodiment, such as Figure 2 As shown, the backrest assembly 2 includes a backrest body 21 and a rotating connecting seat 22. The rotating connecting seat 22 is fixedly disposed on the lower end face of the backrest body 21. The lower part of the rotating connecting seat 22 is rotatably engaged with the upper part of the positioning disk 12. The lower part of the positioning disk 12 extends to the bottom of the rotating connecting seat 22. The locking transmission assembly 3 is disposed inside the rotating connecting seat 22.

[0047] The backrest assembly 2 consists of a backrest body 21 and a rotating connecting seat 22, forming a stable overall structure that together realizes the load-bearing and rotation functions of the backrest assembly 2. The rotating connecting seat 22 is fixedly mounted on the lower end face of the backrest body 21, and the two are firmly connected and maintain synchronous movement. As the core component that the user directly leans on, the backrest body 21 can smoothly transmit the leaning force it bears to the rotating connecting seat 22. The lower part of the rotating connecting seat 22 and the upper part of the positioning plate 12 adopt a rotatable mating structure. The mating gap is precisely controlled to ensure that the rotating connecting seat 22 drives the backrest body 21 to rotate smoothly around the positioning plate 12 without jamming or offset, and to ensure the stability of the mating between the two, avoiding shaking or misalignment during rotation. The lower part of the positioning plate 12 extends below the rotating connecting seat 22. This allows the lower part of the positioning plate 12 to be smoothly and fixedly connected to the base 11, thereby ensuring that the positioning plate 12 remains stationary throughout the operation of the backrest mechanism. This provides a stable and unchanging reference for the engagement and locking of the locking part 31 and the positioning slot 121. The locking transmission assembly 3 is entirely located inside the rotating connecting seat 22. This layout design makes the entire backrest mechanism structure more compact and effectively protects the locking transmission assembly 3 from external collisions, interference from debris, etc. At the same time, it allows the locking transmission assembly 3 to rotate synchronously with the rotating connecting seat 22, ensuring that the locking part 31 always maintains a corresponding relationship with the positioning slot 121 on the positioning plate 12. This provides a reliable structural basis for the subsequent engagement and unlocking actions of the locking part 31, ensuring the smooth and coordinated realization of the rotation and locking functions of the backrest assembly 2.

[0048] In a specific embodiment, such as Figure 3 As shown, the lower part of the rotary connecting seat 22 is provided with a mating groove 221, and the positioning disk 12 is embedded in the mating groove 221 to realize the rotatable mating of the rotary connecting seat 22 and the positioning disk 12.

[0049] The lower part of the rotating connecting seat 22 is integrally formed with a mating groove 221. The shape and size of the mating groove 221 are precisely matched with the upper structure of the positioning plate 12. Its inner wall is smoothed to ensure that the positioning plate 12 can be smoothly embedded in the mating groove 221. After embedding, a reasonable mating gap is formed between the two, which will not cause rotation jamming due to excessive tightness, nor will it cause shaking due to excessive looseness. After the positioning plate 12 is embedded in the mating groove 221, the mating groove 221 can effectively limit the positioning plate 12, restricting the rotation of the rotating connecting seat 22 relative to the positioning plate 12, and ensuring that the rotating connecting seat 22 always rotates with the positioning plate 12 as the center. At the same time, this embedding structure further enhances the mating stability between the rotating connecting seat 22 and the positioning plate 12, so that when the rotating connecting seat 22 drives the backrest body 21 to rotate, it can always maintain a precise rotation trajectory, avoiding misalignment, tilting and other situations during rotation, thereby reliably realizing the rotatable mating between the rotating connecting seat 22 and the positioning plate 12.

[0050] In a specific embodiment, one side of the backrest assembly 2 is the end of the backrest body 21, which is fixedly connected to one end of the traction rope 321. When the end is lifted, a lever structure is formed to reduce the force of pulling the locking part 31.

[0051] One side of the backrest assembly 2 corresponds to the end of the backrest body 21. This end is structurally reinforced, and one end of the traction rope 321 is firmly connected to this end. The connection part and the force trajectory of the end are precisely matched to ensure that the force generated when the end is lifted can be completely and stably transmitted to the traction rope 321, avoiding loosening, falling off or loss of force transmission. When the user needs to unlock the backrest assembly 2 to adjust the angle, they lift this end of the backrest body 21. At this time, the backrest body 21 forms a lever structure with the rotatable engagement point between the rotating connecting seat 22 and the positioning plate 12 as the fulcrum. The end of the backrest body 21 serves as the lever arm, and the connection point between the traction rope 321 and the end serves as the force transmission point. The distance from the fulcrum to the force point at the end is greater than the distance from the fulcrum to the force transmission point. According to the lever principle, the force applied by the user when lifting the end is effectively amplified. When the force is transmitted to the locking part 31 through the traction rope 321, the force required to pull the locking part 31 is significantly reduced. This allows the user to easily pull the locking body 311 without expending much effort, causing the insertion part 312 to disengage from the positioning slot 121, thus unlocking the backrest assembly 2. This greatly improves the convenience of operation and also reduces the wear and breakage of the traction rope 321 due to excessive force, ensuring the service life and operational reliability of the transmission part 32. This ensures that the user can obtain a smooth and effortless operating experience when adjusting the backrest angle.

[0052] The specific working process of the backrest mechanism provided in this embodiment is as follows: When the user needs to adjust the angle of the backrest mechanism, first lift the end of the backrest body 21, such as... Figure 2 As shown, this end is fixedly connected to one end of the traction rope 321. At this time, the backrest body 21 forms a lever structure with the rotatable engagement point between the rotating connecting seat 22 and the positioning plate 12 as the fulcrum. By means of the lever principle, the force required to pull the locking part 31 is significantly reduced. The force applied by the user is transmitted to the traction rope 321 through the end. The traction rope 321 passes in sequence around the guide pulley 322 fixed at the lower end of the backrest assembly 2 and the auxiliary guide wheel 323 located between the guide pulley 322 and the locking part 31, and smoothly transmits the pulling force to the locking body 311, causing the locking body 311 to move upward. At this time, the spring sleeved on the outer side of the top of the locking body 311 is further compressed, storing more elastic potential energy. The two symmetrically arranged plugs 312 at the bottom of the locking body 311 move upward and disengage from the corresponding positioning slots 121 on the positioning plate 12, and the backrest assembly 2 is unlocked. The user then pushes the backrest body 21, which drives the rotating connecting seat 22 to move synchronously. The mating groove 221 at the bottom of the rotating connecting seat 22 forms a stable rotatable fit with the upper part of the positioning plate 12, ensuring that there is no jamming or deviation during the rotation process. The positioning plate 12 remains stationary because it is fixedly connected to the base 11. The user can rotate the backrest assembly 2 to a preset angle as needed. Once the backrest assembly 2 is adjusted to the target angle, the user releases the end of the backrest body 21, the tension of the traction rope 321 disappears, the spring in the pre-compressed state releases its elastic potential energy, generating a downward restoring force that drives the locking body 311 to move down. The arc-shaped guide surface 3121 at the lower end of the insertion part 312 matches the arc of the groove edge of the positioning slot 121, guiding the two insertion parts 312 to slide precisely into the corresponding positioning slots 121, forming a one-to-one engagement. The symmetrical engagement structure of the double insertion parts and double slots enhances the locking stability. At this time, the locking part 31 and the positioning plate 12 cooperate closely, restricting the backrest assembly 2 from continuing to rotate, and the backrest assembly 2 is stably locked at the target angle. The entire working process is smooth and seamless, realizing convenient adjustment and reliable locking of the backrest angle.

[0053] Example 2 This embodiment provides a sofa, such as Figures 6-9 As shown, the sofa includes a seat cushion assembly and a backrest mechanism as described in Embodiment 1. The support component 1 of the backrest mechanism is connected to the seat cushion assembly, and the backrest assembly 2 serves as the backrest of the sofa.

[0054] The sofa provided in this embodiment is centered on flexible adjustment. It is composed of a seat cushion assembly and the backrest mechanism described in Embodiment 1, which are structurally connected to form a stable and ergonomic overall structure. The support assembly 1 provides a stable load-bearing foundation for the backrest mechanism itself and also works in conjunction with the seat cushion assembly to smoothly transfer the leaning force borne by the backrest assembly 2 to the entire bottom of the sofa, ensuring the overall structural stability and lifespan of the sofa and preventing backrest misalignment or loosening during long-term use, which would affect the user experience. The backrest assembly 2 directly serves as the backrest of the sofa. The shape and dimensions of its main body 21 are precisely matched to the seat cushion assembly, conforming to ergonomic design and providing comfortable support for the user. Furthermore, the angle adjustment and stabilization locking functions of the backrest assembly 2 are fully adaptable to the sofa's usage scenarios, allowing users to adjust the backrest according to their needs. Figure 9 As shown, by lifting the end of the backrest body 21 to unlock the backrest mechanism, the backrest body 21 can be pushed to adjust the preset angles such as 30 degrees, 45 degrees, and 60 degrees. After adjusting to the required angle, the backrest mechanism can be stably locked through the locking part 31 and the positioning plate 12. This effectively solves the drawbacks of the fixed backrest angle of traditional sofas and the inability to adjust it flexibly, taking into account both the comfort and flexibility of the sofa and improving the overall user experience.

[0055] In addition, the backrest mechanism in Embodiment 1 can also be applied to soft beds.

[0056] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A backrest mechanism, characterized in that The backrest mechanism comprises a support assembly, a backrest assembly and a locking transmission assembly, the backrest assembly is rotatably connected with the support assembly, and the locking transmission assembly is arranged between the support assembly and the backrest assembly; the locking transmission assembly comprises a locking portion, a transmission portion and a reset member, one end of the transmission portion is fixedly connected with one side of the backrest assembly, the other end is in transmission connection with the locking portion, the locking portion cooperates with the support assembly to limit the rotation of the backrest assembly relative to the support assembly, and the reset member cooperates with the locking portion to drive the locking portion to be engaged with the support assembly.

2. The backrest mechanism of claim 1, wherein The support assembly comprises a base and a positioning disc, the positioning disc is located in the base, a plurality of positioning clamping grooves are formed in the positioning disc in the circumferential direction, the included angle between adjacent positioning clamping grooves corresponds to the preset rotation angle of the backrest assembly, different positioning clamping grooves correspond to different rotation positions of the backrest assembly, and the locking portion is in clamping cooperation with the positioning clamping groove to limit the rotation of the backrest assembly.

3. The backrest mechanism of claim 2, wherein The locking portion comprises a locking body, the bottom of the locking body is provided with a plug-in portion, and the locking body can drive the plug-in portion to rotate to cooperate with different positioning clamping grooves.

4. The backrest mechanism of claim 3, wherein The plug-in portion has two, the two plug-in portions are symmetrically arranged, and the two plug-in portions correspond to two positioning clamping grooves on the positioning disc in a one-to-one manner.

5. The backrest mechanism of claim 3, wherein The lower end of the plug-in portion is provided with an arc-shaped guide surface, the curvature of the arc-shaped guide surface is matched with the curvature of the slot edge of the positioning clamping groove, and the arc-shaped guide surface is used for guiding the plug-in portion to slide into the positioning clamping groove of the corresponding angle.

6. The backrest mechanism of claim 2, wherein The number of the positioning clamping grooves is 4-12, and the positioning clamping grooves are uniformly distributed along the circumferential direction of the positioning disc.

7. The backrest mechanism of claim 3, wherein The reset member is a spring, the spring is sleeved outside the top of the locking body, one end of the spring abuts against the upper surface of the locking body, and the other end abuts against the transmission portion below; the spring is in a pre-compressed state and can drive the plug-in portion to be clamped into the positioning clamping groove of the corresponding angle by relying on the self-restoring force.

8. The backrest mechanism of claim 7, wherein The transmission portion comprises a traction rope, a guide pulley and an auxiliary guide wheel, the guide pulley is fixedly arranged at the lower end of the backrest assembly, the auxiliary guide wheel is arranged between the guide pulley and the locking portion, one end of the traction rope is fixedly connected with the one side of the backrest assembly, and the other end is connected with the locking body after being sequentially wound around the guide pulley and the auxiliary guide wheel; wherein the other end of the spring abuts below the auxiliary guide wheel.

9. The backrest mechanism of claim 2, wherein The backrest assembly comprises a backrest body and a rotary connecting seat, the rotary connecting seat is fixedly arranged at the lower end surface of the backrest body, the lower part of the rotary connecting seat is rotatably matched with the upper part of the positioning disc, the lower part of the positioning disc extends below the rotary connecting seat, and the locking transmission assembly is arranged in the interior of the rotary connecting seat.

10. The backrest mechanism of claim 9, wherein The lower part of the rotary connecting seat is provided with a matching groove, and the positioning disc is embedded in the matching groove to realize the rotatable matching of the rotary connecting seat and the positioning disc.

11. The backrest mechanism of claim 10, wherein The one side of the backrest assembly is the end part of the backrest body, the end part is fixedly connected with one end of the traction rope, and the end part forms a lever structure when being lifted to reduce the acting force of pulling the locking portion.

12. A sofa, characterized in that The sofa comprises a seat cushion assembly and the backrest mechanism according to any one of claims 1-11, the support assembly of the backrest mechanism is connected with the seat cushion assembly, and the backrest assembly serves as the backrest of the sofa.

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