Comfortable sofa iron frame

Abstract

The application discloses a comfortable sofa iron frame, which comprises an iron frame body, a first connecting rod, a first driving element, a backrest element, a second connecting rod, a third connecting rod and a fourth connecting rod; the first connecting rod is pivotally connected with the iron frame body, the first driving element is used for driving the first connecting rod to rotate, the front end and the rear end of the backrest element are respectively pivotally connected with the upper ends of the second connecting rod and the third connecting rod, the two ends of the fourth connecting rod are respectively pivotally connected with the iron frame body and the lower end of the third connecting rod, and the front end and the rear end of the first connecting rod are respectively pivotally connected with the lower end of the second connecting rod and the middle part of the third connecting rod. The comfortable sofa iron frame is characterized in that the multi-connecting rod linkage structure is optimized, so that the backrest element is synchronously moved forward when being inclined backward or is synchronously moved backward when being inclined forward, the movement track of the traditional sofa backrest is changed from mainly overturning to other tracks, the movement gap between the backrest and the seat cushion is effectively eliminated, the relative displacement between the backrest and the human back during the backrest adjustment is avoided, the clothes rubbing and scratching problem is avoided, and the use comfort and the user experience of the sofa are improved.

Description

Technical Field

[0001] This invention belongs to the field of sofa technology, specifically relating to a comfortable sofa frame. Background Technology

[0002] Many existing sofas use a metal frame adjustment mechanism to adjust the backrest angle. When the sofa backrest rotates relative to the seat cushion to adjust the reclining position, gaps can easily form between the two due to the difference in their movement trajectories. At the same time, during the reclining motion, the backrest and the user's back can easily shift relative to each other, causing friction and scratches between the user's clothing and the sofa backrest, reducing comfort and affecting the user experience. Summary of the Invention

[0003] The purpose of this invention is to provide a comfortable sofa frame that does not have at least one of the disadvantages mentioned above.

[0004] To achieve the above objectives, the present invention discloses a comfortable sofa frame, comprising: Iron frame main body; The first connecting rod is pivotally connected to the main body of the iron frame; The first driving member is used to drive the first connecting rod to rotate about its pivot point with the main body of the iron frame; The backrest, the second link, and the third link are provided. The front end of the backrest is pivotally connected to the upper end of the second link, and the rear end of the backrest is pivotally connected to the upper end of the third link. The fourth link is pivotally connected at both ends to the lower ends of the iron frame body and the third link, respectively; The front end of the first link is pivotally connected to the lower end of the second link, and the rear end of the first link is pivotally connected to the middle of the third link, so that when the first link rotates, the backrest tilts backward and moves forward at the same time, or the backrest tilts forward and moves backward at the same time. The first link, the second link, the third link, and the fourth link are configured as a multi-link linkage mechanism, so that the rate of change of the tilt angle and the rate of change of the front and rear displacement of the backrest component change with the change of the tilt angle.

[0005] As an optional implementation, the displacement coupling relationship is manifested as follows: when the backrest is tilted backward by 0° to 20° relative to the vertical direction, the rate of change of the tilt angle and the rate of change of the front-to-back displacement of the backrest are less than the rate of change of the tilt angle and the rate of change of the front-to-back displacement of the backrest when it is tilted backward by 20° to 30° relative to the vertical direction.

[0006] As an optional implementation, it also includes a first drive tube, which is fixedly connected to the first connecting rod; one end of the first drive member is rotatably connected to the first drive tube, and the other end is rotatably connected to the iron frame body.

[0007] As an optional implementation, the main body of the iron frame includes a base frame, an extension member, and a seat frame. One end of the extension member is fixedly connected to the rear end of the seat frame, and the other end is pivotally connected to the base frame. The first connecting rod is pivotally connected to the middle of the extension member. During the process of the main body of the iron frame changing from a sitting posture to a TV posture, the extension member rotates around its pivot point with the base frame.

[0008] As an optional implementation, the main body of the iron frame further includes a second driving member, a driving rod, and a rotating rod. The driving rod is provided with a first pivot point and a second pivot point, and there is a gap between the first pivot point and the second pivot point. The driving rod is pivotally connected to the bottom frame through the first pivot point, and the driving rod is pivotally connected to the rotating rod through the second pivot point. The end of the rotating rod opposite to the driving rod is pivotally connected to the front end of the seat frame. The seat frame, the extension member, the bottom frame, the driving rod, and the rotating rod constitute a first four-bar linkage mechanism. The second driving member is fixedly connected to one end of the driving rod to drive the driving rod to rotate around the first pivot point, thereby realizing the relative rotation of the extension member and the seat frame while adjusting the tilt angle of the seat frame.

[0009] As an optional implementation, the main body of the iron frame further includes a second drive tube, which is fixedly connected to the drive rod. The second drive component is a telescopic component, one end of which is rotatably connected to the second drive tube and the other end of which is rotatably connected to the bottom frame. When the telescopic component retracts, the drive rod will rotate around the first pivot point, thereby realizing the transformation of the main body of the iron frame from a sitting posture to a TV posture.

[0010] As an optional implementation, the main body of the iron frame also includes a fixed base, on one side of which two main rods are movably hinged, and a support plate is pivotally connected to one end of the two main rods away from the fixed base. The support plate is fixedly connected to the front end of the bottom frame. The fixed base, the two main rods and the support plate constitute a second four-bar linkage mechanism. The bottom frame is provided with a limiting rod that can restrict the rotation of the drive rod. When the second drive member extends, the drive rod abuts against the limiting rod and restricts the rotation of the drive rod, the second four-bar linkage is activated to realize the lifting and tilting of the bottom frame.

[0011] As an optional implementation, the main body of the iron frame also includes a leg assembly, a first leg drive rod, a second leg drive rod, and a third leg drive rod; One end of the first leg drive rod is pivotally connected to one end of the drive rod away from the second drive member, and the other end is pivotally connected to the second leg drive rod; The end of the second leg drive rod opposite to the first leg drive rod is pivotally connected to the seat frame; The middle part of the first leg drive rod is pivotally connected to the third leg drive rod, and the end of the third leg drive rod opposite to the second leg drive rod is pivotally connected to the leg assembly; When the drive rod rotates, the third leg drive rod will move forward or backward to unfold or retract the leg assembly.

[0012] As an optional implementation, the leg assembly includes a first leg rod, a second leg rod, and a leg body, wherein one end of the first leg rod and the second leg rod are pivotally connected to the front end of the seat frame, and the other end of each leg rod is connected to the leg body; The first leg and the second leg are pivotally connected to opposite sides of the seat frame, and the leg located outside the seat frame is pivotally connected to the third leg drive.

[0013] As an optional implementation, the pivot point between the first link and the second link is taken as the third pivot point, the pivot point between the first link and the main body of the iron frame is taken as the fourth pivot point, and the pivot point between the first link and the third link is taken as the fifth pivot point. Then, the distance from the third pivot point to the fourth pivot point is less than the distance from the fourth pivot point to the fifth pivot point.

[0014] As an optional implementation, the connecting line between the third pivot point and the fourth pivot point, and the connecting line between the fourth pivot point and the fifth pivot point, form an angle.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention adopts a multi-link linkage structure, enabling the backrest to achieve a compound movement of "tilt angle adjustment + forward and backward translation". Specifically, the backrest moves forward synchronously when tilting backward or backward synchronously when tilting forward, thereby changing the traditional sofa backrest's movement trajectory which is mainly based on flipping, effectively eliminating the movement gap between the backrest and the seat cushion, and also avoiding relative displacement between the backrest and the human back during the backrest adjustment process, avoiding the problem of clothing friction and scratching, thereby improving the sofa's comfort and user experience. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments 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 these drawings without creative effort.

[0017] Figure 1 This is a comparative diagram of the present invention in a TV position and a lying position; Figure 2 This is a schematic diagram of the overall structure of the invention when it is in a lying position; Figure 3 for Figure 2 A magnified view of a portion of the image; Figure 4 for Figure 2 A schematic diagram showing the structure after some parts have been hidden. Figure 5 This is a schematic diagram of the present invention in a standing position; Figure 6 for Figure 5 A magnified view of a portion of the component after it has been partially hidden. Figure 7 This is a schematic diagram of the overall structure of the present invention when it is in a seated position; Figure 8 This is a schematic diagram of the present invention when the backrest is tilted backward in a seated position. Figure 9 This is a schematic diagram of the overall structure of the present invention in the TV posture.

[0018] Explanation of key figure labels: 1. Backrest component; 101. First link; 102. Second link; 103. Third link; 104. Fourth link; 105. Extension component; 2. Leg assembly; 201. First leg bar; 202. Second leg bar; 3. Seat frame; 4. Base frame; 401. Drive rod; 402. Rotating rod; 403. First leg drive rod; 404. Second leg drive rod; 405. Third leg drive rod; 5. First driving component; 501. First driving transistor; 6. Second driving component; 601. Second driving tube; 7. Support plate; 8. Fixing seat; 9. Main rod; 10. Limiting rod. Detailed Implementation

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

[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 the invention and its embodiments, and are not intended to limit the indicated device, element, or component to include a specific orientation, or to be constructed and operated in a specific orientation.

[0021] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in certain situations to indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this invention based on 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 invention 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 the present invention will be further described below with reference to the embodiments and accompanying drawings.

[0025] Please see Figures 1-9As shown, this application embodiment provides a comfortable sofa frame, including a frame body, capable of stably supporting various linkage rods, drive components, and sofa load-bearing parts. It is mainly used to cooperate with the linkage structure to achieve automatic unfolding and retraction of the sofa leg assembly 2, while simultaneously completing the angle adjustment and multi-posture switching of the seat frame 3, ensuring the overall structural stability of the sofa in different usage states such as sitting, reclining, and TV-like positions. In this embodiment, the sofa frame includes a first drive component 5, a backrest component 1, a first connecting rod 101, a second connecting rod 102, a third connecting rod 103, and a fourth connecting rod 104. The first connecting rod 101 is pivotally connected to the frame body and can rotate around... The preset pivot point performs controllable rotational movements in the forward and reverse directions; the first driving component 5 serves as the output component for backrest posture adjustment, driving the first connecting rod 101 to rotate around its pivot point with the main body of the iron frame; the backrest component 1 is a load-bearing component that directly fits and supports the back of the human body, and can be fixed to a backrest cushion to support the human body; the front end of the backrest component 1 is pivotally connected to the upper end of the second connecting rod 102, and the rear end of the backrest component 1 is pivotally connected to the upper end of the third connecting rod 103; the fourth connecting rod 104 is a limiting and guiding transmission rod, with its two ends pivotally connected to the main body of the iron frame and the lower end of the third connecting rod 103 respectively, which can limit and constrain the movement trajectory of the third connecting rod 103; In this design, the front end of the first link 101 is pivotally connected to the lower end of the second link 102, and the rear end of the first link 101 is pivotally connected to the middle of the third link 103. Through this multi-link staggered and cross-pivoted layout, the traditional sofa backrest's movement mode, primarily based on flipping, is changed. This allows the backrest component 1 to tilt backward and move forward simultaneously when the first link 101 rotates, or to tilt forward and return to its original position while moving backward simultaneously. This creates a composite movement trajectory where tilt adjustment and horizontal displacement are synchronously linked. (See attached diagram.) Figure 1 As shown, attached Figure 1 The upper middle position is for the TV posture, and the lower position is for the reclining posture. Therefore, this embodiment eliminates the gaps caused by misalignment of the movement trajectory between the backrest and the seat cushion by linking the tilt adjustment of the backrest with the horizontal displacement, thus avoiding problems such as pinching clothes or skin. It also avoids the relative sliding displacement between the backrest and the human back during the reclining posture adjustment, and avoids the adverse phenomena of clothing friction, pulling, and scratching during the adjustment process. This improves the comfort of using the sofa for leaning and reclining, and optimizes the user's daily use experience.

[0026] In this embodiment, after extensive ergonomic testing and structural transmission simulation optimization, and to meet the needs of daily sofa use and TV relaxation scenarios, the maximum backward tilt angle of the backrest component 1 is controlled within 30°. This satisfies the user's need for slight backward tilting to relax the back and relieve fatigue from prolonged sitting, and is suitable for regular use scenarios such as home leisure, movie watching, and rest. It avoids situations where the center of gravity shifts backward, the sitting posture becomes loose, and the support is unstable due to excessive backrest tilt angle. At the same time, it matches the transmission stroke range of the multi-link composite motion mechanism of this application, ensuring that the backrest component 1 adapts to the forward and backward translation and tilting movements and the transmission trajectory is controllable throughout the tilt angle adjustment process. This avoids problems such as link pulling, movement deviation, jamming, and abnormal noise caused by excessive angle exceeding the design stroke of the mechanism.

[0027] Furthermore, by matching and cooperating with the first link 101, the second link 102, the third link 103, and the fourth link 104, a multi-link linkage mechanism with variable speed adjustment function is constructed. This is achieved by optimizing the length ratio of each link, the layout of the hinge points, and the relationship of the transmission torque. During the motion adjustment process, the backward tilting process of the backrest 1 relative to the vertical direction is divided into two highly differentiated transmission stages: in the initial fine-tuning stage where the backrest 1 tilts backward from 0° to 20° relative to the vertical direction, the tilt angle of the backrest 1 is limited. The rate of change and the rate of change of forward and backward displacement are in a low-speed and stable state. This stage belongs to the adaptation range of sitting posture fine adjustment. The range of motion is small and the adjustment precision is high. It can specifically meet the back support needs of the human body in the upright sitting state. Through small and stable back reclining and slight forward movement, it fills the gap between the human body's waist and the sofa back, eliminates the problem of the waist being unsupported and insufficient support, and avoids the phenomenon of back pain and fatigue caused by prolonged sitting. At the same time, the low-speed adjustment process is without impact and without abrupt displacement, ensuring the stability and comfort of sitting posture fine adjustment. As the backrest posture is continuously adjusted and the tilt angle increases to a deep reclining and relaxation stage of 20°–30°, relying on the torque-gradual transmission characteristics of the multi-link mechanism, the rate of change of the tilt angle of the backrest component 1 and the rate of change of the front-to-back horizontal displacement both accelerate. The reclining amplitude and forward movement distance of the backrest increase proportionally with the increase of the tilt angle, thus adapting to the natural curvature of the spine and the overall backward and downward movement of the back as the body gradually lies down. This segmented speed-changing motion design allows the movement trajectory of the backrest component 1 to conform to the dynamic transformation of the human body from an upright sitting posture to a relaxed lying posture. It adaptively matches the force trajectory and displacement trajectory of the human back throughout the process, with no movement deviation, no gaps, and no relative slippage. Ultimately, it achieves a natural fit and high degree of conformity between the movement trajectory of the backrest and the movement trajectory of the human back when lying down, enhancing the immersive comfort experience of leaning back, watching movies, and resting on the sofa.

[0028] In one embodiment, the main body of the iron frame is also equipped with a first drive tube 501. The first drive tube 501 is fixedly installed on the outer wall of the first connecting rod 101 in an integrated manner, forming an integral linkage structure with the first connecting rod 101. It can rotate synchronously with the first connecting rod 101 without relative displacement or transmission gap, ensuring the integrity and synchronicity of power transmission. The first drive component 5 is preferably configured as a telescopic component structure, such as an electric push rod, to meet the needs of automated posture adjustment of the sofa. One end of the first drive component 5 is rotatably hinged to the first drive tube 501, and the other end is rotatably connected to a fixed position of the main body of the iron frame. Through the hinged installation method at both ends, it can effectively adapt to the rotational swing trajectory of the first drive tube 501 and the first connecting rod 101, avoiding structural interference or jamming during the drive adjustment process. Meanwhile, the outer wall of the first drive tube 501 is integrally formed with a protruding fixing lug structure. The end of the first drive component 5 is hinged to the fixing lug. Compared with the traditional structure that directly hinges the first drive component 5 to the pivot of the first connecting rod 101, this can effectively increase the distance between the hinge point of the telescopic component end and the pivot point of the first connecting rod 101, and extend the overall transmission arm. By increasing the arm through structural design, the drive load and output torque requirements of the first drive component 5 can be effectively reduced, and the workload of the drive component can be reduced.

[0029] In one embodiment, the main body of the iron frame includes a base frame 4, an extension 105, and a seat frame 3. The base frame 4 is a fixed mounting base, constructed entirely of high-strength steel welded together, possessing strong load-bearing capacity, structural stability, and resistance to deformation. It stably supports the entire structure, ensuring the stability of the sofa during placement and adjustment. The extension 105 serves as the connection and transmission transition between the seat frame 3 and the base frame 4. One end of the extension 105 is securely connected to the rear end of the seat frame 3 using welding, bolting, or other fixing methods, ensuring no relative displacement between the extension 105 and the seat frame 3, allowing it to synchronously adjust its posture with the seat frame 3. The other end of the extension 105 is pivotally connected to the base frame 4, enabling the extension 105 to rotate and swing using the fixed fulcrum of the base frame 4. The first link 101 is pivotally mounted at the middle of the extension 105. During the entire process of the main body of the iron frame changing from a regular sitting posture to a relaxed reclining TV posture, the extension 105 can adaptively rotate around its pivot point with the bottom frame 4, driven by power. This causes the seat frame 3 to adjust its tilt angle as a whole, and simultaneously coordinates with the composite displacement tilting action of the backrest 1 to achieve coordinated switching of the overall posture of the sofa. This ensures a smooth and continuous transition between sitting and TV postures, and improves the adaptability and fit of the sofa for multi-mode use.

[0030] In one embodiment, the main body of the iron frame is also equipped with a second driving component 6, a driving rod 401, and a rotating rod 402. These three components work together to form a driving and transmission assembly for adjusting the posture of the seat frame 3, enabling adaptive fine-tuning of the sofa seat frame 3's angle and posture switching. The driving rod 401 has a first pivot point and a second pivot point pre-set on its body, with a reasonable distance reserved between them. The driving rod 401 forms a hinged connection with the bottom frame 4 through the first pivot point, allowing it to rotate and swing around the bottom frame 4 as a fixed fulcrum. The driving rod 401 is hinged to one end of the rotating rod 402 through the second pivot point, transmitting power. The end of the rotating rod 402 facing away from the driving rod 401 is hinged to the front end of the seat frame 3, allowing for flexible adjustment of the seat frame 3's angle by swinging and pushing / pulling the front end of the seat frame 3. Thus, the seat frame 3, the extension 105 (which is essentially an integral part, and the two are fixedly connected), the bottom frame 4, the drive rod 401, and the rotating rod 402 constitute a four-bar linkage mechanism. The second drive member 6, as the power source for adjusting the posture of the seat frame 3, is fixed to the end of the drive rod 401 by a fastening connection, and can push the drive rod 401 to rotate around the first pivot point in a forward or reverse direction. Relying on the linkage characteristics of the first four-bar linkage mechanism, the drive rod 401 can simultaneously drive the extension 105 and the seat frame 3 to rotate relative to each other during rotation, thereby adjusting the upward or downward tilt angle of the seat frame 3. This ensures that the seat cushion and backrest conform to the human body curve during the switching between sitting and TV postures, greatly improving the overall comfort and the smoothness of posture switching.

[0031] In one embodiment, the main body of the iron frame is also provided with a second drive pipe 601. The second drive pipe 601 is fixedly connected to the drive rod 401 by an integrated welding or bolt locking method, and the two do not rotate relative to each other. The second drive component 6 is specifically an automatically retractable drive component such as an electric telescopic component. The upper end of the telescopic component is hinged to the fixed lug on the second drive pipe 601 to form a rotating connection structure, and the lower end is rotatably connected to the fixed installation point of the bottom frame 4. It adopts a floating installation form with hinges at both ends, which can adapt to the arc swing trajectory of the drive rod 401 and avoid structural pulling, motion interference, jamming and sticking during the telescopic component's extension and retraction. In the actual posture adjustment process of this embodiment, when the telescopic component retracts, it can pull the second drive tube 601 and the drive rod 401, causing the drive rod 401 to rotate and swing around the first pivot point. Relying on the transmission characteristics of the four-bar linkage mechanism, it synchronously drives the seat frame 3 and the extension component 105 to complete the angle fine adjustment and posture conversion, and smoothly realizes the switching of the main body of the iron frame from the sitting posture to the TV posture. When the telescopic component extends, it realizes the switching of the main body of the iron frame from the TV posture to the sitting posture.

[0032] In one embodiment, the main body of the iron frame is also equipped with a leg assembly 2 for providing leg support, and a first leg drive rod 403, a second leg drive rod 404, and a third leg drive rod 405 for power transmission. Multiple sets of leg drive rods cooperate to form a multi-stage linkage transmission structure, enabling adjustment of leg support in the sofa's posture. The first leg drive rod 403, as the primary transmission rod for leg power input, serves as a power receiver and transfer mechanism. One end of the first leg drive rod 403 is pivotally mounted to the end of the drive rod 401 away from the second drive member 6, receiving the mechanical power generated by the rotation and swing of the drive rod 401. The other end of the first leg drive rod 403 is hinged to the end of the second leg drive rod 404, achieving step-by-step power transmission. The second leg drive rod 404 is hinged to a preset mounting point on the seat frame 3 at one end away from the first leg drive rod 403. The seat frame 3 serves as a fixed support fulcrum, ensuring the stability of its swing transmission and effectively constraining the installation position and motion reference of the overall leg transmission mechanism. At the same time, the middle part of the first leg drive rod 403 is pivotally connected to the end of the third leg drive rod 405, and the end of the third leg drive rod 405 away from the second leg drive rod 404 is hinged to the leg assembly 2. This is used to transmit the mechanical power generated by the rotation and swing of the drive rod 401 to the leg assembly 2, driving the extension and retraction of the leg assembly 2. Therefore, in actual operation, when the drive rod 401 is driven by the second drive component 6 to rotate and swing in the forward or reverse direction, it can sequentially drive the first leg drive rod 403 and the second leg drive rod 404 to swing in linkage, thereby driving the third leg drive rod 405 to push forward or pull back, and finally drive the leg component 2 to automatically unfold for support or close and retract to reset. The entire multi-stage linkage transmission structure has strong linkage and rapid transmission response, and can be synchronized with the posture adjustment of the sofa back and seat frame 3. When switching to the TV reclining position, the leg component 2 is automatically unfolded to support the legs, and when switching to the sitting position, the leg component 2 is automatically retracted.

[0033] In one embodiment, the leg assembly 2, as the execution structure for supporting the sofa legs, is mainly composed of three parts: the first leg rod 201, the second leg rod 202, and the leg body. The entire leg assembly 2 is similar in structure to existing structures, except that the first leg rod 201 and the second leg rod 202 are pivotally mounted on opposite sides of the seat frame 3. The leg rod located on the outer side of the seat frame 3 is pivotally connected to the end of the third leg drive rod 405, serving as the power input point for the leg assembly 2. It receives the forward and backward pushing and pulling power of the third leg drive rod 405, driving the leg body to complete the horizontal unfolding and retracting actions. Thus, the transmission structure used for leg drive is arranged in the outer area of ​​the seat frame 3, effectively avoiding the problem of contact, collision, and motion interference between the leg drive rod and the inner frame or drive component of the seat frame 3 during the retraction process. At the same time, the drive structure arranged on the outer side can effectively avoid the obstruction and restraint of the sofa's internal filling cotton and lining structure, improving the smoothness of the unfolding and retracting movement of the leg assembly 2. It also facilitates later equipment inspection, maintenance, and upkeep, does not occupy the internal installation space of the sofa, and further improves the stability of the entire sofa frame operation.

[0034] In one embodiment, to limit the rod length ratio and pivot position relationship of the multi-link transmission structure and standardize the motion trajectory of the backrest compound motion, the key hinge points are defined as follows: the pivot point where the first link 101 and the second link 102 are hinged together is the third pivot point; the pivot point where the first link 101 and the extension 105 are hinged together is the fourth pivot point; and the pivot point where the first link 101 and the third link 103 are hinged together is the fifth pivot point. In the structural dimension ratio design, the straight distance from the third pivot point to the fourth pivot point is limited to be less than the straight distance from the fourth pivot point to the fifth pivot point. This constructs a non-equidistant lever transmission structure, making the fourth pivot point the rotation fulcrum of the first link 101, forming a transmission layout with a short lever arm at the front and a long lever arm at the rear. This structural design can change the torque transmission ratio of the first link 101, effectively amplify the swing stroke and displacement amplitude of the rear third link 103, match the composite motion requirements of the backrest 1 for backward tilting + forward movement and forward tilting reset + backward movement, ensure that the backrest translation amount and tilt angle are adapted to the ergonomic curve, and avoid relative slippage between the human body and the backrest. Furthermore, the connecting lines between the third and fourth pivot points, and between the fourth and fifth pivot points, form a preset angle arrangement, resulting in a triangular staggered arrangement of the three sets of key pivot points on the first link 101, ensuring that the three points are not collinear or parallel. This avoids transmission dead points and power lock-up issues in the linkage mechanism at extreme attitude adjustment positions, guaranteeing smooth and unobstructed power transmission throughout the entire range of forward rotation and reverse reset of the first link 101. Simultaneously, it ensures that the first link 101 maintains effective torque output at any swing angle, preventing mechanical stalling, vibration, abnormal noise, and other adverse phenomena, thus guaranteeing a continuous and smooth composite motion trajectory for the backrest.

[0035] Please see Figure 5 and Figure 6 As shown, in another preferred embodiment of the present invention, the overall comfortable sofa frame structure can be adapted and extended to special equipment scenarios such as health and wellness sofas, sofas specifically for the elderly, and assistive sofas for people with mobility impairments. While retaining the original comfort functions of the backrest composite anti-pinch gap, anti-friction and scratching, and multi-posture comfort adjustment, it integrates an adaptive safety assistive standing function, achieving a dual improvement in sofa comfort and safety assistance. This broadens the product's applicable scenarios and target audience, especially addressing the difficulties faced by the elderly, those with back and leg problems, and post-operative rehabilitation patients who have difficulty getting up or have insufficient standing strength. This embodiment upgrades the structure of the aforementioned conventional embodiments with targeted functions. The core structural improvement, differentiating it from all the aforementioned conventional embodiments, is the addition of a dedicated four-bar linkage lifting mechanism at the bottom of the main frame body. This mechanism includes a fixed base 8, two main rods 9, and a support plate 7, forming a stable and reliable heavy-duty lifting transmission structure.

[0036] Among them, the fixed seat 8 is a fixed installation base, which is integrally formed with high-strength thick-walled steel and is firmly fixed to the installation base surface at the bottom of the sofa without displacement or shaking. It serves as the fixed support reference for the entire auxiliary standing mechanism. Two main rods 9 are hinged to one end face of the fixed seat 8, and support plates 7 are hinged to the top of the two main rods 9. The support plates 7 are integral load-bearing connecting plates with strong connection rigidity. The support plates 7 and the bottom front end of the bottom frame 4 are fixed together by welding, bolt locking and other fastening methods to realize the rigid linkage between the lifting mechanism and the main iron frame of the sofa, ensuring that the power transmission is seamless, without lag and without idle stroke. Thus, the fixed base 8, the two main rods 9, and the support plate 7 cooperate to form the second four-bar linkage mechanism, enabling the controllable lifting and forward tilting of the sofa base frame 4, providing a reliable structural support foundation for the auxiliary standing function. Simultaneously, a rigid limiting rod 10 is fixed to the side wall of the base frame 4. The limiting rod 10 is a mechanical limiting component that can cooperate with the drive rod 401 to form a working condition switching structure, distinguishing between the sofa's regular posture adjustment working condition and the auxiliary standing working condition. This allows the two functions to operate independently, switch orderly, and work in layers, effectively improving the integration of the mechanism's functions. To clearly define the transmission logic and working condition, when the second drive component 6 retracts, the drive rod 401 is defined to rotate forward. At this time, the stop end face of the limiting rod 10 separates from the drive rod 401 body, and the limiting rod 10 does not exert any constraint or stopping effect. The drive rod 401 can swing freely forward, and the entire mechanism normally performs the sitting posture switching to the TV posture without affecting the original function of the sofa. When the user needs to stand up and activate the assisted standing function, the second drive component 6 gradually extends from the retracted state, driving the drive rod 401 to rotate in the opposite direction and reset. After the drive rod 401 returns to the initial sitting position, the outer rod of the drive rod 401 will fit against the stop end of the limit rod 10. The rigid mechanical limit of the limit rod 10 completely locks the rotational freedom of the drive rod 401, preventing the drive rod 401 from continuing to rotate in the opposite direction and forming a stable mechanical locking state. At this time, the second driving component 6 continues to extend and push steadily. Relying on the abutting and limiting relationship between the limiting rod 10 and the driving rod 401, the torsional power originally used for the rotation of the driving rod 401 is converted into a linear driving force that lifts the entire base frame 4. This, in turn, synchronously pulls and triggers the second four-bar linkage mechanism to swing in tandem. Based on the lifting principle of the four-bar linkage, the entire base frame 4 is smoothly lifted and tilted forward, causing the sofa seat frame 3 to rise and the center of gravity to shift forward. This effectively supports the user's buttocks and torso, thereby reducing the force required for the user to stand up. This easily assists elderly users and users with mobility difficulties to stand up without external assistance, effectively avoiding the safety hazards of slipping, straining the waist and legs, and falling due to instability. Therefore, this embodiment ensures the sofa's comfort adjustment performance while also providing safety assistance functions, significantly improving the structural practicality, adaptability, and added value of the product.

[0037] The technical means disclosed in this invention 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 principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

Claims

1. A comfortable sofa frame, characterized in that, include: Iron frame main body; The first connecting rod (101) is pivotally connected to the main body of the iron frame; The first driving member (5) is used to drive the first connecting rod (101) to rotate about its pivot point with the main body of the iron frame; Backrest (1), second link (102), third link (103), the front end of the backrest (1) is pivotally connected to the upper end of the second link (102), and the rear end of the backrest (1) is pivotally connected to the upper end of the third link (103). The fourth link (104) is pivotally connected at both ends to the lower ends of the main body of the iron frame and the third link (103), respectively; The front end of the first link (101) is pivotally connected to the lower end of the second link (102), and the rear end of the first link (101) is pivotally connected to the middle part of the third link (103), so that when the first link (101) rotates, the backrest (1) tilts backward and moves forward at the same time, or the backrest (1) tilts forward and moves backward at the same time. The first link (101), the second link (102), the third link (103) and the fourth link (104) are configured as a multi-link linkage mechanism, so that the rate of change of the tilt angle and the rate of change of the front and rear displacement of the backrest (1) change with the change of its tilt angle.

2. The comfortable sofa frame according to claim 1, characterized in that, During the stage when the backrest (1) is tilted backward by 0° to 20° relative to the vertical direction, the rate of change of the tilt angle and the rate of change of the front-to-back displacement of the backrest (1) are less than the rate of change of the tilt angle and the rate of change of the front-to-back displacement of the backrest (1) during the stage when it is tilted backward by 20° to 30° relative to the vertical direction.

3. The comfortable sofa frame according to claim 1, characterized in that, It also includes a first drive tube (501), which is fixedly connected to the first connecting rod (101); one end of the first drive member (5) is rotatably connected to the first drive tube (501), and the other end is rotatably connected to the iron frame body.

4. The comfortable sofa frame according to claim 1, characterized in that, The main body of the iron frame includes a base frame (4), an extension (105) and a seat frame (3). One end of the extension (105) is fixedly connected to the rear end of the seat frame (3), and the other end is pivotally connected to the base frame (4). The first connecting rod (101) is pivotally connected to the middle of the extension (105). During the process of the main body of the iron frame changing from a sitting posture to a TV posture, the extension (105) rotates around its pivot point with the base frame (4).

5. The comfortable sofa frame according to claim 4, characterized in that, The main body of the iron frame also includes a second driving member (6), a driving rod (401) and a rotating rod (402). The driving rod (401) is provided with a first pivot point and a second pivot point. There is a gap between the first pivot point and the second pivot point. The driving rod (401) is pivotally connected to the bottom frame (4) through the first pivot point. The driving rod (401) is pivotally connected to the rotating rod (402) through the second pivot point. The end of the rotating rod (402) away from the driving rod (401) is pivotally connected to the front end of the seat frame (3). The seat frame (3), the extension member (105), the bottom frame (4), the driving rod (401), and the rotating rod (402) constitute a first four-bar linkage mechanism. The second driving member (6) is fixedly connected to one end of the driving rod (401) to drive the driving rod (401) to rotate around the first pivot point, thereby realizing the relative rotation of the extension member (105) and the seat frame (3) while adjusting the tilt angle of the seat frame (3).

6. The comfortable sofa frame according to claim 5, characterized in that, The main body of the iron frame also includes a second drive tube (601), which is fixedly connected to the drive rod (401). The second drive member (6) is a telescopic member. One end of the second drive member (6) is rotatably connected to the second drive tube (601), and the other end is rotatably connected to the bottom frame (4). When the second drive member (6) retracts, the drive rod (401) will rotate around the first pivot point while realizing the transformation of the main body of the iron frame from a sitting posture to a TV posture.

7. The comfortable sofa frame according to claim 6, characterized in that, The main body of the iron frame also includes a fixed seat (8), on one side of the fixed seat (8) are two main rods (9), and the two main rods (9) are pivotally connected to a support plate (7) at the end away from the fixed seat (8). The support plate (7) is fixedly connected to the front end of the bottom frame (4). The fixed seat (8), the two main rods (9) and the support plate (7) constitute a second four-bar linkage mechanism. The bottom frame (4) is provided with a limiting rod (10) that can restrict the rotation of the drive rod (401). After the second drive member (6) extends, the drive rod (401) abuts against the limiting rod (10) and restricts the rotation of the drive rod (401), the second four-bar linkage mechanism is activated to realize the lifting and tilting of the bottom frame (4).

8. The comfortable sofa frame according to claim 5, characterized in that, The main body of the iron frame also includes a leg assembly (2), a first leg drive rod (403), a second leg drive rod (404), and a third leg drive rod (405); One end of the first leg drive rod (403) is pivotally connected to one end of the drive rod (401) away from the second drive member (6), and the other end is pivotally connected to the second leg drive rod (404); The end of the second leg drive rod (404) opposite to the first leg drive rod (403) is pivotally connected to the seat frame (3); The middle part of the first leg drive rod (403) is pivotally connected to the third leg drive rod (405), and the end of the third leg drive rod (405) away from the second leg drive rod (404) is pivotally connected to the leg assembly (2); When the drive rod (401) rotates, the third leg drive rod (405) will move forward or backward to unfold or retract the leg assembly (2).

9. The comfortable sofa frame according to claim 8, characterized in that, The leg assembly (2) includes a first leg rod (201), a second leg rod (202) and a leg body. One end of the first leg rod (201) and the second leg rod (202) are both pivotally connected to the front end of the seat frame (3), and the other end of each is connected to the leg body. The first leg (201) and the second leg (202) are respectively pivotally connected to opposite sides of the seat frame (3), and the leg located outside the seat frame (3) is pivotally connected to the third leg drive rod (405).

10. The comfortable sofa frame according to any one of claims 1-8, characterized in that, The pivot point between the first link (101) and the second link (102) is taken as the third pivot point, the pivot point between the first link (101) and the main body of the iron frame is taken as the fourth pivot point, and the pivot point between the first link (101) and the third link (103) is taken as the fifth pivot point. The distance from the third pivot point to the fourth pivot point is less than the distance from the fourth pivot point to the fifth pivot point.

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