Self-adjusting headrest

Abstract

This invention relates to a self-adjusting backrest seat, belonging to the field of seating technology. It addresses the problem that current backrest seats cannot adjust the backrest support according to the user's weight. The technical solution is as follows: It includes a seat base, a backrest frame, and a four-bar linkage consisting of an upper connecting rod, a lower connecting rod, a backrest connecting seat, and a backrest mounting assembly for connecting the backrest or lumbar support. A linkage mechanism is provided between the seat base and the backrest frame. This linkage mechanism includes a seat movable component, a seat-back connecting rod, and a suspension rod. The front and rear ends of the seat movable component are respectively hinged to the seat base and the seat-back connecting rod. When the seat movable component rotates around the seat base, it drives the seat-back connecting rod to act synchronously on the suspension rod and the four-bar linkage, ultimately adjusting the backrest mounting assembly forward and backward.

Description

Technical Field

[0001] This invention belongs to the field of seating technology, and specifically relates to a self-adjusting top support seat. Background Technology

[0002] A chair is a type of seating furniture with a backrest, widely used in offices, cars, and homes. The backrest provides relaxation, but due to differences in body shape and posture preferences among different people, a fixed backrest often cannot conform to the user's back. To meet individual needs, adjustment mechanisms have been added to existing backrests, ensuring that the backrest always conforms to the user's back and waist.

[0003] Chinese Patent Publication No. CN217447127U discloses an adaptive backrest kneeling chair. By setting an elastic pressing member on the base to press against the movable pivot, in the static state, the elastic pressing member presses against the movable pivot to make the chair back frame tilt forward; in the leaning state, the resulting leaning force causes the chair back frame to rotate around the fixed axis and tilt backward, thereby driving the movable pivot to move together. The elastic pressing member has elasticity to resist the leaning force, thus ensuring that the chair back always fits against the human back.

[0004] While the aforementioned patent can achieve a back-supporting effect, once the elastic support component is selected and installed, the elasticity it provides is a fixed value. For heavier individuals, the elasticity provided by the elastic support component may be insufficient to support their back; for lighter individuals, the elasticity of the elastic support component may be too great, preventing the user from sitting in a comfortable position. The elasticity of the elastic support component cannot be adjusted according to the user's body shape. Summary of the Invention

[0005] To address the problems of existing technologies, this invention provides a self-adjusting top-support seat. Based on the user's weight, the seat's movable component rotates around the seat base, causing the backrest linkage to simultaneously act on the suspension rod and a four-bar linkage mechanism, ultimately adjusting the backrest mounting assembly forward and backward. The greater the user's weight, the greater the rotation amplitude, resulting in the backrest mounting assembly extending further forward and providing greater support to the user. This self-adjusting top-support seat can adaptively provide support matching the user's weight.

[0006] The technical solution adopted in this invention is as follows:

[0007] A self-adjusting top-support seat includes a seat base, a backrest frame, and a four-bar linkage consisting of an upper link, a lower link, a backrest connecting seat, and a backrest mounting assembly for connecting the backrest or lumbar support. A linkage mechanism is provided between the seat base and the backrest frame. This linkage mechanism includes a seat movable component, a seat-back link, and a suspension rod. The front and rear ends of the seat movable component are respectively hinged to the seat base and the seat-back link. The suspension rod is located between the four-bar linkage and the backrest frame, with its lower end hinged to the four-bar linkage. The upper end of the suspension rod is rotatably connected to the upper part of the backrest frame. The backrest connecting seat is located below the suspension rod and is slidably connected to the backrest frame. The other end of the seat-back link is rotatably connected to the seat base. The upper end of the suspension rod has an extension section. The seat-back link extends upward to the upper part of the backrest frame and is hinged to the extension section of the suspension rod. When the seat movable component rotates around the seat base, it drives the seat-back link to act synchronously on the suspension rod and the four-bar linkage, ultimately adjusting the backrest mounting assembly forward and backward. This self-adjusting top-support seat has an initial state and an extended state. In the initial state, the upper end of the suspension rod is vertically separated from the backrest connecting seat, and the backrest mounting component is in a rearward position. When switching from the initial state to the extended state, the seat back linkage is subjected to force and moves, causing it to move in conjunction with the four-bar linkage and the suspension rod to drive and adjust the position of the backrest or lumbar support. In the extended state, the backrest connecting seat is close to the upper end of the suspension rod, and the backrest mounting component is in a forward position.

[0008] The four-bar linkage allows for relative rotation at its joints. When the backrest assembly on the front side rotates and moves, it maintains a horizontal and vertical extension or retraction, preventing the chair back or lumbar support from shifting and ensuring it fits snugly against the user's back. The suspension rod provides counter-support to the four-bar linkage and can also rotate to move the linkage together; the two linkages can mutually influence each other's movement.

[0009] When unloaded, the self-adjusting top-support seat is in its initial state, with the backrest assembly retracted into the backrest frame. When a user sits on the seat, the seat's movable parts rotate downwards under the pressure of the user's weight, causing the backrest linkage to move. This movement pulls the suspension rod, which in turn drives the four-bar linkage. At this point, the backrest assembly moves forward to conform to the user's back, receiving support and then stops extending. The four-bar linkage reaches equilibrium, and the self-adjusting top-support seat transitions from its initial state to its extended state. During this process, the greater the user's weight, the greater the rotation amplitude of the seat's movable parts, resulting in the backrest assembly extending further forward and providing greater support. The self-adjusting top-support mechanism can adaptively provide matching support based on the user's weight. When the user leaves the seat, the pressure on the seat moving parts disappears, the seat moving parts rotate upwards and reset, driving the backrest linkage to move, then pulling the suspension rod to rotate, the suspension rod drives the four-bar linkage to move, the backrest mounting assembly moves backwards and retracts towards the backrest frame, and the self-adjusting top support seat changes from the extended state to the initial state.

[0010] Preferably, the seat-back linkage is L-shaped, comprising a horizontal section and a vertical section, which are integrally formed. The front end of the horizontal section is hinged to the seat's movable component; the vertical section is located behind the seat back frame, and its upper end is hinged to the extension of the suspension rod. The horizontal section of the seat-back linkage is hinged to the seat's movable component, and the vertical section is hinged to the extension of the suspension rod. The L-shape design allows the suspension rod to move with a relatively small rotation amplitude of the horizontal section, making the entire linkage process more agile.

[0011] Preferably, the linkage mechanism further includes an elastic element that resets the extended state to the initial state.

[0012] Furthermore, the elastic element is a spring located under the movable part of the seat and in the slot at the rear of the seat base. When a person leaves the seat, the movable part of the seat can quickly move upward under the action of the spring's rebound force, driving the four-bar linkage to move, causing the backrest mounting assembly to quickly retract back to its initial state.

[0013] Preferably, the lower end of the boom is hinged to the four-bar linkage, meaning that the lower end of the boom is hinged to the upper or lower link.

[0014] Preferably, the two ends of the upper connecting rod are respectively hinged to the backrest mounting assembly and the chair back connecting seat, and the two ends of the lower connecting rod are also respectively hinged to the backrest mounting assembly and the chair back connecting seat to form a four-bar linkage.

[0015] Furthermore, the slidable connection of the chair back connector to the chair back frame means that a through groove is formed in the vertical direction on the chair back frame, and a slider passes through the groove. The chair back connector is connected to the chair back frame through the slider. The groove and slider are designed to make the chair back connector more stable when sliding, preventing tilting or other issues.

[0016] Preferably, the rear end of the slider is provided with a locking block, which is laterally slidably connected to the slider. The back of the chair back frame is provided with a limiting member, which has multiple longitudinally arranged slots. The head of the locking block has locking teeth that engage with the slots. When the locking block slides in one direction, the locking teeth disengage from the slots, allowing the slider to move up and down along the chair back frame. When the locking block slides in the opposite direction, the locking teeth engage with the corresponding slots, thus positioning the slider. The locking block and multiple slots allow for adjustment of the horizontal position of the backrest mounting components as needed. The locking block is controlled by a pull cable connected to a pull cable switch. When the switch is open, the locking teeth disengage from the slots, allowing the slider to slide freely. When the switch is closed, the locking block is released, pushing the locking teeth into the slots, thus fixing the chair back connector to the chair back frame, disabling the self-adjusting top support function, and fixing the chair back and seat in their current position.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. This invention provides a self-adjusting top-support seat. Based on the user's weight, the seat's movable component rotates around the seat base, causing the backrest linkage to simultaneously act on the suspension rod and a four-bar linkage mechanism, ultimately adjusting the backrest mounting assembly forward and backward. The greater the user's weight, the greater the rotation amplitude, and the further the backrest mounting assembly extends forward after linkage, providing greater support to the user. This self-adjusting top-support seat can adaptively provide support matching the user's weight.

[0019] More importantly, the seat-back linkage goes directly around to the back of the chair and extends upwards to the top of the chair back before hinged to the suspension rod, which extends the lever arm. The seat-back linkage can pry the suspension rod to rotate simply by moving it up and down, making the force transmission and drive response more rapid. At the same time, the suspension rod is connected to the four-bar linkage of the chair back in a suspension manner, similar to the principle of a suspension bridge, making the whole structure more stable. In addition, the chair back, the four-bar linkage, and the suspension rod form a stable triangular structure.

[0020] 2. The horizontal section of the seat back linkage is hinged to the moving part of the seat, and the vertical section is hinged to the extension of the suspension rod. The L-shaped design allows the suspension rod to be moved without a large rotation range of the horizontal section, making the entire linkage process more agile.

[0021] 3. The back of the chair back frame is equipped with a limiting component, which has multiple slots arranged side by side. The rear end of the slider is equipped with a corresponding locking block. By engaging the locking teeth of the locking block in the slot, the chair back connecting seat can be fixed to the chair back frame, and the self-adjusting top support function of the chair back can be turned off, so it can be used as a regular chair. The locking teeth of the locking block can be engaged in different slots to adjust the horizontal position of the backrest mounting components. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the self-adjusting top support seat of the present invention in its initial state;

[0023] Figure 2 This is a schematic diagram of the exploded structure of the self-adjusting top support seat of the present invention;

[0024] Figure 3 This is a schematic diagram of the four-bar linkage of the self-adjusting top support seat of the present invention.

[0025] Figure 4 This is a schematic diagram of the structure of the self-adjusting top support seat of the present invention in its initial state;

[0026] Figure 5 This is a schematic diagram of the overall structure of the self-adjusting top support seat of the present invention in its extended state;

[0027] Figure 6 This is a schematic diagram of the structure of the self-adjusting top support seat of the present invention in its extended state;

[0028] Figure 7 This is a schematic diagram of the disassembled structure of the sliding connection between the backrest connecting seat and the backrest frame of the self-adjusting top support seat of the present invention.

[0029] Figure 8 This is a schematic diagram of the backrest frame structure of the self-adjusting top support seat of the present invention;

[0030] Figure 9 This is a schematic diagram of the structure of the self-adjusting top support seat of the present invention after the spring is installed;

[0031] Figure 10 This is a schematic diagram showing the installation position of the self-adjusting top support seat spring of the present invention.

[0032] The markings in the diagram are as follows:

[0033] 1. Seat base; 2. Backrest frame; 3. Upper linkage; 4. Lower linkage; 5. Backrest connector; 6. Backrest mounting assembly; 7. Four-bar linkage; 8. Seat moving parts; 9. Seat-back linkage; 10. Suspension rod; 11. Extension section; 12. Seat chassis; 13. Gas spring; 14. Five-star base; 15. Slide rail; 16. Slider; 17. Mounting position; 18. Locking block; 19. Limiting element; 20. Slot; 21. Spring. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of the present invention and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of the present invention.

[0035] The specific embodiments of the present invention are as follows:

[0036] This invention provides a self-adjusting top support seat, such as Figure 1-6 As shown, the chair includes a seat base 1, a backrest frame 2, and a four-bar linkage 7 consisting of an upper connecting rod 3, a lower connecting rod 4, a backrest connecting seat 5, and a backrest mounting assembly 6 for connecting the backrest or lumbar support. A linkage mechanism is provided between the seat base 1 and the backrest frame 2. The linkage mechanism includes a seat movable component 8, a seat-back connecting rod 9, and a suspension rod 10. The front and rear ends of the seat movable component 8 are respectively hinged to the seat base 1 and the seat-back connecting rod 9. The suspension rod 10 is located between the four-bar linkage 7 and the backrest frame 2, and the lower end of the suspension rod 10 is connected to the four-bar linkage. Mechanism 7 is hinged; the upper end of the suspension rod 10 is rotatably connected to the upper part of the backrest frame 2, the backrest connecting seat 5 is located below the suspension rod 10 and is slidably connected to the backrest frame 2; the other end of the seat-back connecting rod 9 is rotatably connected to the seat base 1, the upper end of the suspension rod 10 has an extension section 11, the seat-back connecting rod 9 extends upward to the upper part of the backrest frame 2 and is hinged to the extension section 11 of the suspension rod 10, when the seat movable part 8 rotates around the seat base 1, it drives the seat-back connecting rod 9 to act synchronously on the suspension rod 10, the four-bar linkage 7 finally adjusts the backrest mounting assembly 6 back and forth. The seat base 1 is fixedly installed on the seat chassis 12, the rear end of the seat chassis 12 is fixedly connected to the backrest frame 2, and a height-adjustable gas spring 13 is provided under the seat chassis 12, and a five-star base 14 supporting the self-adjusting top support seat is connected to the gas spring 13.

[0037] The self-adjusting top support seat has an initial state and an extended state. In the initial state, the upper end of the suspension rod 10 is vertically separated from the backrest connecting seat 5, and the backrest mounting assembly 6 is in a rearward position. When switching from the initial state to the extended state, the backrest connecting rod 9 is subjected to force and moves, causing it to move in conjunction with the four-bar linkage 7 and the suspension rod 10, thereby driving and adjusting the position of the backrest or lumbar support. In the extended state, the backrest connecting seat 5 is close to the upper end of the suspension rod 10, and the backrest mounting assembly 6 is in a forward position.

[0038] Specifically, such as Figure 2-3As shown, the seat-back linkage 9 is L-shaped and is integrally formed from a horizontal section 22 and a vertical section 23. The front end of the horizontal section is hinged to the seat movable part 8 and then passes through a hole provided on the seat back frame 2; the vertical section is located at the rear of the seat back frame 2, and its upper end is hinged to the extension section 11 of the suspension rod 10. The L-shaped design of the seat-back linkage allows the suspension rod 10 to move with a smaller rotation amplitude of the horizontal section, making the entire linkage process more agile.

[0039] like Figure 2-4 As shown, the specific connection structure of the four-bar linkage 7 is as follows: the two ends of the upper linkage 3 are respectively hinged to the backrest mounting component 6 and the backrest connecting seat 5, and the two ends of the lower linkage 4 are also respectively hinged to the backrest mounting component 6 and the backrest connecting seat 5 to form the four-bar linkage 7.

[0040] The upper link 3 and lower link 4 are hinged to the backrest mounting assembly 6 and the chair back connecting seat 5, and the lower end of the suspension rod 10 is also hinged to either the upper link 3 or the lower link 4. Therefore, when one of them moves relative to the other, the others will also move accordingly. The lower end of the suspension rod 10 is hinged to either the upper link 3 or the lower link 4. This allows the suspension rod 10 and the four-bar linkage 7 to move together without interfering with each other. For example, when the chair back connecting seat 5 moves downward, the suspension rod 10 will rotate forward, and the upper link 3 and lower link 4 will also extend forward together, causing the backrest mounting assembly 6 to tend to move forward. Due to the synchronous movement of the upper link 3 and lower link 4, the backrest mounting assembly 6, which is hinged to it, always maintains a horizontal and vertical movement state, which is more in line with actual use.

[0041] To ensure that the chair back or lumbar support fits the lower back, a four-bar linkage is designed so that the two links can rotate relative to each other at their joints. The four-bar linkage also ensures that when the backrest mounting component 6 located at the front rotates and moves, the backrest mounting component 6 can always maintain a horizontal and vertical extension or retraction action, so that the chair back or lumbar support will not deflect at an angle and can fit snugly against the human lower back.

[0042] Then, the four-bar linkage 7 is hinged to the suspension rod 10. The hinge is used because both the four-bar linkage 7 and the suspension rod 10 need to rotate and move during the adjustment. When the four-bar linkage 7 is connected to the chair back frame 2, it is formed by the sliding connection between the chair back connecting seat 5 and the chair back frame 2. At the same time, the suspension rod 10 is also hinged to the chair back frame 2. The extension section 11 of the suspension rod 10 is hinged to the upper end of the seat back connecting rod 9, and the lower end of the seat back connecting rod 9 is hinged to the seat movable part 8, thus forming an adjustment mechanism that is linked with the four-bar linkage 7.

[0043] An even better solution is to add an elastic element to the aforementioned self-adjusting top support seat to return it from the extended state to the initial state, such as... Figure 8-10As shown, the elastic element can be a spring 21 located below the seat movable part 8 and at the slot at the rear of the seat base 1. The spring 21 is longitudinally arranged on the seat chassis 12. When a person sits down, the seat movable part 8 rotates downward under force, and the spring 21 is compressed and deformed. When the person leaves the seat, the spring 21 rebounds and returns to its original position. Under the action of the spring 21's rebound force, the seat movable part 8 can quickly move upward, driving the four-bar linkage 7 to move, so that the backrest mounting assembly 6 quickly retracts and returns to its initial state.

[0044] like Figure 7 As shown, the specific process of slidingly connecting the chair back connecting seat 5 and the chair back frame 2 is as follows: A through groove 15 is provided vertically on the chair back frame 2, and a slider 16 passes through the groove 11. A protruding mounting position 17 is provided at the front end of the slider 16, and the chair back connecting seat 5 is fixedly connected to the slider 16 through the mounting position 17. The groove 15 and the slider 16 are designed to make the chair back connecting seat 5 more stable when sliding, and to prevent tilting or other issues.

[0045] To go further, such as Figure 8 As shown, a locking block 18 is slidably provided at the rear end of the slider 16. The head of the locking block 18 has locking teeth 24. A limiting member 19 is provided on the back of the chair back frame 2. The limiting member 19 has multiple side-by-side slots 20 for engaging with the locking teeth 24 to position the slider 16. Moving the locking block 18 so that the locking teeth 24 are pushed into the slots 20 fixes the chair back connecting seat 5 to the chair back frame 2, thus disabling the self-adjusting top support function of the chair back and allowing it to be used as a regular chair. Simultaneously, the side-by-side slots can adjust the horizontal position of the backrest mounting component 6 as needed, thereby meeting various user requirements.

[0046] Specifically: When unloaded, the self-adjusting top-support seat is in its initial state, with the backrest mounting assembly retracted towards the backrest frame. When a user sits on the self-adjusting top-support seat, the seat movable component 8 rotates downwards under the pressure of the user's weight, causing the seat back linkage 9 to move. The seat back linkage 9 then pulls the suspension rod 10 to rotate, which in turn drives the four-bar linkage. At this point, the backrest mounting assembly 6 moves forward to fit against the user's back, receiving a supportive force, and then stops extending forward. The four-bar linkage 7 reaches force equilibrium, and the self-adjusting top-support seat transitions from its initial state to its extended state. During this process, the greater the user's weight, the greater the rotation amplitude of the seat movable component 8, and the further the backrest mounting assembly 6 extends forward, providing a greater supportive force to the user. The self-adjusting top-support mechanism can adaptively provide matching support force according to the user's weight. When the user leaves the seat, the pressure on the seat movable part 8 disappears, the seat movable part 8 rotates and moves upward to reset, driving the backrest linkage 9 to move, and then pulling the suspension rod 10 to rotate. The suspension rod 10 drives the four-bar linkage 7 to move, and the backrest mounting assembly 6 moves backward to retract towards the backrest frame 2. The self-adjusting top support seat changes from the extended state to the initial state.

[0047] 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. Those skilled in the art should understand that the present invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of the present invention will be included within the scope of the claims.

Claims

1. A self-adjusting headrest chair, characterized by, The chair includes a seat base, a backrest frame, and a four-bar linkage consisting of an upper link, a lower link, a backrest connector, and a backrest mounting assembly for connecting the backrest or lumbar support. The upper link is hinged at both ends to the backrest mounting assembly and the backrest connector, and the lower link is also hinged at both ends to the backrest mounting assembly and the backrest connector to form the four-bar linkage. A linkage mechanism is provided between the seat base and the backrest frame. This linkage mechanism includes a seat movable component, a seat-back linkage, and a suspension rod. The front and rear ends of the seat movable component are hinged to the seat base and the seat-back linkage, respectively. The seat-back linkage is L-shaped and includes a horizontal section and a... The vertical section and horizontal section are integrally formed with the vertical section. The suspension rod is located between the four-bar linkage and the chair back frame, and the lower end of the suspension rod is hinged to the four-bar linkage. The upper end of the suspension rod is rotatably connected to the upper part of the chair back frame. The chair back connecting seat is located below the suspension rod and is slidably connected to the chair back frame. The upper end of the suspension rod has an extension section, and the front end of the horizontal section is hinged to the seat movable part. The vertical section is located behind the chair back frame, and the upper end of the vertical section is hinged to the extension section of the suspension rod. When the seat movable part rotates around the seat base, it drives the seat back linkage to act synchronously on the suspension rod and the four-bar linkage, ultimately adjusting the backrest mounting assembly back and forth. This self-adjusting top-support seat has an initial state and an extended state. In the initial state, the upper end of the suspension rod is vertically separated from the backrest connecting seat, and the backrest mounting component is in a rearward position. When switching from the initial state to the extended state, the seat back linkage is subjected to force and moves, causing it to move in conjunction with the four-bar linkage and the suspension rod to drive and adjust the position of the backrest or lumbar support. In the extended state, the backrest connecting seat is close to the upper end of the suspension rod, and the backrest mounting component is in a forward position.

2. A self-adjusting headrest chair according to claim 1, wherein, The linkage mechanism also includes an elastic element that resets the extended state to the initial state.

3. A self-adjusting headrest chair according to claim 2, wherein, The elastic element is a spring located under the movable part of the chair seat and at the slot at the rear of the chair seat base.

4. A self-adjusting headrest chair according to claim 1, wherein, The lower end of the boom is hinged to the four-bar linkage, which means that the lower end of the boom is hinged to the upper or lower link.

5. A self-adjusting headrest chair according to claim 1 or 3, wherein The backrest connector is slidably connected to the backrest frame, meaning that the backrest frame has a through groove in the vertical direction, the slider passes through the groove, and the backrest connector is connected to the backrest frame through the slider.

6. A self-adjusting headrest chair according to claim 5, wherein, The rear end of the slider is provided with a locking block, which is slidably connected to the slider laterally. The back of the chair back frame is provided with a limiting member, which has multiple slots arranged longitudinally side by side. The head of the locking block is provided with locking teeth that engage with the slots. When the locking block slides in one direction, the locking teeth disengage from the slots, and the slider can move up and down along the chair back frame. When the locking block slides in the opposite direction, the locking teeth engage with the corresponding slots to position the slider.

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