A device for assisting the elderly to sit up by changing the center of gravity and its usage method

Abstract

The present invention relates to a device for assisting the elderly to sit up by changing the center of gravity and a using method thereof. The device comprises a chair frame, a seat cushion assembly, a leg backrest and an upper backrest assembly, wherein: armrests are arranged on both sides of the top of the chair frame; the seat cushion assembly consists of a seat cushion and a seat cushion auxiliary air spring, the rear end of the seat cushion is hinged to the chair frame, and both ends of the seat cushion auxiliary air spring are respectively hinged to the bottom of the seat cushion and the rear side of the chair frame; the top end of the leg backrest is hinged to the front end of the seat cushion; the upper backrest assembly consists of an upper backrest and an upper backrest auxiliary air spring, the upper backrest is hinged to the chair frame behind the seat cushion, the bottom end of the upper backrest extends downward to below the seat cushion and is hinged to the leg backrest through a connecting rod, and both ends of the upper backrest auxiliary air spring are respectively hinged to the back of the upper backrest and the rear side of the chair frame. Compared with the prior art, the present invention can freely switch among three postures of sitting, standing and lying, which is of great benefit to the later life of the elderly.

Description

Technical Field

[0001] The present invention relates to a device for assisting the elderly to sit up, and more particularly to a device for assisting the elderly to sit up by changing the center of gravity and its use method. Background Art

[0002] Currently, in response to the problem that it is difficult for the elderly to sit up, there are many auxiliary products on the market to help the elderly. However, most of the existing auxiliary standing chairs use electric push rods, hydraulic push rods to push the bottom plate up and other methods to help the elderly sit up.

[0003] For example, the most common electric assisted standing chair on the market at present. This seat controls the electric push rod mechanism through a remote control. The seat surface rises under the action of the push rod to complete the process of the elderly changing from a sitting position to a standing position. Similarly, when sitting down, the electric push rod descends, driving the elderly to sit down easily. For the elderly with visual impairments, operating the remote control is a very difficult thing. Therefore, a touch-type remote control has appeared on the seat, which is installed on the side of the seat armrest. Sliding the finger left or right on the touch interface can activate the assist-up switch, and after the assist-up is completed, after a while, the seat automatically returns to its original state. However, for the elderly, the intelligent device is not easy to operate, and the biggest drawback of this method is that it requires power supply, which is not convenient to be placed in outdoor areas without power supply facilities such as parks and squares, and has high environmental requirements and needs to be maintained regularly. At the same time, maintenance will also generate corresponding costs. Compared with pure mechanical products, the application environment of this product and the amount of capital investment have certain defects.

[0004] There are also pure mechanical devices that directly use mechanical spring pushing devices and crank-slider mechanisms. Although this device has fewer corresponding disadvantages compared with the electric assisted standing chair, due to the existence of the concept of cumulative error, this device has very high requirements for the precision of parts. Therefore, this device has not been widely promoted on the market. And this device requires the user to provide corresponding power for the device to operate, so it is not suitable for the elderly with muscle aging. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned defects existing in the prior art and provide a device for assisting the elderly to sit up by changing the center of gravity and its use method. It can freely switch between three postures: sitting, standing, and lying, which is of great benefit to the later life of the elderly.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] The first aspect of the present invention provides a device for assisting the elderly to sit up by changing the center of gravity, including:

[0008] A chair frame with armrests provided on both sides of the top,

[0009] The seat cushion assembly consists of a seat cushion and a seat cushion auxiliary air spring. The rear end of the seat cushion is hinged to the chair frame. The first end of the seat cushion auxiliary air spring is hinged to the bottom of the seat cushion, and the second end is hinged to the rear side of the chair frame.

[0010] The leg backrest, with its top end hinged to the front end of the seat cushion.

[0011] The upper backrest assembly consists of an upper backrest and an upper backrest auxiliary air spring. The upper backrest is hinged to the chair frame behind the seat cushion. The bottom end of the upper backrest extends downward to the lower part of the seat cushion and is hinged to the leg backrest through a connecting rod. The first end of the upper backrest auxiliary air spring is hinged to the back of the upper backrest, and the second end is hinged to the rear side of the chair frame.

[0012] The described armrest is provided with a seat cushion air spring switch and an upper backrest air spring switch for controlling the seat cushion auxiliary air spring and the upper backrest auxiliary air spring respectively.

[0013] This device is used to realize the switching between the standing position, the lying position and the sitting position by changing the center of gravity of the user.

[0014] When this device switches between the standing position and the sitting position, the seat cushion, the leg backrest, the connecting rod, the upper backrest and the part of the chair frame between the upper backrest and the seat cushion form a five-bar linkage mechanism.

[0015] When this device switches between the lying position and the sitting position, the seat cushion and the part of the chair frame between the upper backrest and the seat cushion form an integral connecting rod, so that the integral connecting rod, the leg backrest, the connecting rod and the upper backrest form a four-bar linkage mechanism.

[0016] Preferably, the chair frame is composed of two inverted U-shaped frames arranged side by side, one on the left and one on the right, and a cross bar connected to the rear sides of the two U-shaped frames. The left and right sides of the seat cushion and the upper backrest are hinged to the tops of the two U-shaped frames.

[0017] Preferably, there are two armrests, which are respectively located at the tops of the two U-shaped frames.

[0018] Preferably, the second ends of the seat cushion auxiliary air spring and the upper backrest auxiliary air spring are both hinged and connected to the cross bar.

[0019] Preferably, a shock-absorbing spring is provided on the cross bar, and the second ends of the seat cushion auxiliary air spring and the upper backrest auxiliary air spring are both hinged and connected to the cross bar through the shock-absorbing spring.

[0020] Preferably, the parts of the two inverted U-shaped frames that support on the ground form four legs of the chair frame, and the height of the legs is adjustable.

[0021] Preferably, the bottom end of the leg backrest is provided with a foot support rod for supporting the user's feet, and the foot support rod contacts or is close to the ground when the seat cushion auxiliary air spring moves to the shortest stroke.

[0022] Preferably, the upper backrest, the seat cushion and the leg backrest are all composed of a frame structure main body and a flexible support net supported on the frame structure main body.

[0023] Preferably:

[0024] When the device switches between the standing position, the lying position and the sitting position:

[0025] When the seat cushion auxiliary air spring moves to the shortest stroke, the seat cushion tilts downward for the user to lean on, and the device is in the standing position; when the seat cushion auxiliary air spring moves to the maximum stroke, the seat cushion is horizontal or the front end tilts upward for the user to sit on, and the device is in the sitting position;

[0026] When the upper backrest auxiliary air spring moves to the shortest stroke, the upper backrest is used for the user to lie on, and the device is in the lying position; when the upper backrest auxiliary air spring moves to the maximum stroke, the upper backrest is used for the user to sit on, and the device returns to the sitting position.

[0027] The second aspect of the present invention provides a method for using the device for assisting the elderly to sit up by changing the center of gravity:

[0028] a. Before use: The seat cushion auxiliary air spring of the device is in the shortest stroke state, and the upper backrest auxiliary air spring is in the maximum stroke state;

[0029] b. When the user switches from the standing position, the sitting position to the lying position:

[0030] When switching from the standing position to the sitting position: The user leans on the inclined seat cushion, the upper body tilts backward, and presses the seat cushion air spring switch. Under the combined action of the resistance and the thrust of the seat cushion auxiliary air spring, the lower leg and the thigh slowly lift upward to achieve the conversion from the standing position to the sitting position. When the seat cushion auxiliary air spring moves to the maximum stroke, release the seat cushion air spring switch, and the seat cushion auxiliary air spring is self-locked to complete the switching from the standing position to the sitting position;

[0031] When switching from the sitting position to the lying position: In the sitting position, the user continues to tilt the upper body backward and presses the upper backrest air spring switch. By relying on the change of the center of gravity of the upper body backward, the user realizes the conversion from the sitting position to the lying position. During this process, the gravitational potential energy of the user's upper body is converted into the elastic potential energy of the upper backrest auxiliary air spring, and the connecting rod drives the leg backrest to swing upward to support the legs. When the upper backrest auxiliary air spring moves to the shortest stroke, release the upper backrest air spring switch, and the upper backrest auxiliary air spring is self-locked. Based on the conversion from the five-bar linkage mechanism to the four-bar linkage mechanism, the switching from the sitting position to the lying position is completed;

[0032] c. When the user switches from the lying position, the sitting position to the standing position:

[0033] The user first presses the seat cushion gas spring switch, and the seat cushion auxiliary gas spring shortens, forming an inclined surface. Under the action of the inclined plane effect, the center of gravity of the human body shifts forward. Then, the user presses the upper backrest gas spring switch, and the upper backrest auxiliary gas spring releases the stored elastic potential energy. Based on the conversion from a four-bar linkage mechanism to a five-bar linkage mechanism, the position of the center of gravity of the human body rises, restoring to the standing position.

[0034] This device is mainly made based on the conversion from a five-bar linkage mechanism to a four-bar linkage mechanism. By changing the position of the center of gravity of the human body and leveraging the lever principle (a force-consuming lever) and the inclined plane effect, the switching among the three postures of standing, sitting, and lying of the human body is achieved.

[0035] Conventional sitting is mainly the sitting with the thighs moving backward. The idea of the device of the present invention is exactly the opposite of the traditional way. It is dedicated to the sitting with the human legs moving upward. Changing the center of gravity of the human body can complete the work. Its basic principle is a force-consuming lever based on the inclined plane effect. By changing the balance of the center of gravity and relying on the lever, the switching among the three states of standing, sitting, and lying of the human body is realized. It does not require external resources and is an innovative application of simple machinery. In terms of the operation of the device and the control of the overall frame structure, everything is simplified as much as possible to facilitate promotion and the use by the elderly population.

[0036] Compared with the prior art, the present invention has the following characteristics in terms of design:

[0037] (1) Strange concept: Conventional sitting is mainly the sitting with the thighs moving backward, while the idea of this auxiliary device is exactly the opposite of the traditional way. It is dedicated to the sitting with the human legs moving upward.

[0038] (2) Novel idea: Its basic principle is a force-consuming lever. By changing the balance of the center of gravity and relying on the lever, the switching among the three states of standing, sitting, and lying of the human body is realized, which is an innovative application of simple machinery.

[0039] (3) Simple and beautiful structure: The highest realm of aesthetics is to simplify complexity. In terms of the operation of the product and the control of the overall frame structure, we simplify as much as possible to facilitate promotion.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] (1) In terms of economic benefits: This device has a simple structure and a corresponding fine-tuning system, which is convenient for large-scale production, conducive to large-area promotion, and can better generate economic benefits.

[0042] (2) In terms of user stickiness: This device is simple and effortless to operate, and is more recognized by elderly friends. Moreover, compared with the pure mechanical devices on the market that can only assist in sitting up, this device adds functions such as assisting in sitting and lying, lying and standing, and can better realize the free conversion among the three states of standing, sitting, and lying in people's lives. Brief Description of the Drawings

[0043] Figure 1 It is a schematic diagram of the state (standing position) of the device of the present invention before use.

[0044] Figure 2 It is a schematic diagram of the sitting position state of the device of the present invention.

[0045] Figure 3 It is a schematic diagram of the lying position state of the device of the present invention.

[0046] In the figure, 1 is the upper backrest, 2 is the seat cushion, 3 is the leg backrest, 31 is the foot support rod, 4 is the chair frame, 41 is the armrest, 5 is the connecting rod, 6 is the shock absorber spring mounting bracket, 7 is the cross bar, 8 is the shock absorber spring, 9 is the seat cushion auxiliary gas spring, and 10 is the upper backrest auxiliary gas spring. Detailed Description of the Invention

[0047] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] Embodiment

[0049] A device for assisting the elderly to sit up by changing the center of gravity, as Figures 1 to 3 shown, includes a chair frame 4, a seat cushion assembly, a leg backrest 3 and a leg backrest 3, wherein: armrests 41 are provided on both sides of the top of the chair frame 4, the seat cushion assembly is composed of a seat cushion 2 and a seat cushion auxiliary gas spring 9, the rear end of the seat cushion 2 is hinged to the chair frame 4, the first end of the seat cushion auxiliary gas spring 9 is hinged to the bottom of the seat cushion 2, and the second end is hinged to the rear side of the chair frame 4, the top end of the leg backrest 3 is hinged to the front end of the seat cushion 2, the upper backrest assembly is composed of an upper backrest 1 and an upper backrest auxiliary gas spring 10, the upper backrest 1 is hinged to the chair frame 4 behind the seat cushion 2, the bottom end of the upper backrest 1 extends downward to below the seat cushion 2 and is hinged to the leg backrest 3 through a connecting rod 5, the first end of the upper backrest auxiliary gas spring 10 is hinged to the back of the upper backrest 1, and the second end is hinged to the rear side of the chair frame 4; seat cushion gas spring switches and upper backrest gas spring switches for controlling the seat cushion auxiliary gas spring 9 and the upper backrest auxiliary gas spring 10 are provided on the armrest 41;

[0050] This device is used to realize the switching between the standing position, the lying position and the sitting position by changing the center of gravity of the user. When the device switches between the standing position and the sitting position, the seat cushion 2, the leg backrest 3, the connecting rod 5, the upper backrest 1 and the part of the chair frame 4 between the upper backrest 1 and the seat cushion 2 form a five-bar linkage. When the device switches between the lying position and the sitting position, the seat cushion 2 and the part of the chair frame 4 between the upper backrest 1 and the seat cushion 2 form an integral connecting rod, so that the integral connecting rod, the leg backrest 3, the connecting rod 5 and the upper backrest 1 form a four-bar linkage.

[0051] This device is mainly made by converting a five-bar linkage mechanism into a four-bar linkage mechanism. By changing the position of the human body's center of gravity and leveraging the lever principle (a force-consuming lever) and the inclined plane effect, the switching among the three postures of standing, sitting, and lying down is achieved.

[0052] In this embodiment, more specifically:

[0053] The chair frame 4 preferably consists of two inverted U-shaped frames arranged side by side, one on the left and the other on the right, and a crossbar 7 connected to the rear sides of the two U-shaped frames. The left and right sides of the seat cushion 2 and the upper backrest 1 are hinged to the tops of the two U-shaped frames. There are two armrests 41, which are respectively located at the tops of the two U-shaped frames. The above structure of the chair frame 4 is simple and will not interfere with the posture switching. The second ends of the seat cushion auxiliary gas spring 9 and the upper backrest auxiliary gas spring 10 are both hinged to the crossbar 7. To be suitable for a wide range of people, the parts of the two inverted U-shaped frames that support on the ground form the four legs of the chair frame 4, and the legs can be designed in a form with adjustable height. Further preferably, the legs of each inverted U-shaped frame can be designed in a form that expands outward front and back, improving the stability during use. Further, a shock-absorbing spring 8 can be provided on the crossbar 7 (the shock-absorbing spring 8 is installed on the crossbar 7 through a shock-absorbing spring mounting bracket 6), and the second ends of the seat cushion auxiliary gas spring 9 and the upper backrest auxiliary gas spring 10 are both hinged to the crossbar 7 through the shock-absorbing spring 8, which greatly improves the stability of the device and can reduce the discomfort caused to the body by excessive impact when the elderly sit down. The bottom end of the leg backrest 3 preferably has a foot support rod 31 for supporting the user's feet. When the seat cushion auxiliary gas spring 9 moves to the shortest stroke, the foot support rod 31 contacts or is close to the ground. When in use, the user steps on the foot support rod 31, which is convenient for the user to adjust the center of gravity. Further preferably, a footrest can also be provided on the foot support rod to improve the convenience of use. The upper backrest 1, the seat cushion 2, and the leg backrest 3 can all be composed of a frame structure main body and a flexible support net supported on the frame structure main body, with simple structure, light self-weight, and good use comfort. Other structural forms can also be adopted..

[0054] When this device switches among the standing, lying, and sitting postures: when the seat cushion auxiliary gas spring 9 moves to the shortest stroke, the seat cushion 2 tilts downward for the user to lean on, and the device is in the standing state; when the seat cushion auxiliary gas spring 9 moves to the maximum stroke, the seat cushion 2 is horizontal or the front end tilts upward for the user to sit on, and the device is in the sitting state; when the upper backrest auxiliary gas spring 10 moves to the shortest stroke, the upper backrest is for the user to lie on, and the device is in the lying state; when the upper backrest auxiliary gas spring 10 moves to the maximum stroke, the upper backrest is for the user to sit on and rely on, and the device returns to the sitting state.

[0055] The usage method of the above device for assisting the elderly to sit up by changing the center of gravity:

[0056] a. Before use (see Figure 1 ): The seat cushion auxiliary gas spring 9 of the device is in the shortest stroke state, and the upper backrest auxiliary gas spring 10 is in the maximum stroke state; at this time, the upper backrest 1, the seat cushion 2 and the leg backrest 3 form a relatively inclined slope, which is convenient for the user to lean on.

[0057] b. When the user switches from a standing position, a sitting position to a lying position, during this process, the device changes from Figure 1 , Figure 2 to Figure 3 state:

[0058] When switching from a standing position to a sitting position: The user leans on the inclined seat cushion 2, the upper body tilts backward, and presses the seat cushion gas spring switch (for example, set on the right armrest 41). Due to the center of gravity of the human body shifting backward and downward, according to the principle of lever balance (power × power arm = resistance × resistance arm), under the combined action of the resistance and the thrust of the seat cushion auxiliary gas spring 9, the lower leg and thigh slowly lift upward, realizing the conversion from a standing position to a sitting position. When the seat cushion auxiliary gas spring 9 moves to the maximum stroke, release the seat cushion gas spring switch, and the seat cushion auxiliary gas spring 9 locks. Based on the conversion from a five-link mechanism to a four-link mechanism, the switching from a standing position to a sitting position is completed. See Figure 2 ;

[0059] When switching from a sitting position to a lying position: In the sitting position, the user continues to tilt the upper body backward and presses the upper backrest gas spring switch (for example, set on the left armrest 41). The user realizes the conversion from a sitting position to a lying position by relying on the change of the center of gravity of the upper body backward. During this process, the gravitational potential energy of the user's upper body is converted into the elastic potential energy of the upper backrest auxiliary gas spring 10. The connecting rod 5 drives the leg backrest 3 to swing upward to support the legs. When the upper backrest auxiliary gas spring 10 moves to the shortest stroke, release the upper backrest gas spring switch, and the upper backrest auxiliary gas spring 10 locks, completing the switching from a sitting position to a lying position. See Figure 3 ;

[0060] c. When the user switches from a lying position, a sitting position to a standing position, during this process, the device changes from Figure 3 , Figure 2 to Figure 1 state:

[0061] The user first presses the seat cushion gas spring switch, the seat cushion auxiliary gas spring 9 shortens, the seat cushion 2 forms an inclined plane, and under the action of the inclined plane effect, the center of gravity of the human body shifts forward. Then press the upper backrest gas spring switch, and the upper backrest auxiliary gas spring 10 releases the stored elastic potential energy. Based on the conversion from a four-link mechanism to a five-link mechanism, the position of the center of gravity of the human body rises and returns to the standing position.

[0062] The transformation among the above three postures is also achieved by changing the corresponding center of gravity according to the lever principle and the inclined plane effect. Therefore, this device can freely switch among the three postures of sitting, standing, and lying, which is of great benefit to the later life of the elderly.

[0063] The above description of the embodiments is to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those who are familiar with the technology in this field can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative labor. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A device for assisting the elderly to sit up by changing the center of gravity, characterized in that, it comprises: a chair frame (4) with armrests (41) provided on both sides of the top, a seat cushion assembly composed of a seat cushion (2) and a seat cushion auxiliary air spring (9), the rear end of the seat cushion (2) is hinged to the chair frame (4), the first end of the seat cushion auxiliary air spring (9) is hinged to the bottom of the seat cushion (2), and the second end is hinged to the rear side of the chair frame (4), a leg backrest (3) with the top end hinged to the front end of the seat cushion (2), an upper backrest assembly composed of an upper backrest (1) and an upper backrest auxiliary air spring (10), the upper backrest (1) is hinged to the chair frame (4) behind the seat cushion (2), the bottom end of the upper backrest (1) extends downward to below the seat cushion (2) and is hinged to the leg backrest (3) through a connecting rod (5), the first end of the upper backrest auxiliary air spring (10) is hinged to the back of the upper backrest (1), and the second end is hinged to the rear side of the chair frame (4); a seat cushion air spring switch and an upper backrest air spring switch for controlling the seat cushion auxiliary air spring (9) and the upper backrest auxiliary air spring (10) respectively are provided on the armrest (41); this device is used to realize the switching between the standing position, the lying position and the sitting position by changing the center of gravity of the user; when this device switches between the standing position and the sitting position, the seat cushion (2), the leg backrest (3), the connecting rod (5), the upper backrest (1) and the part of the chair frame (4) between the upper backrest (1) and the seat cushion (2) form a five-bar linkage mechanism, when this device switches between the lying position and the sitting position, the seat cushion (2) and the part of the chair frame (4) between the upper backrest (1) and the seat cushion (2) form an integral connecting rod, so that the integral connecting rod, the leg backrest (3), the connecting rod (5) and the upper backrest (1) form a four-bar linkage mechanism; a foot support rod (31) for supporting the user's feet is provided at the bottom end of the leg backrest (3), and the foot support rod (31) contacts or is close to the ground when the seat cushion auxiliary air spring (9) moves to the shortest stroke; the upper backrest (1), the seat cushion (2) and the leg backrest (3) are all composed of a frame structure main body and a flexible support net supported on the frame structure main body.

2. A device for assisting the elderly to sit up by changing the center of gravity according to claim 1, characterized in that, the chair frame (4) is composed of two inverted U-shaped frames arranged side by side, one on the left and one on the right, and a cross bar (7) connected to the rear sides of the two U-shaped frames, and the left and right sides of the seat cushion (2) and the upper backrest (1) are hinged to the tops of the two U-shaped frames.

3. A device for assisting the elderly to sit up by changing the center of gravity according to claim 2, characterized in that, there are two armrests (41), which are respectively located at the tops of the two U-shaped frames.

4. A device for assisting the elderly to sit up by changing the center of gravity according to claim 2, characterized in that, the second ends of the seat cushion auxiliary air spring (9) and the upper backrest auxiliary air spring (10) are both hinged and connected to the cross bar (7).

5. A device for assisting the elderly to sit up by changing the center of gravity according to claim 4, characterized in that, The cross bar (7) is provided with a shock-absorbing spring (8), and the second ends of the seat cushion auxiliary air spring (9) and the upper backrest auxiliary air spring (10) are hinged to the cross bar (7) through the shock-absorbing spring (8).

6. A device for assisting the elderly to sit up by changing the center of gravity according to claim 2, wherein, The parts of the two inverted U-shaped frames supported on the ground form the four legs of the chair frame (4), and the height of the legs is adjustable.

7. A device for assisting the elderly to sit up by changing the center of gravity according to claim 1, characterized in that: When the device switches between the standing position, the lying position and the sitting position: When the seat cushion auxiliary air spring (9) moves to the shortest stroke, the seat cushion (2) tilts downward for the user to lean on, and the device is in the standing position; when the seat cushion auxiliary air spring (9) moves to the maximum stroke, the seat cushion (2) is horizontal or the front end tilts upward for the user to sit on, and the device is in the sitting position; When the upper backrest auxiliary air spring (10) moves to the shortest stroke, the upper backrest (1) is used for the user to lie on, and the device is in the lying position; when the upper backrest auxiliary air spring (10) moves to the maximum stroke, the upper backrest (1) is used for the user to sit on, and the device returns to the sitting position.

8. The usage method of the device for assisting the elderly to sit up by changing the center of gravity according to any one of claims 1 to 7, characterized in that: a. Before use: The seat cushion auxiliary air spring (9) of the device is in the shortest stroke state, and the upper backrest auxiliary air spring (10) is in the maximum stroke state; b. When the user switches from the standing position, the sitting position to the lying position: When switching from the standing position to the sitting position: The user leans on the inclined seat cushion (2), the upper body tilts backward, and presses the seat cushion air spring switch. Under the combined action of the resistance and the thrust of the seat cushion auxiliary air spring (9), the lower leg and the thigh are slowly lifted upward to achieve the conversion from the standing position to the sitting position. When the seat cushion auxiliary air spring (9) moves to the maximum stroke, release the seat cushion air spring switch, and the seat cushion auxiliary air spring (9) is self-locked. Based on the conversion from the five-bar mechanism to the four-bar mechanism, the switching from the standing position to the sitting position is completed; When switching from the sitting position to the lying position: In the sitting position, the user continues to tilt the upper body backward and presses the upper backrest air spring switch. By relying on the change of the center of gravity of the upper body backward, the user realizes the conversion from the sitting position to the lying position. During this process, the gravitational potential energy of the user's upper body is converted into the elastic potential energy of the upper backrest auxiliary air spring (10), and the connecting rod (5) drives the leg backrest (3) to swing upward to support the legs. When the upper backrest auxiliary air spring (10) moves to the shortest stroke, release the upper backrest air spring switch, and the upper backrest auxiliary air spring (10) is self-locked to complete the switching from the sitting position to the lying position; c. When the user switches from the lying position, the sitting position to the standing position: The user first presses the seat cushion gas spring switch, and the seat cushion auxiliary gas spring (9) shortens, causing the seat cushion (2) to form an inclined plane. Under the action of the inclined plane effect, the center of gravity of the human body shifts forward. Then, the user presses the upper backrest gas spring switch, and the upper backrest auxiliary gas spring (10) releases the stored elastic potential energy. Based on the conversion from a four-bar linkage mechanism to a five-bar linkage mechanism, the position of the center of gravity of the human body rises, restoring the standing position.

Images