A mechanical stretching device with assistive standing function

Abstract

This invention discloses a mechanical extension device with an assisted standing function, including a base, a mechanical extension unit, and an actuator. The mechanical extension unit includes a transmission link, a backrest connector, a seat connector, and a backrest rotating rod. The actuator can drive the transmission link to move relative to the base. When the mechanical extension device switches from a normal sitting state to an assisted standing state, the actuator drives the transmission link to move and simultaneously drives the seat connector and the backrest rotating rod to rotate relative to the base through the seat lifting four-bar linkage and the backrest four-bar linkage. The rear ends of both are lifted upward and suspended in the air. At this time, the backrest connector is also lifted along with the backrest rotating rod. The actuator does not need to lift the entire mechanical extension device, and the backrest can also be lifted along with the seat surface, resulting in a better and safer assisted standing effect.

Description

Technical Field

[0001] This invention relates to the field of furniture, and in particular to a mechanical extension device with an assistive standing function. Background Technology

[0002] Seating furniture appears in various scenarios of life and work and is frequently used by people. In order to cope with various scenarios and meet the needs of different groups of people, seating furniture has gradually developed into more and more types. The main difference lies in the function of the seating furniture. For the elderly and other people with mobility difficulties, it is difficult to get up from a seat. Therefore, there are seats that can help such people get up and stand up, and also have functions that can improve comfort and help rest, such as footrests and reclining, which are very suitable for the elderly to use for leisure.

[0003] The aforementioned types of seating generally achieve their assistive standing function by raising the seat surface. However, there are structural differences, resulting in variations in overall cost, ease of use, user experience, and effectiveness. For example, the elderly chairs with complex structures, numerous connecting rods, and larger size, as described in patents CN201510452057.X, CN201710463006.6, and CN201911060129.0, are more expensive and less convenient to use. Furthermore, these mechanical extension devices that raise the entire seat to assist standing require actuators with greater thrust or even two actuators. In contrast, seating that only raises the seat surface, such as those in patents CN201821353919.9 and CN201910460013.X, are less effective, and the user's back is not supported during the raising process, posing a safety hazard. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a mechanical extension device with an assisted standing function, comprising a base, a mechanical extension unit, and an actuator. The mechanical extension unit includes a transmission link, a backrest connector, a seat connector, and a backrest rotating rod. The actuator can drive the transmission link to move relative to the base. When the mechanical extension device switches from a normal sitting state to an assisted standing state, the actuator drives the transmission link to move and simultaneously drives the seat connector and the backrest rotating rod to rotate relative to the base through the seat lifting four-bar linkage and the backrest four-bar linkage. The rear ends of both are lifted upwards and suspended in the air. At this time, the backrest connector also rises along with the backrest rotating rod. The actuator does not need to lift the entire mechanical extension device, and the backrest can also be lifted along with the seat surface, resulting in a better and safer assisted standing effect.

[0005] The technical solution of this invention is implemented as follows:

[0006] A mechanical extension device with an assisted standing function includes a base, mechanical extension units mirror-distributed on both sides of the base, and an actuator for driving the mechanical extension units. Each mechanical extension unit includes a transmission link, a backrest connector, a seat connector, and a backrest rotating rod. The backrest connector is mounted on the backrest rotating rod. One end of the actuator is rotatably connected to the base, and the other end acts on the transmission link of the mechanical extension unit. The transmission link, seat connector, and backrest rotating rod are all rotatably disposed relative to the base. The transmission link is connected to the seat connector via a seat transmission link, and the transmission link is connected to the backrest rotating rod via a backrest transmission link. The mechanical extension device has a normal sitting state and an assisted standing state. When switching from the normal sitting state to the assisted standing state, the actuator drives the transmission link to rotate upward relative to the base. The transmission link, base, seat connector, and seat transmission rod form a four-bar linkage for seat lifting. The transmission link, base, backrest rotation rod, and backrest transmission rod form a four-bar linkage for backrest lifting. The transmission link drives the backrest rotation rod and seat connector to rotate together relative to the base through the four-bar linkage for seat lifting and backrest lifting. The rear ends of the backrest rotation rod and seat connector are lifted upward and suspended in the air. The backrest connector is lifted together with the backrest rotation rod.

[0007] Structurally, the mechanical extension device uses a four-bar linkage mechanism for lifting the seat, consisting of a transmission link, a base, a seat connector, and a seat transmission rod, as well as a four-bar linkage mechanism for lifting the backrest, consisting of a transmission link, a base, a backrest rotating rod, and a backrest transmission rod. This allows the transmission link to simultaneously lift the backrest and the seat, thus achieving the function of assisting in getting up.

[0008] In terms of function and effect, mechanical extension devices consume more energy for overall lifting and require more demanding actuators. However, the presence of the backrest rotation rod allows the backrest connector to be lifted in the same way as the seat connector, achieving partial lifting of the backrest and seat connectors within the mechanical extension device. This is more energy-efficient, requires less stringent actuators, has a simpler structure, smaller size, is easier to transport and move, and is less expensive. Furthermore, compared to mechanical extension devices that lift the entire body, lifting only the seat and backrest is more targeted. It doesn't simply lift the person but assists the user in getting up and off the seat, providing a better experience. Compared to mechanical extension devices that only lift the seat, the backrest can both propel the user left and right and prevent the upper body from falling backward, thus providing better and safer assistance in getting up.

[0009] Preferably, the seat connector is rotatably connected to a seat crossbar. In the normal sitting position, the seat connector rests against the seat crossbar. In the assisted standing position, the rear end of the seat connector detaches from the seat crossbar and lifts upward. One function of the seat crossbar is to allow the seat connector to rest against it in the normal sitting and lying positions, maintaining a roughly horizontal state. Another function is that when switching to the assisted standing position, it can be considered as an integral part of the base, with the seat connector and transmission linkage rotatably connected to the seat crossbar and rotating relative to the seat crossbar and the base.

[0010] Preferably, the seat crossbar is connected to the base via a first seat link and a second seat link. The lower ends of both the first and second seat links are rotatably connected to the base, and the upper ends of both the first and second seat links are rotatably connected to the seat crossbar. The second seat link is located behind the first seat link, and its upper end is rotatably connected to the rear end of the seat crossbar. The upper end of the first seat link is rotatably connected to the middle of the seat crossbar. The seat crossbar, the first seat link, the second seat link, and the base together form a four-bar linkage, allowing the seat crossbar to move relative to the base while maintaining a roughly horizontal position, either raising it to move backward or lowering it to move forward.

[0011] Preferably, a limiting post is provided on the base. The limiting post is located in front of the first seat link and is configured to abut against the first seat link to prevent the first seat link from continuing to rotate forward and downward. When switching from the normal sitting position to the assisted standing position, the limiting post restricts the first seat link from continuing to rotate forward and downward, so that the seat crossbar remains stationary during this process, thereby causing the transmission link to drive the seat connector and the backrest rotation rod to rotate.

[0012] Preferably, the base is roughly in the shape of a U-shaped frame, including a front fixed tube, a rear fixed tube, and two fixed plates located on the left and right sides. The rear end of the actuator is rotatably connected to the rear fixed tube, and the mechanical extension units on both sides are respectively connected to the fixed plates on both sides.

[0013] Preferably, a side plate is also fixedly provided at the front end of the fixed plate, with both the upper and lower ends of the side plate protruding from the fixed plate; the limiting post is located at the upper end of the side plate near the first seat connecting rod; the lower end of the side plate is rotatably connected to the backrest rotating rod. The side plate added to the fixed plate has multiple functions, such as the front fixing tube being fixedly connected to the two side plates, the side plate providing a rotating connection point, and the side plate also having the limiting post.

[0014] Preferably, the mechanical extension unit also includes a footstool connector, which is connected to the base and the seat crossbar via a footstool linkage assembly. The footstool connector and the footstool linkage assembly retract and extend. In normal sitting and assisted standing positions, both the footstool connector and the footstool linkage assembly are retracted. The mechanical extension device also includes a reclining position. When switching from the normal sitting position to the reclining position, the actuator drives the transmission linkage and moves the seat crossbar backward and upward. The first and second seat linkages rotate backward, and simultaneously, the footstool linkage assembly extends, and the backrest connector rotates backward relative to the backrest rotation rod. The footstool connector and footstool linkage assembly are related to the reclining position, in which they extend to provide footrests for the user. However, their specific movements and connections are similar to those in the applicant's previous patents and are not the focus of this invention.

[0015] Preferably, the backrest rotating component is equipped with a limiting plate, and the second seat connecting rod is equipped with a limiting wheel. In the normal sitting position, the backrest rotating component rests against the base, and the limiting plate is located behind the limiting wheel. In the reclining position, the second seat connecting rod rotates backward and causes the limiting wheel to rest against the limiting plate. When switching from the reclining position to the normal sitting position, the limiting wheel prevents the limiting plate and the backrest rotating component from lifting. In mechanical extension devices, the limiting function is generally used to regulate the movement of the connecting rod, allowing the connecting rod to move along the designed motion trajectory to achieve the function of the mechanical extension device. Here, the limiting wheel and limiting plate also have such functions: firstly, they limit the movement after contact, ending the movement from the normal sitting position to the reclining position; secondly, when switching from the reclining position to the normal sitting position, they prevent the backrest rotating component from lifting (by stopping only the initial movement), so that the overall movement can proceed according to the designed trajectory.

[0016] Preferably, the seat crossbar is generally L-shaped, comprising a generally vertical short connecting rod and a generally horizontal long connecting rod. The front end of the seat connector is rotatably connected to the upper end of the short connecting rod, and the front end of the transmission link is rotatably connected to the lower end of the short connecting rod. The seat crossbar plays a significant role in this invention, no longer merely providing support for the seat connector; the transmission link can also directly pull its movement without the need for other connecting rods. Furthermore, the transmission link can also rotate relative to the seat crossbar, simplifying the overall movement.

[0017] Preferably, the seat connector is located above the transmission link, and the backrest rotation rod is located below the transmission link. During the transition from the normal sitting position to the assisted standing position, the transmission link, seat connector, and backrest rotation rod all rotate forward and upward, with their positions offset from each other and not interfering with each other.

[0018] Preferably, the backrest transmission rod is roughly a triangular plate-shaped body, with its three ends rotatably connected to a transmission link, a backrest rotation rod, and a backrest connecting rod, respectively. The backrest connecting rod is also rotatably connected to the backrest connector and drives the backrest connector to rotate relative to the backrest rotation rod. During the transition from the normal sitting position to the assisted sitting position, the backrest transmission rod is driven by the transmission link and drives the backrest rotation rod to rotate. When the transition from the normal sitting position to the reclining position, the backrest transmission rod is driven by the transmission link and drives the backrest connecting rod to move, thereby causing the backrest connector to rotate backward relative to the backrest rotation rod. After reclining, the user's back can rest comfortably on it.

[0019] Preferably, the seat transmission rod is a straight rod, with its two ends rotatably connected to the seat connector and the transmission link, respectively. When the transmission link rotates upward relative to the base, the seat transmission rod moves upward and drives the seat connector to rotate upward relative to the base.

[0020] Preferably, a drive tube is rotatably connected to the front end of the actuator, and the drive tube is fixedly connected to the transmission linkage of the two mechanical extension units.

[0021] Preferably, the backrest rotation rods on both sides are connected by two connecting pipes and together form a frame structure.

[0022] The design starting point, concept, and beneficial effects of the present invention, which adopts the above technical solution, are as follows:

[0023] Structurally, the mechanical extension device uses a four-bar linkage mechanism for lifting the seat, consisting of a transmission link, a base, a seat connector, and a seat transmission rod, as well as a four-bar linkage mechanism for lifting the backrest, consisting of a transmission link, a base, a backrest rotating rod, and a backrest transmission rod. This allows the transmission link to simultaneously lift the backrest and the seat, thus achieving the function of assisting in getting up.

[0024] In terms of function and effect, mechanical extension devices consume more energy for overall lifting and require more demanding actuators. However, the presence of the backrest rotation rod allows the backrest connector to be lifted in the same way as the seat connector, achieving partial lifting of the backrest and seat connectors within the mechanical extension device. This is more energy-efficient, requires less stringent actuators, has a simpler structure, smaller size, is easier to transport and move, and is less expensive. Furthermore, compared to mechanical extension devices that lift the entire body, lifting only the seat and backrest is more targeted. It doesn't simply lift the person but assists the user in getting up and off the seat, providing a better experience. Compared to mechanical extension devices that only lift the seat, the backrest can both propel the user left and right and prevent the upper body from falling backward, thus providing better and safer assistance in getting up. Attached Figure Description

[0025] Figure 1This is a three-dimensional structural diagram of the mechanical extension device in the assisted standing state in an embodiment of the present invention;

[0026] Figure 2 This is a side view of the mechanical extension device in the assisted standing state in an embodiment of the present invention. Figure 1 ;

[0027] Figure 3 This is a side view of the mechanical extension device in the assisted standing state in an embodiment of the present invention. Figure 2 ;

[0028] Figure 4 This is a three-dimensional structural diagram of the mechanical extension device in the embodiment of the present invention in a normal sitting state;

[0029] Figure 5 This is a side view of the mechanical extension device in the embodiment of the present invention in a normal seated state. Figure 1 ;

[0030] Figure 6 This is a side view of the mechanical extension device in the embodiment of the present invention in a normal seated state. Figure 2 ;

[0031] Figure 7 This is a three-dimensional structural diagram of the mechanical extension device in the embodiment of the present invention in a lying position;

[0032] Figure 8 This is a side view of the mechanical extension device in the lying position in an embodiment of the present invention. Figure 1 ;

[0033] Figure 9 This is a side view of the mechanical extension device in the lying position in an embodiment of the present invention. Figure 2 ;

[0034] Figure 10 This is a schematic diagram of the seat lifting four-bar linkage of the mechanical extension device in an embodiment of the present invention, which switches from a normal sitting state to an assisted standing state;

[0035] Figure 11 This is a schematic diagram of the backrest lifting four-bar linkage of the mechanical extension device in the embodiment of the present invention, which switches from the normal sitting state to the assisted standing state.

[0036] Figure 12 This is a schematic diagram of the four-bar linkage of the mechanical extension device in the embodiment of the present invention, showing the switching from a normal sitting state to a lying state. Figure 1 ;

[0037] Figure 13 This is a schematic diagram of the four-bar linkage of the mechanical extension device in the embodiment of the present invention, showing the switching from a normal sitting state to a lying state. Figure 2 .

[0038] The reference numerals in the attached drawings are as follows: base 1; mechanical extension unit 2; actuator 3; transmission link 4; backrest connector 5; seat connector 6; backrest rotating rod 7; seat transmission rod 8; backrest transmission rod 9; front fixing tube 10; rear fixing tube 11; fixing plate 12; footstool connector 13; footstool link assembly 14; seat crossbar 15; first seat link 16; second seat link 17; backrest link 18; footboard 19; side plate 20; short link 21; long link 22; drive tube 23; connecting tube 24; limiting post 25; limiting plate 26; limiting wheel 27. Detailed Implementation

[0039] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0040] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0041] In the description of this invention, the term "at least one" means one or more, unless otherwise expressly defined. The terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] The specific embodiments of the present invention are as follows:

[0043] like Figure 1As shown, the present invention provides a mechanical extension device with an auxiliary standing function, including a base 1, mechanical extension units 2 mirror-distributed on both sides of the base 1, and an actuator 3 for driving the mechanical extension units 2. The mechanical extension unit 2 includes a transmission link 4, a backrest connector 5, a seat connector 6, and a backrest rotating rod 7. The backrest connector 5 is mounted on the backrest rotating rod 7. One end of the actuator 3 is rotatably connected to the base 1, and the other end acts on the transmission link 4 of the mechanical extension unit 2. The transmission link 4, the seat connector 6, and the backrest rotating rod 7 are all rotatably disposed relative to the base 1. The transmission link 4 is connected to the seat connector 6 via a seat transmission rod 8, and the transmission link 4 is connected to the backrest rotating rod 7 via the backrest... The transmission rod 9 is connected; the mechanical extension device has a normal sitting state and an assisted standing state. When switching from the normal sitting state to the assisted standing state, the actuator 3 drives the transmission link 4 to rotate upward relative to the base 1. The transmission link 4, the base 1, the seat connecting member 6 and the seat transmission rod 8 form a seat lifting four-bar linkage mechanism. The transmission link 4, the base 1, the backrest rotating rod 7 and the backrest transmission rod 9 form a backrest lifting four-bar linkage mechanism. The transmission link 4 drives the backrest rotating rod 7 and the seat connecting member 6 to rotate together relative to the base 1 through the seat lifting four-bar linkage mechanism and the backrest lifting four-bar linkage mechanism. The rear ends of the backrest rotating rod 7 and the seat connecting member 6 are lifted upward and suspended in the air. The backrest connecting member 5 is lifted together with the backrest rotating rod 7.

[0044] Structurally, the mechanical extension device uses a four-bar linkage mechanism for lifting the seat, consisting of a transmission link 4, a base 1, a seat connector 6, and a seat transmission rod 8, and a four-bar linkage mechanism for lifting the backrest, consisting of a transmission link 4, a base 1, a backrest rotating rod 7, and a backrest transmission rod 9. This allows the transmission link 4 to simultaneously lift the backrest and the seat, thus achieving the function of assisting in getting up.

[0045] In terms of function and effect, the mechanical extension device consumes more energy for overall lifting and requires a more demanding actuator 3. However, the presence of the backrest rotation rod 7 allows the backrest connector 5 to be lifted in the same way as the seat connector 6, achieving partial lifting of the backrest connector 5 and the seat connector 6 in the mechanical extension device. This is more energy-efficient, requires less power from the actuator 3, has a simpler structure, smaller size, is easier to transport and move, and is less expensive. Furthermore, compared to the overall lifting mechanical extension device, simply lifting the seat and backrest is more targeted. It does not simply lift the person but assists the user in getting up and off the seat, providing a better experience. Compared to the mechanical extension device that can only lift the seat, the backrest can both propel the user left and right and prevent the upper body from falling backward, thus providing better assistance in getting up and is safer.

[0046] Specifically, such as Figure 1 ,4 As shown in Figure 7, the base 1 is roughly a U-shaped frame, including a front fixed tube 10, a rear fixed tube 11, and two fixed plates 12 located on the left and right sides. The rear end of the actuator 3 is rotatably connected to the rear fixed tube 11. The mechanical extension units 2 on both sides are respectively connected to the fixed plates 12 on both sides. The mechanical extension unit 2 also includes a footstool connector 13, a footstool linkage assembly 14, a seat crossbar 15, a first seat linkage 16, a second seat linkage 17, and a backrest linkage 18. The connecting piece 13 is configured to connect to the footstool of the sofa and is retracted and extended via the footstool connecting rod assembly 14; the backrest connecting piece 5 is rotatably mounted on the backrest rotating rod 7 at a single point, and one end of the backrest connecting rod 18 is rotatably connected to the backrest transmission rod 9, while the other end is rotatably connected to the front end of the backrest connecting piece 5, and can drive the backrest connecting piece 5 to rotate relative to the backrest rotating rod 7; the seat crossbar 15 is connected to the fixing plate 12 of the base 1 via the first seat connecting rod 16 and the second seat connecting rod 17, the first seat... The lower ends of connecting rod 16 and the second seat connecting rod 17 are rotatably connected to the fixed plate 12. The upper ends of the first seat connecting rod 16 and the second seat connecting rod 17 are rotatably connected to the seat crossbar 15. The second seat connecting rod 17 is located behind the first seat connecting rod 16. The upper end of the second seat connecting rod 17 is rotatably connected to the rear end of the seat crossbar 15. The upper end of the first seat connecting rod 16 is rotatably connected to the middle of the seat crossbar 15. In the normal sitting position, the seat connecting piece 6 is engaged. When the seat connector 6 is in an assisted standing position, the rear end of the seat connector 6 detaches from the seat connector 15 and is lifted upwards. A backing plate 19 extends outwards from the rear of the seat connector 6. The backing plate 19 is bent and can rest on the seat connector 15. In addition, a side plate 20 is fixedly provided at the front end of each of the two fixing plates 12. The upper and lower ends of the side plate 20 protrude from the fixing plate 12. The two ends of the front fixing tube 10 are fixedly connected to the middle of the two side plates 20.

[0047] like Figure 7-9As shown, the footstool connector 13 is connected to the footstool linkage assembly 14. The footstool linkage assembly 14 is rotatably connected to the upper end of the side plate 20 and the front part of the seat crossbar 15. In the normal sitting and assisted standing positions, both the footstool connector 13 and the footstool linkage assembly 14 are retracted. Moreover, since the seat crossbar 15 and the side plate 20 remain fixed during this process (the fact that the seat crossbar 15 remains fixed during this process will be explained later), the footstool connector 13 and the footstool linkage assembly 14 do not move at all. Compared with previous mechanical extension devices, the structure is more mature and the movement of the mechanism is simpler. This mechanical extension device also... Including the reclining position, when switching from the normal sitting position to the reclining position, the actuator 3 drives the transmission link 4 and causes the seat crossbar 15 to move backward and upward. The first seat link 16 and the second seat link 17 both rotate backward. At the same time, the footstool link assembly 14 extends, and the transmission link 4 also drives the backrest transmission rod 9 to rotate backward. The backrest link 18 moves accordingly and causes the backrest connector 5 to rotate backward relative to the backrest rotation rod 7. The footstool connector 13 and the footstool link assembly 14 are related to the reclining position. In this state, they extend to provide a place for the user to rest their feet. However, the specific movement and connection of the two are similar to those of the applicant's previous patents and are not the focus of this invention.

[0048] Furthermore, such as Figure 2-5 As shown, the seat crossbar 15 is roughly L-shaped, including a roughly vertical short connecting rod 21 and a roughly horizontal long connecting rod 22. The front end of the seat connector 6 is rotatably connected to the upper end of the short connecting rod 21, and the front end of the transmission link 4 is rotatably connected to the lower end of the short connecting rod 21. The seat crossbar 15 plays a significant role in this invention, no longer simply providing support for the seat connector 6. The transmission link 4 can also directly pull its movement without the need for other connecting rods. Moreover, the transmission link 4 can also rotate relative to the seat crossbar 15, making the overall movement simpler. The front end of the backrest rotating rod 7 is rotatably connected to the lower end of the side plate 20. The seat connector 6 is located above the transmission link 4, and the backrest rotating rod 7 is located below the transmission link 4. The rotation points of the three are also distributed sequentially from top to bottom. Therefore, during the transition from the normal sitting state to the assisted standing state, the transmission link 4, the seat connector 6, and the backrest rotating rod 7 will all rotate forward and upward, with their positions offset from each other and without interference.

[0049] The backrest transmission rod 9 is roughly triangular in shape, with its three ends rotatably connected to the transmission connecting rod 4, the backrest rotating rod 7, and the backrest connecting rod 18, respectively. The upper end of the backrest transmission rod 9 is rotatably connected to the rear end of the transmission connecting rod 4, the front end of the backrest transmission rod 9 is rotatably connected to the front end of the backrest connecting rod 18, and the rear end of the backrest transmission rod 9 is rotatably connected to the backrest rotating rod 7. The seat transmission rod 8 is a straight rod, with its two ends rotatably connected to the seat connecting piece 6 and the transmission connecting rod 4, respectively. When the transmission connecting rod 4... When the base 1 rotates upward, the seat transmission rod 8 moves upward and drives the seat connector 6 to rotate upward relative to the base 1. During the process of switching from the normal sitting state to the assisted standing state, the backrest transmission rod 9 is driven by the transmission link 4 and drives the backrest rotation rod 7 to rotate. When switching from the normal sitting state to the reclining state, the backrest transmission rod 9 is driven by the transmission link 4 and drives the backrest link 18 to move, thereby causing the backrest connector 5 to rotate backward relative to the backrest rotation rod 7. After reclining, the user's back can be reliably rested on it.

[0050] The actuator 3 is rotatably connected to a drive tube 23, which is fixedly connected to the transmission linkage 4 of the two mechanical extension units 2.

[0051] The backrest rotation rods 7 on both sides are connected by two connecting pipes 24 and together form a frame structure. In the normal sitting and lying position, the backrest rotation rods 7 and the connecting pipes 24 rest on the rear fixed pipe 11.

[0052] Furthermore, such as Figure 3 , 9As shown, the mechanical extension device has a normal sitting state, an assisted standing state, and a lying state. Therefore, a specific movement is required to achieve state switching: A limiting post 25 arranged in the left-right direction is fixedly provided at the upper end of the side plate 20 near the first seat link 16. The limiting post 25 is located in front of the first seat link 16 and is configured to abut against the first seat link 16 to prevent the first seat link 16 from continuing to rotate forward and downward. That is, when switching from the normal sitting state to the assisted standing state, the limiting post 25 restricts the first seat link 16 from continuing to rotate forward and downward, so that the seat crossbar 15 remains stationary during this process, thereby causing the transmission link 4 to drive the seat connecting member 6 and the backrest rotating rod 7 to rotate; a limiting plate 26 is provided on the backrest rotating member. The limiting plate 26 is bent and extends outward. A limiting wheel 2 protruding from the second seat link 17 is provided on the second seat link 17. 7; In the normal sitting position, the backrest rotating component rests against the base 1, and the limiting plate 26 is located behind the limiting wheel 27; In the reclining position, the second seat connecting rod 17 rotates backward and causes the limiting wheel 27 to rest against the limiting plate 26, and when switching from the reclining position to the normal sitting position, the limiting wheel 27 prevents the limiting plate 26 and the backrest rotating rod 7 from lifting; In the mechanical extension device, the function of the limiting is generally to regulate the movement of the connecting rod, so that the connecting rod can move along the designed movement trajectory to realize the function of the mechanical extension device. Here, the limiting wheel 27 and the limiting plate 26 also have such functions. First, after they come into contact, they limit the movement, ending the movement from the normal sitting position to the reclining position. Second, when switching from the reclining position to the normal sitting position, they prevent the backrest rotating rod 7 from lifting (only stopping the initial movement is needed), so that the overall movement can proceed according to the designed trajectory.

[0053] like Figure 4-6 As shown, in the normal sitting position, the footstool connector 13 and footstool linkage assembly 14 are folded together at the front of the mechanical extension unit 2. The first seat linkage 16 and the second seat linkage 17 are both tilted forward. The first seat linkage 16 rests on the limiting post 25. The seat crossbar 15 remains roughly horizontal. The seat connector 6 rests on the seat crossbar 15 and remains roughly horizontal with the seat crossbar 15. The transmission linkage 4 also remains roughly horizontal. The backrest rotation rod 7 remains roughly horizontal. The front end of the backrest linkage 18 tilts downward, and the backrest connector 5 tilts slightly backward.

[0054] like Figure 7-9As shown, in the reclining state, both the footstool connector 13 and the footstool linkage assembly 14 extend forward. The first seat linkage 16 and the second seat linkage 17 are roughly vertical, and the limiting wheel 27 of the second seat linkage 17 rests on the limiting plate 26 of the backrest rotation rod 7. The seat connector 6 still rests on the seat crossbar 15, and both are higher and further back than in the normal sitting state. Since the transmission linkage 4 is connected to the seat crossbar 15, its state is similar. The backrest transmission rod 9 rotates upward and backward, the backrest linkage 18 is lifted, and the backrest connector 5 tilts further backward relative to the normal sitting state. The backrest rotation rod 7 remains roughly horizontal.

[0055] like Figure 1-3 As shown, in the assisted standing state, the footstool connector 13 and footstool linkage assembly 14 are folded together at the front of the mechanical extension unit 2. The first seat linkage 16 and the second seat linkage 17 are both tilted forward. The first seat linkage 16 rests on the limiting post 25. The seat crossbar 15 remains roughly horizontal. The rear ends of the seat connector 6, transmission linkage 4, and backrest rotation rod 7 are all raised and tilted. Compared with the normal sitting state, the backrest connector 5 is closer to the backrest rotation rod 7.

[0056] like Figure 12 , 13 As shown, when switching from the normal sitting position to the reclining position, the actuator 3 shortens and drives the transmission link 4 to move backward. The transmission link 4 drives the seat crossbar 15, the seat transmission rod 8, and the backrest transmission rod 9 to move, and maintains a roughly horizontal position under the action of the seat crossbar 15 and the backrest transmission rod 9. The seat crossbar 15 drives the first seat link 16 and the second seat link 17 to rotate upward and backward. The seat crossbar 15, the seat connector 6, and the transmission link 4 all rise and move backward. The backrest transmission rod 9 rotates backward relative to the backrest rotating rod 7, and its front end rotates upward, driving the backrest link 18 to move. The backrest link 18 moves backward. At the same time as the seat crossbar 15 moves, it drives the footstool link assembly 14 to extend until the limit wheel 27 rests on the limit plate 26. The actuator 3 then extends again to switch from the reclining position back to the normal sitting position.

[0057] like Figure 10 , 11As shown, when switching from the normal sitting state to the assisted standing state, the actuator 3 extends and drives the rotating link to move forward. Since the limiting post 25 abuts against the first seat link 16, the first seat link 16 cannot continue to move forward. Therefore, the seat crossbar 15 can only remain stationary. Consequently, the transmission link 4 can only rotate relative to the seat crossbar 15, that is, the rear end of the transmission link 4 rotates forward and upward. The transmission link 4 drives the seat transmission rod 8 and the backrest transmission rod 9 to move. The seat transmission rod 8 drives the seat connector 6 to rotate relative to the seat crossbar 15, and its rear end rotates forward and upward. The backrest transmission rod 9 pulls the backrest rotating rod 7 to rotate relative to the fixed plate 12, and its rear end rotates forward and upward until the actuator 3 can no longer extend. The actuator 3 then shortens again to switch back from the assisted standing state to the normal sitting state.

Claims

1. A mechanical extension device with an assistive standing function, characterized in that: The device includes a base, mechanical extension units mirror-mounted on both sides of the base, and actuators for driving the mechanical extension units. Each mechanical extension unit includes a transmission link, a backrest connector, a seat connector, and a backrest rotating rod. The backrest connector is mounted on the backrest rotating rod. One end of the actuator is rotatably connected to the base, and the other end acts on the transmission link of the mechanical extension unit. The transmission link, seat connector, and backrest rotating rod are all rotatably mounted relative to the base. The transmission link is connected to the seat connector via a seat transmission link, and the transmission link is connected to the backrest rotating rod via a backrest transmission link. This mechanical extension device has a positive... When switching from the normal sitting position to the assisted standing position, the actuator drives the transmission link to rotate upward relative to the base. The transmission link, base, seat connector, and seat transmission rod form a four-bar linkage for seat lifting. The transmission link, base, backrest rotation rod, and backrest transmission rod form a four-bar linkage for backrest lifting. The transmission link drives the backrest rotation rod and seat connector to rotate relative to the base through the four-bar linkage for seat lifting and backrest lifting. The rear ends of the backrest rotation rod and seat connector are lifted upward and suspended in the air. The backrest connector is lifted together with the backrest rotation rod. The seat connector is rotatably connected to a seat crossbar. In the normal sitting position, the seat connector rests against the seat crossbar. In the assisted standing position, the rear end of the seat connector detaches from the seat crossbar and lifts upward. The seat crossbar is connected to the base via a first seat link and a second seat link. The lower ends of both the first and second seat links are rotatably connected to the base. A limiting post is provided on the base. The limiting post is located in front of the first seat link and is configured to abut against the first seat link to prevent the first seat link from continuing to rotate forward and downward. When switching from the normal sitting position to the assisted standing position, the limiting post restricts the first seat link from continuing to rotate forward and downward, so that the seat crossbar remains stationary during this process, thereby causing the transmission link to drive the seat connector and the backrest rotation rod to rotate.

2. The mechanical extension device with assistive standing function according to claim 1, characterized in that: The upper ends of both the first and second seat connecting rods are rotatably connected to the seat crossbar, and the second seat connecting rod is located behind the first seat connecting rod. The upper end of the second seat connecting rod is rotatably connected to the rear end of the seat crossbar, and the upper end of the first seat connecting rod is rotatably connected to the middle of the seat crossbar.

3. The mechanical extension device with assistive standing function according to claim 2, characterized in that: The base is roughly in the shape of a U-shaped frame, including a front fixed tube, a rear fixed tube, and two fixed plates located on the left and right sides. The rear end of the actuator is rotatably connected to the rear fixed tube, and the mechanical extension units on both sides are respectively connected to the fixed plates on both sides.

4. The mechanical extension device with assistive standing function according to claim 3, characterized in that: A side plate is also fixedly provided at the front end of the fixed plate, with both the upper and lower ends of the side plate protruding from the fixed plate; the limiting post is located at the upper end of the side plate near the first seat connecting rod; the lower end of the side plate is rotatably connected to the backrest rotating rod.

5. The mechanical extension device with assistive standing function according to claim 2, characterized in that: The mechanical extension unit also includes a footstool connector, which is connected to the base and the seat crossbar via a footstool linkage assembly. The footstool connector and the footstool linkage assembly are retracted and extended. In the normal sitting and assisted standing states, both the footstool connector and the footstool linkage assembly are retracted. The mechanical extension device also includes a reclining state. When switching from the normal sitting state to the reclining state, the actuator drives the transmission linkage and moves the seat crossbar backward and upward. The first seat linkage and the second seat linkage rotate backward, while the footstool linkage assembly extends and the backrest connector rotates backward relative to the backrest rotation rod.

6. The mechanical extension device with assistive standing function according to claim 5, characterized in that: The backrest rotating component is equipped with a limiting plate, and the second seat connecting rod is equipped with a limiting wheel. In the normal sitting position, the backrest rotating component rests against the base, and the limiting plate is located behind the limiting wheel. In the reclining position, the second seat connecting rod rotates backward and causes the limiting wheel to rest against the limiting plate. When switching from the reclining position to the normal sitting position, the limiting wheel prevents the limiting plate and the backrest rotating rod from lifting.

7. The mechanical extension device with assistive standing function according to claim 1, characterized in that: The seat crossbar is roughly L-shaped, including a roughly vertical short connecting rod and a roughly horizontal long connecting rod. The front end of the seat connector is rotatably connected to the upper end of the short connecting rod, and the front end of the transmission link is rotatably connected to the lower end of the short connecting rod.

8. The mechanical extension device with assistive standing function according to claim 1, characterized in that: The seat connector is located above the transmission link, and the backrest rotating rod is located below the transmission link.

9. The mechanical extension device with assistive standing function according to claim 1, characterized in that: The backrest transmission rod is roughly a triangular plate-shaped body, with its three ends rotatably connected to the transmission link, the backrest rotation rod, and a backrest link, respectively. The backrest link is also rotatably connected to the backrest connector and drives the backrest connector to rotate relative to the backrest rotation rod.

10. The mechanical extension device with assistive standing function according to claim 1, characterized in that: The seat transmission rod is a straight rod, with its two ends rotatably connected to the seat connector and the transmission link, respectively. When the transmission link rotates upward relative to the base, the seat transmission rod moves upward and drives the seat connector to rotate upward relative to the base.

11. The mechanical extension device with assistive standing function according to claim 1, characterized in that: The actuator has a drive tube rotatably connected to its front end, and the drive tube is fixedly connected to the transmission linkage of the two mechanical extension units.

12. The mechanical extension device with assistive standing function according to claim 1, characterized in that: The backrest rotation rods on both sides are connected by two connecting pipes and together form a frame structure.

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