Mechanical stretching device and seat unit

Abstract

The invention discloses a mechanical stretching device and a seat unit. The mechanical stretching device can prevent the mechanical stretching device from overturning when the mechanical stretching device is in a lying posture position. The mechanical stretching device further comprises a swing assembly and a supporting assembly, the swing assembly is movably connected to the base, the supporting assembly comprises a second supporting rod and a third supporting rod, one end of the third supporting rod is rotationally connected to the swing assembly, the other end of the third supporting rod is rotationally connected to the second supporting rod, and one end of the second supporting rod is movably connected to the leg assembly. A roller is arranged at the other end of the second supporting rod; in the process that the mechanical stretching device is changed from the sitting posture position to the TV posture position, the third supporting rod and the swing assembly are relatively static, and the second supporting rod rotates in the third direction so as to reduce the height of the rolling wheel; in the process that the mechanical stretching device is converted from the TV posture position to the lying posture position, the third supporting rod and the swing assembly move relatively, and the second supporting rod moves forwards in the first direction and rotates in the third direction so that the rolling wheel can be supported on the ground.

Description

Technical Field

[0001] This application relates to the field of seating technology, and in particular to a mechanical extension device and a seat unit. Background Technology

[0002] To meet users' needs for comfort and functionality in various complex scenarios, some seats on the market can be adjusted to multiple postures, including an upright sitting posture, a TV posture with legs extended, and a near-fully reclining posture.

[0003] It is worth noting that when transitioning from a standard sitting posture to a TV posture or reclining posture in this type of seating, the moving parts, such as the seat cushion, backrest, and leg support, often move forward as a whole. Since these moving parts integrate components such as motors and frames, they possess considerable weight. When they move forward as a whole, the center of gravity of the seating system shifts significantly forward. If this shift in the center of gravity is not adequately anticipated or properly balanced in the structural design, it may reduce the overall stability of the seating under extreme angles or specific load conditions, posing a potential safety hazard of forward tipping. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a mechanical extension device that can prevent the mechanical extension device from tipping over when in a lying position.

[0005] This application also proposes a seat unit having the aforementioned mechanical extension device.

[0006] According to a first aspect embodiment of the present application, the mechanical extension device includes a base, a seat, a backrest assembly, a leg assembly, and a drive device. The leg assembly and the backrest assembly are rotatably connected to the base and disposed on opposite sides of the base. The drive device is rotatably connected to the leg assembly. The mechanical extension device has a sitting position, a TV position, and a lying position. During the process of changing the mechanical extension device from the sitting position to the TV position, the drive device drives the base to move along a first direction and drives the leg assembly to extend along the first direction. During the process of changing the mechanical extension device from the TV position to the lying position, the drive device drives the base to move along the first direction and drives the backrest assembly to rotate relative to the base along a second direction. The mechanical extension device further includes a swing assembly and a support assembly. The swing assembly is movably connected to the base. The support assembly includes a second support rod and a third support rod. One end of the third support rod is rotatably connected to the swing assembly, and the other end of the third support rod is rotatably connected to the second support rod. The other end of the second support rod is provided with a roller. During the process of the mechanical extension device changing from a seated position to a TV position, the third support rod and the swing assembly remain relatively stationary, and the second support rod rotates in a third direction to lower the height of the roller. During the process of the mechanical extension device changing from a TV position to a reclining position, the third support rod and the swing assembly move relative to each other. The second support rod moves forward in a first direction and rotates in a third direction to support the roller on the ground.

[0007] The mechanical extension device according to the embodiments of this application has at least the following beneficial effects: the base, backrest assembly, and leg assembly respectively provide support for the user's buttocks, back, and legs. The drive device can coordinate the movement of the three components, allowing the device to switch between a sitting position, a TV position, and a lying position to adapt to the sitting posture requirements in different usage scenarios. When the mechanical extension device is in the sitting position, the angle between the base and backrest assembly and the horizontal plane is small, and the leg assembly is in a retracted state; when the mechanical extension device is in the TV position, the angle between the base and backrest assembly is basically maintained, and the leg assembly extends outward; when the mechanical extension device is in the lying position, the angle between the base and backrest assembly further increases, and the leg assembly remains extended. During the transition of the mechanical extension device from a seated position to a TV position, the base moves forward relative to the base along the first direction, causing the overall center of gravity of the device to shift forward. At this time, the third support rod and the swing assembly remain relatively stationary, while the second support rod rotates along the third direction, lowering the height of the rollers. During the transition of the mechanical extension device from the TV position to a reclining position, the base continues to move forward along the first direction, and the overall center of gravity continues to shift forward. The third support rod and the swing assembly generate relative motion, while the second support rod moves forward along the first direction and rotates along the third direction, causing the rollers to contact the ground. This enhances the stability of the device during posture transitions and effectively avoids the risk of tipping over that may be caused by the forward shift of the center of gravity.

[0008] According to some embodiments of this application, the support assembly further includes a first support rod, one end of which is rotatably connected to a second support rod, and the other end of which is rotatably connected to the leg assembly. The first support rod is used to drive the second support rod to rotate. During the process of the mechanical extension device changing from a seated position to a TV position, the first support rod rotates relative to the second support rod in a fourth direction; during the process of the mechanical extension device changing from a TV position to a lying position, the first support rod rotates relative to the second support rod in a fourth direction, and the height of the base is raised by the leg assembly.

[0009] According to some embodiments of this application, one of the swing assembly and the third support rod is provided with a track, and the other is provided with a guide; During the transition of the mechanical extension device from a seated position to a TV position, the guide is stationary relative to the track; during the transition of the mechanical extension device from a TV position to a reclining position, the guide moves along the track to support the support assembly on the ground.

[0010] According to some embodiments of this application, the track is formed as a guide groove disposed in the swing assembly, the guide is disposed in the third support rod, the guide is movably inserted into the guide groove, and the guide groove includes a proximal end and a distal end along a first direction; When the mechanical extension device is in a seated and / or TV position, the guide is located at the distal end; when the mechanical extension device is in a reclining position, the guide is located at the proximal end.

[0011] According to some embodiments of this application, when the mechanical extension device is in a seated position, the track and the guide are in clearance fit, and / or when the mechanical extension device is in a TV position, the track and the guide are in clearance fit, and / or when the mechanical extension device is in a reclining position, the track and the guide are in clearance fit.

[0012] According to some embodiments of this application, the inner wall of the proximal end is provided with a first cushioning pad, and the inner wall of the distal end is provided with a second cushioning pad; when the mechanical extension device is in a sitting position and a TV position, the guide contacts the second cushioning pad; when the mechanical extension device is in a lying position, the guide contacts the first cushioning pad.

[0013] According to some embodiments of this application, the surface of the guide is provided with a third buffer pad, which contacts the inner wall of the guide groove.

[0014] According to some embodiments of this application, the guide is in contact with the inner wall surface of the track.

[0015] According to some embodiments of this application, the guide member is fixedly connected to the third support rod, and the guide member and the third support rod are detachably connected.

[0016] According to some embodiments of this application, the third support rod is provided with at least one first fastener, and the guide is fixedly connected to the third support rod by the first fastener.

[0017] According to some embodiments of this application, the guide is rotatably connected to the third support rod, and the guide and the third support rod are detachably connected.

[0018] According to some embodiments of this application, the third support rod is provided with at least one first fastener, and the guide is rotatably connected to the third support rod through the first fastener so that the guide can rotate about the first fastener as an axis.

[0019] According to some embodiments of this application, the guide has an arc surface, the guide contacts the inner wall of the track through the arc surface, and the connecting force between the guide and the swing assembly or the third support rod is greater than the frictional force generated by the guide moving along the track.

[0020] According to some embodiments of this application, the third support rod includes a first straight section, a second straight section, and a first bent section. The first straight section and the second straight section are connected at an angle through the first bent section. The guide is disposed on the first bent section. The end of the first straight section is rotatably connected to the second support rod, and the end of the second straight section is rotatably connected to the swing assembly. The second straight section is provided with a first non-planar structure, and the portions of the second straight section on both sides of the first non-planar structure are located on different planes.

[0021] According to some embodiments of this application, the second support rod includes a third straight section, a second bent section, a fourth straight section, a third bent section, and a mounting section. The third straight section is rotatably connected to the first support rod, and the mounting section is used to mount the roller. The third straight section is angularly connected to the fourth straight section through the second bent section. The third support rod is rotatably connected to the second bent section, and the fourth straight section is angularly connected to the mounting section through the third bent section. Both the third straight section and the fourth straight section are provided with a second non-plane structure. The portions of the third straight section on both sides of the second non-plane structure are located in different planes, and the portions of the fourth straight section on both sides of the second non-plane structure are located in different planes.

[0022] According to some embodiments of this application, the first support rod includes a fifth straight section, a fourth bent section, and a sixth straight section. The fifth straight section is rotatably connected to the second support rod, and the sixth straight section is rotatably connected to the leg assembly. The fifth straight section is connected to the sixth straight section at an angle through the fourth bent section. The fifth straight section is provided with a third non-plane structure at the position where it connects to the fourth curved section, and the portions of the first support rod on both sides of the third non-plane structure are located on different planes.

[0023] According to some embodiments of this application, the swing assembly includes a first swing rod, a second swing rod, a third swing rod, a fourth swing rod, a fifth swing rod, a sixth swing rod, and a seventh swing rod. The track is disposed on the first swing rod. One end of the first swing rod is rotatably connected to one end of the second swing rod, and the other end of the second swing rod is rotatably connected to one end of the third swing rod. The other end of the third swing rod is rotatably connected to the base. One end of the fourth swing rod is rotatably connected to the second swing rod, and the other end of the fourth swing rod is rotatably connected to one end of the fifth swing rod. The other end of the fifth swing rod is rotatably connected to the base. One end of the sixth swing rod is rotatably connected to the fifth swing rod, and the other end of the sixth swing rod is rotatably connected to the first swing rod. One end of the seventh swing rod is rotatably connected to the fourth swing rod, and the other end of the seventh swing rod is rotatably connected to the sixth swing rod. During the process of the mechanical extension device changing from a seated position to a TV position, the swing component is relatively stationary with respect to the base; during the process of the mechanical extension device changing from a TV position to a reclining position, the swing component moves relative to the base along a first direction. During the process of the mechanical extension device changing from the TV position to the lying position, the height of the sixth swing rod is greater than the height of the second swing rod. The second swing rod swings relative to the third swing rod in the fourth direction, and the sixth swing rod swings relative to the fifth swing rod in the fifth direction, so as to drive the second support rod to rotate and reduce its height through the third support rod.

[0024] According to some embodiments of this application, the base is fixedly provided with a first limiting member; when the mechanical extension device is in a seated position or a TV position, the third swing rod contacts the first limiting member to restrict the movement of the swing assembly.

[0025] According to some embodiments of this application, the base is fixedly provided with a second limiting member; when the mechanical extension device is in a seated position or a TV position, the fifth swing rod contacts the second limiting member to restrict the movement of the swing assembly.

[0026] According to some embodiments of this application, the base is fixedly provided with a third limiting member; when the mechanical extension device is in a lying position, the third swing rod contacts the third limiting member to restrict the movement of the swing assembly.

[0027] According to some embodiments of this application, the leg assembly includes a leg extension assembly and a leg transmission assembly, wherein the leg transmission assembly is used to drive the leg extension assembly to extend or retract. The leg extension assembly includes a first leg link, a second leg link, a third leg link, a fourth leg link, and a leg support mounting assembly. One end of the first leg link is rotatably connected to the base, and the other end of the first leg link is rotatably connected to one end of the second leg link. The other end of the second leg link is rotatably connected to the leg support mounting assembly. One end of the third leg link is rotatably connected to the base, and the other end of the third leg link is rotatably connected to one end of the fourth leg link. The other end of the fourth leg link is rotatably connected to the leg support mounting assembly. The rotatable connection position of the first leg link to the base is higher than the rotatable connection position of the second leg link to the base. The leg transmission assembly is rotatably connected to the first leg link. The fourth leg link is fixedly provided with a fourth limiting member; when the mechanical extension device is in the TV position or lying position, the first leg link contacts the fourth limiting member to restrict the rotation of the first leg link.

[0028] According to some embodiments of this application, the leg transmission assembly includes a first leg transmission rod and a second leg transmission rod. One end of the first leg transmission rod is rotatably connected to a first leg connecting rod, and the other end of the first leg transmission rod is rotatably connected to one end of the second leg transmission rod. The second leg transmission rod is rotatably connected to the base, the swing assembly is rotatably connected to the second leg transmission rod, and the support assembly is rotatably connected to the second leg transmission rod. When the second leg transmission rod rotates, the second leg transmission rod drives the leg extension assembly to extend or retract via the first leg transmission rod.

[0029] According to some embodiments of this application, the swing assembly includes a first swing rod, the first swing rod is rotatably connected to the second leg transmission rod, and a fifth limiting member is fixedly provided at the end of the first swing rod near the leg transmission assembly; When the mechanical extension device is in the TV position and / or lying position, the second leg drive rod contacts the fifth limiting member to restrict the rotation of the second leg drive rod.

[0030] According to some embodiments of this application, when the mechanical extension device is in a sitting position and / or a lying position, the second leg drive rod contacts the fifth limiting member to restrict the rotation of the second leg drive rod; When the mechanical extension device is in a sitting or lying position, the second leg transmission rod contacts the fifth limiting member at different positions.

[0031] According to some embodiments of this application, the driving device includes a driver and a drive rod inserted into the driver, the leg assembly includes a second leg transmission rod, the swing assembly includes a third swing rod, the driver is connected to the third swing rod, and the drive rod is connected to the second leg transmission rod.

[0032] According to some embodiments of this application, the third swing rod is fixedly connected to a support structure, the support structure is fixedly connected to a first ear plate extending toward the driver, and the driver is rotatably connected to the first ear plate; The second leg drive rod is fixedly connected to an extension plate, which extends along a first direction. The extension plate is fixedly connected to a connecting structure, which is fixedly connected to a second ear plate extending toward the drive rod. The drive rod is rotatably connected to the second ear plate.

[0033] According to a second aspect embodiment of the present application, the seat unit includes a seat cushion, a backrest, a leg rest, and the aforementioned mechanical extension device. The seat cushion is connected to the base, the backrest is connected to the backrest assembly, and the leg rest is connected to the leg assembly. When the mechanical extension device is in a reclining position, the angle between the seat cushion and the horizontal plane is 14°-26°, and the height of the leg assembly is greater than the height of the backrest assembly.

[0034] The seat unit according to the embodiments of this application has at least the following beneficial effects: Employing the mechanical extension device of the first aspect of this application, the base, backrest assembly, and leg assembly respectively provide support for the user's buttocks, back, and legs. The drive device can coordinate the movement of the three components, allowing the device to switch between a sitting position, a TV position, and a reclining position to adapt to different seating needs in various usage scenarios. When the mechanical extension device is in the sitting position, the angle between the base and backrest assembly and the horizontal plane is small, and the leg assembly is in a retracted state; when the mechanical extension device is in the TV position, the angle between the base and backrest assembly is basically maintained, and the leg assembly extends outward; when the mechanical extension device is in the reclining position, the angle between the base and backrest assembly further increases, and the leg assembly remains extended. During the transition of the mechanical extension device from a seated position to a TV position, the base moves forward relative to the base along the first direction, causing the overall center of gravity of the device to shift forward. At this time, the third support rod and the swing assembly remain relatively stationary, while the second support rod rotates along the third direction, lowering the height of the rollers. During the transition of the mechanical extension device from the TV position to a reclining position, the base continues to move forward along the first direction, and the overall center of gravity continues to shift forward. The third support rod and the swing assembly generate relative motion, while the second support rod moves forward along the first direction and rotates along the third direction, causing the rollers to contact the ground. This enhances the stability of the device during posture transitions and effectively avoids the risk of tipping over that may be caused by the forward shift of the center of gravity.

[0035] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0036] The present application will be further illustrated below with reference to the accompanying drawings and embodiments. It should be noted that the embodiments illustrated in the following drawings are exemplary and are only used to explain the present application, and should not be construed as limiting the present application.

[0037] Figure 1 This is a schematic diagram of the mechanical extension device of this application in a seated position from one perspective; Figure 2 This is a schematic diagram of the mechanical extension device of this application in a seated position from another perspective; Figure 3 This is a schematic diagram of the mechanical extension device of this application in a TV position from one viewpoint; Figure 4 This is a structural schematic diagram from another perspective when the mechanical extension device of the present application is in the TV position; Figure 5 This is a schematic diagram of the mechanical extension device of this application in a lying position from one perspective; Figure 6 This is a schematic diagram of the mechanical extension device of this application embodiment in a lying position from another perspective; Figure 7 This is a mechanical extension device according to an embodiment of this application. Figure 4 A magnified view of part A in the middle; Figure 8 This is a schematic diagram of the support component in the mechanical extension device according to an embodiment of this application, taken from one perspective. Figure 9 This is a structural schematic diagram of the support component in the mechanical extension device according to another embodiment of this application; Figure 10 This is a schematic diagram of the swing component in the mechanical extension device of this application embodiment; Figure 11 This is a schematic diagram of the leg extension component in the mechanical extension device of this application embodiment; Figure 12 This is a schematic diagram of the leg transmission assembly in the mechanical extension device of this application embodiment; Figure 13 This is a schematic diagram of the installation of the drive device in the mechanical extension device of this application embodiment.

[0038] Figure label: 101. Base; 102. Base; 200. Backrest assembly; 300. Leg assembly; 301. First leg link; 302. Second leg link; 303. Third leg link; 304. Fourth leg link; 305. Leg support mounting assembly; 306. First leg transmission rod; 307. Second leg transmission rod; 308. Second protrusion; 400. Swing assembly; 401. Track; 402. Proximal end; 403. Distal end; 404. First swing rod; 405. Second swing rod; 406. Third swing rod; 407. Fourth swing rod; 408. Fifth swing rod; 409. Sixth swing rod; 410. Seventh swing rod; 411. Synchronizing rod; 500. Support assembly; 501. Guide; 502. First support rod; 503. Second support rod; 504. Third support rod; 505. First straight section; 506. Second straight section; 507. First bending section; 508. Roller; 509. Third straight section; 510. Second bending section; 511. Fourth straight section; 512. Third bending section; 513. Mounting section; 514. Fifth straight section; 515. Fourth bending section; 516. Sixth straight section; 517. First non-planar structure; 518. Second non-planar structure; 519. Third non-planar structure; 601. First limiting component; 602. Second limiting component; 603. Third limiting component; 604. Fourth limiting component; 605. Fifth limiting component; 701. Driving device; 702. Driver; 703. Driving rod; 704. Support structure; 705. First ear plate; 706. Connecting structure; 707. Extension plate; 708. Second ear plate. Detailed Implementation

[0039] The embodiments of this application are described in detail below with reference to the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0040] In the description of this application, it should be understood that the terms "center", "middle", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0041] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0042] In the description of this application, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0043] In the description of this application, the use of terms such as "one embodiment," "some embodiments," "an example," "some instances," "some embodiments," "illustrative embodiment," "example," "specific example," and "some examples" indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0044] This application provides a mechanical extension device, the structure of which includes a base 101, a base 102, a backrest assembly 200, a leg assembly 300, and a drive device 701. The base 102 is the basic support component of the device and its position is fixed; the base 101 can move relative to the base 102, and during the movement, it coordinates with related structures such as the backrest assembly 200 and the leg assembly 300 to jointly achieve posture adjustment. The main function of the base 101 is to support the user's buttocks, providing basic support for the user when seated.

[0045] Specifically, the leg assembly 300 is rotatably connected to the base 101 and can be extended or retracted by rotation. When the leg assembly 300 is extended, it can effectively support the user's legs and relieve leg fatigue; when the leg assembly 300 is retracted, it can be stored at the bottom of the base 101 to avoid interfering with the user's normal sitting posture and to maintain a neat appearance.

[0046] The backrest assembly 200 is also rotatably connected to the base 101 and is used to support the user's back. The backrest assembly 200 can be adjusted by rotating to adjust the angle α between itself and the horizontal plane. When the angle α is small, it helps the user maintain a normal sitting posture or similar posture; when the angle is large, it allows the user to approach a lying posture, improving lying comfort.

[0047] Understandably, the leg assembly 300 and the backrest assembly 200 are respectively arranged on opposite sides of the base 101, corresponding to the user's legs and back, conforming to an ergonomic layout. Simultaneously, the drive device 701 is rotatably connected to the leg assembly 300 and can output linear motion. The drive device 701 is used to drive the base 101, backrest assembly 200, and leg assembly 300 to move collaboratively, achieving smooth switching between postures.

[0048] Furthermore, the mechanical extension device of this application has three usage positions: a sitting position, a TV position, and a lying position. See the accompanying illustrations for details. Figure 1 , Figure 2 As shown, in the seated position, the leg support component 300 retracts to the bottom of the base 101, and the angle α between the backrest component 200 and the horizontal plane is small, which helps to keep the user's back upright; Figure 3 , Figure 4 As shown, in the TV posture position, the leg support component 300 extends to support the legs, while the angle α between the backrest component 200 and the horizontal plane remains small, facilitating user relaxation and entertainment; Figure 5 , Figure 6 As shown, in the lying position, the leg assembly 300 remains extended, and the angle α between the backrest assembly 200 and the horizontal plane is significantly increased, allowing the user to adopt a near-flat posture and thus achieve full-body relaxation.

[0049] During the process of the mechanical extension device changing from a seated position to a TV position, the drive device 701 pushes the base 101 along the first direction (i.e. Figures 1 to 6 The mechanical extension device moves along the X-axis (i.e., in front of the device) and simultaneously drives the leg assembly 300 to extend in the same direction. During the transition from the TV position to the reclining position, the drive device 701 continues to push the base 101 along the first direction and drives the backrest assembly 200 relative to the base 101 along the second direction (i.e., in front of the device). Figure 1 , Figure 3 , Figure 5 The rotation is in the Y direction (corresponding to the leaning-back direction). Similarly, the process of the mechanical extension device changing from the TV position to the sitting position is the reverse of the process of the mechanical extension device changing from the sitting position to the TV position, and will not be described in detail here.

[0050] Based on the above-described motion mechanism, it is known that during the transition from a seated position to a lying position, the base 101 and related structures continuously move forward along the first direction. Since these structures themselves have a certain weight, the center of gravity of the entire device also shifts forward, which may cause the mechanical extension device to tip forward.

[0051] To address potential stability issues arising from the forward shift of the center of gravity, the mechanical extension device of this application also includes a swing assembly 400 and a support assembly 500. The swing assembly 400 is located at the bottom of the base 101 and is movably connected to the base 102. When the device is in a lying position, the support assembly 500 can contact the ground, providing additional support and enhancing overall stability. The support assembly 500 is movably connected to the swing assembly 400. During the transition of the mechanical extension device from the TV position to the lying position, the movement of the swing assembly 400 will cause the support assembly 500 to gradually descend and eventually contact the ground. By forming a support point with the ground, the mechanical extension device can effectively balance the overturning moment caused by the forward shift of the center of gravity, preventing the mechanical extension device from tilting forward and ensuring safe use.

[0052] Furthermore, such as Figure 8 and Figure 9 As shown, the support assembly 500 includes a second support rod 503 and a third support rod 504. One end of the third support rod 504 is rotatably connected to the swing assembly 400, and the other end is rotatably connected to the second support rod 503. One end of the second support rod 503 is movably connected to the leg assembly 300, and the other end is equipped with a freely rotating roller 508. The support assembly 500 mainly forms stable auxiliary support by contacting the ground through the roller 508 at the end of the second support rod 503, thereby enhancing the anti-overturning capability of the mechanical extension device in different postures.

[0053] Specifically, during the process of the mechanical extension device changing from a seated position to a TV position, the third support rod 504 remains relatively stationary with respect to the swing assembly 400; at this time, the third support rod 504 does not participate in posture adjustment. Simultaneously, the second support rod 503 moves along a third direction (i.e., Figure 3 and Figure 5 The roller 508 rotates in the T direction, causing it to move closer to the ground, thus initially lowering its height and preparing for full contact with the ground.

[0054] During the transition of the mechanical extension device from the TV position to the lying position, relative movement begins between the third support rod 504 and the swing assembly 400. At this point, the third support rod 504 begins to participate in the linkage adjustment of the mechanism and performs its function. Simultaneously, the second support rod 503 performs a compound movement, moving forward in the first direction while continuing to rotate in the third direction, thereby further lowering the height of the roller 508 until the roller 508 fully contacts the ground and forms effective support. Through this coordinated movement mechanism, the support assembly 500 can provide ground contact support when the device's center of gravity shifts forward, ensuring the overall stability of the device in the lying position.

[0055] The contents of this application are described in detail below with reference to specific embodiments. It should be noted that the following description is merely illustrative and not a specific limitation of this application.

[0056] In some embodiments, the support assembly 500 further includes a first support rod 502, the first support rod 502, the second support rod 503 and the third support rod 504 together form a motion unit, and the second support rod 503 is connected to the leg assembly 300 through the first support rod 502.

[0057] Furthermore, one end of the first support rod 502 is rotatably connected to the second support rod 503, and the other end of the first support rod 502 is rotatably connected to the leg assembly 300. Since the drive device 701 directly acts on the leg assembly 300 and causes the leg assembly 300 to move accordingly, the leg assembly 300 can drive the first support rod 502 to move during the movement, and then drive the second support rod 503 to rotate through the first support rod 502, so that the roller 508 on the second support rod 503 gradually approaches and contacts the ground.

[0058] Regarding the first support rod 502, during the process of the mechanical extension device changing from a seated position to a TV position, the first support rod 502 moves relative to the second support rod 503 along the fourth direction (i.e., Figure 8 and Figure 9 The first support rod 502 rotates in the S direction, causing the first support rod 502 to initially move away from the second support rod 503. During the process of the mechanical extension device changing from the TV position to the lying position, the first support rod 502 continues to rotate relative to the second support rod 503 in the fourth direction and increases in height, causing the first support rod 502 and the second support rod 503 to continue to move away from each other until the roller 508 on the second support rod 503 contacts the ground.

[0059] In some embodiments, one of the swing assembly 400 and the support assembly 500 is provided with a track 401, and the other is provided with a guide 501. The guide 501 can move along the track 401 under the constraint of the track 401. Under the constraint of the guide 501 and the track 401, the support assembly 500 can move in a preset direction of movement, ensuring that the support assembly 500 gradually approaches and contacts the ground during the movement.

[0060] Specifically, during the process of the mechanical extension device changing from a seated position to a TV position, the swing component 400 does not move, and the second support rod 503 approaches the ground by rotating, but does not touch the ground. During this process, the guide 501 and the track 401 remain relatively stationary. During the process of the mechanical extension device changing from a TV position to a lying position, the swing component 400 and the support component 500 move in coordination, and the guide 501 moves along the track 401, so that the second support rod 503 gradually approaches and supports the ground.

[0061] In some embodiments, in order to ensure that the guide 501 can move smoothly along the track 401, a clearance fit is required between the track 401 and the guide 501. However, when the mechanical extension device is located in certain specific positions, a transition fit or an interference fit may also be used between the track 401 and the guide 501.

[0062] Specifically, when the mechanical extension device is in a seated position, the track 401 and the guide 501 are in clearance fit; and / or, when the mechanical extension device is in a TV position, the track 401 and the guide 501 are in clearance fit; and / or, when the mechanical extension device is in a reclining position, the track 401 and the guide 501 are in clearance fit.

[0063] like Figure 7 As shown, in some embodiments, the track 401 is formed as a guide groove, and the guide groove is disposed on the swing assembly 400. Meanwhile, the guide 501 is disposed on the third support rod 504 and protrudes from the side of the third support rod 504.

[0064] Furthermore, the guide groove defines the movement space of the guide member 501, which is inserted into the guide groove and can move within its range. When the mechanical extension device changes between the TV position and the lying position, the guide groove and the guide member 501 can limit the movement of the support assembly 500. Therefore, the length and extension direction of the guide groove need to be set according to the preset movement mode of the support assembly 500.

[0065] Specifically, in the first direction, the guide groove extends in a manner that gradually increases in height, forming a certain angle.

[0066] Simultaneously, both the proximal end 402 and the distal end 403 of the guide groove are closed in the first direction. When the guide member 501 moves to the proximal end 402 or the distal end 403, the guide member 501 reaches its limit position. Furthermore, the closed proximal end 402 and distal end 403 also prevent the guide member 501 from dislodging from the guide groove, ensuring a continuous and effective connection. When the mechanical extension device is in a seated or TV position, the guide member 501 is always located at the distal end 403; when the mechanical extension device is in a reclining position, the guide member 501 is located at the proximal end 402. Therefore, when the mechanical extension device changes between the TV position and the reclining position, the guide member 501 moves along the guide groove.

[0067] In some embodiments, to prevent the guide 501 from violently colliding with the inner wall of the proximal end 402 or the inner wall of the distal end 403 at the extreme position of movement, the inner wall of the proximal end 402 is provided with a first buffer pad, and the inner wall of the distal end 403 is provided with a second buffer pad.

[0068] Furthermore, the first and second buffer pads can be made of elastic materials such as rubber to cushion collisions. When the mechanical extension device is in a seated or TV position, the guide 501 contacts the second buffer pad, which cushions the impact between the guide 501 and the inner wall of the distal end 403. When the mechanical extension device is in a reclining position, the guide 501 contacts the first buffer pad, which cushions the impact between the guide 501 and the inner wall of the proximal end 402.

[0069] In some embodiments, the surface of the guide 501 is provided with a third cushioning pad. When the mechanical extension device is in a seated position and a TV position, the third cushioning pad on the guide 501 contacts the inner wall of the distal end 403 and provides cushioning between the guide 501 and the inner wall of the distal end 403; when the mechanical extension device is in a reclining position, the third cushioning pad on the guide 501 contacts the inner wall of the proximal end 402 and provides cushioning between the guide 501 and the inner wall of the proximal end 402.

[0070] In addition, since the third buffer pad is disposed on the surface of the guide 501, when the guide 501 is located between the distal end 403 and the proximal end 402, the third buffer pad on the guide 501 will also contact the inner wall of the guide groove.

[0071] In some embodiments, the guide 501 and the inner wall of the track 401 are in surface contact. Surface contact helps to reduce the pressure generated during the contact process, thereby protecting the guide 501 and the inner wall of the track 401 and preventing structural damage to them.

[0072] In some embodiments, the guide 501 is fixedly connected to the third support rod 504. Since the guide 501 cannot move relative to the third support rod 504, after the guide 501 is installed on the track 401, the guide 501 and the track 401 are slidably connected. Therefore, there is sliding friction between the guide 501 and the track 401.

[0073] Furthermore, the guide 501 is detachably connected to the third support rod 504. During installation, the position on the third support rod 504 for installing the guide 501 is first aligned with the rail 401, and then the guide 501 is installed. Therefore, the guide 501 does not require excessive installation space to ensure a match with the rail 401.

[0074] Meanwhile, the third support rod 504 is provided with at least one first fastener, and the guide 501 is connected to the third support rod 504 through the first fastener. Since the guide 501 is fixedly connected to the support assembly 500 in this embodiment, the first fastener needs to lock the guide 501 to the support assembly 500.

[0075] In some embodiments, the guide 501 is rotatably connected to the third support rod 504. Since the guide 501 can rotate on the support assembly 500, when the guide 501 is installed on the track 401, the guide 501 and the track 401 are in a rolling connection. Therefore, rolling friction occurs between the guide 501 and the track 401. This embodiment uses rolling friction instead of sliding friction, which significantly reduces the frictional force between the guide 501 and the track 401. Furthermore, in this embodiment, the guide 501 is also detachably connected to the third support rod 504, facilitating the installation of the guide 501.

[0076] Furthermore, the third support rod 504 is provided with at least one first fastener, and the guide 501 is connected to the third support rod 504 through the first fastener. It is understood that the guide 501 can rotate about the first fastener as an axis. Since the guide 501 is rotatably connected to the third support rod 504 in this embodiment, the first fastener needs to allow sufficient space for the rotation of the guide 501. Therefore, the first fastener in this embodiment cannot lock the guide 501 to the third support rod 504.

[0077] In some embodiments, two first fasteners are provided, which clamp the guide 501 on opposite sides. The two first fasteners can be screws or nuts. If the guide 501 needs to be fixedly connected to the third support rod 504, the two first fasteners are tightened on opposite sides of the guide 501, thereby clamping the guide 501 and preventing it from rotating. If the guide 501 needs to be rotatably connected to the third support rod 504, the distance between the two first fasteners is adjusted so that the distance is slightly greater than the thickness of the guide 501, thus reserving space for the guide 501 to rotate.

[0078] In some embodiments, the guide 501 has an arcuate surface, through which the guide 501 contacts the inner wall of the track 401. Specifically, the guide 501 is generally cylindrical, and the size of its arcuate surface matches the inner wall shape of the proximal end 402 and the distal end 403, ensuring that the guide 501 stably contacts the proximal end 402 or the distal end 403.

[0079] Furthermore, during the movement of the guide 501 within the track 401, in order to prevent the guide 501 from detaching from the third support rod 504, the connecting force between the guide 501 and the swing assembly 400 or the third support rod 504 is greater than the frictional force generated by the guide 501 moving along the track 401, ensuring that the guide 501 can overcome the frictional force to move.

[0080] like Figure 8 and Figure 9 As shown, in some embodiments, the support assembly 500 includes a first support rod 502, a second support rod 503, a third support rod 504, and a roller 508. When the mechanical extension device is in a lying position, the roller 508 is used to contact the ground, thereby providing stable support for the mechanical extension device and preventing it from tipping over due to changes in its center of gravity.

[0081] Furthermore, the third support rod 504 includes a first straight section 505, a second straight section 506, and a first bent section 507. The first straight section 505 and the second straight section 506 are connected at an angle through the first bent section 507, so that the third support rod 504 is generally formed in an "L" shape. A guide member 501 is disposed on the first bent section 507. The end of the first straight section 505 is rotatably connected to the second support rod 503, and the end of the second straight section 506 is rotatably connected to the swing assembly 400.

[0082] Understandably, since the position where the guide 501 needs to be installed on the third support rod 504 is not on the line connecting the end of the first straight section 505 and the end of the second straight section 506, a first bending section 507 needs to be provided in the middle of the third support rod 504 to extend the extension range of the third support rod 504. Understandably, the first bending section 507 on the third support rod 504 can pass through the position where the guide 501 needs to be installed; therefore, when the guide 501 is installed at the first bending section 507, it can meet the actual requirements.

[0083] Specifically, provided that the roller 508 on the second support rod 503 can contact the ground, the specific shapes of the first support rod 502 and the second support rod 503 can be set according to the actual situation.

[0084] Furthermore, the second straight section 506 is provided with a first non-planar structure 517, and the portions of the second straight section 506 on both sides of the first non-planar structure 517 are located on different planes. It is understood that during the movement of the third support rod 504, the third support rod 504 will pass through other rods of the device, and the first non-planar structure 517 can avoid interference with other rods when the third support rod 504 moves, thereby optimizing the spatial distribution of the rods in the device.

[0085] like Figure 8 and Figure 9 As shown, in some embodiments, the second support rod 503 includes a third straight portion 509, a second bent portion 510, a fourth straight portion 511, a third bent portion 512, and a mounting portion 513. The third straight portion 509 is rotatably connected to the first support rod 502, and the end of the mounting portion 513 is used to mount a roller 508. Furthermore, the third straight portion 509 is angularly connected to the fourth straight portion 511 via the second bent portion 510, the third support rod 504 is rotatably connected to the second bent portion 510, and the fourth straight portion 511 is angularly connected to the mounting portion 513 via the third bent portion 512.

[0086] The third support rod 504 and the second support rod 503 need to be rotatably connected at a preset position. Under the limitation of the preset position, the second support rod 503 is provided with a second bending part 510 connecting the third straight part 509 and the fourth straight part 511, thereby expanding the extension range of the second support rod 503. The requirement can be met by rotatably connecting the third support rod 504 and the second support rod 503 at the position of the second bending part 510.

[0087] Meanwhile, if the second support rod 503 does not have the third bending portion 512, the fourth straight portion 511 and the mounting portion 513 are located on the same straight line. Therefore, the structural strength remains consistent at any position on the entire structure formed by the fourth straight portion 511 and the mounting portion 513. However, when the roller 508 on the second support rod 503 contacts the ground and bears the weight of the device, the second support rod 503 is tilted, which can easily lead to deformation and damage to the entire structure formed by the fourth straight portion 511 and the mounting portion 513. However, this application provides the third bending portion 512 at the position most prone to bending damage in the entire structure formed by the fourth straight portion 511 and the mounting portion 513. The third bending portion 512 can improve the structural strength at that position, thereby ensuring the structural strength of the second support rod 503 and enabling it to bear a greater weight.

[0088] Furthermore, both the third straight section 509 and the fourth straight section 511 are provided with a second non-planar structure 518. The portions of the third straight section 509 on both sides of the second non-planar structure 518 are located on different planes, and the portions of the fourth straight section 511 on both sides of the second non-planar structure 518 are also located on different planes. The second non-planar structure 518 can avoid other rods when the second support rod 503 moves, preventing structural interference between the second support rod 503 and other rods, thereby optimizing the spatial distribution of the rods in this device.

[0089] like Figure 8 and Figure 9 As shown, in some embodiments, the first support rod 502 includes a fifth straight section 514, a fourth bent section 515, and a sixth straight section 516. The fifth straight section 514 is rotatably connected to the second support rod 503, and the sixth straight section 516 is rotatably connected to the leg assembly 300. The fifth straight section 514 and the sixth straight section 516 are connected at an angle through the fourth bent section 515.

[0090] When the mechanical extension device is in a seated position, the distance between the second support rod 503 and the first support rod 502 is minimal, and the second support rod 503 will rotate to reach the position where the first support rod 502 is hinged to the leg assembly 300. If the first support rod 502 is a straight rod, the second support rod 503 will structurally interfere with the first support rod 502 in this state. Therefore, this application provides a fourth bending portion 515 on the first support rod 502, so that the first support rod 502 is appropriately moved away from the second support rod 503, thereby avoiding the movement space of the second support rod 503.

[0091] Furthermore, a third non-planar structure 519 is provided at the position where the fifth straight section 514 connects to the fourth curved section 515. The portions of the first support rod 502 on both sides of the third non-planar structure 519 are located on different planes. The third non-planar structure 519 can avoid other rods when the first support rod 502 moves, preventing structural interference between the first support rod 502 and other rods, thereby optimizing the spatial distribution of the rods in this device.

[0092] like Figure 10 As shown, in some embodiments, the swing assembly 400 includes a first swing rod 404, a second swing rod 405, a third swing rod 406, a fourth swing rod 407, a fifth swing rod 408, a sixth swing rod 409, and a seventh swing rod 410. A track 401 is disposed on the first swing rod 404. One end of the first swing rod 404 is rotatably connected to one end of the second swing rod 405, and the other end of the second swing rod 405 is rotatably connected to one end of the third swing rod 406. The other end of the third swing rod 406 is rotatably connected to the base 102. The fourth... One end of the swing arm 407 is rotatably connected to the middle of the second swing arm 405. The other end of the fourth swing arm 407 is rotatably connected to one end of the fifth swing arm 408. The other end of the fifth swing arm 408 is rotatably connected to the base 102. One end of the sixth swing arm 409 is rotatably connected to the fifth swing arm 408. The other end of the sixth swing arm 409 is rotatably connected to the first swing arm 404. One end of the seventh swing arm 410 is rotatably connected to the fourth swing arm 407. The other end of the seventh swing arm 410 is rotatably connected to the middle of the sixth swing arm 409. Simultaneously, the end of the second straight section 506 is rotatably connected to the middle of the sixth swing arm 409.

[0093] In terms of shape, the first swing arm 404, the second swing arm 405, the fourth swing arm 407, and the fifth swing arm 408 roughly form a quadrilateral. Furthermore, since the third swing arm 406 and the fifth swing arm 408 are both rotatably connected to the base 102, the swing assembly 400 is movably connected to the base 102 as a whole.

[0094] During the process of the mechanical extension device changing from a seated position to a TV position, the swing component 400 is relatively stationary with respect to the base 102, and the swing component 400 does not function at this time; during the process of the mechanical extension device changing from a TV position to a reclining position, the swing component 400 moves relative to the base 102 along the first direction.

[0095] Specifically, during the movement of the swing assembly 400, the height of the sixth swing rod 409 is greater than the height of the second swing rod 405, and the second swing rod 405 swings in a "V" shape relative to the third swing rod 406 along the fifth direction, meaning that the second swing rod 405 is positioned on opposite sides of the third swing rod 406 at its two extreme swing positions. Simultaneously, the sixth swing rod 409 also swings in a "V" shape relative to the fifth swing rod 408 along the sixth direction. Since the end of the second straight section 506 is rotatably connected to the middle of the sixth swing rod 409, as the sixth swing rod 409 swings, it can drive the second support rod 503 to lower its height via the third support rod 504, ensuring that the roller 508 is supported on the ground. The fifth direction is... Figure 10 In the M direction, the sixth direction is... Figure 10 The N direction in the middle.

[0096] In addition, the specific shapes of the first swing rod 404, the second swing rod 405, the third swing rod 406, the fourth swing rod 407, the fifth swing rod 408, the sixth swing rod 409, and the seventh swing rod 410 can be set according to the actual situation.

[0097] It is worth noting that the mechanical extension device is equipped with a backrest assembly 200, a leg assembly 300, a swing assembly 400, and a support assembly 500 on both opposite sides to ensure the stability of the mechanical extension device. To ensure synchronous movement of the backrest assembly 200, leg assembly 300, swing assembly 400, and support assembly 500 on both opposite sides, such as... Figure 13 As shown, the first swing rod 404 and the fifth swing rod 408 are provided with synchronizing rods 411 extending along the width direction of the mechanical extension device. One synchronizing rod 411 connects the first swing rod 404 on opposite sides, and the other synchronizing rod 411 connects the fifth swing rod 408 on opposite sides.

[0098] like Figure 3 As shown, in some embodiments, a first limiting member 601 is fixedly provided on the base 102, and the first limiting member 601 protrudes from the side of the base 102. When the mechanical extension device is in a seated or TV position, the third swing arm 406 contacts the first limiting member 601, thereby restricting the movement of the swing assembly 400; when the mechanical extension device is in a reclining position, the third swing arm 406 disengages from the first limiting member 601.

[0099] like Figure 3As shown, in some embodiments, a second limiting member 602 is fixedly provided on the base 102, and the second limiting member 602 protrudes from the side of the base 102. When the mechanical extension device is in a seated or TV position, the fifth swing rod 408 contacts the second limiting member 602, thereby restricting the movement of the swing assembly 400; when the mechanical extension device is in a reclining position, the fifth swing rod 408 disengages from the second limiting member 602.

[0100] like Figure 3 As shown, in some embodiments, the base 102 is fixedly provided with a third limiting member 603, and the third limiting member 603 protrudes from the side of the base 102; when the mechanical extension device is in a lying position, the third swing rod 406 contacts the third limiting member 603, thereby restricting the movement of the swing assembly 400; when the mechanical extension device is in a sitting position or a TV position, the third swing rod 406 disengages from the third limiting member 603.

[0101] like Figure 11 As shown, in some embodiments, the leg assembly 300 includes a leg extension assembly and a leg transmission assembly. The leg transmission assembly is used to drive the leg extension assembly to extend or retract.

[0102] Furthermore, the leg extension assembly includes a first leg link 301, a second leg link 302, a third leg link 303, a fourth leg link 304, and a leg support mounting assembly 305. The leg support mounting assembly 305 is used to mount a leg support that supports the user's legs. One end of the first leg link 301 is rotatably connected to the base 101, and the other end of the first leg link 301 is rotatably connected to one end of the second leg link 302. The other end of the second leg link 302 is rotatably connected to the leg support mounting assembly 305.

[0103] One end of the third leg link 303 is rotatably connected to the base 101, and the other end of the third leg link 303 is rotatably connected to one end of the fourth leg link 304. The other end of the fourth leg link 304 is rotatably connected to the leg support mounting assembly 305. The rotatable connection position of the first leg link 301 and the base 101 is higher than the rotatable connection position of the second leg link 302 and the base 101, and the leg transmission assembly is rotatably connected to the first leg link 301. Simultaneously, the middle portion of the first leg link 301 is rotatably connected to the middle portion of the fourth leg link 304.

[0104] Specifically, the shapes of the first leg link 301, the second leg link 302, the third leg link 303, and the fourth leg link 304 can be set according to the actual situation.

[0105] In addition, a fourth limiting member 604 is fixedly provided on the fourth leg link 304, and the fourth limiting member 604 protrudes from the fourth leg link 304. When the mechanical extension device is in the TV position or the lying position, the first leg link 301 contacts the fourth limiting member 604, thereby restricting the rotation of the first leg link 301; when the mechanical extension device is in the sitting position, the first leg link 301 disengages from the fourth limiting member 604.

[0106] like Figure 12 As shown, in some embodiments, the leg transmission assembly includes a first leg transmission rod 306 and a second leg transmission rod 307. One end of the first leg transmission rod 306 is rotatably connected to a first leg connecting rod 301, and the other end of the first leg transmission rod 306 is rotatably connected to one end of the second leg transmission rod 307. The second leg transmission rod 307 is rotatably connected to a base 101, a first swing rod 404 is rotatably connected to the second leg transmission rod 307, and a first support rod 502 is rotatably connected to the second leg transmission rod 307.

[0107] Understandably, when the second leg drive rod 307 rotates, it drives the leg extension assembly to extend or retract via the first leg drive rod 306. Specifically, the shapes of the first leg link 301, the second leg link 302, the third leg link 303, and the fourth leg link 304 can be set according to actual conditions.

[0108] like Figure 5 As shown, in some embodiments, a fifth limiting member 605 is fixedly provided at the end of the first swing arm 404 near the leg transmission assembly, that is, at the end away from the second swing arm 405, and the fifth limiting member 605 protrudes from the first swing arm 404.

[0109] When the mechanical extension device is in the TV position or lying position, the second leg transmission rod 307 contacts the fifth limiting member 605, thereby restricting the rotation of the second leg transmission rod 307; when the mechanical extension device is in the sitting position, the second leg transmission rod 307 disengages from the fifth limiting member 605.

[0110] In some embodiments, the fifth limiting member 605 can not only restrict the rotation of the second leg transmission rod 307 in the TV position and lying position of the mechanical extension device, but also restrict the rotation of the second leg transmission rod 307 in the sitting position of the mechanical extension device.

[0111] Furthermore, one end of the second leg drive rod 307, which is rotatably connected to the second swing rod 405, extends outward, and its outwardly extended portion can contact the fifth limiting member 605. Specifically, when the mechanical extension device is in a seated position, the outwardly extended portion of the second leg drive rod 307 contacts the fifth limiting member 605, thereby restricting the rotation of the second leg drive rod 307; during the process of the mechanical extension device changing from a seated position to a TV position, the outwardly extended portion of the second leg drive rod 307 disengages from the fifth limiting member 605, and as the second leg drive rod 307 rotates, the main body of the second leg drive rod 307 gradually approaches the fifth limiting member 605; when the mechanical extension device is in the TV position, the main body of the second leg drive rod 307 contacts the fifth limiting member 605, thereby restricting the rotation of the second leg drive rod 307. In addition, during the process of the mechanical extension device changing from the TV position to the lying position, the second leg transmission rod 307 is always in contact with the fifth limiting member 605, continuously restricting the rotation of the second leg transmission rod 307.

[0112] In some embodiments, the numerous limiting components involved in the mechanical extension device of this application can be installed in the form of fasteners, facilitating the disassembly and replacement of the limiting components. Furthermore, the rotational connection positions involved in the mechanical extension device of this application can all be set in the form of hinges.

[0113] like Figure 13 As shown, in some embodiments, the drive device 701 includes a driver 702 and a drive rod 703, with the drive rod 703 inserted into the driver 702. When the driver 702 is activated, it can drive the drive rod 703 to move, thereby increasing or decreasing the overall length of the drive device 701. Therefore, the drive device 701 can output linear motion.

[0114] Furthermore, the end of the actuator 702 is connected to the third swing arm 406, and the end of the drive arm 703 is connected to the second leg transmission arm 307. When the mechanical extension device changes from a seated position to a TV position, the drive device 701 can drive the leg assembly 300 and the support assembly 500 to move, but the backrest assembly 200 and the swing assembly 400 do not move; when the mechanical extension device changes from a TV position to a reclining position, the drive device 701 can drive the backrest assembly 200, the support assembly 500, and the swing assembly 400 to move, but the leg assembly 300 does not move.

[0115] In some embodiments, two swing assembly 400, two leg assembly 300, two back assembly and two support assembly 500 are provided and located on opposite sides of the mechanical extension device.

[0116] Furthermore, the mechanical extension device includes a support structure 704 and a connecting structure 706, which extend along the width direction of the mechanical extension device, such that the components located on opposite sides of the mechanical extension device are connected as a whole.

[0117] The support structure 704 is fixedly connected to the third swing rods 406 on both sides of the mechanical extension device, and the driver 702 is rotatably connected to the support structure 704. Specifically, a first ear plate 705 extending towards the driver 702 is fixedly connected to the support structure 704. The first ear plate 705 is equipped with a corresponding pivot, which connects the end of the driver 702 to the first ear plate 705. Therefore, the driver 702 is rotatably connected to the support structure 704 through the first ear plate 705.

[0118] Meanwhile, the connecting structure 706 is fixedly connected to the second leg transmission rods 307 on both sides of the mechanical extension device, and the drive rod 703 is rotatably connected to the connecting structure 706. Specifically, the second leg transmission rod 307 is fixedly connected to an extension plate 707, which extends along a first direction. The connecting structure 706 is fixedly connected to the extension plate 707, thus the connecting structure 706 is fixedly connected to the second leg transmission rod 307 via the extension plate 707. In addition, the connecting structure 706 is fixedly connected to a second ear plate 708 extending towards the drive rod 703. The second ear plate 708 is also equipped with a corresponding pivot, which connects the end of the drive rod 703 to the second ear plate 708. Therefore, the drive rod 703 is rotatably connected to the connecting structure 706 via the second ear plate 708.

[0119] In some embodiments, multiple drive devices 701 may be provided, with multiple drive devices 701 arranged side by side between the support structure 704 and the connecting structure 706, and each drive device 701 needs to maintain synchronous movement.

[0120] This application provides a seat unit, which includes a seat cushion, a backrest, a leg rest, and the aforementioned mechanical extension device. The seat cushion is connected to a base 101, the backrest is connected to a backrest assembly 200, and the leg rest is connected to a leg assembly 300.

[0121] When the mechanical extension device is in a reclining position, the angle between the seat cushion and the horizontal plane is 14°-26°, and the height of the leg assembly 300 is greater than the height of the backrest assembly 200.

[0122] In actual implementation, the base 101, backrest assembly 200, leg assembly 300, swing assembly 400, support assembly 500, and drive device 701 together constitute a collaborative support system. The base 101, as the main component supporting the user's buttocks, provides basic support for the body; the backrest assembly 200 conforms to the curve of the user's back, providing stable support; and the leg assembly 300 supports the legs. The drive device 701, as the power source, can control the movement of the base 101, backrest assembly 200, and leg assembly 300 according to user commands, allowing the mechanical extension device to switch between various preset postures, including common sitting, TV, and lying positions, meeting the user's posture needs in different usage scenarios. Specifically, in the sitting position, the angle between the base 101 and the horizontal plane is small, and the angle between the backrest assembly 200 and the horizontal plane is also small, providing relatively upright back support. At this time, the leg assembly 300 is in a retracted state, allowing the user's feet to land naturally. When shifting to the TV position, the tilt angle of the base 101 and the backrest assembly 200 remains basically unchanged, but the leg assembly 300 gradually extends, allowing the user's legs to stretch out, suitable for relaxing scenarios such as watching TV. When shifting to the reclining position, the angle between the base 101 and the horizontal plane increases significantly, and the backrest assembly 200 also tilts backward accordingly, putting the user in a near-flat position, while the leg assembly 300 remains extended, providing full-body support.

[0123] Furthermore, during the transition of the mechanical extension device from a seated position to a TV position, the base 101 moves relative to the base 102 along the first direction, thereby moderately shifting the center of gravity of the entire device forward. During this process, the swing component 400 remains stationary, while the support component 500 and leg component 300 move, causing the leg component 300 to gradually extend and the rollers 508 on the support component 500 to lower to a certain height. Simultaneously, the guide 501 remains relatively stationary within the track 401. As the mechanical extension device continues to transition from the TV position to a reclining position, the base 101 continues to move along the first direction, further pushing the overall center of gravity forward. During this process, the height of the base 101, along with the leg component 300, increases, the backrest component 200 adjusts its angle through a main rotation, and the swing component 400 and support component 500 move in coordination. At the same time, the guide 501 begins to move along the track 401, constrains the support assembly 500 to move along a predetermined path, and gradually rotates towards the ground until the roller 508 contacts the ground, forming an additional support point, which effectively improves the overall stability and safety of the device in the lying position and prevents the mechanical extension device from tipping forward when it is in the lying position.

[0124] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

Claims

1. A mechanical extension device, comprising a base, a seat, a backrest assembly, a leg assembly, and a drive device, wherein the leg assembly and the backrest assembly are rotatably connected to the base and disposed on opposite sides of the base, and the drive device is rotatably connected to the leg assembly; the mechanical extension device has a sitting position, a TV position, and a reclining position; during the process of the mechanical extension device changing from the sitting position to the TV position, the drive device drives the base to move along a first direction and drives the leg assembly to extend along the first direction; during the process of the mechanical extension device changing from the TV position to the reclining position, the drive device drives the base to move along the first direction and drives the backrest assembly to rotate relative to the base along a second direction, characterized in that: The mechanical extension device further includes a swing assembly and a support assembly. The swing assembly is movably connected to the base. The support assembly includes a second support rod and a third support rod. One end of the third support rod is rotatably connected to the swing assembly, and the other end of the third support rod is rotatably connected to the second support rod. The other end of the second support rod is provided with a roller. During the process of the mechanical extension device changing from a seated position to a TV position, the third support rod and the swing assembly remain relatively stationary, and the second support rod rotates in a third direction to lower the height of the roller. During the process of the mechanical extension device changing from a TV position to a reclining position, the third support rod and the swing assembly move relative to each other. The second support rod moves forward in a first direction and rotates in a third direction to support the roller on the ground.

2. The mechanical extension device according to claim 1, characterized in that, The support assembly further includes a first support rod, one end of which is rotatably connected to a second support rod, and the other end of which is rotatably connected to the leg assembly. The first support rod is used to drive the second support rod to rotate. During the process of the mechanical extension device changing from a seated position to a TV position, the first support rod rotates relative to the second support rod in a fourth direction; during the process of the mechanical extension device changing from a TV position to a lying position, the first support rod rotates relative to the second support rod in a fourth direction, and the height of the base is raised by the leg assembly.

3. The mechanical extension device according to claim 1, characterized in that, One of the swing assembly and the third support rod is provided with a track, and the other is provided with a guide. During the transition of the mechanical extension device from a seated position to a TV position, the guide is stationary relative to the track; during the transition of the mechanical extension device from a TV position to a reclining position, the guide moves along the track to support the support assembly on the ground.

4. The mechanical extension device according to claim 3, characterized in that, The track is formed as a guide groove disposed in the swing assembly, the guide is disposed on the third support rod, the guide is movably inserted into the guide groove, and the guide groove includes a proximal end and a distal end along a first direction; When the mechanical extension device is in a seated and / or TV position, the guide is located at the distal end; when the mechanical extension device is in a reclining position, the guide is located at the proximal end.

5. The mechanical extension device according to claim 3, characterized in that, When the mechanical extension device is in a seated position, the track and the guide are in clearance fit, and / or when the mechanical extension device is in a TV position, the track and the guide are in clearance fit, and / or when the mechanical extension device is in a reclining position, the track and the guide are in clearance fit.

6. The mechanical extension device according to claim 4, characterized in that, The inner wall of the proximal end is provided with a first cushioning pad, and the inner wall of the distal end is provided with a second cushioning pad; when the mechanical extension device is in a sitting position and a TV position, the guide contacts the second cushioning pad; when the mechanical extension device is in a lying position, the guide contacts the first cushioning pad.

7. The mechanical extension device according to claim 4, characterized in that, The surface of the guide is provided with a third buffer pad, which contacts the inner wall of the guide groove.

8. The mechanical extension device according to claim 3, characterized in that, The guide element contacts the inner wall surface of the track.

9. The mechanical extension device according to any one of claims 4-8, characterized in that, The guide component is fixedly connected to the third support rod, and the guide component and the third support rod are detachably connected.

10. The mechanical extension device according to claim 9, characterized in that, The third support rod is provided with at least one first fastener, and the guide is fixedly connected to the third support rod through the first fastener.

11. The mechanical extension device according to any one of claims 4-8, characterized in that, The guide is rotatably connected to the third support rod, and the guide and the third support rod are detachably connected.

12. The mechanical extension device according to claim 11, characterized in that, The third support rod is provided with at least one first fastener, and the guide is rotatably connected to the third support rod through the first fastener so that the guide can rotate about the first fastener as an axis.

13. The mechanical extension device according to any one of claims 3-8, characterized in that, The guide has an arc surface, and the guide contacts the inner wall of the track through the arc surface. The connecting force between the guide and the swing assembly or the third support rod is greater than the frictional force generated by the guide moving along the track.

14. The mechanical extension device according to claim 3, characterized in that, The third support rod includes a first straight section, a second straight section, and a first bent section. The first straight section and the second straight section are connected at an angle through the first bent section. The guide is disposed on the first bent section. The end of the first straight section is rotatably connected to the second support rod, and the end of the second straight section is rotatably connected to the swing assembly. The second straight section is provided with a first non-planar structure, and the portions of the second straight section on both sides of the first non-planar structure are located on different planes.

15. The mechanical extension device according to claim 2, characterized in that, The second support rod includes a third straight section, a second bent section, a fourth straight section, a third bent section, and a mounting section. The third straight section is rotatably connected to the first support rod. The mounting section is used to mount the roller. The third straight section is connected to the fourth straight section at an angle through the second bent section. The third support rod is rotatably connected to the second bent section. The fourth straight section is connected to the mounting section at an angle through the third bent section. Both the third straight section and the fourth straight section are provided with a second non-plane structure. The portions of the third straight section on both sides of the second non-plane structure are located in different planes, and the portions of the fourth straight section on both sides of the second non-plane structure are located in different planes.

16. The mechanical extension device according to claim 2, characterized in that, The first support rod includes a fifth straight section, a fourth bent section, and a sixth straight section. The fifth straight section is rotatably connected to the second support rod, and the sixth straight section is rotatably connected to the leg assembly. The fifth straight section and the sixth straight section are connected at an angle through the fourth bent section. The fifth straight section is provided with a third non-plane structure at the position where it connects to the fourth curved section, and the portions of the first support rod on both sides of the third non-plane structure are located on different planes.

17. The mechanical extension device according to claim 3, characterized in that, The swing assembly includes a first swing rod, a second swing rod, a third swing rod, a fourth swing rod, a fifth swing rod, a sixth swing rod, and a seventh swing rod. The track is disposed on the first swing rod. One end of the first swing rod is rotatably connected to one end of the second swing rod, and the other end of the second swing rod is rotatably connected to one end of the third swing rod. The other end of the third swing rod is rotatably connected to the base. One end of the fourth swing rod is rotatably connected to the second swing rod, and the other end of the fourth swing rod is rotatably connected to one end of the fifth swing rod. The other end of the fifth swing rod is rotatably connected to the base. One end of the sixth swing rod is rotatably connected to the fifth swing rod, and the other end of the sixth swing rod is rotatably connected to the first swing rod. One end of the seventh swing rod is rotatably connected to the fourth swing rod, and the other end of the seventh swing rod is rotatably connected to the sixth swing rod. During the process of the mechanical extension device changing from a seated position to a TV position, the swing component is relatively stationary with respect to the base; during the process of the mechanical extension device changing from a TV position to a reclining position, the swing component moves relative to the base along a first direction. During the process of the mechanical extension device changing from the TV position to the lying position, the height of the sixth swing rod is greater than the height of the second swing rod. The second swing rod swings relative to the third swing rod in the fourth direction, and the sixth swing rod swings relative to the fifth swing rod in the fifth direction, so as to drive the second support rod to rotate and reduce its height through the third support rod.

18. The mechanical extension device according to claim 17, characterized in that, The base is fixedly provided with a first limiting member; when the mechanical extension device is in a seated or TV position, the third swing rod contacts the first limiting member to restrict the movement of the swing assembly.

19. The mechanical extension device according to claim 17, characterized in that, The base is fixedly provided with a second limiting member; when the mechanical extension device is in a seated or TV position, the fifth swing rod contacts the second limiting member to restrict the movement of the swing assembly.

20. The mechanical extension device according to claim 17, characterized in that, The base is fixedly provided with a third limiting member; when the mechanical extension device is in a lying position, the third swing rod contacts the third limiting member to restrict the movement of the swing assembly.

21. The mechanical extension device according to any one of claims 1-8, 10, 12, 14-20, characterized in that, The leg assembly includes a leg telescopic assembly and a leg transmission assembly, wherein the leg transmission assembly is used to drive the leg telescopic assembly to extend or retract. The leg extension assembly includes a first leg link, a second leg link, a third leg link, a fourth leg link, and a leg support mounting assembly. One end of the first leg link is rotatably connected to the base, and the other end of the first leg link is rotatably connected to one end of the second leg link. The other end of the second leg link is rotatably connected to the leg support mounting assembly. One end of the third leg link is rotatably connected to the base, and the other end of the third leg link is rotatably connected to one end of the fourth leg link. The other end of the fourth leg link is rotatably connected to the leg support mounting assembly. The rotatable connection position of the first leg link to the base is higher than the rotatable connection position of the second leg link to the base. The leg transmission assembly is rotatably connected to the first leg link. The fourth leg link is fixedly provided with a fourth limiting member; when the mechanical extension device is in the TV position or lying position, the first leg link contacts the fourth limiting member to restrict the rotation of the first leg link.

22. The mechanical extension device according to claim 21, characterized in that, The leg transmission assembly includes a first leg transmission rod and a second leg transmission rod. One end of the first leg transmission rod is rotatably connected to the first leg connecting rod, and the other end of the first leg transmission rod is rotatably connected to one end of the second leg transmission rod. The second leg transmission rod is rotatably connected to the base. The swing assembly is rotatably connected to the second leg transmission rod, and the support assembly is rotatably connected to the second leg transmission rod. When the second leg drive rod rotates, it drives the leg extension assembly to extend or retract via the first leg drive rod.

23. The mechanical extension device according to claim 22, characterized in that, The swing assembly includes a first swing rod, which is rotatably connected to the second leg transmission rod. A fifth limiting member is fixedly provided at the end of the first swing rod near the end of the leg transmission assembly. When the mechanical extension device is in the TV position and / or lying position, the second leg drive rod contacts the fifth limiting member to restrict the rotation of the second leg drive rod.

24. The mechanical extension device according to claim 23, characterized in that, When the mechanical extension device is in a seated and / or lying position, the second leg drive rod contacts the fifth limiting member to restrict the rotation of the second leg drive rod; When the mechanical extension device is in a sitting or lying position, the second leg transmission rod contacts the fifth limiting member at different positions.

25. The mechanical extension device according to claims 1-8, 10, 12, 14-20, characterized in that, The drive device includes a driver and a drive rod inserted into the driver, the leg assembly includes a second leg transmission rod, the swing assembly includes a third swing rod, the driver is connected to the third swing rod, and the drive rod is connected to the second leg transmission rod.

26. The mechanical extension device according to claim 25, characterized in that, The third swing rod is fixedly connected to a support structure, and the support structure is fixedly connected to a first ear plate extending toward the driver, and the driver is rotatably connected to the first ear plate. The second leg drive rod is fixedly connected to an extension plate, which extends along a first direction. The extension plate is fixedly connected to a connecting structure, which is fixedly connected to a second ear plate extending toward the drive rod. The drive rod is rotatably connected to the second ear plate.

27. A seat unit, characterized in that, The device includes a seat cushion, a backrest, a leg rest, and a mechanical extension device as described in any one of claims 1 to 26, wherein the seat cushion is connected to the base, the backrest is connected to the backrest assembly, and the leg rest is connected to the leg assembly. When the mechanical extension device is in a reclining position, the angle between the seat cushion and the horizontal plane is 14°-26°, and the height of the leg assembly is greater than the height of the backrest assembly.

Images