Mechanical extension device for a seat unit and movable seat unit

Abstract

The invention provides a mechanical stretching device for a seating unit. The mechanical stretching device comprises a side plate; the seat frame can move relative to the side plates; the leg mechanism can be switched between a folded position and an unfolded position and comprises a main leg side plate and an auxiliary leg side plate which are used for being connected with the footstool in an attached mode and a leg stretching assembly hinged to the rear end of the main leg side plate and the rear end of the auxiliary leg side plate, and in the process that the leg mechanism is switched from the folded position to the unfolded position, the leg stretching assembly stretches out of the main leg side plate and the auxiliary leg side plate. The leg stretching assembly is unfolded, so that the main leg side plate and the auxiliary leg side plate are promoted to translate forwards relative to the seat frame; the transmission mechanism comprises a carrying connecting rod and a seat frame lifting assembly, and the seat frame lifting assembly is pivotally connected to the seat frame, the leg stretching assembly and the carrying connecting rod, so that the front part of the seat frame is lifted relative to the carrying connecting rod while the seat frame moves forwards relative to the carrying connecting rod. The invention also relates to a movable seating unit.

Description

Technical Field

[0001] The present invention relates to a mechanical extension device for a seat unit and a movable seat unit. Background Technology

[0002] Various types of movable seating are known in the prior art, such as sofas or chairs with multi-position conversion functions. As people's living standards improve, the demand for comfort in sofas and chairs is also increasing. In known designs, movable seating units typically have a mechanical extension mechanism, allowing them to switch between a sitting position, a TV position, and a reclining position. When the seat changes from a sitting position to a TV position, the footrest extends forward, while the angle between the backrest and the seat remains essentially unchanged. When the seat changes from a TV position to a reclining position, the footrest extends further forward and upward compared to the TV position, and the backrest reclines significantly backward.

[0003] In existing designs of this type of chair, to achieve a more comfortable posture, the legs of the attached footrest are often designed to be longer, so that the footrest can be positioned higher when unfolded and fully support the user's legs. However, this presents a risk of the legs accidentally falling off due to the excessive size of the leg structure and the large number of parts. Furthermore, the weight of the leg structure can hinder the achievement of a "zero-gravity" posture. Moreover, as users' demands for comfort continue to increase and their pursuit of zero-wall placement becomes increasingly extreme, existing designs of movable chairs cannot fully meet users' needs in terms of both comfort and space saving. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a more comfortable mechanical extension device for movable seats and a corresponding movable seat unit. The seat unit should meet the user's space requirements for zero-wall arrangement of the movable seat, and on the other hand, be able to achieve a "zero-gravity" posture with a reliable structure.

[0005] To address the aforementioned technical problem, the present invention provides a mechanical extension device for a seat unit, the mechanical extension device comprising: a side plate fixed relative to a support surface of the seat unit; a seat frame movable relative to the side plate, wherein the seat frame is used to mount the seat portion of the seat unit; a leg mechanism, wherein the leg mechanism is capable of changing between a folded position and an extended position, and includes a main leg side plate and a secondary leg side plate for attaching a footstool, and a leg extension assembly hinged to the rear ends of the main leg side plate and the secondary leg side plate, wherein, during the process of the leg mechanism changing from the folded position to the extended position, the leg extension assembly extends, thereby causing the main leg side plate and the secondary leg side plate to translate forward relative to the seat frame; and a transmission mechanism including a carrier linkage and a seat frame lifting assembly, wherein the seat frame lifting assembly is pivotally connected to the seat frame, the leg extension assembly, and the carrier linkage, thereby causing the front portion of the seat frame to lift relative to the carrier linkage while the seat frame moves forward relative to the carrier linkage.

[0006] According to the present invention, a seat frame lifting assembly is connected between the seat frame, the leg extension assembly, and the transport link, respectively. Thus, when the leg extension assembly moves relative to the seat frame, the seat frame lifting assembly deforms, causing the front portion of the seat frame connected thereto to change relative to the transport link in both the longitudinal and vertical directions. Accordingly, when the seat frame moves forward relative to the transport link, the front portion of the seat frame rises relative to the transport link; when the seat frame moves backward relative to the transport link, the front portion of the seat frame falls relative to the transport link. This facilitates the lifting of the leg assembly connected to the front portion of the seat frame.

[0007] In one embodiment, the leg mechanism further includes a leg support with supporting rollers, wherein the circumferential surface of the supporting rollers is provided with a groove, and the lower edge of the main leg side plate is slidably accommodated in the groove.

[0008] The leg support provides additional support for the leg mechanism, thus preventing it from accidentally falling off when extended.

[0009] In one embodiment, the leg support has a support link, wherein the upper end of the support link is hinged to the seat frame, and the support roller is rotatably connected to the lower end of the support link.

[0010] In one embodiment, the transmission mechanism further includes a seat frame swing arm, wherein the upper end of the seat frame swing arm is hinged to the rear of the seat frame, and the lower end of the seat frame swing arm is hinged to the rear of the transport link.

[0011] In one embodiment, the seat frame lifting assembly includes a rocker arm, a front lifting rod, a first rear lifting rod, and a second rear lifting rod, wherein the front lifting rod is hinged to the front end of the seat frame and the rocker arm, the rear end of the rocker arm is hinged to the leg extension assembly via the first rear lifting rod and the second rear lifting rod, and the rocker arm is hinged to a transport link between its front end and rear end.

[0012] According to the present invention, the rocker arm functions similarly to a lever. When the seat frame lifting assembly deforms, if the first and second rear lifting rods open, the rear end of the rocker arm is pressed down and the front end is raised, thereby lifting the front of the seat frame with the aid of the front lifting rod; if the first and second rear lifting rods close together, the rear end of the rocker arm rises and the front end falls, thereby lowering the front of the seat frame with the aid of the front lifting rod.

[0013] In one embodiment, the leg extension assembly includes a rear leg swing arm, wherein the upper end of the rear leg swing arm is hinged to the seat frame, wherein, during the transition from a retracted position to an extended position, the rear leg swing arm swings forward, and the main leg side plate and the secondary leg side plate translate forward relative to the seat frame.

[0014] In one embodiment, the lower end of the first rear lifting rod is hinged to the rear end of the rocker arm at a first transition point, the upper end of the first rear lifting rod is hinged to the rear end of the second rear lifting rod at a second transition point, and the second rear lifting rod is hinged to the rear leg swing arm at a third transition point, wherein the third transition point is located below the hinge point between the rear leg swing arm and the seat frame.

[0015] Therefore, when the leg extension assembly changes from the retracted position to the extended position, the swing of the rear leg lever causes the seat frame lifting assembly to deform, thereby causing the front of the seat frame to rise.

[0016] In one embodiment, the front end of the second rear lifting rod is hinged to the upper end of the front lifting rod at a fourth transition point, wherein the third transition point is located between the second transition point and the fourth transition point.

[0017] In one embodiment, as the rear leg swing arm swings forward, the angle formed by the line connecting the first rotation point to the second rotation point and the line connecting the third rotation point to the second rotation point increases, thereby causing the front of the seat frame to rise relative to the transport link.

[0018] In one embodiment, the leg extension assembly further includes a front leg swing arm, a front leg connecting rod, and a rear leg connecting rod, wherein the upper end of the front leg swing arm is hinged to the seat frame, the lower end of the front leg swing arm is hinged to the auxiliary leg side plate via the front leg connecting rod, and the lower end of the rear leg swing arm is hinged to the main leg side plate via the rear leg connecting rod.

[0019] In one embodiment, during the movement of the leg mechanism, the hinge points between the main leg side plate and the secondary leg side plate and the leg extension assembly are always located behind the front end of the seat frame.

[0020] According to the present invention, when the leg mechanism changes, the leg extension assembly remains within the longitudinal dimension of the seat frame and is not exposed from the front end of the seat frame, thereby avoiding the risk of pinching injury to the user's body parts when the seat unit changes posture, and greatly improving safety. Furthermore, when the leg mechanism is viewed from the side, only the main leg side plate and the secondary leg side plate are visible, and the intersecting hinges of the leg mechanism are not seen, thus further improving aesthetics.

[0021] In one embodiment, the mechanical extension device further includes a backrest mechanism, wherein the backrest mechanism includes a backrest bracket, a first backrest link, and a second backrest link, wherein the backrest bracket is used to attach the backrest of the seat unit and is hinged to the seat frame via the first backrest link and the second backrest link.

[0022] In one embodiment, the mechanical extension device is configured to switch between a sitting position and a lying position, wherein in the sitting position the leg mechanism is in a retracted position; and in the lying position the leg mechanism is in an extended position, the backrest support rotates rearward relative to the seat frame, and the seat frame moves forward relative to the side panel, wherein the highest point of the leg mechanism is higher than the highest point of the backrest support.

[0023] According to the present invention, the corresponding angle range of the seat unit ensures a comfortable angle between the user's thigh and calf, thigh and torso, and head and torso. Furthermore, in the reclining position, the highest point of the leg mechanism, i.e., the height of the footstool, is slightly higher than the highest point of the backrest mechanism, i.e., the height of the highest end of the backrest support, so that each part of the seat conforms to the user's body curve and achieves a "zero gravity" posture.

[0024] In one embodiment, the transmission mechanism further includes a front linkage assembly and a rear linkage assembly connected between the transport link and the side plate.

[0025] In one embodiment, the backrest mechanism further includes a backrest control assembly hinged between the side plate and the second backrest link, such that the rearward rotation of the backrest support relative to the seat frame lags behind the forward movement of the seat frame relative to the side plate.

[0026] In one embodiment, the backrest control assembly includes a first control link, a second control link, a third control link, and a fourth control link, wherein the lower ends of the first control link and the second control link are respectively hinged to the side plate, and the upper end of the first control link is hinged to the second backrest link at least through the fourth control link.

[0027] In one embodiment, the third control link, together with the first control link, the second control link, and the side plate, forms a four-bar linkage.

[0028] In one embodiment, the backrest control assembly further includes a fifth control link hinged between the fourth control link and the second backrest link.

[0029] In one embodiment, during the transition between a seated and a reclining position of the mechanical extension device, the translation of the main leg side plate and the auxiliary leg side plate relative to the seat frame and the rotation of the backrest support relative to the seat frame are mutually exclusive. This ensures the correct sequence of movements of the mechanical extension device. When the leg mechanism begins to translate outward relative to the seat frame, the backrest support does not rotate backward simultaneously. Thus, the main leg side plate and the auxiliary leg side plate extend outward relative to the seat frame first, while the backrest support remains substantially unchanged in relative position with respect to the seat frame, thereby achieving the TV position. Subsequently, as the transport linkage moves forward relative to the side plates, the backrest support rotates backward relative to the seat frame, thereby achieving the reclining position.

[0030] In one embodiment, the mechanical extension device further includes a linear electro-actuator.

[0031] Furthermore, the present invention also relates to a movable seat unit that includes the aforementioned mechanical extension device. Attached Figure Description

[0032] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0033] Figure 1a A perspective view schematically illustrates a mechanical extension device for a movable seat unit according to the present invention, in a TV position;

[0034] Figure 1b A perspective view schematically illustrates a mechanical extension device for a movable seat unit according to the present invention, in a reclining position;

[0035] Figure 2 A schematic side view of a mechanical extension device for a movable seat unit according to the invention, in a seated position, is shown.

[0036] Figure 3a schematically shown Figure 1aA partial perspective view of the mechanical extension device shown;

[0037] Figure 3b schematically shown Figure 1b A partial perspective view of the mechanical extension device shown;

[0038] Figure 4a A schematic side view of some components of the mechanical extension device according to the invention in a TV position is shown.

[0039] Figure 4b schematically shown Figure 4a A side view of the mechanical extension device shown from another angle;

[0040] Figure 5 schematically shown Figure 4a A partial side view of the mechanical extension device in a lying position;

[0041] Figure 6 A schematic view of the leg mechanism of the mechanical extension device according to the present invention is shown separately;

[0042] Figure 7 A separate view of the leg mechanism according to the invention is shown schematically;

[0043] Figure 8 A perspective view of the leg mechanism according to the present invention is shown schematically;

[0044] Figure 9 schematically shown Figure 2 The side view of the mechanical extension device shown is in the TV position;

[0045] Figure 10 schematically shown Figure 2 The side view of the mechanical extension device shown is in a lying position; and

[0046] Figure 11 The diagram schematically illustrates the posture changes of a mechanical extension device according to one embodiment of the present invention. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] The term "one embodiment" or "implementation" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. In the description of the present invention, it should be understood that the terms "upper," "lower," "left," "right," "top," "bottom," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the present invention and for 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 the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the present invention described herein can be implemented in orders other than those illustrated or described herein.

[0049] Unless otherwise stated, the term "front-to-back direction" as used in this application refers to the direction of extension of the leg units of the furniture unit, especially the seat unit. Specifically, "front" refers to the direction toward the leg units, and "rear" refers to the direction toward the backrest unit. The term "left-right direction" or "lateral direction" refers to the direction of the furniture unit, especially the seat unit, in the horizontal direction that is perpendicular to the "front-to-back direction".

[0050] like Figure 1a , Figure 1b As shown, the mechanical extension device 100 is configured as a movable seat with armrests on the floor, and includes mechanical extension device halves arranged mirror-symmetrically on both sides. Each mechanical extension device half has a fixing plate 12 extending longitudinally along the front-rear direction of the movable seat, and each mechanical extension device half is mounted by means of its respective fixing plate 12. Figure 1a , Figure 1b The inner side plate of the handrail (not shown). The bottom of the handrail is directly supported on the ground, thus allowing the mechanical extension device to be "suspended" above the ground.

[0051] The mechanical extension device 100 also includes a seat frame 10, a backrest mechanism 2 pivotally connected to the rear of the seat frame 10, and a leg mechanism 3 connected to the front of the seat frame 10.

[0052] like Figure 2 , Figure 3a and Figure 3bAs shown, the backrest mechanism 2 is pivotally connected to the rear of the seat frame 10 and is used to attach a backrest (not specifically shown). The backrest mechanism 2 includes a backrest bracket 21 for attaching the backrest, a first backrest link 22, and a second backrest link 23.

[0053] The upper end of the backrest bracket 21 is attached to the backrest, and a first backrest connecting rod 22 is connected between its front end and the seat frame 10, and a second backrest connecting rod 23 is connected between its rear end and the seat frame 10.

[0054] In this embodiment, the first backrest link 22 is constructed generally vertically, with its upper end hinged to the front end of the backrest bracket 21 at the first pivot point P1, and its lower end hinged to the rear of the seat frame 10 at the second pivot point P2. For example, in this embodiment, an upwardly extending seat frame extension 11 is fixedly provided at the rear end of the seat frame 10. This seat frame extension 11 can be integrally formed with the seat frame 10, or it can be fixedly connected to the seat frame 10 as a separate component, for example, by welding, riveting, or other methods. In this embodiment, the lower end of the first backrest link 22 is hinged to the seat frame extension 11 at the second pivot point P2.

[0055] The second backrest link 23 is constructed in a curved shape and includes three pivot points: a front pivot point P3, a rear pivot point P4, and a middle pivot point P5 located between the two. In this embodiment, the second backrest link 23 is hinged to the rear end of the backrest support 21 at its front pivot point P3 and to the rear extension 11 of the seat frame at its rear pivot point P4.

[0056] In addition, the backrest mechanism 2 also includes a backrest control assembly 24, which is connected between the side plate 12 and the first backrest link 22 or the second backrest link 23, so that the second backrest link 23 moves relative to the side plate 12 during the movement of the seat frame 10.

[0057] In such Figure 2 In the embodiment shown, the backrest control assembly 24 includes a first control link 241, a second control link 242, a third control link 243, a fourth control link 244, and a fifth control link 245.

[0058] The first control link 241 and the second control link 242 are respectively hinged at their lower ends to the side plate 12, and respectively hinged at their upper ends to the third control link 243, thus forming a four-bar linkage mechanism together with the side plate 12, the first control link 241, the second control link 242, and the third control link 243. The lower end of the fourth control link 244 is hinged to the upper end of the first control link 241. In this embodiment, the hinge point connecting the third control link 243 to the first control link 241 is different from the hinge point connecting the fourth control link 244 to the first control link 241. The fourth control link 244 is pivotally connected to the second backrest link 23 via a fifth control link 245, wherein one end of the fifth control link 245 is hinged to the upper end of the fourth control link 244, and the other end of the fifth control link 245 is hinged to the middle pivot point P5 of the second backrest link 23. The central pivot point P5 is lower than the previous pivot point P3, such as Figure 3b As shown.

[0059] Figures 6 to 8 The leg mechanism 3 according to the invention is shown in a separate view. Figure 9 , Figure 10 The mechanical extension device is schematically shown in the TV position and the lying position.

[0060] The leg mechanism 3 has a multi-link structure, which includes a leg extension assembly, a main leg side plate 37 and a secondary leg side plate 38. The leg extension assembly includes at least a front leg swing arm 31, a rear leg swing arm 32 and a first intermediate link 33.

[0061] The upper ends of the front leg swing arm 31 and the rear leg swing arm 32 are respectively hinged to the front of the seat frame 10. The hinge point between the front leg swing arm 31 and the seat frame 10 is further forward than the hinge point between the rear leg swing arm 32 and the seat frame 10. The first intermediate link 33 is located below the seat frame 10 and extends generally along the front-rear direction of the seat frame 10. The front end of the first intermediate link 33 is hinged to the front leg 31, and the rear end of the first intermediate link 33 is hinged to the rear leg swing arm 32, so that the front leg swing arm 31, the rear leg swing arm 32, the first intermediate link 33, and the seat frame 10 together form a four-bar linkage structure.

[0062] The leg extension assembly also includes a front leg link 34, a rear leg link 35, and a second intermediate link 36. The upper end of the rear leg link 35 is hinged to the rear end of the main leg side plate 37, and the lower end of the rear leg link 35 is hinged to the lower end of the rear leg swing arm 32; the lower end of the front leg link 34 is hinged to the lower end of the front leg swing arm 31, and the upper end of the front leg link 34 is hinged to the rear of the main leg side plate 37 and the rear end of the secondary leg side plate 38, respectively; the second intermediate link 36 is hinged to the rear leg link 35 and the front leg swing arm 31. Here, the hinge point between the second intermediate link 36 and the rear leg link 35 is located above the hinge point between the rear leg swing arm 32 and the rear leg link 35; the hinge point between the second intermediate link 36 and the front leg swing arm 31 is located below the hinge point between the front leg link 34 and the front leg swing arm 31. Furthermore, the hinge point between the front leg link 34 and the main leg side plate 37 is located above the hinge point between the front leg link 34 and the secondary leg side plate 38. Therefore, when the leg mechanism unfolds, the upper end of the front leg link 34 moves forward, causing the main leg side plate 37 to move forward at a speed greater than the secondary leg side plate 38.

[0063] The leg mechanism 3 also includes a first footrest 391, a second footrest 392, and a footrest connector 393. The front end of the main leg side plate 37 is hinged to the first footrest 391, the rear end of the second footrest 392 is hinged to the first footrest 391, the front end of the footrest connector 393 is hinged to the middle of the second footrest 392, and the rear end of the footrest connector 393 is hinged to the front end of the secondary leg side plate 38. The first footrest 391 is also hinged between the rear end and the front end of the secondary leg side plate 38, wherein the hinge point between the first footrest 391 and the secondary leg side plate 38 is located above the hinge point between the first footrest 391 and the main leg side plate 37.

[0064] When the leg mechanism 3 moves, there is a speed difference between the main leg side plate 37 and the secondary leg side plate 38, causing the first foot rest 391 to flip. When the leg mechanism 3 changes from the retracted position to the extended position, the first foot rest 391 flips upward, and under the action of the foot rest connector 393, it simultaneously drives the second foot rest 392 to unfold outward.

[0065] In addition, the leg mechanism 3 also includes a leg support 30, which includes a support link 301 and a support roller 302. The upper end of the support link 301 is hinged to the seat frame 10, and the support roller 302 is rotatably connected to the lower end of the support link 301 about a rotation axis. The hinge point between the support link 301 and the seat frame 10 is located in front of the hinge point between the front leg swing arm 31 and the seat frame 10. The circumferential surface of the support roller 302a is provided with a groove, and the lower edge of the main leg side plate 37 is slidably accommodated in the groove 302a.

[0066] When the mechanical extension device 100 is in a seated position, the leg mechanism 3 is in a retracted position; when the mechanical extension device 100 is in a TV position or a lying position, the leg mechanism 3 is in an extended position.

[0067] When leg mechanism 3 needs to move from Figure 2 The shown closing position has been changed to Figure 9 , Figure 10 In the extended position shown, the front leg swing arm 31 and the rear leg swing arm 32 swing forward around their respective hinge points with the seat frame 10, thereby driving the first intermediate link 33 and the second intermediate link 36 to move, and simultaneously causing the upper ends of the front leg link 34 and the rear leg link 35 to extend forward, which in turn drives the main leg side plate 37 and the secondary leg side plate 38 to translate forward. As mentioned above, since the forward movement speed of the main leg side plate 37 is greater than that of the secondary leg side plate 38, the first footrest 391 is caused to flip upward, and under the action of the footrest connector 393, the second footrest 392 is simultaneously driven to unfold outward, thereby achieving... Figure 9 , Figure 10 The unfolded position is shown. During this process, the lower edge of the main leg side plate 37 is slidably accommodated in the groove 302a of the support roller 302 of the leg support 30. Thus, the main leg side plate 37 is auxiliaryly supported from below by the leg support 30, thereby preventing the leg mechanism 3 from accidentally falling relative to the seat frame 10.

[0068] For clarity, Figure 4a and Figure 4b The image shows a side view of some components of the mechanical extension device in the TV position, with some leg mechanisms omitted. Figure 5 This schematically shows a partial side view of the mechanical extension device in a lying position.

[0069] The seat frame 10 is movably connected to the side plate 12 via a transmission mechanism. The transmission mechanism includes a transport link 13, a seat frame swing rod 14 connected between the seat frame 10 and the transport link 13, a seat frame lifting assembly 15, a front linkage assembly and a rear linkage assembly connected between the transport link 13 and the side plate 12.

[0070] like Figure 3a As shown, the transport link 13 extends longitudinally along the front-back direction of the seat frame, and a transversely extending synchronous beam 131 is provided between the transport links 13 on the left and right sides. The two ends of the synchronous beam 131 are fixedly connected to the transport link 13, thereby realizing the motion synchronization of the two mechanical extension device halves.

[0071] The upper end of the seat frame swing arm 14 is hinged to the rear of the seat frame 10, and the lower end of the seat frame swing arm 14 is hinged to the rear of the transport link 13.

[0072] The seat frame lifting assembly 15 includes at least two links, at least one of which is hinged to the transport link 13. In such a case... Figure 5 In the illustrated embodiment, the seat frame lifting assembly 15 includes a rocker arm 150, a front lifting rod 151, a first rear lifting rod 152, and a second rear lifting rod 153. The middle portion of the rocker arm 150 is hinged to the front portion of the transport link 13, the front end of the rocker arm 150 is hinged to the lower end of the front lifting rod 151, and the rear end of the rocker arm 150 is hinged to the lower end of the first rear lifting rod 152 at a first transition point A1. The rear end of the second rear lifting rod 153 is hinged to the upper end of the first rear lifting rod 152 at a second transition point A2, and the front end of the second rear lifting rod 153 is hinged to the upper end of the front lifting rod 151 at a fourth transition point A4. The middle portion of the front lifting rod 151 is hinged to the seat frame 10. The middle part of the second rear lifting rod 153 is hinged to the rear leg swing arm 32 at the third transition point A3. The hinge point between the second rear lifting rod 153 and the rear leg swing arm 32, i.e., the third transition point A3, is located below the hinge point between the rear leg swing arm 32 and the seat frame 10. Therefore, as the rear leg swing arm 32 swings, the second rear lifting rod 153 moves accordingly, thereby causing deformation of the seat frame lifting assembly 15. The angle α formed by the line connecting the first transition point A1 to the second transition point A2 and the line connecting the third transition point A3 to the second transition point A2 changes. For example, when the seat unit is in a seated position, the angle α formed by the line connecting the first transition point A1 to the second transition point A2 and the line connecting the third transition point A3 to the second transition point A2 is less than 90°. As the seat unit changes from a sitting position to a TV position, the second rear lifting lever 153 moves forward accordingly as the rear leg swing lever 32 swings forward. The angle α between the second rear lifting lever 153 and the first rear lifting lever 152 increases, and the lower end of the first rear lifting lever 152 moves downward, causing the rear end of the rocker arm 150 to press down and the front end to tilt upward. During this process, the front lifting lever 151 rises as a whole, thereby causing the front of the seat frame 10 to rise. This achieves the TV position, where the angle α formed between the first rear lifting lever 152 and the second rear lifting lever 153 is greater than 90° and less than 180°. When the seat unit changes from the TV position to a reclining position, this angle α further increases but remains less than 180°.

[0073] The front linkage assembly includes a first linkage link 161 and a second linkage link 162, and the rear linkage assembly includes a third linkage link 171 and a fourth linkage link 172. The lower end of the first linkage link 161 is hinged to the front end of the side plate 12, the lower end of the second linkage link 162 is hinged to the front end of the transport link 13, and the upper end of the second linkage link 162 is hinged to the middle of the first linkage link 161. The lower end of the third linkage link 171 is hinged to the rear of the side plate 12, the lower end of the fourth linkage link 172 is hinged to the rear end of the transport link 13, and the upper end of the fourth linkage link 172 is hinged to the middle of the third linkage link 171. The transmission mechanism also includes a first intermediate linkage rod 181 and a second intermediate linkage rod 182. The front end of the first intermediate linkage rod 181 is hinged to the upper end of the first linkage rod 161, and the rear end of the first intermediate linkage rod 181 is hinged to the upper end of the third linkage rod 171. The front end of the second intermediate linkage rod 182 is hinged to the middle of the first intermediate linkage rod 181, and the rear end of the second intermediate linkage rod 182 is hinged to the middle of the fourth linkage rod 172.

[0074] Figure 1a The illustrated mechanical extension device 100 also includes a linear electro-actuator 4, which comprises a drive motor 41 and a motor push rod 42 retractable relative to the drive motor 41. For example, in Figure 1a In the illustrated embodiment, the drive motor 41 is pivotally connected to the drive motor bracket 41a, which is fixedly mounted on the rear crossbeam 44 of the motor. In this embodiment, the third control link 243 is L-shaped, with its upper section hinged to the first control link 241 and the second control link 242, and its lower section extending substantially perpendicular to the upper section. Laterally extending rear motor crossbeams 44 are connected to the free ends of the lower section. The drive motor bracket 41a can pivot about an axis transverse to the front-rear direction during the transition of the seat unit from a sitting position to a reclining position. The motor push rod 42 acts on the front drive tube 43, which is transversely connected between the front leg swing arms 31 of the leg mechanism 3. Of course, in embodiments not shown, the positions of the drive motor 41 and the motor push rod 42 can be reversed. Figure 1a As shown, the motor push rod 42 is attached to the front drive tube 43 by means of the push rod bracket 42a. The motor push rod 42 is pivotally connected to the push rod bracket 42a, and the push rod bracket 42a is fixedly connected to the front drive tube 43.

[0075] Figure 11 A schematic diagram illustrating the posture changes of the mechanical extension device according to the present invention is shown, wherein, Figure 11 The mechanical extension device is shown above in a seated position. Figure 11 The central section shows the mechanical extension device in the TV position, and Figure 11The mechanical extension device is shown below in a lying position.

[0076] If the seat unit needs to be from Figure 2 , Figure 11 The sitting position shown above has been changed to Figure 9 , Figure 11 In the TV pose position shown in the middle, the mechanical extension device 100 begins to extend under the action of the linear electro-actuator 4. The motor push rod 42 extends relative to the drive motor 41, pushing the front leg swing rod 31 of the leg mechanism 3 to swing forward, and driving the seat frame 10 to move forward. The front end of the seat frame swing rod 14 tilts forward, and the front end of the rocker arm 150 of the seat frame lifting assembly 15 rises, thereby causing the front part of the seat frame 10 to rise while moving forward, thus achieving... Figure 9 The TV pose position is shown. During this process, the tilt angle b of the upper surface of the seat frame 10 relative to the horizontal plane increases by at least 10 degrees.

[0077] During the transition of the mechanical extension device from a seated position to a TV position, the backrest control assembly 24 deforms. The first control link 241 and the second control link 242 swing forward around their hinge points with the side plate 12, thereby causing the backrest support 21, the first backrest link 22, and the second backrest link 23 to descend during forward movement via the fourth control link 244 and the fifth control link 245. During this process, the first pivot point P1 of the backrest support 21 and the first backrest link 22 has a forward trajectory, and the rearmost end of the backrest support 21 has a forward component. This avoids interference between the backrest and the rear wall, achieving zero wall contact. In addition, during this process, the upper end of the first backrest link 22 is close to the seat frame 10 to avoid an unwanted gap between the backrest and the seat part of the seat unit. This avoids pulling the user's clothes out when leaning back, thus avoiding the so-called "back rubbing sensation," and also avoids the risk of foreign objects falling into the seat unit due to the gap between the backrest and the seat part.

[0078] If the seat unit needs to be from Figure 9 , Figure 11 The TV pose position shown in the middle changes to Figure 10 , Figure 11In the lying position shown below, the motor push rod 42 continues to extend further relative to the drive motor 41, and the seat frame 10 is driven by the leg mechanism 3 to move further forward and tilt upward, thereby driving the front linkage assembly and the rear linkage assembly to move, thus realizing the movement of the transport link 13 relative to the side plate 12. During this process, the first linkage link 161 and the third linkage link 171 respectively pivot forward around the pivot point of their lower ends and the side plate 12. Furthermore, the backrest control assembly 24 undergoes further deformation. The first control link 241 and the second control link 242 swing forward further around their hinge points with the side plate 12, the front end of the third control link 243 presses down, the upper end of the fourth control link 244 tilts forward, and the front end of the fifth control link 245 presses down at the fifth hinge point P5 between it and the second backrest link 23. This causes the first backrest link 22 to pivot forward around the second pivot point P2 with its upper end, and the second backrest link 23 to pivot forward around the fourth pivot point P4 with its upper end. This causes the upper part of the backrest support 21 to tilt further backward and reduces the angle of the first backrest link 22 relative to the seat frame 10. This achieves a reclining position. During this process, although the backrest support 21 tilts backward around the third pivot point P3, the seat frame 10 itself moves forward. On the other hand, the backrest support 21 also moves forward relative to the seat frame 10 with the help of the linkage between the first backrest link 22 and the second backrest link 23. Therefore, the first pivot point P1 of the backrest support 21 and the rearmost end point of the backrest support 21 both have a trajectory of moving forward.

[0079] Compared to the sitting position, the tilt angle b of the upper surface of the seat frame 10 relative to the horizontal plane can be increased by 12°-17°, preferably by 14°. In the reclining position, the highest point of the leg mechanism 3 exceeds the highest point of the backrest support, preferably by 25cm to 35cm, more preferably by 33cm. Thus, the corresponding angle range of the movable seat unit according to the present invention ensures a comfortable angle between the user's thighs and calves, thighs and torso, and head and torso, and the height of the upper end of the leg mechanism is higher than the height of the upper end of the backrest assembly in the reclining position, so that each part of the seat unit conforms to the user's body curve, achieving a "zero gravity" posture.

[0080] According to an exemplary embodiment of a mechanical extension device, in a sitting position, the angle b formed by the upper surface of the seat frame 10 and the horizontal plane is, for example, 7°, the height H1 of the highest point of the backrest support relative to the horizontal plane is, for example, 45cm, and the height H2 of the highest point of the leg mechanism relative to the horizontal plane is, for example, 27cm; in a TV position, the angle b of the upper surface of the seat frame 10 relative to the horizontal plane increases to 17°, the height H1 of the highest point of the backrest support relative to the horizontal plane is, for example, 39cm, and the height H2 of the highest point of the leg mechanism relative to the horizontal plane is, for example, 56cm; in a reclining position, the angle b of the upper surface of the seat frame 10 relative to the horizontal plane increases to 22°, the height H1 of the highest point of the backrest support relative to the horizontal plane is, for example, 31cm, and the height H2 of the highest point of the leg mechanism relative to the horizontal plane is, for example, 64cm.

Claims

1. A mechanical extension device for a seat unit, characterized in that, The mechanical extension device includes: A side plate fixed relative to the supporting surface of the seat unit; A seat frame that is movable relative to the side panel, wherein the seat frame is used to mount the seat portion of the seat unit; A leg mechanism, wherein the leg mechanism is convertible between a retracted position and an extended position, and includes a main leg side plate, a secondary leg side plate, and a leg extension assembly hinged to the rear ends of the main leg side plate and the secondary leg side plate, wherein, during the conversion of the leg mechanism from the retracted position to the extended position, the leg extension assembly extends, thereby causing the main leg side plate and the secondary leg side plate to translate forward relative to the seat frame; and The transmission mechanism includes a carrier link and a seat frame lifting assembly, wherein the seat frame lifting assembly is pivotally connected to the seat frame, a leg extension assembly and the carrier link, such that while the seat frame moves forward relative to the carrier link, the front of the seat frame is raised relative to the carrier link.

2. The mechanical extension device according to claim 1, characterized in that, The leg mechanism also includes a leg support with supporting rollers, wherein the circumferential surface of the supporting rollers is provided with grooves, and the lower edge of the main leg side plate is slidably accommodated in the grooves.

3. The mechanical extension device according to claim 2, characterized in that, The leg support has a support link, wherein the upper end of the support link is hinged to the seat frame, and the support roller is rotatably connected to the lower end of the support link.

4. The mechanical extension device according to claim 1, characterized in that, The transmission mechanism further includes a seat frame swing arm, wherein the upper end of the seat frame swing arm is hinged to the rear of the seat frame, and the lower end of the seat frame swing arm is hinged to the rear of the transport link.

5. The mechanical extension device according to claim 1, characterized in that, The seat frame lifting assembly includes a rocker arm, a front lifting rod, a first rear lifting rod, and a second rear lifting rod. The front lifting rod is hinged to the front end of the seat frame and the rocker arm. The rear end of the rocker arm is hinged to the leg extension assembly via the first and second rear lifting rods. The rocker arm is hinged to a transport link between its front and rear ends.

6. The mechanical extension device according to claim 5, characterized in that, The leg extension assembly includes a rear leg swing arm, the upper end of which is hinged to the seat frame. During the transition from a retracted position to an extended position, the rear leg swing arm swings forward, and the main leg side plate and the secondary leg side plate translate forward relative to the seat frame.

7. The mechanical extension device according to claim 6, characterized in that, The lower end of the first rear lifting rod is hinged to the rear end of the rocker arm at the first transition point, the upper end of the first rear lifting rod is hinged to the rear end of the second rear lifting rod at the second transition point, and the second rear lifting rod is hinged to the rear leg swing arm at the third transition point, wherein the third transition point is located below the hinge point between the rear leg swing arm and the seat frame.

8. The mechanical extension device according to claim 7, characterized in that, The front end of the second rear lifting rod is hinged to the upper end of the front lifting rod at the fourth transition point, wherein the third transition point is located between the second transition point and the fourth transition point.

9. The mechanical extension device according to claim 7, characterized in that, During the forward swing of the rear leg lever, the angle formed by the line connecting the first rotation point to the second rotation point and the line connecting the third rotation point to the second rotation point increases, thereby causing the front of the seat frame to rise relative to the transport link.

10. The mechanical extension device according to claim 6, characterized in that, The leg extension assembly also includes a front leg swing arm, a front leg connecting rod, and a rear leg connecting rod. The upper end of the front leg swing arm is hinged to the seat frame, the lower end of the front leg swing arm is hinged to the auxiliary leg side plate via the front leg connecting rod, and the lower end of the rear leg swing arm is hinged to the main leg side plate via the rear leg connecting rod.

11. The mechanical extension device according to claim 1, characterized in that, During the movement of the leg mechanism, the hinge points between the main leg side plate and the secondary leg side plate and the leg extension assembly are always located behind the front end of the seat frame.

12. The mechanical extension device according to claim 1, characterized in that, The mechanical extension device further includes a backrest mechanism, wherein the backrest mechanism includes a backrest bracket, a first backrest link, and a second backrest link, wherein the backrest bracket is used to attach the backrest of the seat unit and is hinged to the seat frame by means of the first backrest link and the second backrest link.

13. The mechanical extension device according to claim 12, characterized in that, The mechanical extension device is configured to switch between a sitting position and a lying position. In the sitting position, the leg mechanism is in a retracted position; in the lying position, the leg mechanism is in an extended position, the backrest support rotates backward relative to the seat frame, and the seat frame moves forward relative to the side panel, wherein the highest point of the leg mechanism is higher than the highest point of the backrest support.

14. The mechanical extension device according to claim 13, characterized in that, The transmission mechanism also includes a front linkage assembly and a rear linkage assembly connected between the transport link and the side plate.

15. The mechanical extension device according to claim 13, characterized in that, The backrest mechanism also includes a backrest control assembly hinged between the side plate and the second backrest link, such that the rearward rotation of the backrest support relative to the seat frame lags behind the forward movement of the seat frame relative to the side plate.

16. The mechanical extension device according to claim 15, characterized in that, The backrest control assembly includes a first control link, a second control link, a third control link, and a fourth control link. The lower ends of the first and second control links are respectively hinged to the side plates, and the upper end of the first control link is hinged to the second backrest link at least through the fourth control link.

17. The mechanical extension device according to claim 16, characterized in that, The third control link, together with the first control link, the second control link, and the side plate, forms a four-bar linkage.

18. The mechanical extension device according to claim 16, characterized in that, The backrest control assembly also includes a fifth control link, which is hinged between the fourth control link and the second backrest link.

19. The mechanical extension device according to claim 13, characterized in that, During the transition between the seated and reclining positions of the mechanical extension device, the translation of the main leg side plate and the auxiliary leg side plate relative to the seat frame and the rotation of the backrest support relative to the seat frame are mutually exclusive.

20. The mechanical extension device according to any one of claims 1 to 19, characterized in that, The mechanical extension device also includes a linear electro-actuator.

21. A movable seat unit comprising the mechanical extension device according to any one of claims 1 to 20.

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