Mechanical extension device for a movable seat and movable seat unit
By combining the linkage and the electric actuator, the problems of complex structure and asynchronous movement in existing movable seats are solved, and the backrest unit and the leg extension unit are adjusted synchronously, which improves the comfort and structural compactness of the seat.
Patent Information
- Application Number
- CN202520425785.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-12
- Publication Date
- 2025-12-23
- Estimated Expiration
- 2035-03-12
AI Technical Summary
Existing movable seats have problems with their mechanical extension mechanisms, such as complex structures, asynchronous movements, and excessive backrest recline, resulting in discomfort during use.
The design combines a linkage and an electric actuator. The linkage enables synchronous movement of the backrest unit and the leg extension unit, while the electric actuator ensures synchronous adjustment of the backrest unit and the leg extension unit by transmitting power, thus reducing the lag in the transmission of motion chains in the mechanical structure.
It achieves smooth, synchronized movement between the backrest unit and the leg extension unit, simplifying the structure, reducing costs and space requirements, while improving user comfort.
Smart Images
Figure CN223695341U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a kind of mechanical stretching device for movable seat and a kind of movable seat unit comprising the mechanical leg stretching unit. BACKGROUND
[0002] Various movable seats are known in the prior art, such as sofas or chairs with multi-position conversion function. With the improvement of people's living standards, the comfort requirement of sofa and chair is also increasing. In the known design, the movable seat unit usually has a mechanical stretching device, by which the seat can be converted between a sitting position and a lying position. When the seat is converted from the sitting position to the lying position, the ottoman of the seat unit is stretched forward, and the backrest is significantly reclined.
[0003] In the prior design of such seats, a large number of mechanical structures with complex connection relationship are often required, and sometimes the attitude conversion of the seat is stuck due to unreasonable design. In addition, for some users, the excessive reclining of the backrest does not meet their living habits. SUMMARY
[0004] The technical problem to be solved by the utility model is to provide a mechanical stretching device for movable seat with higher comfort and a corresponding movable seat unit. The seat unit should meet the needs of users for backrest adjustment on one hand, and achieve smooth and simple attitude change during the attitude conversion of the movable seat on the other hand.
[0005] It is to be noted that the "front-rear direction", "front-rear" in this application refers to the stretching direction of the leg stretching unit of the seat unit or the mechanical stretching device. Specifically, "front" refers to the direction towards the leg stretching unit, and "rear" refers to the direction towards the backrest. "Left-right direction", "left-right" refers to the left-right hand direction of the user when sitting on the seat unit or the mechanical stretching device.
[0006] To solve the above technical problems, the utility model provides a mechanical stretching device for movable seat, comprising:
[0007] a base unit fixedly supported on the ground;
[0008] a backrest unit movably connected to the rear part of the base unit, wherein each backrest unit comprises a first backrest connecting rod, a second backrest connecting rod and a backrest mounting plate for attaching a backrest, wherein the first backrest connecting rod and the second backrest connecting rod are respectively pivotally connected to the base unit;
[0009] two leg stretching units movably connected to the front part of the base unit on the left and right sides;
[0010] a linkage connecting between the backrest unit and the leg extension unit; and
[0011] an electric actuator acting between the base unit and the linkage, through the working stroke of the electric actuator, the telescopic movement of the leg extension unit relative to the base unit is synchronized with the movement of the backrest unit relative to the base unit, wherein, when the leg extension unit extends forward relative to the base unit, the upper end of the first backrest linkage and the upper end of the second backrest linkage are simultaneously pivoted backward; when the leg extension unit retracts backward relative to the base unit, the upper end of the first backrest linkage and the upper end of the second backrest linkage are simultaneously pivoted forward.
[0012] According to the utility model, the front end of the linkage is pivotally connected with a transverse linkage transversely connecting between the two leg extension units, and the rear end of the linkage is pivotally connected with the backrest unit.
[0013] According to the utility model, one end of the linkage acts at the backrest unit, and the other end acts at the leg extension unit. The linkage directly connects the backrest unit and the leg extension unit, thereby realizing the linkage between the backrest unit and the leg extension unit. Advantageously, the linkage is further connected to the electric actuator, so that the power generated by the working stroke of the electric actuator is transmitted to the two leg extension units through the front end of the linkage and the transverse linkage, and at the same time, is transmitted to the backrest unit through the rear end of the linkage, without the incomplete synchronization of the movement of the backrest unit and the leg extension unit caused by the movement chain transmission lag of the mechanical structure. This not only further improves the synchronization of the linkage between the backrest unit and the leg extension unit, but also fully ensures the movement synchronization between the backrest units, thereby realizing a smoother posture transformation process of the mechanical extension device and avoiding movement jamming.
[0014] Due to the linkage between the backrest unit and the leg extension unit, only one electric actuator acting between the leg extension unit and the base unit can complete the synchronized adjustment of the backrest unit and the leg extension unit. This not only reduces the parts, saves the process, reduces the installation cost and the material cost, but also saves the product structure space, realizes the compactness and lightness of the product structure.
[0015] Preferably, the upper end of the first backrest linkage and the upper end of the second backrest linkage are respectively pivotally connected with the backrest mounting plate, wherein, during the extension and retraction of the leg extension unit, the angle change of the backrest mounting plate relative to the horizontal plane is not greater than 15°.
[0016] It is particularly preferred that the angle of the backrest mounting plate relative to the horizontal plane remains constant during extension and retraction of the leg rest extension unit.
[0017] It is particularly preferred that the backrest mounting plate remains parallel relative to the horizontal plane during extension and retraction of the leg rest extension unit.
[0018] In a preferred embodiment, the first backrest link comprises a first pivot point in the middle, a second pivot point in the upper end and a third pivot point in the lower end, wherein the first backrest link is pivotally connected to the base unit at the first pivot point, to the backrest mounting plate at the second pivot point and to the rear end of the linkage link at the third pivot point. The second backrest link comprises a fourth pivot point in the upper end and a fifth pivot point in the lower end, wherein the second backrest link is pivotally connected to the backrest mounting plate at the fourth pivot point and to the base unit at the fifth pivot point. The first pivot point is located in front of the fifth pivot point and the second pivot point is located in front of the fourth pivot point. The straight line distance between the first pivot point and the second pivot point is equal to the straight line distance between the fourth pivot point and the fifth pivot point, and the straight line distance between the first pivot point and the fifth pivot point is equal to the straight line distance between the second pivot point and the fourth pivot point.
[0019] Thereby, the first backrest link, the second backrest link, the base unit and the backrest mounting plate to which they are pivotally connected form a parallelogram four-bar linkage, wherein the backrest mounting plate is located at the upper ends of the first backrest link and the second backrest link. In this case, the parallelogram four-bar linkage formed by the backrest unit deforms under the influence of the linkage link as the leg rest extension unit is extended and retracted, wherein the backrest mounting plate can substantially always remain oriented upwards during the posture change of the mechanical extension device. This almost constant orientation ensures that also the backrest attached to the backrest mounting plate remains almost constantly oriented. That is, when the parallelogram four-bar linkage is stretched and deformed, each point on the backrest mounting plate experiences an arcuate trajectory first upwards and then downwards, which results in a horizontal translation of the backrest mounting plate as a whole without a significant angular change with the horizontal plane. For the user, the backrest moves backwards as the leg rest extension unit is extended without a significant backward tilt.
[0020] According to a preferred embodiment, the base unit comprises two side plates opposite to each other and a leg fixation bar fixedly connected to the side plates, wherein the leg rest extension unit is pivotally connected to the leg fixation bar.
[0021] As a part of the base unit, the shape of the leg fixing rod can be designed as needed. Thus, more flexible and larger operation space can be provided for the installation of the leg extension unit, and the installation process is simplified. The leg fixing rod can also be made of suitable materials according to the needs of strength and hardness to ensure the reliability of the product.
[0022] According to a preferred embodiment, the base unit comprises a top plate and a backrest fixing support fixedly connected to the top plate, wherein the first backrest connecting rod and the second backrest connecting rod are respectively pivotally connected to the backrest fixing support.
[0023] As a part of the base unit, the shape of the backrest fixing support can be designed as needed, or the backrest fixing support can be made of suitable materials. Thus, the installation process is simplified and the reliability of the product is ensured.
[0024] According to a preferred embodiment, the mechanical extension device comprises a front driving rod connected between the linkage connecting rods in the transverse direction, one end of the electric actuator is connected to the base unit, and the other end is connected to the front driving rod.
[0025] According to a preferred embodiment, the electric actuator comprises a linear electric actuator.
[0026] To solve the above technical problems, the utility model also provides a movable seat unit, at least comprising:
[0027] An armrest part, a backrest, and a footrest part;
[0028] A mechanical extension device comprising:
[0029] A base unit fixedly supported on the ground, wherein the armrest part is attached to the base unit;
[0030] A backrest unit movably connected to the rear part of the base unit, wherein each backrest unit comprises a first backrest connecting rod, a second backrest connecting rod, and a backrest mounting plate for attaching the backrest, wherein the first backrest connecting rod and the second backrest connecting rod are respectively pivotally connected to the base unit;
[0031] Two leg extension units movably connected to the front part of the base unit on the left and right sides;
[0032] Linkage connecting rods connected between the backrest unit and the leg extension unit; and
[0033] An electric actuator acting between the base unit and the linkage link, the working stroke of the electric actuator causing the telescopic movement of the leg extension units relative to the base unit to be synchronized with the movement of the backrest unit relative to the base unit, wherein, when the leg extension units are extended forward relative to the base unit, the backrest attached to the backrest mounting plate moves rearward, and when the leg extension units are retracted rearward relative to the base unit, the backrest attached to the backrest mounting plate moves forward.
[0034] According to a preferred embodiment, the front end of the linkage link is pivotally connected to a transverse link transversely connected between two leg extension units, and the rear end of the linkage link is pivotally connected to the backrest unit.
[0035] According to a preferred embodiment, the upper end of the first backrest link and the upper end of the second backrest link are respectively pivotally connected to the backrest mounting plate, wherein the angle of the backrest relative to the horizontal plane does not change by more than 15° during the extension and retraction of the leg extension units.
[0036] According to a preferred embodiment, the angle of the backrest relative to the horizontal plane remains constant during the extension and retraction of the leg extension units.
[0037] According to a preferred embodiment, the first backrest link comprises a first pivot point in the middle, a second pivot point in the upper end, and a third pivot point in the lower end, wherein the first backrest link is pivotally connected to the base unit at the first pivot point, pivotally connected to the backrest mounting plate at the second pivot point, and pivotally connected to the rear end of the linkage link at the third pivot point.
[0038] According to a preferred embodiment, the second backrest link comprises a fourth pivot point in the upper end and a fifth pivot point in the lower end, wherein the second backrest link is pivotally connected to the backrest mounting plate at the fourth pivot point, and pivotally connected to the base unit at the fifth pivot point.
[0039] According to a preferred embodiment, the first pivot point is located forward of the fifth pivot point, and the second pivot point is located forward of the fourth pivot point.
[0040] According to a preferred embodiment, the straight-line distance between the first pivot point and the second pivot point is equal to the straight-line distance between the fourth pivot point and the fifth pivot point, and the straight-line distance between the first pivot point and the fifth pivot point is equal to the straight-line distance between the second pivot point and the fourth pivot point.
[0041] According to a preferred embodiment, the base unit comprises two mutually opposite side plates and a leg fixation bar fixedly connected to the side plates, wherein the leg extension unit is pivotally connected to the leg fixation bar.
[0042] According to a preferred embodiment, the base unit comprises a top plate and a backrest fixation support fixedly connected to the top plate, wherein the first backrest link and the second backrest link are respectively pivotally connected to the backrest fixation support.
[0043] According to a preferred embodiment, the mechanical extension device comprises a front drive bar connected between the linkage links in a transverse direction, one end of the electric actuator is connected to the base unit, and the other end is connected to the front drive bar.
[0044] According to a preferred embodiment, the electric actuator comprises a linear electric actuator device.
[0045] The advantages described above for the mechanical extension device also apply to the movable seat unit having such a mechanical extension device. BRIEF DESCRIPTION OF DRAWINGS
[0046] The embodiments of the present application are described in detail below with the aid of the accompanying drawings.
[0047] Figure 1 a mechanical extension device for a movable seat according to an embodiment of the present application is schematically shown in a sitting position in perspective view;
[0048] Figure 2 a mechanical extension device is shown in a lying position; Figure 2 a mechanical extension device is shown in a lying position;
[0049] Figure 3 a mechanical extension device is shown in a lying position; Figure 1 a mechanical extension device is shown in a lying position;
[0050] Figure 4 a mechanical extension device is shown in a lying position; Figure 1 a mechanical extension device is shown in a lying position;
[0051] Figure 5 a mechanical extension device is shown in a lying position; Figure 1 a mechanical extension device is shown in a lying position;
[0052] Figure 6 a mechanical extension device is shown in a lying position; and Figure 1 a mechanical extension device is shown in a lying position; and
[0053] Figure 7Fig. 1 shows a schematic view of a mechanical extension device with a backrest in a sitting position and in a lying position. DETAILED DESCRIPTION
[0054] The technical solutions in the embodiments of the present application will be apparently and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0055] The term "one embodiment" or "an embodiment" as used herein means that a particular implementation can include a particular feature, structure, or characteristic, but every embodiment can not necessarily include the particular feature, structure, or characteristic. Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in the various embodiments. In the description of the present application, it should be understood that the terms "upper", "lower", "left", "right", "top", "bottom", and the like refer to the orientation or positional relationship shown in the drawings, and are only used for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only used for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second", etc. can explicitly or implicitly include one or more of the features. Moreover, the terms "first", "second", etc. are used to distinguish similar objects, and do not necessarily describe a particular order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.
[0056] Figure 1 and Figure 2 A mechanical extension device 100 of a movable seat according to the present application is shown in a perspective view, which includes a multi-link mechanism and is configured to enable the movable seat to be transformed between a sitting position and a lying position.
[0057] As shown in Figure 1 The mechanical extension device 100 is configured for a movable seat with armrests on the floor, and includes a base unit 1 fixedly supported on the ground, and mechanical extension device halves symmetrically arranged on the left and right sides, wherein each mechanical extension device half respectively includes a backrest unit 2 and a leg extension unit 3.
[0058] The base unit 1 is frame-shaped and includes two side plates 12 extending longitudinally along the front and rear directions of the movable seat, a rear plate 14 fixedly connected between the two side plates 12 in a transverse direction and perpendicular to the horizontal plane, a top plate 15 fixedly connected with the side plates 12 and parallel to the horizontal plane, and a base crossbeam 16 fixedly connected with the side plates 12 and located in front of the top plate 15. The top plate 15 of the base unit 1 is provided with a slot corresponding to the backrest unit 2, so as to provide the backrest unit 2 with necessary moving space. The front part of the base unit 1 is open, so that the leg stretching unit 3 can stretch forward.
[0059] The backrest unit 2 is movably connected to the rear part of the base unit 1, respectively. The backrest unit 2 includes a first backrest connecting rod 21, a second backrest connecting rod 22, and a backrest mounting plate 23 for attaching a backrest, respectively. The base unit 1 includes backrest fixing supports 20 designed for mounting the backrest unit 2, which include horizontal sections 20a fixedly connected with the top plate 15 and vertical sections 20b fixedly connected with the horizontal sections 20a, and two through holes are provided on the vertical sections 20b, so as to be pivotally connected with the first backrest connecting rod 21 and the second backrest connecting rod 22. Each two backrest fixing supports 20 are oppositely arranged to form a group, so as to pivotally connect the first backrest connecting rod 21 and the second backrest connecting rod 22 to the base unit 1.
[0060] The first backrest link 21 comprises three pivot points, namely a first pivot point P1 at its middle, a second pivot point P2 at its upper end and a third pivot point P3 at its lower end. The second backrest link 22 comprises two pivot points, namely a fourth pivot point P4 at its upper end and a fifth pivot point P5 at its lower end. The first backrest link 21 is located in front of the second backrest link 22 in the front-rear direction of the seat unit. The backrest mounting plate 23 is oriented upwardly and substantially parallel to the horizontal plane. The bottom side of the backrest mounting plate 23 is provided with mounting flanges for pivotally connecting with the first backrest link 21 and the second backrest link 22. Specifically, the first backrest link 21 is pivotally connected with the backrest fixed bracket 20 of the base unit 1 at the first pivot point P1 and with the backrest mounting plate 23 at the second pivot point P2. The second backrest link 22 is pivotally connected with the backrest mounting plate 23 at the fourth pivot point P4 and with the backrest fixed bracket 20 of the base unit 1 at the fifth pivot point P5. Here, the straight-line distance between the first pivot point P1 and the second pivot point P2 is substantially equal to the straight-line distance between the fourth pivot point P4 and the fifth pivot point P5, and the straight-line distance between the first pivot point P1 and the fifth pivot point P5 is substantially equal to the straight-line distance between the second pivot point P2 and the fourth pivot point P4. Thus, the first backrest link 21, the second backrest link 11, the backrest fixed bracket 20 and the backrest mounting plate 23 constitute a parallelogram four-link mechanism. When the first backrest link 21 and the second backrest link 22 pivot about their respective pivot points with the base unit 1, the backrest mounting plate 23 is correspondingly translated forwardly or rearwardly. During this process, the included angle between the backrest mounting plate 23 and the horizontal plane remains unchanged. In this embodiment, the backrest mounting plate 23 extends parallel to the horizontal plane, and during the posture transformation of the backrest unit 2, the backrest mounting plate 23 always maintains an orientation substantially parallel to the horizontal plane.
[0061] Two leg extension units 3 are movably connected to the front of the base unit 1. Each leg extension unit 3 comprises a first leg link 31, a second leg link 32, a third leg link 33, a fourth leg link 34 and a footrest mounting plate 35. The base unit 1 comprises a leg fixing bar 30 designed for mounting the leg extension units 3. The rear end of the leg fixing bar 30 is fixedly connected to the side plate 12 of the base unit 1, and the front of the leg fixing bar 30 is bent inwardly to provide operating space for the mounting of the leg extension units 3. The first leg link 31 is pivotally connected at its rear end to the leg fixing bar 30, and at its front end to the rear end of the second leg link 32, the second leg link 32 is pivotally connected at its rear end to the leg fixing bar 30, and at its front end to the rear end of the fourth leg link 34, and the front end of the third leg link 33 and the front end of the fourth leg link 34 are pivotally connected to the footrest mounting plate 35, respectively. The pivot point of the first leg link 32 with the leg fixing bar 30 is located behind the pivot point of the second leg link 32 with the leg fixing bar 30. The second leg link 32 is pivotally connected with the third backrest link 33. The leg extension units 3 can be transformed between the folded position as shown in Figure 1 、 Figure 3 、 Figure 5 and the unfolded position as shown in Figure 2 、 Figure 4 、 Figure 6 . To ensure the synchronization of the movement between the leg extension units 3, a transverse link 36 is connected between the two leg extension units 3.
[0062] The mechanical extension device 1 further comprises a linkage link 4 connected between the backrest unit 2 and the leg extension units 3. The rear end of the linkage link 4 is configured as a tab 40 with a hole, so that the linkage link 4 is pivotally connected at its rear end to the third pivot point P3 of the lower end of the first backrest link 21, and the transverse link 36 comprises a bracket 37 with a hole, and the linkage link 4 is pivotally connected at its front end to the bracket 37. The linkage between the backrest unit 2 and the leg extension units 3 is realized by the direct connection of the linkage link 4 to the backrest unit 2 and the leg extension units 3.
[0063] The mechanical extension device 100 further comprises an electric actuator 5 acting between the base unit 1 and the linkage link 4. The electric actuator 5 is configured as a linear electric actuator device comprising a motor head 51 and a motor push rod 52 telescopically movable relative to the motor head 51. The motor head 51 is fixedly mounted relative to the base unit 1. For the sake of simplicity, the side plate 12, the rear plate 14, the top plate 15 and the base crossbeam 16 of the base unit 1 are omitted in the embodiments as shown in Figure 3 and Figure 4 . The bottom side of the top plate 15 of the base unit 1 is fixedly mounted with Figure 3The L-shaped fixtures 25 and the motor crossbeam 26 connected between the L-shaped fixtures 25 are shown, wherein the motor crossbeam 26 is located behind the transverse connecting rod 36. The motor head 51 is pivotally connected with the motor head support fixedly connected to the motor crossbeam 51, so as to install the motor head 51 at the rear of the base unit 1. Here, the motor head has no forward and backward movement component during the transformation of the seat unit from the sitting position to the lying position, but can be pivoted around an axis transverse to the forward and backward direction. The motor push rod 52 acts on the front drive rod 42 transversely connected between the two linkage connecting rods 4. Of course, the positions of the motor head 51 and the motor push rod 52 can also be reversed in an unshown embodiment.
[0064] If the seat unit is to be transformed from the sitting position shown in Figure 1 , Figure 3 and Figure 5 to the 2-lying position shown in Figure 2 , Figure 4 and Figure 6 , the motor push rod 52 of the electric drive 5 is elongated relative to the motor head 51, and the power generated thereby is transmitted to the leg stretching unit 3 and the backrest unit 2, respectively, in synchronization through the front drive rod 42 and the linkage connecting rod 4 rigidly connected thereto. In this case, as the linkage connecting rod 4 pair moves forward, the second connecting rod 32 of the leg stretching unit 3 moves forward, thereby causing the leg stretching unit 3 to unfold relative to the base unit 1. At the same time, the lower end of the first backrest connecting rod 21 pivotally connected with the linkage connecting rod 4 is pivoted forward around the first pivot point P1, and causes the entire backrest unit 2 to pivot. Here, the upper end of the first backrest connecting rod 21 and the second backrest connecting rod 2 are respectively pivoted backward around the first pivot point P1 and the second pivot point P2 fixed relative to the base unit, and the backrest fixing plate 23 moves backward.
[0065] If the seat unit is to be transformed from the 2-lying position shown in Figure 2 , Figure 4 and Figure 6 to the sitting position shown in Figure 1 , Figure 3 and Figure 5In the seated position shown, the motor push rod 52 of the electric actuator 5 retracts relative to the motor head 51, and the resulting power is synchronously transmitted to the leg extension unit 3 and the backrest unit 2 via the front drive rod 42 and the linkage 4 rigidly connected thereto. In this case, as the linkage 4 moves backward, the second linkage 32 of the leg extension unit 3 moves backward, thereby causing the leg extension unit 3 to retract relative to the base unit 1. At the same time, the lower end of the first backrest linkage 21, which is pivotally connected to the linkage 4, pivots backward around the first pivot point P1, causing the entire backrest unit 2 to pivot. Here, the upper ends of the first backrest linkage 21 and the second backrest linkage 2 pivot forward around the first pivot point P1 and the second pivot point P2, respectively, and the backrest fixing plate 23 moves forward.
[0066] In other words, once the leg extension unit 3 extends or retracts relative to the base unit 1, the backrest fixing plate 23 of the backrest unit 2 moves backward or forward relative to the base unit 1 at the same time.
[0067] Figure 5 and Figure 6 Side views of the mechanical extension device in seated and reclining positions are shown respectively. Figure 5 In the seated position shown, the leg extension unit 3 is retracted relative to the base unit 1, and the backrest mounting plate 23 is substantially parallel to the horizontal plane. Figure 6 In the reclining position shown, the leg extension unit 3 extends forward relative to the base unit 1, and the backrest mounting plate 23 remains substantially parallel to the horizontal plane, but moves backward relative to the sitting position. During this process, as the upper ends of the first backrest link 21 and the second backrest link 22 traverse arc trajectories around the first pivot point P1 and the second pivot point P2, respectively, the height of the backrest mounting plate 23 also changes accordingly. The height difference H between the backrest mounting plate 23 and the top plate 15 can undergo a process of first increasing and then decreasing. In this embodiment, this height difference can change from approximately 160 mm to 220 mm, and then decrease back to 160 mm.
[0068] Accordingly, Figure 7 A mechanical extension device 100 with an illustrative backrest 200 is shown. This backrest 200 is attached to a backrest mounting plate 23. Figure 7 In the seated position shown above, the leg extension unit 3 is retracted. Figure 7 In the reclining position shown below, the leg extension unit 3 is retracted relative to the base unit 1. Since the backrest mounting plate 23 remains horizontal throughout the transition between the sitting and reclining positions, the angle of the backrest 200 relative to the horizontal plane remains constant, while only forward and backward movement relative to the base unit 1 occurs.
Claims
1. A mechanical extension device for a movable seat, characterized in that, The mechanical extension device includes: A base unit that is fixedly supported on the ground; A backrest unit movably connected to the rear of the base unit, wherein each backrest unit includes a first backrest link, a second backrest link, and a backrest mounting plate for attaching the backrest, wherein the first backrest link and the second backrest link are pivotally connected to the base unit respectively. Two leg extension units that are movably connected to the front of the base unit on the left and right sides; A linkage connecting the backrest unit and the leg extension unit; and An electric actuator acting between the base unit and the linkage causes the extension and retraction of the leg extension unit relative to the base unit and the movement of the backrest unit relative to the base unit to be synchronized through the working stroke of the electric actuator. Specifically, when the leg extension unit extends forward relative to the base unit, the upper ends of the first backrest linkage and the second backrest linkage pivot backward simultaneously; when the leg extension unit retracts backward relative to the base unit, the upper ends of the first backrest linkage and the second backrest linkage pivot forward simultaneously.
2. The mechanical extension device according to claim 1, characterized in that, The front end of the linkage is pivotally connected to a transverse linkage that is laterally connected between the two leg extension units, and the rear end of the linkage is pivotally connected to the backrest unit.
3. The mechanical extension device according to claim 1, characterized in that, The upper ends of the first backrest link and the second backrest link are pivotally connected to the backrest mounting plate, wherein during the extension and retraction of the leg extension unit, the angle change of the backrest mounting plate relative to the horizontal plane is no more than 15°.
4. The mechanical extension device according to claim 3, characterized in that, During the extension and retraction of the leg extension unit, the angle of the backrest mounting plate relative to the horizontal plane remains unchanged.
5. The mechanical extension device according to claim 4, characterized in that, During the extension and retraction of the leg extension unit, the backrest mounting plate remains parallel to the horizontal plane.
6. The mechanical extension device according to claim 3, characterized in that, The first backrest link includes a first pivot point located in the middle, a second pivot point located at the upper end, and a third pivot point located at the lower end. The first backrest link is pivotally connected to the base unit at the first pivot point, pivotally connected to the backrest mounting plate at the second pivot point, and pivotally connected to the rear end of the linkage link at the third pivot point.
7. The mechanical extension device according to claim 6, characterized in that, The second backrest link includes a fourth pivot point at the upper end and a fifth pivot point at the lower end, wherein the second backrest link is pivotally connected to the backrest mounting plate at the fourth pivot point and pivotally connected to the base unit at the fifth pivot point.
8. The mechanical extension device according to claim 7, characterized in that, The first pivot point is located in front of the fifth pivot point, and the second pivot point is located in front of the fourth pivot point.
9. The mechanical extension device according to claim 7, characterized in that, The straight-line distance between the first pivot point and the second pivot point is equal to the straight-line distance between the fourth pivot point and the fifth pivot point, and the straight-line distance between the first pivot point and the fifth pivot point is equal to the straight-line distance between the second pivot point and the fourth pivot point.
10. The mechanical extension device according to claim 1, characterized in that, The base unit includes two opposing side plates and a leg fixing rod fixedly connected to the side plates, wherein the leg extension unit is pivotally connected to the leg fixing rod.
11. The mechanical extension device according to claim 1, characterized in that, The base unit includes a top plate and a backrest fixing bracket fixedly connected to the top plate, wherein the first backrest link and the second backrest link are pivotally connected to the backrest fixing bracket.
12. The mechanical extension device according to claim 2, characterized in that, The mechanical extension device includes a front drive rod that is laterally connected between the linkages, with one end of the electric actuator connected to the base unit and the other end connected to the front drive rod.
13. The mechanical extension device according to claim 1, characterized in that, The electric actuator includes a linear electric actuator.
14. A movable seat unit, characterized in that, The movable seat unit includes at least: Armrests; Backrest; Footstool; A mechanical extension device (100), comprising: A base unit fixedly supported on the ground, wherein the handrail is attached to the base unit; A backrest unit movably connected to the rear of the base unit, wherein each backrest unit includes a first backrest link, a second backrest link, and a backrest mounting plate for attaching the backrest, wherein the first backrest link and the second backrest link are pivotally connected to the base unit respectively. Two leg extension units are movably connected to the front of the base unit on the left and right sides, and the footstool is attached to the leg extension units; A linkage connecting the backrest unit and the leg extension unit, wherein the front end of the linkage is pivotally connected to a transverse linkage laterally connected between the two leg extension units, and the rear end of the linkage is pivotally connected to the backrest unit; and An electric actuator acting between the base unit and the linkage rod causes the extension and retraction of the leg extension unit relative to the base unit and the movement of the backrest unit relative to the base unit to be synchronized through the working stroke of the electric actuator. Specifically, when the leg extension unit extends forward relative to the base unit, the backrest attached to the backrest mounting plate moves backward; when the leg extension unit retracts backward relative to the base unit, the backrest attached to the backrest mounting plate moves forward.
15. The movable seat unit according to claim 14, characterized in that, The front end of the linkage is pivotally connected to a transverse linkage that is laterally connected between the two leg extension units, and the rear end of the linkage is pivotally connected to the backrest unit.
16. The movable seat unit according to claim 14, characterized in that, The upper ends of the first backrest link and the second backrest link are pivotally connected to the backrest mounting plate, wherein during the extension and retraction of the leg extension unit, the angle change of the backrest relative to the horizontal plane is no more than 15°.
17. The movable seat unit according to claim 16, characterized in that, During the extension and retraction of the leg extension unit, the angle of the backrest relative to the horizontal plane remains unchanged.
18. The movable seat unit according to claim 16, characterized in that, The first backrest link includes a first pivot point located in the middle, a second pivot point located at the upper end, and a third pivot point located at the lower end. The first backrest link is pivotally connected to the base unit at the first pivot point, pivotally connected to the backrest mounting plate at the second pivot point, and pivotally connected to the rear end of the linkage link at the third pivot point.
19. The movable seat unit according to claim 18, characterized in that, The second backrest link includes a fourth pivot point at the upper end and a fifth pivot point at the lower end, wherein the second backrest link is pivotally connected to the backrest mounting plate at the fourth pivot point and pivotally connected to the base unit at the fifth pivot point.
20. The movable seat unit according to claim 19, characterized in that, The first pivot point is located in front of the fifth pivot point, and the second pivot point is located in front of the fourth pivot point.
21. The movable seat unit according to claim 19, characterized in that, The straight-line distance between the first pivot point and the second pivot point is equal to the straight-line distance between the fourth pivot point and the fifth pivot point, and the straight-line distance between the first pivot point and the fifth pivot point is equal to the straight-line distance between the second pivot point and the fourth pivot point.
22. The movable seat unit according to claim 14, characterized in that, The base unit includes two opposing side plates and a leg fixing rod fixedly connected to the side plates, wherein the leg extension unit is pivotally connected to the leg fixing rod.
23. The movable seat unit according to claim 14, characterized in that, The base unit includes a top plate and a backrest fixing bracket fixedly connected to the top plate, wherein the first backrest link and the second backrest link are pivotally connected to the backrest fixing bracket.
24. The movable seat unit according to claim 15, characterized in that, The mechanical extension device includes a front drive rod that is laterally connected between the linkages, with one end of the electric actuator connected to the base unit and the other end connected to the front drive rod.
25. The movable seat unit according to claim 14, characterized in that, The electric actuator includes a linear electric actuator.