CN113509017A

CN113509017A - Mechanical stretching device for a movable seat unit and seat unit

Info

Publication number: CN113509017A
Application number: CN202110651109.1A
Authority: CN
Inventors: 李晓鸿; 刘伟; 宋刚; 李元坤
Original assignee: Remacro Machinery and Technology Wujiang Co Ltd
Current assignee: Ruimai Technology Co ltd
Priority date: 2021-06-10
Filing date: 2021-06-10
Publication date: 2021-10-19
Anticipated expiration: 2041-06-10
Also published as: CN113509017B

Abstract

The invention relates to a mechanical extension device for a movable seating unit, comprising: -a tilting mechanism (2) comprising a multi-link mechanism and for attachment to the seat part, backrest and ottoman of the seating unit, configured to enable the seating unit to be changed between two end positions, i.e. a sitting position in which the ottoman is stowed under the seat part and a lying position; in the lying position, the backrest is inclined backwards and the footrest extends forwards in front of the seat part; wherein the tilting mechanism (2) is configured such that a change of the seat unit between the sitting position and the recumbent position is effected by means of an electric actuating unit (4), wherein, when the seat unit is changed from the sitting position to the recumbent position, the footrest is extended forward to the front of the seat part while the backrest is tilted backward, and when the seat unit is changed from the recumbent position to the sitting position, the footrest is retracted backward under the seat part while the backrest is tilted back forward.

Description

Mechanical stretching device for a movable seat unit and seat unit

Technical Field

The present invention relates to a mechanical extension device for a movable seating unit and a seating unit comprising said mechanical extension device.

Background

A variety of seating units for movable seating, such as rocking chairs, swinging chairs, sofas with a rocking function are known in the art. The seating unit typically has a base, a back rest support, a seat support, a tilt mechanism, and is capable of changing between several different positions. However, the known seat units often do not meet the comfort requirements of the user, for example, the user has to perform the above-described posture changes in a manually operated manner with great effort, or the postures are set in advance so that the user has to go through a long changing process to finally obtain the desired seat posture. Obviously, this also leads to a more complex structure of the seat unit, with a higher risk of failure and higher manufacturing and maintenance costs.

Disclosure of Invention

The invention is based on the object of providing a seat unit which is simpler in construction, simpler to operate and less expensive to produce.

To solve the above technical problem, the present invention provides a mechanical extension arrangement for a movable seating unit, comprising a reclining mechanism comprising a multi-link mechanism and intended to be attached to a seat portion, a backrest and a footrest of the seating unit, configured to enable the seating unit to be shifted between two end positions, namely a sitting position in which the footrest is folded under the seat portion and a lying position; in the reclined position, the backrest is reclined and the footrest is extended forwardly in front of the seat portion.

According to the invention, the tilting mechanism is configured such that the change of the seat unit between the sitting position and the lying position is effected by the electric actuator unit, wherein, when the seat unit is changed from the sitting position to the lying position, the footrest is extended forward to the front of the seat part while the backrest is tilted backward, and when the seat unit is changed from the lying position to the sitting position, the footrest is returned backward to be folded under the seat part while the backrest is returned forward to be tilted.

The invention is based on the idea that the movable seat unit can be changed between only two end positions, i.e. between the sitting position and the recumbent position, which are most common for the user, and that the change in position of the backrest and the change in position of the footrest take place simultaneously. This, on the one hand, eliminates the less common seat position, makes the associated design simpler and less expensive to produce, and on the other hand, the user can thus obtain his desired seat position in the most convenient manner. Furthermore, the change of the two end positions is effected by the electric actuator unit, whereby the user can operate the seat unit with little effort.

In a preferred design, the reclining mechanism includes a leg stretching unit for mounting the footrest, a seat bracket for mounting the seat portion, and a backrest bracket for mounting the backrest, which are pivotally connected in this order.

In a preferred design, the mechanical extension device comprises a support assembly for direct or indirect support on the ground, preferably for providing a swinging or rocking function to the seating unit.

In a preferred design, the recliner mechanism is configured to allow the seating unit to swing or rock fore and aft relative to the ground in the seating position when the recliner mechanism is configured for a swinging or rocking seating unit, and to not allow the seating unit to swing or rock fore and aft relative to the ground in the reclined position. To achieve this, the reclining mechanism includes a swing limiting mechanism designed to allow the seat and backrest brackets of the reclining mechanism to swing back and forth relative to the base of the seating unit in a sitting position and to prevent the seat bracket from swinging back and forth relative to the base in a recumbent position.

The leg stretching units are connected with front cross rods, the seat support is fixedly connected with rear cross rods, and the front cross rods can move forwards relative to the rear cross rods through the electric actuating units so that the footrest can move to the front of the seat portion.

In a particularly preferred embodiment, the rear transverse bar is directly or indirectly fixed or rigidly connected to the seat carrier.

In a particularly preferred embodiment, the tilting mechanism further comprises a linkage for linking the leg extension unit to the backrest support, which linkage is pivotally connected to the backrest support and to the leg extension unit, so that the backrest support can be tilted backwards about a backrest pivot point, at which the backrest support is pivotally connected to the seat support, while the leg extension unit is extended forwards, and the backrest support can be tilted forwards about the backrest pivot point while the leg extension unit is retracted backwards.

In one embodiment, the linkage is formed at least by a linkage link of one-piece design, by which a synchronous movement of the backrest support and the leg extension unit is achieved by a pivotal connection of the linkage link to the backrest support on the one hand and to the leg extension unit on the other hand. In this embodiment, the coupling link is directly pivoted at one end to the backrest support and at its other end to the leg extension unit, preferably to the foot bar of the leg extension unit closest to the seat support.

In this embodiment, the linkage preferably also comprises a backrest connection in addition to the linkage for structural stability. The backrest connecting piece is pivotally connected at its upper end to the backrest support at a pivot point behind the backrest pivot point, the backrest connecting piece is pivotally connected at its lower end to the rear end of the linkage link, and the front end of the linkage link is pivotally connected to the leg extension unit, preferably to the foot bar of the leg extension unit closest to the seat support. In this case, the backrest support is turned backward in synchronization with the leg stretching units being extended forward, and the backrest support is turned forward in synchronization with the leg stretching units being retracted backward by a simple linkage, so that the seat unit is changed between the sitting position and the lying position in a simple and reliable manner.

In order to further advantageously achieve a change of the seat unit between the sitting position and the reclining position, it is further preferred that the support assembly comprises a transmission connecting rod fixedly connected to the seat support, wherein a support connecting rod is provided between the transmission connecting rod and the seat support, which support connecting rod is connected, preferably fixedly connected, or also pivotably connected, at one end to the transmission connecting rod and is fixedly connected to the seat support at the other end to achieve a fixing of the relative position between the transmission connecting rod and the seat support. By means of this design, the seat carrier can be held positionally stable relative to the support assembly particularly effectively during a change of position of the seat unit, so that the pivotal connection point between the seat carrier and the backrest carrier, i.e. the position of the backrest pivot point relative to the support assembly, remains unchanged, which facilitates the backrest pivot point to be tilted forwards or backwards by the backrest link.

In a preferred embodiment, the mechanical stretching device comprises an electric actuating unit, preferably in the form of a linear motor unit, the components of which are connected to the front and rear transverse bars, respectively.

In this embodiment, it is preferred that the linear motor unit comprises a motor head, a motor slide connected to the motor head, and a motor slide slidable relative to the motor slide. One end of the electric actuating unit, such as a motor head, is pivotally connected to a front cross bar fixedly connected with the leg stretching unit, and the other end of the electric actuating unit, such as a motor sliding block, is pivotally connected to a rear cross bar fixedly connected with the seat part support, so that when the motor head moves longitudinally along a longitudinal axis of the motor sliding rail relative to the motor sliding block, the front cross bar drives the leg stretching unit to be unfolded forwards or retracted backwards, and the seat unit is changed between a sitting posture position and a lying posture position. Of course, the opposite design is also possible, for example, the motor slide of the electric actuating unit is pivotally connected to the front cross bar fixedly connected to the leg stretching unit, and the motor head of the electric actuating unit is pivotally connected to the rear cross bar fixedly connected to the seat support.

The mechanical extension apparatus further includes a base for directly supporting on the ground, the support assembly being fixedly supported on the base. The base may be a circular support designed to be supported on the ground, to which a fixed support consisting of a set of support rods extending in parallel is rotatably attached, so that the seat unit has a swivel function as well as a tilt, swing/rock function. Alternatively, the base may simply be configured as a set of parallel extending ground-contacting supports supported directly on the ground.

Preferably, the supporting assembly comprises a mounting swing base plate, a front swing rod, a rear swing rod and a transmission connecting rod, wherein the swing base plate is mounted on the base at the bottom, the front end of the swing base plate is pivotally connected with the top end of the front swing rod, the rear end of the swing base plate is pivotally connected with the top end of the rear swing rod, and the transmission connecting rod is respectively pivotally connected with the lower end of the front swing rod and the lower end of the rear swing rod.

Furthermore, the invention relates to a movable seating unit comprising: a base for supporting on the ground, a seat part positioned above the base, a backrest positioned behind the seat part, a footstool positioned in front of or below the seat part, and the mechanical stretching device. The movable seating unit may be a movable rocker chair, a rocking chair, in particular a sofa with a rocking or rocking function, or the like.

Drawings

Embodiments of the invention are explained in detail below with the aid of the figures.

FIG. 1 illustrates a perspective view of one embodiment of a mechanical extension device of a seating unit configured as a swing chair in a sitting position, in accordance with the present invention;

fig. 2 shows a side view of the mechanical stretching device according to fig. 1;

fig. 3 is a perspective view of the mechanical extension apparatus shown in fig. 1 in a reclined position;

FIG. 4 shows a side view of the mechanical stretching assembly according to FIG. 3;

fig. 5a and 5b show a swing release state and a swing limit state, respectively, of a swing limit mechanism for a mechanical stretching device according to the present invention;

FIG. 6 illustrates a perspective view of an embodiment of a mechanical extension device of a seating unit configured as a swing in accordance with the present invention in a seating position;

FIG. 7 illustrates a side view of an embodiment of a mechanical stretching assembly according to FIG. 6;

fig. 8 illustrates a perspective view of the mechanical extension device of fig. 6 in a prone position; and is

Fig. 9 shows a side view of the mechanical stretching device according to fig. 8.

Detailed Description

Fig. 1 is a schematic illustration of an embodiment of a mechanical extension device for a movable seating unit. The seat unit includes: base 1, tilt mechanism 2, support assembly 3, electric actuation unit 4.

The base 1 can be designed as shown in fig. 1 as a circular support 11 which rests on the ground and to which a fastening bracket 12 consisting of a set of parallel supporting rods is rotatably connected.

Alternatively, in other embodiments not shown, the base 1 may also be configured as a set of parallel extending ground-contacting supports supported directly on the ground.

Above the base 1, in particular in the exemplary embodiment shown in fig. 1, a tilting mechanism 2 is fixedly connected to the fixed support 12. The reclining mechanisms are arranged mirror-symmetrically on the left and right with reference to the longitudinal direction of the seat unit, and only half of them are shown and specifically explained here for the sake of simplicity. The reclining mechanism includes a seat bracket 21, a backrest bracket 22, and a leg stretching unit 23.

In this embodiment, the backrest support 22 is configured with a horizontal section 221 extending substantially horizontally in the sitting position, at the front end of which is pivotably connected with the rear end of the seat support 21 at a backrest pivot point M about which the backrest support 22 can be flipped back and forth, and a vertical section 222 extending substantially vertically.

As shown in fig. 1 to 4, the leg stretching unit 23 is composed of a plurality of links pivotally connected to each other, wherein the seat bracket 21 is pivotally connected to the rear end of the front link 230 at a first pivot point a, the front end of the front link 230 is pivotally connected to the rear end of the first foot bar 231 at a second pivot point B, the front ends of the first and

second foot bars

231 and 232 are respectively pivotally connected to the footrest support plate 234, the rear end of the second foot bar 232 is pivotally connected to the front end of the third foot bar 233 at a third pivot point C, the rear end of the third foot bar 233 is pivotally connected to the seat bracket 3 at a fourth pivot point D, and the second foot bar 232 is in turn pivotally connected to the front link 230 at a fifth pivot point E.

As shown in fig. 2 and 4, the reclining mechanism 2 further includes a linkage 24, and the linkage 24 includes a backrest connector 241 and a linkage link 242 extending substantially in the longitudinal direction of the seat unit. In the illustrated design, the linkage link 242 is pivotally connected at its front end to the middle of the third leg 233 of the leg unit 23 at a sixth pivot point F, the linkage link 242 is pivotally connected at its rear end to the backrest connection 241 at a seventh pivot point G, and the backrest connection 241 is pivotally connected to the backrest bracket 22 at an eighth pivot point H.

The mechanical extension arrangement further comprises a support assembly 3. As shown in fig. 1 and 3 in particular, the support assembly 3 includes a swing base plate 31, a front swing rod 32, a rear swing rod 33 and a transmission connecting rod 34, wherein the bottom of the swing base plate 31 is fixedly connected to the fixed bracket 12 of the base 1, the swing base plate 31 is pivotally connected to the top end of the front swing rod 32 at the front end of the top thereof, the swing base plate 31 is pivotally connected to the top end of the rear swing rod 33 at the rear end of the top thereof, and the lower end of the front swing rod 32 and the lower end of the rear swing rod 33 are pivotally connected to the transmission connecting rod 34 extending lengthwise, respectively.

Preferably in the embodiment shown, the transmission connecting rod 34 is fixedly connected, in particular riveted or welded, with its front end to the seat support 21 and is pivotably connected with its rear end via a rear connecting piece 243 to the backrest connecting piece 241. In the illustrated design, the top end of the rear link 243 is pivotally connected to the back link 241 at a ninth pivot point I, and the lower end of the rear link 243 is pivotally connected to the rear end of the drive link 34 at a tenth pivot point J.

In a preferred embodiment, a support link 35 is additionally provided between the transmission connecting rod 34 and the seat support 21, said support link 35 being pivotably connected at one end to the transmission connecting rod 34 and being fixedly connected at its other end to the seat support 21, so that in conjunction with the fixed connection of the transmission connecting rod 34 to the seat support 21, a fixing of the relative position between the transmission connecting rod 34 and the seat support 21 is achieved.

As shown in particular in fig. 1 and 3, the seat unit further comprises an electric actuating unit 4, which in this embodiment is a linear motor unit, comprising a motor head 41, a motor slide 42 connected to the motor head 41, and a motor slide 43 slidable relative to the motor slide 42, wherein the motor head 41 is pivotably connected to a front crossbar 44 fixedly connected to the front link 230 of the leg extension unit 23, the motor slide 43 is pivotably connected to a rear crossbar 45, and the rear crossbar 45 is fixedly connected at both ends to the middle of the seat support 21 by means of intermediate links 46, respectively. Therefore, when the motor head 41 moves back and forth along the motor slide rail 42 relative to the motor slide block 43, the front cross bar 44 drives the leg stretching unit 230 to expand forwards or retract backwards through the front connecting piece 230.

The operation of the seat unit for changing between the sitting position and the reclining position is explained below with reference to fig. 1 to 4.

In the sitting position as shown in fig. 1 and 2, the back support 22 is oriented generally vertically, the seat support 21 is oriented generally horizontally, the footrest support plate 234 is oriented generally vertically and the leg extension units 23 are fully stowed beneath the seat support 21; in the reclined position shown in figures 3 and 4, the leg units 23 are fully extended forward and the back rest 22 is fully reclined.

When the motor head 41 is operated in the forward direction, the position of the seat support 3 is kept substantially unchanged in the longitudinal direction due to the gravity of the user, the motor head 41 moves forward along the motor slide rail 42 relative to the motor slide block 43, so that the distance between the motor head 41 and the motor slide block 43 is increased, the front cross bar 44 drives the front connecting piece 230 to lift forward, and the leg stretching units 23 are completely unfolded from the folded state in the sitting position shown in fig. 1 and 2 to the unfolded state in the lying position shown in fig. 3 and 4. Meanwhile, as the leg stretching unit 23 is unfolded, the link 242 pivotally connected to the third leg 233 of the leg stretching unit 23 at the sixth pivot point F is moved forward accordingly, thereby moving the seventh pivot point G connecting the rear end of the link 242 and the backrest link 241 forward. Since the relative position between the seat support 21 and the transmission link 34 is fixed, the position of the backrest pivot point M remains substantially unchanged during the unfolding of the leg stretching unit 23, which brings the eighth pivot point H on the backrest link 241 to move downwards, thereby drawing the backrest support 22 to turn backwards and downwards around the backrest pivot point M. This allows the backrest support 22 to be tilted backward while the leg extension unit 23 is extended forward, thereby allowing the seat unit to be changed from the sitting position to the reclining position.

From the lying position shown in fig. 3 and 4, if the motor head 41 runs in the reverse direction, the motor head 41 moves along the motor slide rail 42 toward the motor slider 43, so that the distance between the motor head 42 and the motor slider 43 is shortened, and the leg stretching unit 23 retracts backward, and further the linkage link 242 is driven to move backward and the seventh pivot point G of the backrest connecting member 241 is pushed to move backward. At the same time, also due to the fixed position of the backrest pivot point M, the eighth pivot point H on the backrest connection 241 moves upwards, which in turn pushes the backrest bracket 22 to flip upwards and forwards around the backrest pivot point. This allows the backrest support 22 to be tilted back to the front while the leg extension unit 23 is retracted back, so that the seat unit can be changed from the recumbent position to the sitting position.

In a preferred embodiment, as shown in fig. 3 to 5b, the mechanical stretching device has a swing limiting mechanism 25, which includes a first limiting member 251, a second limiting member 252, a chute limiting member 253, and a limiting link 254. The middle of the first limiting member 251 is pivotally connected to the transmission connecting rod 34 at a limiting pivot point K, a first limiting bushing 251a is disposed at the front end of the first limiting member 251, the rear end of the first limiting member 251 is pivotally connected to the front end of the second limiting member 252, and a second limiting bushing 252a is disposed at the rear end of the second limiting member 252. The sliding slot stopper 253 is fixedly connected to the transmission connecting rod 34 and extends upward from the transmission connecting rod to form a section with a stopping sliding slot 253a, and the second stopping bushing 252a is movably embedded in the swinging stopping sliding slot 253 a. One end of the limit link 254 is pivotally connected between the limit pivot point K of the first limiting member 251 and the first limit bushing 251a, and the other end thereof is pivotally connected to the link 242, so that the limit link 254 can be moved by the link 242, whereby the swing limit mechanism 25 can be switched between the swing release state and the swing limit state.

In the swing release state as shown in fig. 5a, the seat unit is in the seating position, and the first and

second check bushings

251a and 252a are not in contact with both the front and

rear swing rods

32 and 33, thereby allowing forward and backward pivotal movement of the front and

rear swing rods

32 and 33 such that the reclining mechanism 2 can swing forward and backward with respect to the base 1. When the seat unit is changed from the sitting position to the lying position, the leg stretching unit 23 is unfolded, causing the linkage link 242 to move forward, and the limit link 254 also moves forward under the traction of the linkage link 242, thereby driving the first limit member 251 to pivot about the limit pivot point K, moving with the first limit bushing 251a thereof, until the first limit bushing 251a abuts against the inner side of the front swing rod 32; at the same time, the rear end of the first limiting member 251 moves backward, so as to push the second limiting member 252 to move backward with its second limiting bushing 252a in the limiting chute 253a of the third limiting member 253 until the second limiting bushing 252a abuts against the inner side of the rear swing lever 33. This reaches the swing limit state shown in fig. 5b, and the pivoting of the forward and backward swing levers 32, 33 is prevented, so that the reclining mechanism 2 can no longer swing forward and backward with respect to the base 1.

An embodiment of a mechanical extension apparatus configured as a swing is shown in fig. 6-9. In this case, the swing base plate 31 'is used instead of the swing base plate in the above-described support assembly, and the swing base plate 31' is mounted on the base 1 having a swing function with its bottom portion. In the illustrated embodiment, the rocking base plate 31 'is mounted on a set of parallel extending ground-contacting brackets 13 configured to be supported directly on the ground, with the drive link of the bearing assembly 3 being fixedly connected to the rocking base plate 31'. In this embodiment, the drive link consists of a substantially vertically extending first part 341 of the drive link and a substantially longitudinally extending second part 342 of the drive link, which are adjacent to the leg extension unit 23, but the drive link can also be constructed in one piece, as in the embodiment of the swing chair.

A support link 35 is likewise arranged between the drive link and the seat support 21, one end of the support link 35 being fixedly connected to the seat support 21 and the other end being fixedly connected to the drive link, in this embodiment to the second part 342 of the drive link. The mechanical stretching device thus also ensures a fixation of the relative position between the seat support 21 and the transmission linkage during the change between the sitting position and the recumbent position.

An eleventh pivot point L is additionally provided on the backrest link 241 between the seventh pivot point G and the ninth pivot point I. In this embodiment, the support assembly 3 further comprises a first auxiliary link 36 and a second auxiliary link 37, wherein one end of the first auxiliary link 36 is pivotally connected to the backrest connection 241 by means of an eleventh pivot point L. The second auxiliary link 37 is provided with an auxiliary bush 37a at one end thereof and the other end, which is not provided with an auxiliary bush, is pivotally connected to the transmission connecting rod, in this embodiment preferably pivotally connected to the transmission connecting rod second part 342. The other end of the first auxiliary connecting rod 36 is pivotally connected to the second auxiliary connecting rod 37 at an auxiliary pivot point N near its auxiliary bushing 37 a. The remaining technical features that are the same as those of the embodiment of fig. 1 to 4 are not described herein again.

Fig. 6 and 7 illustrate a configuration of the seating unit in a seating position, designed as a swing. As shown in fig. 6 and 7, the first auxiliary link 36 is pivotally connected to the second auxiliary link 37 via the auxiliary pivot point N, and at this time, the auxiliary bushing 37a at the end of the second auxiliary link 37 is spaced from the base 1, and in this embodiment, the ground-contacting bracket 13. In the lying position shown in fig. 8 and 9, the auxiliary bushing 37a rests against the base 1.

When the mechanical stretching device is changed from the sitting position shown in fig. 6 and 7 to the lying position shown in fig. 8 and 9, the leg stretching unit 23 is stretched forward by the electric actuating unit 4, so as to move the linkage link 242 forward and further to turn the backrest connecting member 241, so that the seventh pivot point G on the backrest connecting member 241 is moved forward, in this case, the backrest support 22 is turned backward around the backrest pivot point M by the backrest connecting member 241 because the position of the backrest pivot point M relative to the transmission link is kept fixed. At the same time, the eleventh pivot point L on the backrest link 241 is also moved forward, as one end of the second auxiliary link 37 is pivotally connected to the stationary transmission link, in this embodiment to the transmission link second part 342, pushing the auxiliary pivot point N between the first auxiliary link 36 and the second auxiliary link 37 downward and causing the second auxiliary link 37 to pivot downward with its end provided with the auxiliary bushing 37a about its pivot point on the transmission link second part 342 until the auxiliary bushing 37a abuts against the base 1, preferably against the ground-contacting bracket 13. In this embodiment, the reclining mechanism 2 is prevented from swinging backwards in the recumbent position by the auxiliary bushing 37a, enabling additional support of the backrest support in the recumbent position, thereby preventing the risk of tipping over due to excessive reclining of the backrest in the recumbent position and ensuring safe use of the seating furniture.

List of reference numerals

1 base

11 circular support

12 fixed support

13 touchdown bracket

2 Tilt mechanism

21 seat support

22 backrest support

221 horizontal segment

222 vertical section

23 leg telescoping unit

230 front connector

231 first leg bar

232 second leg bar

233 third leg bar

234 foot stool support plate

24 linkage device

241 backrest connecting piece

242 linkage connecting rod

243 rear connecting piece

25 swing limiting mechanism

251 first position limiting component

251a first position-limiting bush

252 second position limiter

252a second Limit bushing

253 chute stopper

253a limit chute

254 spacing connecting rod

3 support assembly

31 swing base plate

31' rocking of the substrate

Swing rod before 32

33 rear swing rod

34 transmission connecting rod

341 first sub-assembly of transmission connecting rod

342 drive connecting rod second sub-component

35 support link

36 first auxiliary link

37 second auxiliary link

4 electric actuating unit

41 electric machine head

42 motor slide rail

43 electric motor slide block

44 front cross bar

45 rear cross bar

46 middle connecting piece

A first pivot point

B second pivot point

C third pivot point

D fourth pivot point

E fifth pivot point

Fsixth pivot point

G seventh pivot point

H eighth pivot point

I ninth Pivot Point

J tenth pivot point

K-position limiting pivot point

L eleventh Pivot Point

M backrest pivot point

N assist the pivot point.

Claims

1. A mechanical extension device for a movable seating unit, comprising:

-a tilting mechanism (2) comprising a multi-link mechanism and for attachment to the seat part, backrest and ottoman of the seating unit, configured to enable the seating unit to be changed between two end positions, i.e. a sitting position in which the ottoman is stowed under the seat part and a lying position; in the lying position, the backrest is inclined backwards and the footrest extends forwards in front of the seat part;

wherein the tilting mechanism (2) is configured such that a change of the seat unit between the sitting position and the recumbent position is effected by means of an electric actuating unit (4), wherein, when the seat unit is changed from the sitting position to the recumbent position, the footrest is extended forward to the front of the seat part while the backrest is tilted backward, and when the seat unit is changed from the recumbent position to the sitting position, the footrest is retracted backward under the seat part while the backrest is tilted back forward.

2. Mechanical stretching device according to claim 1, wherein said tilting mechanism (2) comprises: a leg stretching unit (23) for installing the footrest, a seat support (21) for installing the seat part and a backrest support (22) for installing the backrest are connected in turn in a pivoting manner.

3. Mechanical extension device according to claim 1 or 2, characterized in that it comprises a bearing assembly (3) for direct or indirect support on the ground, preferably for providing a rocking or rocking function to the seating unit.

4. A mechanical extension arrangement according to claim 1, wherein the tilt mechanism (2) is configured to allow the seating unit to swing or rock fore and aft relative to the ground in a sitting position while not allowing the seating unit to swing or rock fore and aft relative to the ground in a lying position when the seating unit is swinging or rocking.

5. Mechanical stretching device according to claim 2, wherein a front crossbar (44) is connected to the leg stretching unit (23) and a rear crossbar (45) is fixedly connected to the seat support (21), wherein the front crossbar (44) can be moved forward relative to the rear crossbar (45) by means of the electric actuating unit (4) to move the footrest in front of the seat portion.

6. Mechanical stretching device according to claim 5, wherein said rear crossbar (45) is directly or indirectly fixed or rigidly connected to said seat support (21).

7. Mechanical stretching device according to one of the claims 2 to 6, wherein the tilting mechanism (2) further comprises a linkage (24) for linking the leg stretching unit (23) with the backrest support (22), said linkage being pivotally connected with the backrest support (22) and the leg stretching unit (23) such that the backrest support (22) can be flipped backwards around a backrest pivot point (M) at which the backrest support (22) is pivotally connected with the seat support (21) while the leg stretching unit (23) is stretched forwards, and the backrest support (22) can be flipped forwards around said backrest pivot point (M) while the leg stretching unit (23) is folded backwards.

8. Mechanical stretching device according to claim 7, wherein the linkage (24) comprises a backrest connection (241) and a linkage link (242), wherein the backrest connection (241) is pivotally connected with its upper end to the backrest support (22) at a pivot point behind the backrest pivot point (M), the backrest connection is pivotally connected with its lower end to the rear end of the linkage link (242), and the front end of the linkage link (242) is pivotally connected to the leg stretching unit (23), preferably to the foot bar of the leg stretching unit (23) closest to the seat support (21).

9. Mechanical stretching device according to one of the claims 2 to 8, wherein the support assembly (3) comprises a transmission connecting rod (34) fixedly connected to the seat support (21), wherein a support link (35) is provided between the transmission connecting rod (34) and the seat support (21), which support link is connected, preferably fixedly connected, at one end to the transmission connecting rod (34) and at the other end to the seat support (21).

10. Mechanical stretching device according to one of claims 5 to 9, further comprising an electric actuation unit (4), preferably designed as a linear motor unit, the components of which are connected to the front crossbar (44) and the rear crossbar (45), respectively.

11. Mechanical stretching apparatus as in claim 3, further comprising a base (1) for directly supporting on the ground, said support assembly (3) being fixedly supported on said base.

12. A movable seating unit, comprising: -a base (1) for supporting on a floor, -a seat part above the base (1), -a backrest behind the seat part, -a footrest in front of or below the seat part, -a mechanical stretching device according to any of the preceding claims.