CN220876338U - Mechanical stretcher for a movable seat and movable seat unit - Google Patents

Abstract

The utility model relates to a mechanical stretching device for a movable seat, comprising: a seat frame for attaching a seat portion; a backrest assembly coupled to a rear portion of the seat frame; a leg extension device coupled to the front of the seat. The backrest assembly comprises a backrest bracket, a first backrest link and a second backrest link, wherein the backrest bracket is used for attaching a backrest of a movable seat, the backrest bracket is coupled with a seat frame by means of the first backrest link and the second backrest link, wherein the upper end of the first backrest link is pivotally connected with the front end of the backrest bracket at a first pivot point, and the lower end of the first backrest link is pivotally connected with the rear part of the seat frame at a second pivot point. The utility model also relates to a movable seating unit.

Description

Mechanical stretcher for a movable seat and movable seat unit

Technical Field

The present utility model relates to a mechanical stretcher for a movable seat and a movable seat unit comprising the mechanical stretcher.

Background

A variety of seats for use in a movable seat, such as a sofa or a seat having a multi-position changing function, are known in the art. Along with the improvement of the living standard of people, the comfort requirements on sofas and seats are also increasingly improved. In known designs, the movable seating units are generally provided with mechanical extension means, whereby the seat unit can be shifted between a stowed position, a rest position (or TV position), in which the footrests of the seating unit extend forward, and a lying position, in which the angle between the backrest and the seat part is substantially unchanged, and in which the footrests are further raised forward and upward than in the rest position, in which the backrest is significantly reclined.

However, in such a seat unit according to the prior art, the complicated connection of the mechanical structure and the numerous parts required lead to high manufacturing costs on the one hand and to a jamming of the mechanical structure in the change of posture on the other hand. Furthermore, such prior art seating units do not achieve a true zero wall, i.e. the rear end of the backrest part moves backwards during the transition from the sitting to the lying position, so that a larger active space needs to be reserved behind the seating unit. In addition, a gap occurs due to the separation between the backrest portion and the seat portion during the unfolding of the seat unit, and the user's coat is pulled out, failing to meet the user's requirement for comfort.

Disclosure of utility model

The utility model aims to solve the technical problems of providing a mechanical stretching device for a movable seat and a corresponding movable seat unit, which are smooth and reliable in posture change and high in comfort, on one hand, the mechanical stretching device should meet the space requirement of a user on the zero-leaning wall arrangement of the movable seat, and on the other hand, in the posture change process of the movable seat, gaps between the rear edge of a seat part and the lower edge of a backrest are avoided, zero-clearance design is realized, and the phenomenon that the upper garment of the user is pulled out due to improper relative displacement between the backrest and the seat part when the seat is unfolded is avoided, so that the comfortable experience of zero back rubbing is provided.

To solve the above technical problem, the present utility model provides a mechanical stretching device for a movable seat, which is capable of being changed between a sitting position, a TV position and a lying position. In the sitting position, the leg extension means is stowed under the seat frame; in the TV pose position, the leg extension means is raised forward and upward; in the recumbent position, the leg extension device is lifted forward and upward and the back support is reclined.

The mechanical stretching device comprises:

a fixed plate fixedly connected with the armrest part of the movable seat;

a seat frame movable back and forth with respect to the fixing plate for attaching a seat portion;

A backrest assembly coupled to a rear portion of the seat frame;

a leg extension device coupled to the front of the seat.

The backrest assembly comprises a backrest bracket, a first backrest link and a second backrest link, wherein the backrest bracket is used for attaching a backrest of a movable seat, the backrest bracket is coupled with a seat frame by means of the first backrest link and the second backrest link, wherein the upper end of the first backrest link is pivotally connected with the front end of the backrest bracket at a first pivot point, and the lower end of the first backrest link is pivotally connected with the rear part of the seat frame at a second pivot point.

In one embodiment according to the utility model, the rearmost end of the back rest support has a forward component of motion and the first pivot point has a motion trajectory in the horizontal direction towards the leg extension means and a motion trajectory in the height direction first downwards and upwards during the transition of the mechanical extension means from the sitting position to the TV position and to the lying position.

In this embodiment, during the change from the sitting position to the lying position, the first pivot point is brought by the seat frame such that the backrest support, together with the backrest attached thereto, moves with the first pivot point in the direction of the leg extension means, i.e. in the forward direction. In addition, as the first pivot point has a stage of downward and forward movement in the height direction, improper separation movement of the backrest and the seat part is avoided, and no gap is formed between the backrest and the seat part, so that foreign matter is prevented from being clamped, and safety is improved; on the other hand, the pull-out of the coat and quilt backrest of the user is avoided, and the use comfort is improved.

In an alternative embodiment according to the utility model, the rearmost end of the back rest support has a forward component of motion during the transition of the mechanical extension device from the sitting position to the TV position and vice versa, wherein the distance between the first pivot point and the second pivot point is 80mm to 150mm and the first angle of the first back rest link to the seat frame forming an opening towards the leg extension device is less than 90 °.

Preferably, the distance between the first and second pivot points is 100mm to 140mm, particularly preferably 115mm to 120mm.

In this alternative embodiment, the first backrest link is optimized in terms of structural design and connection relationship. Because the included angle formed by the first backrest connecting rod and the seat frame and facing the leg stretching device is always smaller than 90 degrees, namely an acute angle is always formed, in the process of changing from a sitting position to a lying position, the first backrest connecting rod connected between the front end of the backrest bracket and the seat frame is further pressed down when the backrest bracket moves forward, namely the upper end of the first backrest connecting rod is further overturned and inclined forwards around the second pivot point, the forward movement of the backrest bracket is further promoted, and therefore a thorough zero wall of the posture changing process from the sitting position to the lying position is realized. On the other hand, the clamping stagnation in the gesture conversion process is avoided, so that the operation is smoother, and the functional reliability is improved.

In the present application, the "front-rear direction" refers to the extending direction of the leg extending device of the seating chair unit or the mechanical extending device, specifically, "front" refers to the direction toward the leg extending device, and "rear" refers to the direction toward the backrest.

Preferably, the first pivot point moves forward and downward during the transition of the mechanical extension device from the sitting position to the TV position and moves forward and upward during the transition of the mechanical extension device from the TV position to the lying position.

Preferably, the first pivot point is higher in the recumbent position than in the sitting position.

Preferably, the second backrest link is pivotally connected to the rear end of the backrest bracket at a third pivot point and to the rear of the seat frame at a fourth pivot point, wherein the fourth pivot point is further rearward than the second pivot point.

Preferably, the rear end of the seat frame is lowered relative to the fixed plate during the transition of the mechanical stretching device from the sitting position to the TV position; the seat is raised relative to the fixed plate during the transition of the mechanical stretching device from the TV position to the recumbent position.

Further preferably, the second backrest link is configured as a bell crank and further comprises a fifth pivot point, wherein the third and fifth pivot points are located on the free ends of the upper and lower arms of the bell crank, respectively, and a fourth pivot point is located between the third and fifth pivot points, wherein the second backrest link is directly or indirectly coupled with the fixed plate at the fifth pivot point.

According to the utility model, the seat frame is attached to the fixed plate in a back-and-forth movable manner through the main interlocking assembly and the auxiliary interlocking assembly, wherein the seat frame is pivotally connected with the main interlocking assembly, and the auxiliary interlocking assembly is pivotally connected with the fixed plate.

Further preferably, the main linkage assembly comprises an intermediate link pivotally connected with the auxiliary linkage assembly, and the rear end of the seat frame is driven to move downwards and forwards relative to the intermediate link by the main linkage assembly in the process of changing the mechanical stretching device from the sitting position to the TV position, wherein the intermediate link has no relative displacement relative to the fixed plate; during the process of changing the mechanical stretching device from the TV position to the lying position, the auxiliary linkage assembly drives the seat frame and the main linkage assembly to move forwards and upwards relative to the fixing plate.

Preferably, the mechanical stretching device according to the utility model is used for a movable seat with a floor-standing armrest. Alternatively, however, the mechanical stretching device can also be applied in a rational manner to other configurations of movable seats.

In a preferred embodiment, the mechanical stretching means further comprises linear electric actuation means. However, in alternative embodiments, the mechanical stretching means may be manual or combined with a motor driven means.

In order to solve the technical problem, the utility model also provides a mechanical stretching device, a handrail part, a backrest, a seat part and a footstool part, wherein the handrail part, the backrest, the seat part and the footstool part are attached to the mechanical stretching device, and the mechanical stretching device can enable the seat unit to be changed between at least a sitting position and a lying position. In the sitting position, the footrest section is folded under the seat frame; in the TV pose position, the footrest section is raised forward and upward; in the recumbent position, the footrest section is raised forward and upward and the backrest is reclined.

The mechanical stretching device comprises:

a fixing plate fixedly connected with the armrest part;

a seat frame movable back and forth with respect to the fixing plate for attaching a seat portion;

A backrest assembly coupled to a rear portion of the seat frame;

a leg extension device coupled to the front of the seat.

In one such embodiment according to the utility model, the backrest assembly comprises a backrest bracket, a first backrest link and a second backrest link, wherein the backrest bracket is used for attaching a backrest of a movable seat, the backrest bracket being coupled to a seat frame by means of the first backrest link and the second backrest link, wherein an upper end of the first backrest link is pivotally connected to a front end of the backrest bracket at a first pivot point and a lower end of the first backrest link is pivotally connected to a rear portion of the seat frame at a second pivot point. During the transition of the mechanical stretcher from the sitting position to the TV position and vice versa, the rearmost end of the back rest has a forward motion component and the first pivot point has a motion trajectory in the horizontal direction towards the leg stretcher and a motion trajectory in the height direction, first downward and then upward.

In an alternative embodiment according to the utility model, the backrest assembly comprises a backrest bracket, a first backrest link and a second backrest link, wherein the backrest bracket is used for attaching a backrest of a movable seat, the backrest bracket being coupled with a seat frame by means of the first backrest link and the second backrest link, wherein an upper end of the first backrest link is pivotally connected with a front end of the backrest bracket at a first pivot point and a lower end of the first backrest link is pivotally connected with a rear portion of the seat frame at a second pivot point; during the transition of the mechanical stretcher from the sitting position to the TV position and vice versa, the rearmost end of the back rest has a forward component of motion, wherein the distance between the first pivot point and the second pivot point is 80mm to 150mm and the first angle of the opening formed by the first back rest link and the seat frame towards the leg stretcher is less than 90 °.

Preferably, the first pivot point moves forward and downward during the change of the seating unit from the sitting position to the TV pose position, and moves forward and upward during the change of the seating unit from the TV pose position to the recumbent position.

Preferably, the first pivot point is higher in the recumbent position than in the sitting position.

Preferably, the second backrest link is pivotally connected to the rear end of the backrest bracket at a third pivot point and to the rear of the seat frame at a fourth pivot point, wherein the fourth pivot point is further rearward than the second pivot point.

Preferably, the rear end of the seat frame is lowered relative to the fixed plate during the transition of the seat unit from the sitting position to the TV position; the seat frame is raised relative to the fixed plate during the transition of the seating unit from the TV position to the recumbent position.

Preferably, the second backrest link is configured as a bell crank and further comprises a fifth pivot point, wherein the third and fifth pivot points are located on the free ends of the upper and lower arms of the bell crank, respectively, and a fourth pivot point is located between the third and fifth pivot points, wherein the second backrest link is directly or indirectly coupled with the fixed plate at the fifth pivot point.

Preferably, the seat frame is attached to the fixed plate in a back and forth movable manner by a main interlocking assembly and a sub interlocking assembly, wherein the seat frame is pivotally connected to the main interlocking assembly, and the sub interlocking assembly is pivotally connected to the fixed plate.

Preferably, the main linkage assembly comprises an intermediate link pivotally connected with the auxiliary linkage assembly, and the rear end of the seat frame is driven to move downwards and forwards relative to the intermediate link by the main linkage assembly in the process of changing the seat unit from the sitting position to the TV pose position, wherein the intermediate link has no relative displacement relative to the fixed plate; during the process of changing the seat unit from the TV position to the lying position, the auxiliary linkage assembly drives the seat frame and the main linkage assembly to move forwards and upwards relative to the fixed plate.

Preferably, the seating unit is a armrest floor type seating unit.

Preferably, the seating unit further comprises a linear electric actuation device.

The advantages described above in relation to the mechanical stretcher section apply equally to a movable seating unit with such a mechanical stretcher.

Drawings

Embodiments of the present utility model are described in detail below with reference to the drawings.

FIG. 1 schematically illustrates in perspective view a mechanical stretcher for a movable seat according to one embodiment of the utility model, in a sitting position;

FIG. 2 schematically illustrates a perspective view of the mechanical stretcher apparatus of FIG. 1 in a TV pose position;

FIG. 3 schematically illustrates a perspective view of the mechanical stretcher apparatus of FIG. 1 in a recumbent position;

FIG. 4 schematically illustrates in side view the seated position of the mechanical stretcher of FIG. 1;

FIG. 5 schematically illustrates in side view the TV pose position of the mechanical stretcher of FIG. 1;

FIG. 6 schematically illustrates in side view the recumbent position of the mechanical stretcher apparatus shown in FIG. 1;

FIG. 7 schematically illustrates a partial side view of a mechanical stretching device according to an embodiment of the present utility model; and

Fig. 8 shows a schematic representation of the posture change of the mechanical stretching device according to the utility model.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present utility model without making any inventive effort, are intended to fall within the scope of the present utility model.

Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic can be included in at least one implementation of the utility model. In the description of the present utility model, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "top", "bottom", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may include one or more of the feature, either explicitly or implicitly. Moreover, the terms "first," "second," and the like, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that embodiments of the utility model described herein may be implemented in sequences other than those illustrated or otherwise described herein.

Fig. 1 to 3 show in perspective a mechanical stretching device 1 of a movable seat according to the utility model, comprising a multi-link mechanism, and configured to enable the movable seat to be transformed between a sitting position, a TV position and a lying position.

As shown in fig. 1 to 3, the mechanical stretcher is configured as a movable seat for a floor standing armrest and includes mechanical stretcher halves disposed mirror-symmetrically on both left and right sides. Each mechanical stretcher half has a fixed plate 12 extending lengthwise in the fore-and-aft direction of the movable seat, and each mechanical stretcher half is mounted by its respective fixed plate 12 on the inner side plate of the armrest portion, not shown. Each of the fixing plates 12 is attached to a common fixing cross member 52 by means of a fixing tab 51, respectively, which fixing cross member 52 is located on the back side, i.e. the rear of the movable seat. The bottom of the armrest portion is supported directly on the ground, thereby supporting the mechanical stretcher "suspended" above the ground.

The mechanical stretcher 1 further comprises a seat 10, a backrest assembly 2 pivotably connected to the rear of the seat 10, and a leg stretcher 3 pivotably connected to the front of the seat 10.

The seat frame 10 is used for bearing a seat part of the movable seat, and a seat frame rear extension part 11 extending upwards is fixedly arranged at the rear part of the seat frame 10, and the seat frame rear extension part 11 can be integrally formed with the seat frame 10 or can be fixedly connected with the seat frame 10 as a separate component, and can be fixedly arranged on the seat frame 10 in a welding, riveting or other manners.

The backrest assembly 2 includes a backrest bracket 21 for attaching a backrest of a movable seat, a first backrest link 22, and a second backrest link 23. The back bracket 21 is of generally L-shaped configuration with a front end pivotally connected to an upper end of the first back link 22 at a first pivot point P1 and a lower end of the first back link 22 pivotally connected to a rear portion of the seat frame 10 at a second pivot point P2. The second backrest link 23 is configured as a bell crank and has three pivot points at the middle of the bell crank and at the ends of the two arms, respectively. Specifically, the second back link 23 is pivotably connected with its upper end to the rear end of the back bracket 21 at the third pivot point P3, and the second back link 23 is pivotably connected with its middle portion to the upper end of the seat frame rear extension 11 at the fourth pivot point P4. The fourth pivot point P4 is disposed further rearward than the second pivot point P2. Thus, a four-bar mechanism is formed by the back support 21, the seat frame 10 (together with the seat frame rear extension 11 fixedly connected thereto), and the first back link 22 and the second back link 23 connecting the two. Further, the lower end of the second backrest link 23 is pivotally connected to the upper end of the fixed plate link 24 at a fifth pivot point P5, and the lower end of the fixed plate link 24 is pivotally connected to the rear of the fixed plate 12.

Fig. 7 shows a detail of the backrest module 2 in a side view. The distance L between the first pivot point P1 and the second pivot point P2 of the first backrest link 22 is in the range of 80mm to 150mm, preferably can be 100mm to 140mm, wherein the distance L between the first pivot point P1 and the second pivot point P2 is particularly preferably selected to be 115mm to 120mm, preferably in the embodiment shown in fig. 1 to 8. The first backrest link 22 forms a first angle α with the seat 10, which is open towards the leg extension means 3, the first angle being acute. Furthermore, the distance between the third pivot point P3 and the fourth pivot point P4 of the second backrest link 23 may be 45mm to 90mm, and in this embodiment may be selected to be 60mm to 80mm; the distance between the fourth pivot point P4 and the fifth pivot point P5 may be 85mm to 200mm, and in this embodiment may be selected to be 120mm to 160mm.

As previously mentioned, the fixed plate 12 of the mechanical stretching device 1 is fixedly mounted on a handrail portion not shown in the drawings. The seat 10 is movably connected with respect to the fixed plate 12 by means of a link assembly. The connecting rod assembly comprises a main linkage assembly and an auxiliary linkage assembly, wherein the main linkage assembly at least comprises a front swinging rod 13, a rear swinging rod 14 and a middle connecting rod 15; the secondary linkage assembly includes at least a secondary front swing lever 17, a secondary rear swing lever 18, and a secondary intermediate link 19a. The main linkage assembly is used for enabling the driving seat frame 10 to move forwards and downwards relative to the middle connecting rod 15 during the conversion process of the seat unit between the sitting position and the TV position, and meanwhile, the middle connecting rod 15 does not move relative to the armrest part and further does not move relative to the fixed plate 12; the secondary linkage assembly is used to drive the seat frame 10 along with the primary linkage assembly forward and upward relative to the armrest portion during transition of the seating unit between the TV and recumbent positions.

The upper ends of the front swing lever 13 and the rear swing lever 14 are pivotally connected to the seat frame 10, respectively, and the intermediate link 15 is pivotally connected between the front swing lever 13 and the rear swing lever 14. A seat frame link lever 16 is also pivotally connected between the front end of the intermediate link 15 and the seat frame 10. So that a four-bar linkage is constituted by the seat frame 10, the front swing lever 13, the rear swing lever 14, and the intermediate link 15. When the leg extension device 3 is extended from the sitting position by the linear electric drive device, the seat frame 10 is moved forward, and the front swing lever 13 and the rear swing lever 14 are tilted forward about their pivot points on the intermediate link 15, respectively.

The lower ends of the sub front swing lever 17 and the sub rear swing lever 18 are pivotally connected to the fixed plate 12, respectively. The upper end of the auxiliary front linkage rod 17a is pivotally connected with the upper end of the auxiliary front swinging rod 17, and the lower end is pivotally connected with the front part of the middle connecting rod 15; the upper end of the sub-rear link lever 18a is pivotally connected to the upper end of the sub-rear swing lever 18, and the lower end is pivotally connected to the rear portion of the intermediate link 15.

The rear end of the sub intermediate link 19a is pivotally connected to the middle part of the sub rear link 18a, the front end of the sub intermediate link 19a is pivotally connected to the top end of the sub front swing lever 17, and a follower link 19b is pivotally connected between the middle part of the sub intermediate link 19a and the top end of the sub rear swing lever 18.

Thus, the intermediate link 15 is suspended and supported on the fixed plate 12 so as to be movable in the front-rear direction by the sub-front swing lever 17, the sub-front link 17a, the sub-rear swing lever 18, and the sub-rear link 18 a.

When the seat frame link lever 16 is moved forward to the limit position, that is, to the TV pose position shown in fig. 2, if the linear electric drive device continues to act in the same direction, the intermediate link lever 15 moves forward together with the seat frame 10, thereby driving the sub front swing lever 17 and the sub rear swing lever 18 to pivot forward around the pivot points of the lower ends thereof and the fixed plate 12, respectively.

The leg extension device 3 comprises a first extension 31, a second extension 32 and a foot pedal 33 for attaching a footrest section. The first extension 31 includes a first link 311 and a second link 312. The second link 312 is provided with a limiting groove 3120. The second extension 32 includes a third link 321 and a fourth link 322. The fourth link 322 includes a stop staple 3220. The first link 311 is rotatably connected to the fourth link 322, and the second link 312 is rotatably connected to the third link 321. The foothold 33 includes a connecting end face 331 and an end face 332. Wherein, the first link 311 and the second link 312 are both rotatably mounted to the seat frame 10, wherein the pivot point of the first link 311 and the seat frame 10 is located behind the pivot point of the second link 312 and the seat frame 10. The pedal 33 is rotatably connected to the third link 321 and the fourth link 322. When the leg extension device 3 is deployed, i.e., in the TV position shown in fig. 2 and the lying position shown in fig. 3, the second link 312 protrudes farther forward than the first link 311.

Optionally, as shown in fig. 1 and 2, a return spring means may also be provided between the linkage assembly and the inner side plate to assist in returning the attitude change.

The mechanical stretching device 1 further comprises a linear electric actuator 4, which linear electric actuator 4 comprises a motor head 41 and a motor push rod 42 which is retractable with respect to the motor head 41. The motor head 41 is fixedly mounted with respect to the armrest, for example in the embodiment shown in fig. 1 to 3, the motor head 41 is pivotably connected to a motor head holder 41a, the motor head holder 41a being fixedly mounted on a fixed cross member 52. Here, the motor head bracket 41a has no component of movement in the front-rear direction during the transition of the seat unit from the sitting position to the lying position, but is pivotable about an axis transverse to the front-rear direction. The motor pushrod 42 acts on the front drive tube 44 which is connected transversely between the second links 312 of the leg extension unit 3. Of course, in an embodiment not shown, the positions of the motor head 41 and the motor plunger 42 can also be reversed. As shown in fig. 1, the motor pushrod 42 is attached to the front drive tube 44 by means of a motor bracket 43, wherein the motor pushrod 42 is pivotally connected to the motor bracket 43 and the motor bracket 43 is fixedly connected to the front drive tube 44.

If the seat unit is to be changed from the sitting position shown in fig. 1 and 4 to the TV position shown in fig. 2 and 5, the mechanical stretching device 1 starts to stretch under the action of the linear electric actuator 4, the motor push rod 42 stretches relative to the motor head 41, pushing the second link 312 of the leg stretching device 3 forward and driving the seat frame 10 forward, and the front swing lever 13 and the rear swing lever 14 incline forward, thereby achieving the TV position shown in fig. 2 or 5. In the process, as the seat frame 10 moves in the horizontal direction in the direction of the leg extension device 3, i.e., forward, the first backrest link 22 has a tendency to pivot slightly rearward, i.e., rotate in the clockwise direction in the drawing, about the second pivot point P2 of its lower end. For this reason, the first stopper 101 located at the rear of the first back link 22 is provided on the seat frame 10, so that the first back link 22 can be supported from the rear side of the first back link 22 to prevent the first back link 22 from shaking at the sitting position, thereby maintaining stable support of the back bracket 21. In this case, the back bracket 21, the first back link 22, the second back link 23, together with the seat frame 10 and the seat frame rear extension 11, are moved forward in the horizontal direction together, thereby driving the fixed plate link 24 to rotate forward about the pivot point of the lower end thereof and the fixed plate 12. At the same time, since the front swing lever 13 and the rear swing lever 14 are inclined forward, the seat frame 10, particularly, the rear end of the seat frame 10 is lowered in the height direction.

In addition, in the process of changing from the sitting position to the TV pose position, since the seat frame 10 drives the backrest bracket 21 to move forward as a whole, the rearmost end point of the backrest bracket 21 has a component of forward movement. At the same time, the first pivot point P1 of the back bracket 21 and the first back link 22 has a track of forward movement in the horizontal direction. In addition, since the rear end of the seat frame 10 descends in the height direction, the first pivot point P1 also has a descending movement trace in the height direction.

If the seat unit is to be changed from the TV posture position shown in fig. 2 and 5 to the lying posture position shown in fig. 3 and 6, the motor push rod 42 continues to be further extended with respect to the motor head 41, the seat frame 10 is driven forward by the leg stretching device 3, the front swing lever 13 and the rear swing lever 14 are tilted forward to the extreme positions, and the intermediate link 15 is moved forward together with the seat frame 10 while being lifted upward, thereby driving the sub-front swing lever 17 and the sub-rear swing lever 18 to be pivoted forward about the pivot points of the lower ends thereof and the fixed plate 12, respectively. Further, the second backrest link 23 is rotated in a counterclockwise direction about the fifth pivot point P5 of which the lower end is hinged with the fixed plate link 24, i.e., is inclined toward the leg stretching means, so that the difference in height of the upper end thereof with respect to the fourth pivot point P4 of the middle portion becomes small, thereby pushing the backrest bracket 21 as a whole forward, and the upper portion of the backrest bracket 21 is further inclined rearward, and the angle of the first backrest link 22 with respect to the seat frame 10 is reduced. Thereby, the lying position shown in fig. 3 and 6 is achieved. In this process, although the back bracket 21 is pivoted backward in the clockwise direction about the third pivot point P3, since the seat frame 10 itself moves forward on the one hand, and the back bracket 21 also moves forward with respect to the seat frame 10 by the linkage of the first and second back links 22 and 23 on the other hand, both the first pivot point P1 of the back bracket 21 and the rearmost end point of the back bracket 21 have a track of forward movement.

Fig. 8 schematically shows the posture change of the mechanical stretching device according to the present utility model between a sitting posture position, a TV posture position and a lying posture position. The fixing plate 12 is fixedly mounted with respect to the armrest portion of the seat unit, and for the sake of clarity, a vertical plane in which the rearmost end of the fixing plate 12 is located is taken as a first reference plane E1 in the horizontal direction, and a horizontal plane in which the lower region of the fixing plate 12 is located is taken as a second reference plane E2. During the posture changing process, the first reference surface E1 and the second reference surface E2 are both kept stationary in position by the floor armrest portion of the seat unit. Wherein fig. 8 shows the sitting position of the mechanical stretcher in the upper part, the TV position of the mechanical stretcher in the middle part and the lying position of the mechanical stretcher in the lower part.

The front side of the first backrest link 22 forms a first angle α with the top surface of the seat 10 which opens forward, i.e. in the direction of the leg extension; the backrest bracket 21 forms a second forward included angle beta with the second reference plane E2; the vertical heights of the first pivot point P1 of the back bracket 21 and the first back link 22 and the second reference plane E1 are H1, H2, and H3 in the sitting position, the TV position, and the lying position, respectively.

During the transition from the sitting position to the lying position, the first angle α is always smaller than 90 °, and the first angle α is significantly reduced in the lying position compared to the sitting position, while the second angle β is significantly increased.

In the process of shifting from the sitting position to the TV pose position, since the front swing lever 13 and the rear swing lever 14 are pivoted forward without relative movement of the intermediate link 15 with respect to the fixed plate 12, the seat frame 10 is moved forward while the rear end of the seat frame 10 is lowered. At the same time, the first pivot point P1 moves forward in the horizontal direction and descends in the height direction with the rear end of the bezel 10 such that the height H2 of the first pivot point P1 in the TV pose position is smaller than the height H1 thereof in the sitting position.

In the course of the change from the TV position to the lying position, the intermediate link 15 moves forward and upward with respect to the fixed plate 12 together with the seat frame 10 and with the first backrest link 22 the backrest support 21 moves forward and upward, wherein the first pivot point P1 moves forward and upward therewith such that the height H3 of the first pivot point P1 in the lying position is greater than the height H2 in the TV position. By selecting an appropriate length of the first backrest link 22, the height H3 of the first pivot point P1 in the lying position can be made greater than the height H1 in the sitting position. In this process, since the first included angle α is smaller than 90 °, the first backrest link 22 is advantageously tilted forward in the counterclockwise direction about the second pivot point P2 without interfering with or impeding the lifting of the seat frame 10.

The foregoing description has fully disclosed specific embodiments of this utility model. It should be noted that any modifications to the specific embodiments of the utility model may be made by those skilled in the art without departing from the scope of the utility model as defined in the appended claims. Accordingly, the scope of the claims of the present utility model is not limited to the foregoing detailed description.

List of reference numerals

1. Mechanical stretching device

10. Seat frame

101. First limit part

11. Seat frame rear extension

12. Fixing plate

13. Front swinging rod

14. Rear swing lever

15. Intermediate connecting rod

16. Seat frame linkage rod

17. Auxiliary front swinging rod

17A pair front linkage rod

18. Auxiliary rear swing rod

18A pair rear linkage rod

19A auxiliary intermediate connecting rod

19B follow-up connecting rod

2. Backrest assembly

21. Backrest support

22. First backrest connecting rod

23. Second backrest connecting rod

24. Fixed plate connecting rod

3. Leg stretching device

31. First extension part

311. First connecting rod

312. Second connecting rod

3120. Limiting groove

32. Second extension part

321. Third connecting rod

322. Fourth connecting rod

3220. Spacing nail

33. Pedal

331. Connection end face

332. End face

4. Linear electric actuator

41. Motor head

41A motor head support

42. Motor push rod

43. Motor support

44. Front driving tube

51. Fixing tab

52. Fixed cross beam

P1 first pivot point

P2 second pivot point

P3 third pivot point

P4 fourth pivot point

P5 fifth pivot point

E1 A first reference plane

E2 And a second reference surface.

Claims (22)

1. A mechanical stretching device for a movable seat, the mechanical stretching device being convertible between a sitting position, a TV position and a lying position, the mechanical stretching device comprising:

a fixed plate fixedly connected with the armrest part of the movable seat;

a seat frame movable back and forth with respect to the fixing plate for attaching a seat portion;

A backrest assembly coupled to a rear portion of the seat frame;

A leg extension device coupled to a front portion of the seat frame;

wherein the backrest assembly comprises a backrest bracket, a first backrest link and a second backrest link, wherein the backrest bracket is for attaching a backrest of a movable seat, the backrest bracket is coupled with a seat frame by means of the first backrest link and the second backrest link, wherein an upper end of the first backrest link is pivotally connected with a front end of the backrest bracket at a first pivot point and a lower end of the first backrest link is pivotally connected with a rear portion of the seat frame at a second pivot point; during the transition of the mechanical stretcher from the sitting position to the TV position and vice versa, the rearmost end of the back rest has a forward motion component and the first pivot point has a motion trajectory in the horizontal direction towards the leg stretcher and a motion trajectory in the height direction, first downward and then upward.

2. A mechanical stretching device for a movable seat, the mechanical stretching device being convertible between a sitting position, a TV position and a lying position, the mechanical stretching device comprising:

a fixed plate fixedly connected with the armrest part of the movable seat;

a seat frame movable back and forth with respect to the fixing plate for attaching a seat portion;

A backrest assembly coupled to a rear portion of the seat frame;

A leg extension device coupled to a front portion of the seat frame;

Wherein the backrest assembly comprises a backrest bracket, a first backrest link and a second backrest link, wherein the backrest bracket is for attaching the backrest, the backrest bracket is coupled with a seat frame by means of the first backrest link and the second backrest link, wherein an upper end of the first backrest link is pivotally connected with a front end of the backrest bracket at a first pivot point and a lower end of the first backrest link is pivotally connected with a rear portion of the seat frame at a second pivot point; during the transition of the mechanical stretcher from the sitting position to the TV position and vice versa, the rearmost end of the back rest has a forward component of motion, wherein the distance between the first pivot point and the second pivot point is 80mm to 150mm and the first angle of the opening formed by the first back rest link and the seat frame towards the leg stretcher is less than 90 °.

3. A mechanical extension device according to claim 1 or 2 wherein the first pivot point moves forward and downward during the change of the mechanical extension device from the sitting position to the TV position and moves forward and upward during the change of the mechanical extension device from the TV position to the lying position.

4. A mechanical stretching device according to claim 3, wherein the first pivot point is higher in the lying position than in the sitting position.

5. The mechanical extension device of claim 1 or 2, wherein the second back link is pivotally connected to a rear end of the back bracket at a third pivot point and to a rear of the seat frame at a fourth pivot point, wherein the fourth pivot point is further rearward than the second pivot point.

6. The mechanical stretching device of claim 1 or 2, wherein the rear end of the seat is lowered relative to the fixing plate during the transition of the mechanical stretching device from the sitting position to the TV position; the seat frame is raised relative to the fixed plate during the transition of the mechanical stretching device from the TV position to the recumbent position.

7. The mechanical stretcher according to claim 5 wherein the second backrest link is configured as a bell crank and further comprising a fifth pivot point, wherein the third and fifth pivot points are located on the free ends of the upper and lower arms of the bell crank, respectively, and a fourth pivot point is located between the third and fifth pivot points, wherein the second backrest link is directly or indirectly coupled with the fixed plate at the fifth pivot point.

8. The mechanical stretching device of claim 1 or 2, wherein the seat frame is movably attached back and forth to the fixed plate by a main interlocking assembly and a sub interlocking assembly, wherein the seat frame is pivotally connected to the main interlocking assembly and the sub interlocking assembly is pivotally connected to the fixed plate.

9. The mechanical extension device of claim 8, wherein the primary linkage assembly includes an intermediate link pivotally connected to the secondary linkage assembly, the rear end of the seat frame being urged downwardly and forwardly relative to the intermediate link by the primary linkage assembly during the transition of the mechanical extension device from the seated position to the TV position, wherein the intermediate link is relatively free of displacement relative to the fixed plate; during the process of changing the mechanical stretching device from the TV position to the lying position, the auxiliary linkage assembly drives the seat frame and the main linkage assembly to move forwards and upwards relative to the fixing plate.

10. A mechanical stretching device according to claim 1 or 2, wherein the mechanical stretching device is for a movable seat with a floor-standing armrest.

11. A mechanical stretching device according to claim 1 or 2, wherein the mechanical stretching device further comprises a linear electric actuation device.

12. A movable seating unit including a mechanical extension device, a armrest portion attached to the mechanical extension device, a backrest, a seat portion, and a footrest portion, wherein the mechanical extension device is capable of transitioning the seating unit between at least a seating position and a lying position, the mechanical extension device comprising:

a fixing plate fixedly connected with the armrest part;

a seat frame movable back and forth with respect to the fixing plate for attaching a seat portion;

A backrest assembly coupled to a rear portion of the seat frame;

A leg extension device coupled to a front portion of the seat frame;

wherein the backrest assembly comprises a backrest bracket, a first backrest link and a second backrest link, wherein the backrest bracket is for attaching a backrest of a movable seat, the backrest bracket is coupled with a seat frame by means of the first backrest link and the second backrest link, wherein an upper end of the first backrest link is pivotally connected with a front end of the backrest bracket at a first pivot point and a lower end of the first backrest link is pivotally connected with a rear portion of the seat frame at a second pivot point; during the transition of the mechanical stretcher from the sitting position to the TV position and vice versa, the rearmost end of the back rest has a forward motion component and the first pivot point has a motion trajectory in the horizontal direction towards the leg stretcher and a motion trajectory in the height direction, first downward and then upward.

13. A movable seating unit including a mechanical extension device, a armrest portion attached to the mechanical extension device, a backrest, a seat portion, and a footrest portion, wherein the mechanical extension device is capable of transitioning the seating unit between at least a seating position and a lying position, the mechanical extension device comprising:

a fixing plate fixedly connected with the armrest part;

a seat frame movable back and forth with respect to the fixing plate for attaching a seat portion;

A backrest assembly coupled to a rear portion of the seat frame;

A leg extension device coupled to a front portion of the seat frame;

Wherein the backrest assembly comprises a backrest bracket, a first backrest link and a second backrest link, wherein the backrest bracket is for attaching a backrest of a movable seat, the backrest bracket is coupled with a seat frame by means of the first backrest link and the second backrest link, wherein an upper end of the first backrest link is pivotally connected with a front end of the backrest bracket at a first pivot point and a lower end of the first backrest link is pivotally connected with a rear portion of the seat frame at a second pivot point; during the transition of the mechanical stretcher from the sitting position to the TV position and vice versa, the rearmost end of the back rest has a forward component of motion, wherein the distance between the first pivot point and the second pivot point is 80mm to 150mm and the first angle of the opening formed by the first back rest link and the seat frame towards the leg stretcher is less than 90 °.

14. A seating unit in accordance with claim 12 or 13 wherein the first pivot point moves forward and downward during the change of the seating unit from a sitting position to a TV pose position and moves forward and upward during the change of the seating unit from a TV pose position to a lying position.

15. A seating unit as claimed in claim 12 or claim 13, wherein the first pivot point is higher in the recumbent position than in the sitting position.

16. The seating unit defined in claim 12 or claim 13, wherein the second back link is pivotally connected to a rear end of the back bracket at a third pivot point and to a rear of the seat frame at a fourth pivot point, wherein the fourth pivot point is further rearward than the second pivot point.

17. A seating unit in accordance with claim 12 or 13 wherein the rear end of the seat frame is lowered relative to the fixed plate during the transition of the seating unit from the sitting position to the TV position; the seat frame is raised relative to the fixed plate during the transition of the seating unit from the TV position to the recumbent position.

18. The seating unit of claim 16, wherein the second backrest link is configured as a bell crank and further comprises a fifth pivot point, wherein the third and fifth pivot points are located on free ends of the upper and lower arms of the bell crank, respectively, and a fourth pivot point is located between the third and fifth pivot points, wherein the second backrest link is directly or indirectly coupled with the fixed plate at the fifth pivot point.

19. The seating unit of claim 12 or 13 wherein the seat frame is movably attached back and forth to the fixed plate by a primary linkage assembly and a secondary linkage assembly, wherein the seat frame is pivotally connected to the primary linkage assembly and the secondary linkage assembly is pivotally connected to the fixed plate.

20. The seating unit defined in claim 19, wherein the primary linkage assembly includes an intermediate link pivotally connected to the secondary linkage assembly, the rear end of the seat frame being urged downwardly and forwardly relative to the intermediate link by the primary linkage assembly during the transition of the seating unit from the sitting position to the TV position, wherein the intermediate link is relatively free of displacement relative to the fixed plate; during the process of changing the seat unit from the TV position to the lying position, the auxiliary linkage assembly drives the seat frame and the main linkage assembly to move forwards and upwards relative to the fixed plate.

21. A seating unit as claimed in claim 12 or claim 13, wherein the seating unit is an armrest floor type seating unit.

22. A seating unit as claimed in claim 12 or claim 13, wherein the seating unit further comprises a linear electrical actuation means.