CN212698294U

CN212698294U - Leg supporting mechanism and sofa stretching device with same

Info

Publication number: CN212698294U
Application number: CN202021552493.7U
Authority: CN
Inventors: 李云海; 沈勤英; 王志禹; 毕大岩
Original assignee: Kuka Home Co Ltd
Current assignee: Kuka Home Co Ltd
Priority date: 2020-07-30
Filing date: 2020-07-30
Publication date: 2021-03-16
Anticipated expiration: 2030-07-30

Abstract

The application discloses a leg supporting mechanism, which comprises a folding part used for installing the leg supporting mechanism on a seat frame, wherein the folding part comprises two folding assemblies which are symmetrically arranged, each folding assembly comprises a first folding rod, a second folding rod which is connected to the first folding rod in a sliding mode along the length direction of the first folding rod and a force transmission assembly which is connected to the seat frame in a rotating mode, the first folding rod and the second folding rod are mutually abutted and are relatively fixed along the thickness direction of the first folding rod and the second folding rod, and the force transmission assembly is used for converting the rotating force of the force transmission assembly into a driving force for driving the first folding rod and the second folding rod to move relatively; a force application member for providing a driving force to the force transmission assembly to drive the force transmission assembly to rotate relative to the seat frame; a installation department for installing sofa shank cushion, first folding rod rotate to be connected in the installation department, and the second folding rod rotates to be connected in the installation department and follows sliding connection in the installation department. Through adopting above-mentioned technical scheme, the shank does not have scissors hand structure, does not have the risk of pressing from both sides wounded the finger.

Description

Leg supporting mechanism and sofa stretching device with same

Technical Field

The application relates to the field of functional sofas, in particular to a leg supporting mechanism and a sofa stretching device with the same.

Background

The functional sofa is a multifunctional sofa. The most common are functional sofas: the method is divided into two types, one type: the sofa has the advantages that the sofa has a manual function of stretching, can be manually matched with a sofa with shaking and rotating functions, and also has the following functions: the electric function is extended, and the electric function can also have two functions of shaking and rotating.

Present function iron stand leg rest position structure is mostly polygon link mechanism, has the clearance between part and the part, and the clearance can grow or diminish in the operation process, if the careless entering of fruit user's finger, then there is the risk of pressing from both sides the wound.

SUMMERY OF THE UTILITY MODEL

To the not enough that prior art exists, the aim at of this application provides a shank supporting mechanism, reduces the risk of pressing from both sides hindering the user.

In order to achieve the purpose, the application provides the following technical scheme:

a leg supporting mechanism comprises

The folding part is used for installing the leg supporting mechanism on the seat frame and comprises two symmetrically arranged folding assemblies, each folding assembly comprises a first folding rod, a second folding rod and a force transmission assembly, the second folding rod is connected to the first folding rod in a sliding mode along the length direction of the first folding rod, the force transmission assembly is connected to the seat frame in a rotating mode, the first folding rod and the second folding rod are mutually abutted and relatively fixed along the thickness direction of the first folding rod and the second folding rod, and the force transmission assembly is used for converting the rotating force of the force transmission assembly into a driving force for driving the first folding rod and the second folding rod to move relatively;

a force application member for providing a driving force to the force transmission assembly to drive the force transmission assembly to rotate relative to the seat frame;

a installation department for installing sofa shank cushion, the installation department is equipped with two and corresponds two folding assembly respectively, and first folding rod rotates to be connected in the installation department, and the second folding rod rotates to be connected in the installation department and along sliding connection in the installation department.

Through adopting above-mentioned technical scheme, pass power subassembly and rotate under the effect of application of force spare, drive first folding rod and second folding rod through passing power subassembly and rotate, and just first folding rod and second folding rod can only follow its length direction relative slip of itself at the rotation in-process, drive the installation department and move. Thereby achieving deployment of the leg support mechanism.

When the leg supporting mechanism needs to be folded, the force application component drives the force transmission component, the force transmission component drives the first folding rod and the second folding rod to rotate, and the first folding rod and the second folding rod slide relatively in the rotating process to drive the installation part to move, so that the leg supporting mechanism is folded. The sofa leg cushion arranged on the mounting part is turned to one side of the seat frame. In the process, a gap can not be formed between the first folding rod and the second folding rod, so that a user can not stretch fingers into the gap, and the problem can not occur when the leg supporting mechanism is folded. The probability of pinching the hand for the above reasons is reduced.

The application is further provided with: the power transmission assembly comprises a first transmission rod and a second transmission rod, the first transmission rod is rotatably connected to the seat frame, the second transmission rod is rotatably connected to the seat frame, the first transmission rod is parallel to the second transmission rod, and the first transmission rod and the second transmission rod are rotatably connected to the second folding rod.

Through adopting above-mentioned technical scheme to make and form parallelogram between seat frame, first transfer line, second transfer line and the second folding pole, make motion structure more stable. The second folding rod can stably rotate relative to the seat frame.

The application is further provided with: the first transmission rod is fixedly arranged on the seat frame, and a limiting groove is formed in the side wall of one side, facing the second transmission rod, of the first transmission rod; when the leg supporting mechanism is fully extended, the limiting shaft is abutted to the limiting groove.

Through adopting above-mentioned technical scheme, the cooperation of spacing groove and spacing axle can play a limiting displacement to when making shank supporting mechanism expand completely, spacing axle can butt in the spacing groove, prevents that shank supporting mechanism from continuing to move, destroys its expansion state.

The application is further provided with: the force application part comprises a linkage rod and a driving cylinder used for giving driving force to the linkage rod, two ends of the linkage rod are respectively and fixedly connected to the second transmission rod, and the driving cylinder gives the driving force to the linkage rod to be perpendicular to the linkage rod.

Through adopting above-mentioned technical scheme, play fine linkage effect through the second transfer line, guarantee that two folding assembly can be synchronous expand and fold, the operation is stable.

The application is further provided with: at least one first guide post is arranged on the second folding rod along the length direction of the second folding rod, at least one first guide groove is formed in the first folding rod along the length direction of the first folding rod, the first guide groove at least corresponds to the first guide post, and the first guide post is embedded in the first guide groove in a sliding mode.

Through adopting above-mentioned technical scheme, the cooperation between guide way and the first guide post can play spacing effect, ensures to follow its length direction relative motion between first folding rod and the second folding rod to make the gap can not appear between the two, thereby reduce and stretch into the gap with the hand and the probability of tong.

The application is further provided with: one end, far away from the second folding rod, of the first guide column is provided with a limiting block for limiting the first folding rod, and the limiting block is abutted to the first folding rod.

Through adopting above-mentioned technical scheme to make first folding rod and the better butt of second folding rod together, can not appear appearing the gap between the two, and lead to the people to stretch into the gap with the hand and the condition of tong.

The application is further provided with: the first guide post sleeve is provided with a gasket, and the gasket is located between the first folding rod and the second folding rod and is abutted against the first folding rod and the second folding rod.

Through adopting above-mentioned technical scheme to reduce the frictional force between first folding rod and the second folding rod, made two relative slip that can be more stable.

The application is further provided with: the first folding rod is fixedly provided with an ear piece along the side wall of one side of the length direction of the first folding rod, the ear piece and the first folding rod are located on the same plane, the second transmission rod is provided with a second guide column, and the second guide column is connected to the ear piece in a sliding mode.

By adopting the technical scheme, the guiding function is further realized, and meanwhile, when the second transmission rod rotates, the first folding rod can be driven by one driving force instead of the second folding rod. Therefore, the first folding rod and the second folding rod can move relatively more efficiently, and the leg supporting mechanism can be unfolded more quickly.

The application is further provided with: a second guide groove is formed in the lug, the second guide column is connected to the second guide column in a sliding mode, and an included angle is formed between the second guide groove and the first guide groove.

Through adopting above-mentioned technical scheme to make first folding rod have the direction and the support of multiple spot in the relative second folding rod motion's in-process, make its motion more stable.

Another object of the present application is to provide a sofa stretching apparatus:

a sofa stretching device comprises an underframe, a backrest component, a seat frame, a leg supporting mechanism, a linkage mechanism and a driving piece;

the backrest component is rotationally connected with the underframe, and a rotating point of the backrest component relative to the seat frame is positioned at one end of the backrest component;

one end of the seat frame is rotatably connected with the backrest component, the other end of the seat frame is rotatably connected with the leg supporting mechanism, and the seat frames are rotatably connected with the bottom frame through the linkage mechanism;

the driving part is used for providing linear thrust along the length direction of the seat frame for the seat frame, one end of the driving part is connected to the linkage mechanism or the seat frame, and the other end of the driving part is connected to the bottom frame.

The application has the following advantages: 1. the legs have no scissor structure, so that the risk of clamping fingers is avoided; 2. the occupied space is small; 3. the leg support mechanism is smoothly unfolded and folded.

Drawings

FIG. 1 is a schematic structural view of the embodiment in a deployed state;

FIG. 2 is a schematic structural view of the embodiment in a folded state;

FIG. 3 is an enlarged view taken at A in FIG. 2;

FIG. 4 is a schematic structural view of the leg support mechanism of the embodiment in a folded state;

FIG. 5 is an exploded view of the leg support mechanism of the embodiment in state transition;

FIG. 6 is a schematic structural view of a leg support mechanism in a state transition according to the embodiment;

FIG. 7 is a partial schematic view of the embodiment with the mid-leg support mechanism in a deployed state;

fig. 8 is a schematic structural view of the leg support mechanism in a deployed state according to the embodiment.

Reference numerals: 1. a chassis; 2. a backrest support bar; 3. a seat frame; 4. a leg support mechanism; 5. a linkage mechanism; 6. A drive mechanism; 7. a third connecting rod; 8. a first connecting rod; 9. a second connecting rod; 10. a limiting bulge; 11. a limiting surface; 12. a driving member; 13. a force application member; 14. a first transfer lever; 15. a second dowel bar; 16. a folding part; 17. an installation part; 18. a lower leg support; 19. mounting a platform; 20. a first folding bar; 21. a second folding bar; 22. a first guide post; 23. a first guide groove; 24. a gasket; 25. a tab; 26. a second guide groove; 27. a second guide post; 28. a first drive lever; 29. a second transmission rod; 30. a linkage rod; 31. a drive cylinder; 32. a limiting shaft; 33. a limiting groove; 34. a third guide groove; 35. a third guide post; 36. a force-changing rod; 37. a stopper; 38. and a limiting block.

Detailed Description

Example (b):

as shown in fig. 1, a sofa stretching device comprises an underframe 1, a backrest assembly, a seat frame 3, a leg support mechanism 4, a linkage mechanism 5 and a driving mechanism 6. The middle part of the backrest component is rotationally connected with the underframe 1, and the rotation point of the backrest component relative to the seat frame 3 is positioned at one end of the backrest component; one end of the seat frame 3 is rotatably connected with the backrest component, the other end of the seat frame is rotatably connected with the leg supporting mechanism 4, and the seat frame 3 is rotatably connected with the bottom frame 1 through the linkage mechanism 5.

Under the normal sitting state of the sofa using the stretching device, the leg supporting mechanism 4 is folded and contracted under the seat frame 3, the angle formed between the backrest component and the ground is 113 degrees, the angle formed between the seat frame 3 and the ground is 9 degrees, and the angle formed between the seat frame 3 and the backrest component is 99 degrees, so that a person is in a comfortable sitting state.

If a person needs to support the legs, the driving mechanism 6 gives a driving force to the leg supporting mechanism 4 along the length direction of the seat frame 3, so that the leg supporting mechanism 4 extends outwards until the whole body is parallel to the seat frame 3, thereby supporting the legs of the user.

When a person lies on his back, the seat frame 3 is rotated and slightly moved forward relative to the base frame 1 by the driving force of the driving mechanism 6 along the length direction of the seat frame 3 until the angle formed between the seat frame and the ground is 20 degrees. At this time, the backrest mechanism is rotated relative to the seat frame 3 and the underframe 1 due to the force transmission of the linkage mechanism 5, so that the angle formed between the backrest assembly and the ground reaches 150 degrees. Thereby enabling the user to be in a zero-gravity state of lying behind and enabling the user to be more comfortable. The leg support means 4 is now raised at least 15 cm.

As shown in fig. 2, the chassis 1 is specifically an Contraband-shaped frame formed by connecting rod bodies. The vertical direction all is equipped with third connecting rod 7 along 1 both sides of chassis, and third connecting rod 7 is used for connecting the back subassembly. The backrest component comprises two backrest support rods 2 symmetrically arranged along the length direction of the seat frame 3, the backrest support rods 2 are Z-shaped, and the lower ends of the backrest support rods 2 are rotatably connected to the seat frame 3. The backrest support rod 2 is rotatably connected to the upper end of the third connecting rod 7, and the rotating points of the backrest support rod 2 and the third connecting rod 7 are located at a second turning point of the backrest support rod 2 from top to bottom. So that the backrest module is stably rotatably mounted to the base frame 1 by the third link 7.

The linkage 5 is provided with two and one linkage 5 for one backrest support bar 2. The linkage 5 comprises a first connecting rod 8 and a second connecting rod 9 rotatably connected to the first connecting rod 8. One end of the first connecting rod 8 is rotatably connected with one end of the opening end of the underframe 1. One end of the first connecting rod 8, which is far away from the underframe 1, is rotatably connected with the middle part of the seat frame 3. The second connecting rod 9 is Z-shaped. The rotation point between the second connecting rod 9 and the first connecting rod 8 is located between the rotation point of the first connecting rod 8 relative to the seat frame 3 and the rotation point of the first connecting rod 8 relative to the chassis 1. One end of the second connecting rod 9, which is far away from the first connecting rod 8, is rotatably connected to the backrest supporting rod 2, and a connecting point of the second connecting rod 9 and the backrest supporting rod 2 is located between a rotating point of the backrest supporting rod 2 relative to the underframe 1 and a rotating point of the backrest supporting rod 2 relative to the third connecting rod 7.

At this moment, exert the power along its length direction to seat frame 3, can drive seat frame 3 and back bracing piece 2 synchronous rotation, and seat frame 3 can move forward slightly at the rotation in-process, realizes stepping down to back bracing piece 2, makes this extension device can be better reach zero gravity state.

As shown in fig. 3, in order to better keep the extension device in a zero gravity state, a limit protrusion 10 is fixedly installed at the middle of the backrest support rod 2. The upper end of the third connecting rod 7 is inclined to form a limiting surface 11; when the stretching device is in a zero gravity sitting feeling state, the limiting bulge 10 abuts against the limiting surface 11 on the third connecting rod 7.

As shown in fig. 2, the driving mechanism 6 includes an active member 12 for providing the bezel 3 with a linear thrust in the lengthwise direction of the bezel 3 and a force application member 13 for providing the leg support mechanism 4 with a linear thrust in the lengthwise direction of the bezel 3. The seat frame 3 comprises a first transmission rod 14 arranged along the width direction of the seat frame, the driving part 12 is an electric cylinder, the driving part 12 is arranged along the length direction of the seat frame 3, and two ends of the driving part 12 are respectively connected to the first transmission rod 14 and the underframe 1 in a rotating mode.

As shown in fig. 4, the leg support mechanism 4 includes:

a folding portion 16 for mounting the leg support mechanism 4 to the seat frame 3,

a mounting part 17 for mounting a sofa leg cushion, wherein the mounting part 17 is mounted at one end of the folding part 16;

a lower leg supporting part 18 for supporting the sofa leg cushion, the lower leg supporting part 18 is rotatably connected with the folding part 16, and the lower leg supporting part 18 is provided with an installation platform 19;

during installation, sofa leg cushions can be installed on the installation platform 19 and the installation part 17, when the folding part 16 is in the unfolded limit state, the upper end face of the installation platform 19 and the upper end face of the installation part 17 are located on the same plane, and the two cushions are spliced into a complete cushion, so that the legs of a human body can be better supported. When the folded portion 16 is folded, the mounting platform 19 is perpendicular to the mounting portion 17 and the lower leg support portion 18 is folded under the folded portion 16.

As shown in fig. 5 and 6, the folding portion 16 includes two symmetrically disposed folding components, which include a first folding rod 20, a second folding rod 21 slidably connected to the first folding rod 20 along the length direction of the first folding rod 20, and a force transmission component rotatably connected to the seat frame 3. The first folding bar 20 and the second folding bar 21 abut against each other and are relatively fixed in the thickness direction thereof. Specifically, the second folding rod 21 is provided with two first guide posts 22 along the length direction thereof, the first folding rod 20 is provided with two first guide grooves 23 along the length direction thereof, and the first guide grooves 23 are provided along the length direction of the first folding rod 20. A first guide groove 23 corresponds to a first guide post 22, and the first guide post 22 is slidably inserted into the first guide groove 23.

As shown in fig. 5, the first guiding column 22 is sleeved with a pad 24, and the pad 24 is located between the first folding rod 20 and the second folding rod 21 and abuts against the first folding rod 20 and the second folding rod 21. One end of the first guiding column 22, which is far away from the second folding rod 21, is provided with a limiting block 38 for limiting the first folding rod 20, and the limiting block 38 abuts against the first folding rod 20.

As shown in fig. 5 and 6, a tab 25 is fixedly disposed on one side wall of the first folding bar 20 along the length direction thereof, and a second guide groove 26 is formed in the tab 25. The lug 25 and the first folding rod 20 are located on the same plane, the second transmission rod 29 is provided with a second guide post 27, and the second guide post 27 is slidably connected to the second guide groove 26.

As shown in fig. 5 and 6, the force transmission assembly comprises a first transmission rod 28 rotatably connected to the seat frame 3 and a second transmission rod 29 rotatably connected to the seat frame 3, the first transmission rod 28 being parallel to the second transmission rod 29, both the first transmission rod 28 and the second transmission rod 29 being rotatably connected to the second folding rod 21. The force application part 13 comprises a linkage rod 30 and a driving cylinder 31 for applying driving force to the linkage rod 30, two ends of the linkage rod 30 are respectively and fixedly connected to the second transmission rod 29, and the driving force applied to the linkage rod 30 by the driving cylinder 31 is perpendicular to the linkage rod 30.

As shown in fig. 5, a limiting shaft 32 is disposed on the seat frame 3, and a limiting groove 33 is disposed on a side wall of the first transmission rod 28 facing the second transmission rod 29; when the leg support mechanism 4 is fully extended, the stopper shaft 32 abuts against the stopper groove 33.

As shown in fig. 5 and 7, the mounting portion 17 is provided with two folding members, the first folding rod 20 is rotatably connected to the mounting portion 17, and the second folding rod 21 is rotatably connected to the mounting portion 17 and slidably connected to the mounting portion 17. Specifically, the mounting portion 17 is provided with a third guide groove 34, the third folding portion 16 is provided with a third guide pillar 35, and the third guide pillar 35 is embedded in the third guide groove 34 and is slidably connected with the third guide groove 34.

As shown in fig. 4 and 5, an exchange bar 36 is disposed between the lower leg support portion 18 and the first folding bar 20, and both ends of the exchange bar 36 are respectively rotatably connected to the lower leg support portion 18 and the first folding bar 20. The lower leg support 18 is provided with a stopper 37. As shown in fig. 4, when the folded portion 16 is in the folded limit state, the stopper 37 abuts against the force changing lever 36, and the stopper 38 abuts against the force changing lever 36.

In the folded state, as shown in fig. 4, the folding assembly and the force transmission assembly in the leg support mechanism 4 are both in a mutually folded state, the mounting end face of the mounting portion 17 is perpendicular to the ground, and the mounting platform 19 of the lower leg support portion 18 is parallel to the ground, so that the ground occupied by the lower leg support portion is small.

When the lower leg support assembly 4 is converted from the folded state to the unfolded state, the piston rod of the driving cylinder 31 is extended, and the linkage rod 30 is provided with driving force along the length direction of the seat frame 3, so that the first driving rod 28 and the second driving rod 29 are rotated. At this time, the first transmission rod 28 and the second transmission rod 29 directly drive the second folding rod 21 to rotate, the first guide post 22 slides in the first guide slot 23, and the second guide post 27 slides in the second guide slot 26, so that the first folding rod 20 and the second folding rod 21 slide relatively.

When the first folding rod 20 and the second folding rod 21 slide relatively, the movement difference between the first folding rod 20 and the second folding rod 21 provides a driving force for the mounting table 17 to rotate the mounting table 17 until the mounting table 17 rotates to a degree that the upper end surface thereof is parallel to the ground. At the same time, the first folding bar 20 rotates, which rotates the force-changing bar 36, and the force-changing bar 26 rotates the lower leg support 18 relative to the mounting portion 17. When the mounting table 17 is rotated to the extent that the upper end surface thereof is parallel to the ground, the lower leg support portion 18 is rotated 9 ° relative to the mounting table 17, so that the mounting platform 19 on the lower leg support portion 18 and the mounting plane of the mounting portion 17 are located on the same plane. At the moment, the lower leg supporting component 4 is completely unfolded, so that the legs of the human body can be well supported. At this time, the stopper shaft 3 abuts against the stopper groove 33.

When the lower leg support assembly 4 is converted from the unfolded state to the folded state, similarly, the piston rod of the driving cylinder 31 is shortened, and the linkage rod 30 is provided with a driving force along the length direction of the seat frame 3, so that the first transmission rod 28 and the second transmission rod 29 are rotated, the first folding rod 20 and the second folding rod 21 are relatively slid, and at this time, the lower leg support portion 18 is retracted, as shown in fig. 6. This is until the stopper 37 is returned to the state of abutting against the force changing lever 36 and the stopper 38 abuts against the force changing lever 36. The calf support assembly 4 is now fully collapsed and returned to the collapsed condition.

In the above process, no gap is formed between the folding members of the lower leg support assembly 4, thereby reducing the probability of pinching the hand by inserting the hand into the gap. The safety is greatly improved.

The principle of the application is as follows:

comprises three states, namely a sitting posture state, a leisure state and a zero gravity state;

in the sitting position, the leg support mechanism 4 is folded and contracted under the seat frame 3, the angle formed between the backrest assembly and the ground is 113 degrees, the angle formed between the seat frame 3 and the ground is 9 degrees, and the angle formed between the seat frame 3 and the backrest assembly is 99 degrees, so that the person is in a comfortable sitting position.

In a leisure state, that is, a state in which the upper half and the lower half of the body are supported, an angle formed between the backrest unit and the floor surface is 113 °, an angle formed between the seat frame 3 and the floor surface is 9 °, and an angle formed between the seat frame 3 and the backrest unit is 99 °. The leg support means 4 extends outwardly until it is generally parallel to the seat frame 3 so as to support the legs of the user. The person is in a comfortable half lying state. In this state, operations such as reading a book and watching a television can be performed.

As shown in fig. 1, in the zero gravity state, the angle formed between the backrest module and the ground is 150 °, the angle formed between the seat frame 3 and the ground is 20 °, the angle formed between the seat frame 3 and the backrest module is 130 °, and the leg support mechanism 4 is extended outward until it is entirely parallel to the seat frame 3, thereby supporting the legs of the user. Thereby enabling the person to be in a zero-gravity fully supine position for resting a nap.

When the stretching device is switched between the sitting posture and the leisure posture, the piston rod of the force application part 13 is extended, the force application part 13 gives an outward driving force to the second force transmission rod 15 along the length direction of the seat frame 3, the first leg rod 16 and the second leg rod 17 rotate, so that the third leg rod 18 and the fourth leg rod 19 are driven to rotate, the knee support block 20 and the foot support rod 22 are unfolded outwards to be positioned in a straight line with the seat frame 3, and at the moment, the whole leg support mechanism 4 is extended outwards to be opened, so that the foot is supported. When the piston rod of the force application member 13 is shortened, the motion tracks are opposite, and the whole leg support mechanism 4 is contracted and folded back to the lower part of the seat frame 3, thereby completing the state conversion.

When the stretching device is switched between a zero gravity state and a leisure state, the piston rod of the driving part 12 extends to provide an outward driving force for the first transmission rod 14 along the length direction of the seat frame 3, the seat frame 3 rotates relative to the base frame 1 and moves towards one side far away from the backrest component relative to the base frame 1, and the backrest component rotates relative to the seat frame 3 under the driving of the linkage mechanism 5, so that the forward tilting of the seat frame 3 and the backward tilting of the backrest component are completed, and the complete state is converted. When the piston rod of the force application part 13 is shortened, the motion tracks are opposite, the seat frame 3 is reset, the backrest assembly tilts forwards, and the leisure state is recovered.

The above description is only a preferred embodiment of the present application, and the protection scope of the present application is not limited to the above embodiments, and all technical solutions belonging to the idea of the present application belong to the protection scope of the present application. It should be noted that several improvements and modifications to the present application without departing from the principles of the present application will occur to those skilled in the art, and such improvements and modifications should also be considered within the scope of the present application.

Claims

1. A leg support mechanism is characterized in that: comprises that

The folding part (16) is used for installing the leg supporting mechanism (4) on the seat frame (3), the folding part (16) comprises two folding assemblies which are symmetrically arranged, each folding assembly comprises a first folding rod (20), a second folding rod (21) which is connected to the first folding rod (20) in a sliding mode along the length direction of the first folding rod (20), and a force transmission assembly which is connected to the seat frame (3) in a rotating mode, the first folding rod (20) and the second folding rod (21) are mutually abutted and are relatively fixed along the thickness direction of the first folding rod, and the force transmission assembly is used for converting the rotating force of the force transmission assembly into a driving force which drives the first folding rod (20) and the second folding rod (21) to move relatively;

a force application member (13) for providing a driving force to the force transmission assembly for driving the force transmission assembly to rotate relative to the seat frame (3);

a installation department (17) for installing sofa leg cushion, installation department (17) are equipped with two and correspond two folding assembly respectively, and first folding rod (20) rotate to be connected in installation department (17), and second folding rod (21) rotate to be connected in installation department (17) and along sliding connection in installation department (17).

2. A leg support mechanism as claimed in claim 1, wherein: the power transmission assembly comprises a first transmission rod (28) and a second transmission rod (29), wherein the first transmission rod (28) is rotatably connected to the seat frame (3), the second transmission rod (29) is rotatably connected to the seat frame (3), the first transmission rod (28) is parallel to the second transmission rod (29), and the first transmission rod (28) and the second transmission rod (29) are rotatably connected to the second folding rod (21).

3. A leg support mechanism as claimed in claim 2, wherein: the first transmission rod (28) is provided with a limiting groove (33) towards the side wall of one side of the second transmission rod (29); when the leg support mechanism (4) is fully extended, the limit shaft (32) abuts against the limit groove (33).

4. A leg support mechanism as claimed in claim 1, wherein: the force application piece (13) comprises a linkage rod (30) and a driving cylinder (31) used for giving driving force to the linkage rod (30), two ends of the linkage rod (30) are respectively and fixedly connected to a second transmission rod (29), and the driving force given to the linkage rod (30) by the driving cylinder (31) is perpendicular to the linkage rod (30).

5. A leg support mechanism as claimed in claim 2, wherein: at least one first guide post (22) is arranged on the second folding rod (21) along the length direction of the second folding rod, at least one first guide groove (23) is formed in the first folding rod (20) along the length direction of the first folding rod, the first guide groove (23) is formed in the first folding rod (20) along the length direction of the first folding rod, one first guide groove (23) at least corresponds to one first guide post (22), and the first guide post (22) is slidably embedded in the first guide groove (23).

6. A leg support mechanism according to claim 5, wherein: one end, far away from the second folding rod (21), of the first guide column (22) is provided with a limiting block (10) for limiting the first folding rod (20), and the limiting block (10) abuts against the first folding rod (20).

7. A leg support mechanism according to claim 6, wherein: a gasket (24) is sleeved on the outer sleeve of the first guide column (22), and the gasket (24) is located between the first folding rod (20) and the second folding rod (21) and abuts against the first folding rod (20) and the second folding rod (21).

8. A leg support mechanism according to claim 5, wherein: the first folding rod (20) is fixedly provided with a lug (25) along one side wall of the length direction of the first folding rod, the lug (25) and the first folding rod (20) are located on the same plane, a second guide column (27) is arranged on a second transmission rod (29), and the second guide column (27) is connected to the lug (25) in a sliding mode.

9. A leg support mechanism according to claim 8, wherein: the lug piece (25) is provided with a second guide groove (26), the second guide column (27) is connected to the second guide column (27) in a sliding mode, and an included angle is formed between the second guide groove (26) and the first guide groove (23).

10. A sofa stretching device is characterized in that: comprises an underframe (1), a backrest component, a seat frame (3), a leg supporting mechanism (4), a linkage mechanism (5) and a driving part (12);

the backrest component is rotationally connected with the underframe (1), and a rotating point of the backrest component relative to the seat frame (3) is positioned at one end of the backrest component; one end of the seat frame (3) is rotatably connected with the backrest component, the other end of the seat frame is rotatably connected with the leg supporting mechanism (4), and the seat frame (3) is rotatably connected with the bottom frame (1) through the linkage mechanism (5);

the driving part (12) is used for providing linear thrust along the length direction of the seat frame (3) for the seat frame (3), one end of the driving part is connected to the linkage mechanism (5) or the seat frame (3), and the other end of the driving part is connected to the bottom frame (1);

the leg support means (4) is a leg support means (4) according to any of claims 1-9.