CN113749460A - Sofa seat stretching device - Google Patents

Abstract

The invention relates to the technical field of furniture and discloses a sofa seat stretching device. Compared with the prior art that one end of the second supporting piece, which is far away from the first supporting piece, is hinged to the middle part of the third supporting piece, the sofa seat stretching device provided by the invention has the advantages that one end of the second supporting piece, which is far away from the first supporting piece, and the second leg rest connecting piece are hinged to the fourth hinge point, so that the stretching speed of the stretching assembly is reduced in the process of switching from the sitting posture state to the lying posture state under the condition that the driving assemblies act the same, and the weightlessness feeling can be effectively avoided; and the drive component drives the extension component to ensure that the process of switching the extension from the lying state to the sitting state is smoother.

Description

Sofa seat stretching device

Technical Field

The invention relates to the technical field of furniture, in particular to a sofa seat stretching device.

Background

With the improvement of social productivity and the development of economic level, people's demand for beautiful life is increasing and the demand for furniture is also increasing, and at present, many furniture such as lounge chairs and sofas are provided with mechanical stretching devices on which backrests, cushions and leg rest plates are arranged.

In order to improve the operation convenience, the mechanical stretching device is usually provided with an electric driving assembly, and the driving assembly is used for pushing the mechanical stretching device to stretch or retract so as to enable the sofa seat to have different postures and meet the requirement of people on comfort.

In order to further improve the functional requirements of people on the sofa seat, the sofa seat is put forward, the sofa seat is in a lying posture state, the legs of a user lying on the sofa seat are not lower than the heart, the unsuitable state of a special user is relieved, and the using requirements of the user with diseases such as hypertension are met.

However, in the process of switching from a sitting posture state to a lying posture state, the conventional sofa seat realizing the functions is switched at an excessively high speed, so that sudden weightlessness is caused; moreover, the process of switching from the lying posture state to the sitting posture state is not smooth and easy to block.

Disclosure of Invention

The invention aims to provide a sofa seat stretching device which can reduce the switching speed when switching from a sitting posture state to a sitting and lying posture state and avoid the weightlessness feeling; the process of switching from the lying posture state to the sitting posture state is smoother.

In order to achieve the purpose, the invention adopts the following technical scheme:

a sofa seat extension apparatus comprising a base and, disposed on the base:

the extension assembly comprises a backrest unit, a seat frame unit and a leg extension unit which are positioned at two ends of the base in the width direction and symmetrically arranged, and the front end and the rear end of the seat frame unit are respectively hinged with one end of the backrest unit and one end of the leg extension unit;

the driving assembly is used for driving the two stretching assemblies to synchronously stretch or furl along the front-back direction so as to switch the stretching assemblies among a sitting posture state, a TV posture state and a lying posture state;

the leg extension unit comprises a first leg placing plate connecting piece and a second leg placing plate connecting piece, and the middle part of the first leg placing plate connecting piece and the middle part of the second leg placing plate connecting piece are hinged to a third hinged point;

the seat frame unit comprises a seat frame supporting piece, a first supporting piece, a second supporting piece and a third supporting piece, wherein one end of the seat frame supporting piece is hinged to a first hinge point with one end of the second leg placing plate connecting piece, the first supporting piece and the second supporting piece can rotate relative to the seat frame supporting piece, and one end of the third supporting piece is hinged to a fifth hinge point with the seat frame supporting piece; the other end of the third support piece is hinged with the first leg rest connecting piece, one end of the second support piece is hinged with one end of the first support piece, the other end of the second support piece is hinged with the second leg rest connecting piece at a fourth hinge point, the fourth hinge point is positioned between the first hinge point and the third hinge point, and the first hinge point is positioned in front of the fifth hinge point;

the seat frame unit also comprises a first connecting piece, a second connecting piece, a third connecting piece, a fourth connecting piece, a fifth connecting piece and a sixth connecting piece;

one end of the first connecting piece is hinged with the seat frame supporting piece, the middle of the first connecting piece is hinged with one end of the third connecting piece, the other end of the first connecting piece is hinged with one end of the second connecting piece, and the other end of the second connecting piece is hinged with the front end of the base; the other end of the third connecting piece is hinged with the backrest unit;

one end of the fourth connecting piece is hinged with the middle part of the third supporting piece, and the other end of the fourth connecting piece is hinged with one end of the sixth connecting piece; the middle part of the sixth connecting piece is hinged with the seat frame supporting piece, the other end of the sixth connecting piece is hinged with one end of the fifth connecting piece, and the other end of the fifth connecting piece is hinged with the middle part of the second connecting piece;

the first connecting piece is provided with a first limiting piece, the seat frame supporting piece is provided with a second limiting piece used for limiting the furling of the extension assembly and a third limiting piece used for limiting the extension of the extension assembly, and the second limiting piece and the third limiting piece are positioned on two sides of the first connecting piece;

when the stretching assembly is in a lying posture state, the third limiting piece abuts against the first connecting piece;

when the extension assembly is in a sitting posture state, the second limiting piece abuts against the first connecting piece, and the first limiting piece is clamped between the seat frame supporting piece and the third supporting piece;

and a fourth limiting part used for limiting the upper end face of the first leg placing plate connecting part is arranged on the second leg placing plate connecting part.

As a preferable technical solution of the sofa seat stretching device, the backrest unit includes a first backrest connecting member, a second backrest connecting member, a third backrest connecting member and a fourth backrest connecting member;

one end of the lower part of the first backrest connecting piece is hinged with one end of the second backrest connecting piece, and the other end of the lower part of the first backrest connecting piece is hinged with the seat frame supporting piece; one end of the third backrest connecting piece is hinged to the other end of the second backrest connecting piece, the middle of the third backrest connecting piece is hinged to one end of the third connecting piece, the other end of the third backrest connecting piece is hinged to one end of the fourth backrest connecting piece at a tenth hinge point, the third backrest connecting piece is hinged to the seat frame supporting piece, and the other end of the fourth backrest connecting piece is hinged to the rear end of the base.

As a preferable technical solution of the sofa seat stretching device, the third backrest connecting member is connected to the seat frame supporting member through a backrest spring, the stretching length of the backrest spring is a1 when the stretching assembly is in the sitting posture state and the TV posture state, the stretching length of the backrest spring is a2 when the stretching assembly is in the lying posture state, and the ratio of a1 to a2 is in the range of 0.7-0.9.

As a preferable mode of the sofa seat stretching device, the seat frame support member includes a first seat frame member having one end connected to the leg stretching unit and a second seat frame member having one end connected to the backrest unit, and the other end of the first seat frame member and the other end of the second seat frame member are connected to form a "v" shape; one end of the backrest spring is connected to the third backrest connecting piece, and the other end of the backrest spring is connected to the middle position of the second seat frame piece.

As a preferable technical solution of the sofa seat stretching device, when the stretching assembly is in the sitting posture, an included angle between a side surface of the third supporting member facing the base and a rear side surface of the third supporting member when the stretching assembly is in the zero gravity posture is a;

the tenth hinge point is always located below the middle of the second seat frame member, so that 100 DEG & lt A & lt 110 deg.

As a preferable technical solution of the sofa seat stretching device, a seat frame mounting part is respectively arranged at the outer side of the first seat frame member and the outer side of the second seat frame member;

the included angles between the lower side surfaces of the two seat frame mounting pieces on the same seat frame supporting piece and the base are B1 and B2 respectively, and when the stretching assembly is in a lying posture state, B1 and B2 are both 13-23 degrees.

As a preferable technical solution of the sofa seat stretching device, a fifth limiting member is disposed on the sixth connecting member, and is used for limiting the movement of the third connecting member and the third backrest connecting member;

when the extension assembly is in a sitting posture state, the fifth limiting piece is abutted to the upper side face of the third connecting piece and the upper side face of the third backrest connecting piece.

As a preferable technical solution of the extension device for a sofa seat, the second limiting member and the third limiting member are both configured as V-shaped limiting protrusions integrally formed with the seat frame supporting member;

the fourth limiting part, the first limiting part and the fifth limiting part are all set to be columnar structures.

As a preferable technical solution of the sofa seat stretching device, the driving assembly includes:

the guide rail is provided with a sliding block which is connected with the guide rail in a sliding manner along the front-back direction, and the sliding block is connected with the third supporting pieces of the two seat frame units through a connecting unit;

and the output end of the linear driving unit is fixedly connected to the sliding block.

As a preferable technical solution of the sofa seat stretching device, the first hinge point, the fourth limiting member and the third hinge point are sequentially distributed along an extending direction of the second leg rest connecting member.

The invention has the beneficial effects that: compared with the prior art that one end of the second supporting piece, which is far away from the first supporting piece, is hinged to the middle part of the third supporting piece, the sofa seat stretching device provided by the invention has the advantages that one end of the second supporting piece, which is far away from the first supporting piece, and the second leg rest connecting piece are hinged to the fourth hinge point, so that the stretching speed of the stretching assembly is reduced in the process of switching from the sitting posture state to the lying posture state under the condition that the driving assemblies act the same, and the weightlessness feeling can be effectively avoided; and the drive component drives the stretching component to move so that the process of switching the stretching component from the lying state to the sitting state is smoother.

When the extension assembly is in different states, the fourth locating part can play a role in locating the first leg placing plate connecting piece, and stability of the extension assembly in different states is improved.

When the extension assembly is in a sitting posture state, the first limiting piece is clamped between the seat frame supporting piece and the third supporting piece, the second limiting piece is limited by the seat safety, the extension assembly is limited to continue moving to the side where the backrest unit is located, and therefore the extension assembly is stably kept in the sitting posture state when the driving assembly stops acting.

When the extension assembly is in the lying posture state, the third limiting part is clamped on the lower side face of the first connecting piece, and the third limiting part plays a role in supporting and limiting the first connecting piece, so that the extension assembly is stably kept in the lying posture state.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

FIG. 1 is a schematic view of a portion of a first embodiment of a sofa seat stretcher with the stretcher components in the TV position according to the present invention;

FIG. 2 is a schematic view of a second embodiment of the sofa seat stretcher with the extendable members in the TV position according to the present invention;

FIG. 3 is a schematic view of a portion of a first embodiment of a sofa extension apparatus having a extension assembly in a reclined position;

FIG. 4 is a schematic view of a second embodiment of the extension device of the sofa seat with the extension member in the reclining position according to the present invention;

FIG. 5 is a schematic view of a portion of a third embodiment of a sofa extension apparatus having an extension member in a reclined position in accordance with the present invention;

FIG. 6 is an enlarged view of a portion of the invention at G in FIG. 5;

FIG. 7 is a schematic view of a portion of a first embodiment of a sofa extension apparatus with the extension member in a sitting position according to the present invention;

FIG. 8 is a schematic view of a second embodiment of the extension device of the sofa seat with the extension member in the sitting position according to the present invention;

fig. 9 is a diagram of the position relationship between the third support member in the sitting position of the extension assembly and the third support member in the lying position of the extension assembly according to the embodiment of the present invention.

In the figure:

1. a base;

2. a backrest unit; 21. a first backrest connector; 22. a second backrest connector; 23. a third backrest connector; 24. a fourth backrest connector;

3. a seat frame unit; 30. a sixth connecting member; 31. a seat frame support; 311. a first seat frame member; 312. a second seat frame member; 32. a first support member; 33. a second support member; 34. a third support member; 35. a first connecting member; 36. a second connecting member; 37. a third connecting member; 38. a fourth connecting member; 39. a fifth connecting member;

4. a leg extension unit; 41. a first leg rest panel connection; 42. a second leg rest panel connection; 43. a third leg rest panel connection; 44. a leg rest frame;

50. a tenth hinge point; 51. a first hinge point; 52. a second hinge point; 53. a third hinge point; 54. a fourth hinge point; 55. a fifth hinge point; 56. a sixth hinge point; 57. a seventh hinge point; 58. an eighth hinge point; 59. a ninth hinge point;

61. a first fixing lever; 62. a second fixing bar; 63. a third fixing bar;

71. a linear drive unit; 72. a guide rail; 73. a slider; 74. a drive connection; 75. a drive link; 76. a first connecting rod; 77. a second connecting rod;

8. a seat frame mounting member;

91. a first limit piece; 92. a second limiting member; 93. a third limiting member; 94. a fourth limiting member; 95. a fifth limiting member;

100. a back spring.

Detailed Description

In order to make the technical problems solved, the technical solutions adopted and the technical effects achieved by the present invention clearer, the technical solutions of the present invention are further described below by way of specific embodiments with reference to the accompanying drawings. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some but not all of the elements associated with the present invention are shown in the drawings.

As shown in fig. 1 to 9, the present embodiment provides a sofa seat stretching apparatus, which includes a base 1, and a driving assembly and a stretching assembly provided on the base 1, wherein the stretching assembly includes a backrest unit 2, a seat frame unit 3, and a leg stretching unit 4, which are symmetrically provided at both sides of the base 1 in a width direction (W direction shown in fig. 2), and front and rear ends of the seat frame unit 3 are respectively hinged to one end of the backrest unit 2 and one end of the leg stretching unit 4. The front and rear ends of the seat frame unit 3 refer to both ends of the seat frame unit 3 in the L direction shown in fig. 2, wherein the front end of the seat frame unit 3 refers to the end where the leg extension unit 4 is located, and the rear end of the seat frame unit 3 refers to the end where the back unit 2 is located. The H direction shown in fig. 2 is the height direction.

The driving component is connected with the two seat frame units 3 through the connecting unit, so that the two stretching components can be synchronously stretched or folded along the front-back direction to switch the stretching components among a sitting posture state, a TV posture state and a lying posture state.

The structure of the base 1 will be described in detail.

The base 1 includes two front and rear connecting members and two left and right connecting members, the two front and rear connecting members and the two left and right connecting members are connected by fasteners such as bolts to form a rectangular frame, and the base 1 serves as a support member for supporting a structural member connected thereto. In other embodiments, two front and rear connecting members and two left and right connecting members may be welded to form a rectangular frame.

Next, the structure of the leg stretching unit 4 will be described.

The leg extension unit 4 comprises a first leg placing plate connecting piece 41, a second leg placing plate connecting piece 42, a third leg placing plate connecting piece 43 and a leg placing plate frame 44, wherein one end of the first leg placing plate connecting piece 41 is hinged with the seat frame unit 3, one end of the second leg placing plate connecting piece 42 is hinged with the front end of the seat frame unit 3 at a first hinge point 51, the other end of the second leg placing plate connecting piece 42 is hinged with one end of the third leg placing plate connecting piece 43 at a second hinge point 52, the other end of the first leg placing plate connecting piece 41 and the other end of the third leg placing plate connecting piece 43 are respectively hinged with the leg placing plate frame 44, the first leg placing plate connecting piece 41 is parallel to the third leg placing plate connecting piece 43, and the middle part of the first leg placing plate connecting piece 41 and the middle part of the second leg placing plate connecting piece 42 are hinged with a third hinge point 53. The second leg rest board connecting member 42 is provided with a fourth limiting member 94 for limiting the upper end surface of the first leg rest board connecting member 41, and the first hinge point 51, the fourth limiting member 94, the third hinge point 53 and the second hinge point 52 are sequentially distributed along the extending direction of the second leg rest board connecting member 42.

Next, the structure of the bezel unit 3 will be described.

The seat frame unit 3 includes a seat frame support 31, a first support 32, a second support 33, and a third support 34, the two seat frame units 3 are connected by a driving connecting rod 75, and two axial ends of the driving connecting rod 75 respectively penetrate through the corresponding seat frame units 3 and are fixedly connected to one end of the first support 32, so that the first support 32 can rotate relative to the seat frame support 31. The other end of the first supporting member 32 is hinged to one end of the second supporting member 33, the other end of the second supporting member 33 and the middle portion of the second leg rest connecting member 42 are hinged to a fourth hinge point 54, one end of the second leg rest connecting member 42 far away from the third leg rest connecting member 43 is hinged to the first hinge point 51 and the seat frame supporting member 31, and the fourth hinge point 54 is located between the first hinge point 51 and the fourth limiting member 94. One end of the third supporting member 34 is hinged to one end of the first leg rest connecting member 41, and the other end of the third supporting member 34 is hinged to the seat frame supporting member 31 at a fifth hinge point 55.

The seat frame unit 3 further comprises a first connecting piece 35, a second connecting piece 36, a third connecting piece 37, a fourth connecting piece 38, a fifth connecting piece 39 and a sixth connecting piece 30, wherein one end of the first connecting piece 35 is hinged to a sixth hinge point 56 with the seat frame supporting piece 31, the middle part of the first connecting piece 35 is hinged to one end of the third connecting piece 37, the other end of the first connecting piece 35 is hinged to one end of the second connecting piece 36, and the other end of the second connecting piece 36 is hinged to the front ends of the left and right connecting pieces; the other end of the third link 37 is hinged to the back unit 2. One end of the fourth connecting member 38 is hinged to the middle of the third supporting member 34, the other end is hinged to one end of the sixth connecting member 30, the middle of the sixth connecting member 30 is hinged to the seventh hinge point 57 with the seat frame supporting member 31, the other end of the sixth connecting member 30 is hinged to one end of the fifth connecting member 39, and the other end of the fifth connecting member 39 is hinged to the middle of the second connecting member 36.

Next, the structure of the backrest unit 2 will be specifically described.

The backrest unit 2 includes a first backrest connecting member 21, a second backrest connecting member 22, a third backrest connecting member 23 and a fourth backrest connecting member 24, wherein one end of the lower portion of the first backrest connecting member 21 is hinged to one end of the second backrest connecting member 22, the other end of the lower portion of the first backrest connecting member 21 is hinged to an eighth hinge point 58 with the seat frame supporting member 31, the third backrest connecting member 23 is substantially V-shaped, one end of the third backrest connecting member 23 is hinged to the other end of the second backrest connecting member 22, the middle portion of the third backrest connecting member 23 is hinged to one end of the third connecting member 37, the other end of the third backrest connecting member 23 is hinged to a tenth hinge point 50 with one end of the fourth backrest connecting member 24, the third backrest connecting member 23 is hinged to the seat frame supporting member 31 at a ninth hinge point 59, the ninth hinge point 59 is located between the other end and the middle portion of the third backrest connecting member 23, the other end of the fourth backrest connecting member 24 is hinged to the rear ends of the left and right connecting members, a backrest spring 100 is connected to the vicinity of the hinge point of the third backrest connecting member 23 and the second backrest connecting member 22, and the other end of the backrest spring 100 is connected to the seat frame supporter 31.

In this embodiment, the seat frame supporting member 31 includes a first seat frame member 311 and a second seat frame member 312, a lower end of the first seat frame member 311 and a lower end of the second seat frame member 312 are connected to form a "v" shaped seat frame supporting member 31, the first hinge point 51, the fifth hinge point 55 and the sixth hinge point 56 are all located on the first seat frame member 311 and sequentially distributed along a direction from the first seat frame member 311 to the second seat frame member 312, the eighth hinge point 58 is located at a free end of the second seat frame member 312, and the ninth hinge point 59 is located at a connecting position of the first seat frame member 311 and the second seat frame member 312, i.e., at a turning position of the "v" shaped structure. The other end of the back spring 100 is attached to a middle portion of the second frame member 312.

Referring to fig. 9, the angle between the side of the third supporting member 34 facing the base 1 when the extension assembly is in the sitting position and the rear side of the third supporting member 34 when the extension assembly is in the lying position is a, and the tenth hinge point 50 is always located below the middle position of the second seat frame 312 during the extension or retraction of the extension assembly, so that 100 ° < a < 110 °. Alternatively, a may be 100 °, 101 °, 102 °, 103 °, 104 °, 105 °, 106 °, 107 °, 108 °, 109 °, and 110 °. Exemplarily, a ═ 106 °. The position of the tenth hinge point 50 is limited, and the size of the hinge point a is adjusted, so that the position of the tenth hinge point 50 is lower, that is, the unfolding distance of the third backrest connecting piece 23 and the fourth backrest connecting piece 24 is shorter, the smoothness of unfolding or folding the extension assembly is improved, and when the extension assembly is in a lying posture state, the zero gravity feeling of a user lying on the sofa seat is obvious.

A first fixing rod 61 is disposed between the two second connecting members 36 positioned at the left and right sides of the base 1, a second fixing rod 62 is disposed between the two third backrest connecting members 23 positioned at the left and right sides of the base 1, and a third fixing rod 63 is disposed between the two fourth backrest connecting members 24 positioned at the left and right sides of the base 1.

The driving assembly includes a linear driving unit 71, a guide rail 72 and a connecting unit, which are disposed on the base 1, exemplarily, the linear driving unit 71 is a linear motor, a slider 73 is slidably disposed on the guide rail 72, an output end of the linear driving unit 71 is connected to the slider 73, the connecting unit includes the driving connecting rod 75 and the driving connecting rod 74, two ends of the driving connecting rod 74 are respectively hinged to a first connecting rod 76 and a second connecting rod 77, wherein the first connecting rod 76 is fixedly connected to the driving connecting rod 75, the second connecting rod 77 is fixedly connected to the slider 73, two ends of the driving connecting rod 75 are respectively connected to the first supporting members 32 of the two seat frame units 3 on the left side and the right side, and the linear driving unit 71 drives the slider 73 to move back and forth along the guide rail 72 to drive the stretching assembly to stretch or furl. Specifically, the linear driving unit 71 is a linear motor, a fixed end of the linear driving unit 71 is mounted on the front and rear connecting members, the guide rail 72 is located between the two left and right connecting members, front and rear ends of the guide rail 72 are respectively fixedly connected to the two front and rear connecting members, and the guide rail 72 is disposed parallel to the left and right connecting members.

The seat frame supporting member 31 is provided with a third limiting member 93 for limiting the extension of the extension assembly, and specifically, the third limiting member 93 is used for limiting the movement position of the first connecting member 35. The seat frame supporting member 31 is further provided with a second limiting member 92 for limiting the folding of the extending member, specifically, the second limiting member 92 is used for limiting the movement of the first connecting member 35, and the sixth hinge point 56 is located between the second limiting member 92 and the third limiting member 93. In this embodiment, the seventh hinge point 57 is located between the ninth hinge point 59 and the third limiting member 93.

In this embodiment, the seat frame supporting member 31, the third supporting member 34, the fourth connecting member 38, and the sixth connecting member 30 constitute a four-bar linkage; the second seat frame member 312, the second backrest connector 22, the third backrest connector 23 and the first backrest connector 21 constitute a four-bar linkage; the seat frame supporting member 31, the third supporting member 34, the second leg rest connecting member 42, and the first leg rest connecting member 41 constitute a four-bar linkage.

The linear driving unit 71 drives the sliding block 73 to slide back and forth on the guide rail 72, the sliding block 73 drives the driving connecting rod 75 to move back and forth through the driving connecting piece 74, the first connecting rod 76 and the second connecting rod 77, the driving connecting rod 75 drives the seat frame supporting pieces 31 and the first supporting pieces 32 on the left side and the right side to move synchronously, and the seat frame supporting pieces 31 and the first supporting pieces 32 drive the extending components to extend or retract. When the stretching assembly stretches, the stretching assembly changes from a sitting posture to a TV posture and then to a lying posture in sequence; when the stretching assembly is folded, the stretching assembly is changed from a lying posture to a TV posture and then to a sitting posture in sequence. The first connecting member 35 is provided with a first limiting member 91 for limiting the movement of the third supporting member 34. When the extension assembly is in the sitting posture, the sliding block 73 moves to the side of the backrest unit 2, the first limiting member 91 is clamped on the lower side surface of the seat frame supporting member 31 and the upper side surface of the third supporting member 34, the second limiting member 92 is a safety limiting member, so that the extension assembly is limited to move continuously to the side of the backrest unit 2, and at the moment, the linear driving unit 71 stops working, namely, the stable sitting posture is maintained. The sixth connecting member 30 is provided with a fifth limiting member 95 for limiting the movement of the third connecting member 37 and the third backrest connecting member 23, and when the extension assembly is in the sitting posture state, the fifth limiting member 95 abuts against the upper side surface of the third connecting member 37 and the upper side surface of the third backrest connecting member 23.

When the stretching assembly is unfolded, the linear driving unit 71 drives the sliding block 73 to move towards the side of the leg stretching unit 4, the sliding block 73 drives the driving connecting rod 75 to move back and forth through the driving connecting piece 74, the first connecting rod 76 and the second connecting rod 77, the driving connecting rod 75 drives the first supporting piece 32, the first supporting piece 32 drives the second supporting piece 33, the second supporting piece 33 pushes the second leg placing plate connecting piece 42 to stretch towards the front end of the seat frame unit 3, and the second leg placing plate connecting piece 42 simultaneously pushes the first leg placing plate connecting piece 41 and the third leg placing plate connecting piece 43 until the leg stretching unit 4 is completely unfolded, so that the conversion from the sitting posture to the TV posture is completed. The expansion of the leg extension unit 4 requires only one force transfer through the second leg rest connecting piece 42, and the loss in the transfer process is extremely small, so that the extension assembly runs smoothly, and the energy is saved.

When the extension assembly needs to be extended continuously, the linear driving unit 71 drives the sliding block 73 to move towards the leg extension unit 4, at this time, the limiting function of the first limiting member 91 on the third supporting member 34 fails, when the extension assembly extends to the TV posture state, the first limiting member 91 is located on the lower side surface of the seat frame supporting member 31, the second limiting member 92 is a safety limiting position, at this time, the first limiting member 91 and the second limiting member 92 act together to enable the supporting member 31 and the first connecting member 35 to be in a relatively static and stable state, so as to avoid the seat frame unit 3 from collapsing, and under the action of the driving connecting rod 75, the first fixing rod 61, the second fixing rod 62, the third fixing rod 63, the first limiting member 91 and the second limiting member 92, the extension assembly can maintain the TV posture state; when the linear driving unit 71 continues to drive the sliding block 73 to move towards the leg extension unit 4, the first connecting member 35 moves downwards, the limiting function of the second limiting member 92 is disengaged, and when the sliding block moves to a position where the sliding block contacts the third limiting member 93, the third limiting member 93 is completely clamped on the lower side surface of the first connecting member 35, and at this time, a stable lying posture state is achieved. When the stretching assembly is folded, the stretching assembly and the stretching assembly move in opposite directions in sequence.

The first limiting member 91 is arranged to be a columnar structure, and can adapt to stress at different angles when the seat frame supporting member 31 and the third supporting member 34 are limited simultaneously, and both can play a role in stabilizing and limiting. The fourth limiting member 94 is configured to be a column structure, which is convenient to adapt to limiting at different angles of the bearing 41. The fifth limiting member 95 is provided as a column structure, which facilitates the limitation of the third connecting member 37 and the third backrest connecting member 23 at the same time.

The second limiting member 92 and the third limiting member 93 are both V-shaped limiting protrusions integrally formed with the seat frame supporting member 31, and the side surfaces of the V-shaped limiting protrusions are a plane and can be adapted to the edge of the first connecting member 35, so that the limiting is more stable, and the V-shaped limiting protrusions are not prone to shaking and deformation.

Compared with the prior art that one end of the second supporting member 33, which is far away from the first supporting member 32, is hinged to the middle of the third supporting member 34, in the embodiment, one end of the second supporting member 33, which is far away from the first supporting member 32, is hinged to the fourth hinge point 54 with the second leg rest connecting member 42, so that the extension speed of the extension assembly is reduced in the process of switching from the sitting posture state to the lying posture state under the condition that the sliding block 73 moves for the same distance, and the generation of weightlessness can be effectively avoided; and the drive component drives the stretching component to move so that the process of switching the stretching component from the lying state to the sitting state is smoother.

The stretching length of the backrest spring 100 is a1 when the stretching assembly is in a sitting posture state and a TV posture state, the stretching length of the backrest spring 100 when the stretching assembly is in a lying posture state is a2, and the ratio of a1 to a2 ranges from 0.7 to 0.9. This embodiment provides a backrest spring 100 in the extension assembly, a 1: a2 is 0.84, the length of the backrest spring 100 is 105.22mm in the sitting posture, when the stretching component stretches, the leg stretching unit 4 stretches first, and the backrest unit 2 rotates; when the extension assembly is extended to the recumbent position, the back spring 100 is extended to the longest length, which is 125.02 mm; when the extension assembly is furled, the backrest unit 2 rotates back first, the leg extension units 4 are furled again, and in the furling process, the contraction force of the backrest spring 100 enables the furling process to become natural and smooth, so that the furling process is easier.

Further, two seat frame mounting members 8 are provided outside the seat frame support 31 for mounting a seat cushion. In this embodiment, the outer side of the first seat frame member 311 and the outer side of the second seat frame member 312 are respectively provided with a seat frame mounting member 8, the included angles between the lower side surfaces of the two seat frame mounting members 8 of the same seat frame supporting member 31 and the base 1 are respectively B1 and B2, and referring to fig. 4, when the extension assembly is in the lying posture state, the values of B1 and B2 are both 13 ° to 23 °; accords with the ergonomic structure, thereby ensuring that the lying posture is flatter and reaches the posture of zero gravity of the human body, namely being more comfortable.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Claims (10)

1. A sofa seat stretching device comprises a base (1) and a support arranged on the base (1):

the stretching assembly comprises backrest units (2), seat frame units (3) and leg stretching units (4) which are positioned at two ends of the base (1) in the width direction and are symmetrically arranged, and the front end and the rear end of each seat frame unit (3) are hinged with one end of each backrest unit (2) and one end of each leg stretching unit (4) respectively;

the driving assembly is used for driving the two stretching assemblies to synchronously stretch or furl along the front-back direction so as to switch the stretching assemblies among a sitting posture state, a TV posture state and a lying posture state;

characterized in that the leg extension unit (4) comprises a first leg rest connecting piece (41) and a second leg rest connecting piece (42), the middle part of the first leg rest connecting piece (41) and the middle part of the second leg rest connecting piece (42) are hinged to a third hinge joint (53);

the seat frame unit (3) comprises a seat frame supporting piece (31) hinged to a first hinge point (51) with one end of the second leg rest board connecting piece (42), a first supporting piece (32) capable of rotating relative to the seat frame supporting piece (31), a second supporting piece (33) and a third supporting piece (34) hinged to a fifth hinge point (55) with one end of the seat frame supporting piece (31); the other end of the third supporting part (34) is hinged with the first leg rest connecting part (41), one end of the second supporting part (33) is hinged with one end of the first supporting part (32), the other end of the second supporting part (33) is hinged with the second leg rest connecting part (42) at a fourth hinge point (54), the fourth hinge point (54) is positioned between the first hinge point (51) and the third hinge point (53), and the first hinge point (51) is positioned in front of the fifth hinge point (55);

the seat frame unit (3) further comprises a first connecting piece (35), a second connecting piece (36), a third connecting piece (37), a fourth connecting piece (38), a fifth connecting piece (39) and a sixth connecting piece (30);

one end of the first connecting piece (35) is hinged with the seat frame supporting piece (31), the middle of the first connecting piece (35) is hinged with one end of the third connecting piece (37), the other end of the first connecting piece (35) is hinged with one end of the second connecting piece (36), and the other end of the second connecting piece (36) is hinged with the front end of the base (1); the other end of the third connecting piece (37) is hinged with the backrest unit (2);

one end of the fourth connecting piece (38) is hinged with the middle part of the third supporting piece (34), and the other end of the fourth connecting piece (38) is hinged with one end of the sixth connecting piece (30); the middle part of the sixth connecting piece (30) is hinged with the seat frame supporting piece (31), the other end of the sixth connecting piece (30) is hinged with one end of the fifth connecting piece (39), and the other end of the fifth connecting piece (39) is hinged with the middle part of the second connecting piece (36);

a first limiting piece (91) used for limiting the movement of the third supporting piece (34) is arranged on the first connecting piece (35), a second limiting piece (92) used for limiting the furling of the extension component and a third limiting piece (93) used for limiting the extension of the extension component are arranged on the seat frame supporting piece (31), and the second limiting piece (92) and the third limiting piece (93) are positioned on two sides of the first connecting piece (35);

when the stretching assembly is in a lying posture state, the third limiting piece (93) abuts against the first connecting piece (35);

when the extension assembly is in a sitting posture state, the second limiting piece (92) abuts against the first connecting piece (35), and the first limiting piece (91) is clamped between the seat frame supporting piece (31) and the third supporting piece (34);

and a fourth limiting part (94) used for limiting the upper end face of the first leg placing plate connecting part (41) is arranged on the second leg placing plate connecting part (42).

2. The sofa seat extension according to claim 1, wherein the backrest unit (2) comprises a first backrest connector (21), a second backrest connector (22), a third backrest connector (23) and a fourth backrest connector (24);

one end of the lower part of the first backrest connecting piece (21) is hinged with one end of the second backrest connecting piece (22), and the other end of the lower part of the first backrest connecting piece (21) is hinged with the seat frame supporting piece (31); one end of the third backrest connecting piece (23) is hinged to the other end of the second backrest connecting piece (22), the middle of the third backrest connecting piece (23) is hinged to one end of the third connecting piece (37), the other end of the third backrest connecting piece (23) is hinged to a tenth hinge point (50) at one end of the fourth backrest connecting piece (24), the third backrest connecting piece (23) is hinged to the seat frame supporting piece (31), and the other end of the fourth backrest connecting piece (24) is hinged to the rear end of the base (1).

3. The sofa seat stretcher according to claim 2, wherein the third backrest connector (23) is connected to the seat frame support (31) by a backrest spring (100), the backrest spring (100) has a telescopic length a1 in the stretching assembly in the sitting position and the TV position, the backrest spring (100) has a telescopic length a2 in the stretching assembly in the lying position, and the ratio of a1 to a2 is 0.7-0.9.

4. The sofa seat stretching apparatus according to claim 3, wherein the seat frame supporter (31) includes a first seat frame member (311) having one end connected to the leg stretching unit (4) and a second seat frame member (312) having one end connected to the backrest unit (2), the other end of the first seat frame member (311) and the other end of the second seat frame member (312) being connected to form the seat frame supporter (31) in a "√" shape; one end of the backrest spring (100) is connected to the third backrest connecting member (23), and the other end is connected to the middle position of the second seat frame member (312).

5. The sofa seat extension according to claim 4, wherein the angle between the side of the third support (34) facing the base (1) when the extension assembly is in the sitting position and the rear side of the third support (34) when the extension assembly is in the recumbent position is A;

the tenth hinge point (50) is always located below the middle of the second frame member (312) such that 100 < A < 110.

6. The sofa seat extension according to claim 4, wherein one seat frame mounting member (8) is provided on each of the outer side of the first seat frame member (311) and the outer side of the second seat frame member (312);

the included angles between the lower side surfaces of the two seat frame mounting pieces (8) on the same seat frame supporting piece (31) and the base (1) are B1 and B2 respectively, and when the stretching assembly is in a lying posture state, B1 and B2 are both 13-23 degrees.

7. The sofa seat extension apparatus according to claim 2, wherein a fifth stop (95) is provided on the sixth link (30) for limiting the movement of the third link (37) and the third backrest link (23);

when the extension assembly is in a sitting posture, the fifth limiting piece (95) abuts against the upper side face of the third connecting piece (37) and the upper side face of the third backrest connecting piece (23).

8. The sofa seat stretching apparatus according to claim 7, wherein the second limiting member (92) and the third limiting member (93) are each provided as a V-shaped limiting protrusion integrally formed with the seat frame support member (31);

the fourth limiting part (94), the first limiting part (91) and the fifth limiting part (95) are all set to be columnar structures.

9. The sofa seat stretching apparatus according to any one of claims 1 to 8, wherein the driving assembly comprises, fixedly arranged on the base (1):

the guide rail (72) is provided with a sliding block (73) which is connected with the guide rail (72) in a sliding manner along the front-back direction, and the sliding block (73) is connected with the third supporting pieces (34) of the two seat frame units (3) through a connecting unit;

the output end of the linear driving unit (71) is fixedly connected to the sliding block (73).

10. The sofa seat extension device according to any one of claims 1-8, wherein the first hinge point (51), the fourth hinge point (54), the fourth retaining member (94) and the third hinge point (53) are distributed in sequence along the extension direction of the second leg rest board connection member (42).

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