Sofa seat stretching device

Abstract

The present invention relates to the field of furniture technology, and discloses a sofa seat extension device. Compared with the prior art in which one end of a second support member away from a first support member is hinged to the middle of a third support member, the sofa seat extension device provided by the present invention hinges one end of the second support member away from the first support member and a second legrest connecting member at a fourth hinge point, so that when the driving component has the same action, the extension speed of the extension component is reduced during the process of switching from a sitting state to a lying state, which can effectively avoid the feeling of weightlessness; and the driving component drives the extension component to make the process of switching from a lying state to a sitting state smoother.

Description

Technical Field

[0001] The invention relates to the technical field of furniture, and in particular to a sofa seat stretching device. Background Art

[0002] With the improvement of social productivity and the development of economic level, people's needs for a better life are growing, and the requirements for furniture are getting higher and higher. At present, many recliners, sofas and other furniture are equipped with mechanical extension devices, on which backrests, seat cushions and legrests are installed.

[0003] In order to improve the convenience of operation, the mechanical extension device is usually equipped with an electric drive component, which is used to push the mechanical extension device to extend or retract, so that the sofa seat can have different postures to meet people's comfort requirements.

[0004] In order to further improve people's functional requirements for sofa seats, a sofa seat is proposed. When the sofa seat is in a lying state, the legs of the user lying on the sofa seat are not lower than the heart, which alleviates the discomfort of special users and meets the needs of users with diseases such as hypertension.

[0005] However, in the process of switching from a sitting position to a lying position, the existing sofa seats realizing the above functions switch too fast, resulting in a sudden feeling of weightlessness; and the process of switching from a lying position to a sitting position is not smooth and is prone to getting stuck. Summary of the invention

[0006] The object of the present invention is to provide a sofa seat stretching device, which can reduce the switching speed when switching from a sitting position to a sitting or lying position, avoid the feeling of weightlessness, and make the process of switching from a lying position to a sitting position smoother.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] A sofa seat stretching device comprises a base and:

[0009] An extension assembly, the extension assembly comprising a backrest unit, a seat frame unit and a leg extension unit which are symmetrically arranged at both ends of the base in the width direction, and the front and rear ends of the seat frame unit are respectively hinged to one end of the backrest unit and the leg extension unit;

[0010] A driving component, used for driving the two extending components to extend or retract synchronously in the front-rear direction so that the extending components can switch between a sitting position, a TV position and a lying position;

[0011] The leg extension unit comprises a first legrest connecting member and a second legrest connecting member, wherein the middle portion of the first legrest connecting member and the middle portion of the second legrest connecting member are hinged at a third hinge point;

[0012] The seat frame unit comprises a seat frame support member hinged to one end of the second legrest connecting member at a first hinge point, a first support member capable of rotating relative to the seat frame support member, a second support member, and a third support member with one end hinged to the seat frame support member at a fifth hinge point; the other end of the third support member is hinged to the first legrest connecting member, one end of the second support member is hinged to one end of the first support member, the other end of the second support member is hinged to the second legrest connecting member at a fourth hinge point, the fourth hinge point is located between the first hinge point and the third hinge point, and the first hinge point is located in front of the fifth hinge point;

[0013] The seat frame unit further includes a first connecting member, a second connecting member, a third connecting member, a fourth connecting member, a fifth connecting member and a sixth connecting member;

[0014] One end of the first connecting member is hinged to the seat frame support member, the middle part of the first connecting member is hinged to one end of the third connecting member, the other end of the first connecting member is hinged to one end of the second connecting member, the other end of the second connecting member is hinged to the front end of the base; the other end of the third connecting member is hinged to the backrest unit;

[0015] One end of the fourth connecting member is hinged to the middle of the third supporting member, and the other end of the fourth connecting member is hinged to one end of the sixth connecting member; the middle of the sixth connecting member is hinged to the seat frame supporting member, the other end of the sixth connecting member is hinged to one end of the fifth connecting member, and the other end of the fifth connecting member is hinged to the middle of the second connecting member;

[0016] The first connecting member is provided with a first limiting member, the seat frame supporting member is provided with a second limiting member for limiting the folding of the extending assembly, and a third limiting member for limiting the extension of the extending assembly, the second limiting member and the third limiting member are located on both sides of the first connecting member;

[0017] When the extension assembly is in a lying state, the third limiting member abuts against the first connecting member;

[0018] When the extension assembly is in a sitting position, the second limiting member abuts against the first connecting member, and the first limiting member is sandwiched between the seat frame supporting member and the third supporting member;

[0019] The second legrest connecting member is provided with a fourth limiting member for limiting the upper end surface of the first legrest connecting member.

[0020] As a preferred technical solution of the sofa seat stretching device, the backrest unit includes a first backrest connector, a second backrest connector, a third backrest connector and a fourth backrest connector;

[0021] One end of the lower portion of the first backrest connector is hinged to one end of the second backrest connector, and the other end of the lower portion of the first backrest connector is hinged to the seat frame support; one end portion of the third backrest connector is hinged to the other end of the second backrest connector, the middle portion of the third backrest connector is hinged to one end of the third connector, the other end portion of the third backrest connector is hinged to one end of the fourth backrest connector at a tenth hinge point, the third backrest connector is hinged to the seat frame support, and the other end of the fourth backrest connector is hinged to the rear end of the base.

[0022] As a preferred technical solution of the above-mentioned sofa seat extension device, the third backrest connecting member is connected to the seat frame support member through a backrest spring. When the extension component is in a sitting state and a TV state, the telescopic length of the backrest spring is a1. When the extension component is in a lying state, the telescopic length of the backrest spring is a2. The ratio of a1 to a2 is in the range of 0.7 to 0.9.

[0023] As a preferred technical solution of the above-mentioned sofa seat extension device, the seat frame support member includes a first seat frame member connected to the leg extension unit at one end and a second seat frame member connected to the backrest unit at one end, the other end of the first seat frame member and the other end of the second seat frame member are connected to form a "√"-shaped seat frame support member; one end of the backrest spring is connected to the third backrest connecting member, and the other end is connected to the middle position of the second seat frame member.

[0024] As a preferred technical solution of the sofa seat stretching device, the angle between the side of the third support member facing the base when the stretching assembly is in a sitting state and the rear side of the third support member when the stretching assembly is in a zero gravity state is A;

[0025] The tenth hinge point is always located below the middle of the second seat frame member, so that 100°<A<110°.

[0026] As a preferred technical solution of the sofa seat extension device, a seat frame mounting member is respectively provided on the outer side of the first seat frame member and the outer side of the second seat frame member;

[0027] The included angles between the lower sides of the two seat frame mounting members on the same seat frame supporting member and the base are B1 and B2 respectively. When the extension assembly is in a lying state, B1 and B2 are both 13° to 23°.

[0028] As a preferred technical solution of the sofa seat stretching device, the sixth connecting member is provided with a fifth limiting member for limiting the movement of the third connecting member and the third backrest connecting member;

[0029] When the extending assembly is in a sitting position, the fifth limiting member abuts against an upper side surface of the third connecting member and an upper side surface of the third backrest connecting member.

[0030] As a preferred technical solution of the sofa seat extension device, the second limiting member and the third limiting member are both configured as V-shaped limiting protrusions integrally formed with the seat frame support member;

[0031] The fourth limiting member, the first limiting member and the fifth limiting member are all configured as columnar structures.

[0032] As a preferred technical solution of the sofa seat extension device, the driving assembly includes:

[0033] A guide rail, wherein a slider is provided on the guide rail and connected thereto in a slidable manner along a front-rear direction, and the slider is connected to the third support members of the two seat frame units through a connecting unit;

[0034] A linear drive unit, wherein the output end of the linear drive unit is fixedly connected to the slider.

[0035] As a preferred technical solution of the sofa seat extension device, the first hinge point, the fourth hinge point, the fourth limiter and the third hinge point are sequentially distributed along the extension direction of the second legrest connector.

[0036] Beneficial effects of the present invention: Compared with the prior art in which an end of the second support member away from the first support member is hinged to the middle part of the third support member, the sofa seat extension device provided by the present invention hinges an end of the second support member away from the first support member and the second legrest connecting member at a fourth hinge point, so that when the driving component moves in the same manner, the extension speed of the extension component is reduced during the process of switching from a sitting state to a lying state, which can effectively avoid the feeling of weightlessness; and the driving component drives the extension component to move so that the process of switching the extension component from a lying state to a sitting state is smoother.

[0037] When the extension assembly is in different states, the fourth limiting member can serve as a limiting member for the first legrest connecting member, thereby improving the stability of the extension assembly when it is in different states.

[0038] When the extension component is in a sitting state, the first limit member is stuck between the seat frame support member and the third support member, and the second limit member is set as a seat safety limit, restricting the extension component from continuing to move toward the side where the backrest unit is located, so that the extension component can be stably maintained in a sitting state when the driving component stops moving.

[0039] When the extending component is in the lying state, the third limiting member is clamped on the lower side of the first connecting member, playing the role of supporting and limiting the first connecting member, so that the extending component is stably maintained in the lying state. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0041] Figure 1 The schematic diagram of the partial structure of the sofa seat stretching device provided by the embodiment of the present invention with the stretching part in the TV posture Figure 1 ;

[0042] Figure 2 The schematic diagram of the partial structure of the sofa seat stretching device provided by the embodiment of the present invention with the stretching part in the TV posture Figure 2 ;

[0043] Figure 3 The schematic diagram of the partial structure of the sofa seat stretching device provided by the embodiment of the present invention with the stretching component in a lying position is Figure 1 ;

[0044] Figure 4 The schematic diagram of the partial structure of the sofa seat stretching device provided by the embodiment of the present invention with the stretching part in a lying position Figure 2 ;

[0045] Figure 5 The schematic diagram of the partial structure of the sofa seat stretching device provided by the embodiment of the present invention with the stretching part in a lying position Figure 3 ;

[0046] Figure 6 The present invention Figure 5 A partial enlarged view of the G in the middle;

[0047] Figure 7 The schematic diagram of the partial structure of the sofa seat stretching device provided by the embodiment of the present invention with the stretching part in the sitting position Figure 1 ;

[0048] Figure 8The schematic diagram of the partial structure of the sofa seat stretching device provided by the embodiment of the present invention with the stretching part in the sitting position Figure 2 ;

[0049] Fig. 9 It is a position relationship diagram between the third support member when the extension assembly is in a sitting position and the third support member when the extension assembly is in a lying position provided by an embodiment of the present invention.

[0050] In the figure:

[0051] 1. Base;

[0052] 2. backrest unit; 21. first backrest connecting piece; 22. second backrest connecting piece; 23. third backrest connecting piece; 24. fourth backrest connecting piece;

[0053] 3. seat frame unit; 30. sixth connecting member; 31. seat frame support member; 311. first seat frame member; 312. second seat frame member; 32. first support member; 33. second support member; 34. third support member; 35. first connecting member; 36. second connecting member; 37. third connecting member; 38. fourth connecting member; 39. fifth connecting member;

[0054] 4. Leg extension unit; 41. First legrest connecting piece; 42. Second legrest connecting piece; 43. Third legrest connecting piece; 44. Legrest frame;

[0055] 50, tenth hinge point; 51, first hinge point; 52, second hinge point; 53, third hinge point; 54, fourth hinge point; 55, fifth hinge point; 56, sixth hinge point; 57, seventh hinge point; 58, eighth hinge point; 59, ninth hinge point;

[0056] 61. first fixing rod; 62. second fixing rod; 63. third fixing rod;

[0057] 71. Linear drive unit; 72. Guide rail; 73. Sliding block; 74. Driving connecting member; 75. Driving connecting rod; 76. First connecting rod; 77. Second connecting rod;

[0058] 8. Seat frame mounting parts;

[0059] 91, first limiting member; 92, second limiting member; 93, third limiting member; 94, fourth limiting member; 95, fifth limiting member;

[0060] 100. Backrest spring. DETAILED DESCRIPTION

[0061] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the present invention are further described below in conjunction with the accompanying drawings and through specific implementation methods. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings, not all.

[0062] like Figures 1 to 9 As shown, this embodiment provides a sofa seat extension device, including a base 1 and a driving component and an extension component arranged on the base 1, the extension component includes a base 1 in the width direction ( Figure 2 The backrest unit 2, the seat frame unit 3 and the leg extension unit 4 are symmetrically arranged on both sides (in the W direction shown in FIG), and the front and rear ends of the seat frame unit 3 are respectively hinged to one end of the backrest unit 2 and the leg extension unit 4. The front and rear ends of the seat frame unit 3 refer to the seat frame unit 3 located at Figure 2 The two ends of the L direction are shown in the figure, 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 backrest unit 2 is located. Figure 2 The H direction shown in is the height direction.

[0063] The driving assembly connects the two seat frame units 3 via a connecting unit, so that the two extension assemblies can be synchronously extended or retracted along the front-back direction so that the extension assemblies can switch between a sitting position, a TV position and a lying position.

[0064] The structure of the base 1 will be specifically introduced below.

[0065] The base 1 includes two front and rear connecting members and two left and right connecting members, which are connected to form a rectangular frame by fasteners such as bolts, etc. The base 1 serves as a support member for supporting the structural members 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.

[0066] Next, the structure of the leg extension unit 4 will be introduced.

[0067] The leg extension unit 4 includes a first legrest connector 41, a second legrest connector 42, a third legrest connector 43 and a legrest frame 44, wherein one end of the first legrest connector 41 is hinged to the seat frame unit 3, one end of the second legrest connector 42 is hinged to the front end of the seat frame unit 3 at a first hinge point 51, the other end of the second legrest connector 42 and one end of the third legrest connector 43 are hinged to the second hinge point 52, the other end of the first legrest connector 41 and the other end of the third legrest connector 43 are hinged to the legrest frame 44 respectively, the first legrest connector 41 is parallel to the third legrest connector 43, and the middle part of the first legrest connector 41 and the middle part of the second legrest connector 42 are hinged to the third hinge point 53. The second legrest connecting member 42 is provided with a fourth limiting member 94 for limiting the upper end surface of the first legrest 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 distributed in sequence along the extension direction of the second legrest connecting member 42 .

[0068] Next, the structure of the seat frame unit 3 will be described.

[0069] 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. The axial ends of the driving connecting rod 75 pass through the corresponding seat frame unit 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 support 32 is hinged to one end of the second support 33, and the other end of the second support 33 is hinged to the middle of the second legrest connecting member 42 at the fourth hinge point 54. The end of the second legrest connecting member 42 away from the third legrest connecting member 43 is hinged to the seat frame support 31 at the first hinge point 51, and the fourth hinge point 54 is located between the first hinge point 51 and the fourth limiter 94. One end of the third support 34 is hinged to one end of the first legrest connecting member 41, and the other end of the third support 34 is hinged to the seat frame support 31 at the fifth hinge point 55.

[0070] The seat frame unit 3 further includes a first connecting member 35, a second connecting member 36, a third connecting member 37, a fourth connecting member 38, a fifth connecting member 39 and a sixth connecting member 30, wherein one end of the first connecting member 35 is hinged to the seat frame support member 31 at a sixth hinge point 56, the middle of the first connecting member 35 is hinged to one end of the third connecting member 37, the other end of the first connecting member 35 is hinged to one end of the second connecting member 36, the other end of the second connecting member 36 is hinged to the front end of the left and right connecting members; the other end of the third connecting member 37 is hinged to the backrest unit 2. One end of the fourth connecting member 38 is hinged to the middle of the third support member 34, and 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 seat frame support member 31 at a seventh hinge point 57, 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.

[0071] Next, the structure of the backrest unit 2 will be described in detail.

[0072] The backrest unit 2 includes a first backrest connector 21, a second backrest connector 22, a third backrest connector 23 and a fourth backrest connector 24, wherein one end of the lower portion of the first backrest connector 21 is hinged to one end of the second backrest connector 22, the other end of the lower portion of the first backrest connector 21 is hinged to the seat frame support 31 at an eighth hinge point 58, the third backrest connector 23 is roughly V-shaped, one end of the third backrest connector 23 is hinged to the other end of the second backrest connector 22, the middle portion of the third backrest connector 23 is hinged to the third connector 37 One end is hinged, the other end of the third backrest connector 23 and one end of the fourth backrest connector 24 are hinged at the tenth hinge point 50, the third backrest connector 23 and the seat frame support 31 are hinged at the ninth hinge point 59, the ninth hinge point 59 is located between the other end and the middle of the third backrest connector 23, the other end of the fourth backrest connector 24 is hinged to the rear ends of the left and right connectors, and a backrest spring 100 is connected near the hinge point between the third backrest connector 23 and the second backrest connector 22, and the other end of the backrest spring 100 is connected to the seat frame support 31.

[0073] In this embodiment, the seat frame support member 31 includes a first seat frame member 311 and a second seat frame member 312. The lower end of the first seat frame member 311 and the lower end of the second seat frame member 312 are connected to form a "√"-shaped seat frame support 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 are sequentially distributed along the direction from the first seat frame member 311 to the second seat frame member 312. The eighth hinge point 58 is located at the free end of the second seat frame member 312. The ninth hinge point 59 is located at the connection position of the first seat frame member 311 and the second seat frame member 312, that is, at the turning position of the "√"-shaped structure. The other end of the backrest spring 100 is connected to the middle position of the second seat frame member 312.

[0074] Reference Fig. 9 As shown, the angle between the side of the third support member 34 facing the base 1 when the extension assembly is in a sitting state and the rear side of the third support member 34 when the extension assembly is in a lying state is A, and the tenth hinge point 50 is always located below the middle position of the second seat frame member 312 during the extension or folding process of the extension assembly, so that 100°<A<110°. Optionally, A can be 100°, 101°, 102°, 103°, 104°, 105°, 106°, 107°, 108°, 109° and 110°. Exemplarily, A=106°. By limiting the position of the tenth hinge point 50 and adjusting the size of A, the position of the tenth hinge point 50 is lowered, that is, the unfolding distance of the third backrest connecting member 23 and the fourth backrest connecting member 24 is shorter, the smoothness of the extension or folding of the extension assembly is improved, and when the extension assembly is in a lying state, the user lying on the sofa seat has a clear sense of zero gravity.

[0075] A first fixing rod 61 is arranged between the two second connecting members 36 on the left and right sides of the base 1 , a second fixing rod 62 is arranged between the two third backrest connecting members 23 on the left and right sides of the base 1 , and a third fixing rod 63 is arranged between the two fourth backrest connecting members 24 on the left and right sides of the base 1 .

[0076] The driving assembly includes a linear driving unit 71, a guide rail 72 and a connecting unit arranged on the base 1. For example, the linear driving unit 71 is a linear motor, a slider 73 is slidably arranged on the guide rail 72, the 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 member 74, the two ends of the driving connecting member 74 are respectively hinged with 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, and the second connecting rod 77 is fixedly connected to the slider 73, the two ends of the driving connecting rod 75 are respectively connected to the first supporting members 32 of the seat frame unit 3 on the left and right sides, and the slider 73 is driven by the linear driving unit 71 to move forward and backward along the guide rail 72 to drive the extension assembly to extend or retract. Specifically, the linear driving unit 71 is a linear motor, the fixed end of the linear driving unit 71 is installed on the front and rear connecting members, the guide rail 72 is located between the two left and right connecting members, the 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 arranged parallel to the left and right connecting members.

[0077] The seat frame support member 31 is provided with a third stopper 93 for limiting the extension of the extension assembly, specifically, the third stopper 93 is used to limit the movement position of the first connection member 35. The seat frame support member 31 is also provided with a second stopper 92 for limiting the retraction of the extension assembly, specifically, the second stopper 92 is used to limit the movement of the first connection member 35, and the sixth hinge point 56 is located between the second stopper 92 and the third stopper 93. In this embodiment, the seventh hinge point 57 is located between the ninth hinge point 59 and the third stopper 93.

[0078] In this embodiment, the seat frame support 31, the third support member 34, the fourth connecting member 38 and the sixth connecting member 30 form a four-bar linkage; the second seat frame member 312, the second backrest connecting member 22, the third backrest connecting member 23 and the first backrest connecting member 21 form a four-bar linkage; the seat frame support 31, the third support member 34, the second legrest connecting member 42, the first legrest connecting member 41 form a four-bar linkage.

[0079] The linear drive unit 71 drives the slider 73 to slide forward and backward on the guide rail 72. The slider 73 drives the driving connecting rod 75 to move back and forth through the driving connecting member 74, the first connecting rod 76 and the second connecting rod 77. The driving connecting rod 75 then drives the seat frame support members 31 and the first supporting member 32 on the left and right sides to move synchronously. The seat frame support members 31 and the first supporting member 32 drive the extension assembly to extend or retract. When the extension assembly is extended, the extension assembly changes from a sitting position to a TV position and then to a lying position in sequence; when the extension assembly is retracted, the extension assembly changes from a lying position to a TV position and then to a sitting position in sequence. A first limiting member 91 is provided on the first connecting member 35 for limiting the movement of the third supporting member 34. When the extension assembly is in the sitting position, the slider 73 moves to the side of the backrest unit 2, the first limiter 91 is clamped on the lower side of the seat frame support member 31 and the upper side of the third support member 34, and the second limiter 92 is a safety limiter, thereby limiting the extension assembly from continuing to move toward the side of the backrest unit 2. At this time, the linear drive unit 71 stops working and maintains a stable sitting position. The sixth connecting member 30 is provided with a fifth limiter 95, which is used to limit the movement of the third connecting member 37 and the third backrest connecting member 23. When the extension assembly is in the sitting position, the fifth limiter 95 abuts against the upper side of the third connecting member 37 and the upper side of the third backrest connecting member 23.

[0080] When the extension assembly is unfolded, the linear drive unit 71 drives the slider 73 to move toward the leg extension unit 4, and the slider 73 drives the driving connecting rod 75 to move back and forth through the driving connecting member 74, the first connecting rod 76 and the second connecting rod 77, and the driving connecting rod 75 drives the first support member 32, and the first support member 32 drives the second support member 33, and the second support member 33 pushes the second legrest board connector 42 to extend toward the front end of the seat frame unit 3, and the second legrest board connector 42 simultaneously pushes the first legrest board connector 41 and the third legrest board connector 43 until the leg extension unit 4 is fully unfolded, completing the conversion from the sitting posture to the TV posture. The unfolding of the leg extension unit 4 only requires one force transmission through the second legrest board connector 42, and the loss during the transmission process is extremely small, so that the extension assembly runs smoothly and saves energy.

[0081] When the extension assembly needs to continue to extend, the linear drive unit 71 drives the slider 73 to move toward the leg extension unit 4. At this time, the limiting effect of the first limit member 91 on the third support member 34 fails. When the extension assembly is extended to the TV posture state, the first limit member 91 is located on the lower side of the seat frame support member 31, and the second limit member 92 is a safety limit. At this time, the first limit member 91 and the second limit member 92 work together to make the support member 31 and the first connecting member 35 in a relatively static and stable state to prevent the seat frame unit 3 from collapsing. Under the action of the connecting rod 75, the first fixing rod 61, the second fixing rod 62 and the third fixing rod 63 and the first stopper 91 and the second stopper 92, the stretching assembly can maintain the TV posture state; when the linear drive unit 71 continues to drive the slider 73 to move toward the leg stretching unit 4, the first connecting member 35 moves downward, breaking away from the stopper of the second stopper 92, and moves to the position of contacting the third stopper 93, and the third stopper 93 is completely stuck on the lower side of the first connecting member 35, at this time, a stable lying posture is achieved. When the stretching assembly is folded, it can move in the opposite direction in sequence.

[0082] The first limiting member 91 is configured as a columnar structure, which can adapt to forces at different angles and play a role in stabilizing the limiting position when limiting the seat frame support member 31 and the third support member 34 at the same time. The fourth limiting member 94 is configured as a columnar structure, which is convenient for limiting the position of the seat frame support member 31 and the third support member 34 at different angles. The fifth limiting member 95 is configured as a columnar structure, which is convenient for limiting the position of the third connecting member 37 and the third backrest connecting member 23 at the same time.

[0083] The second limiting member 92 and the third limiting member 93 both adopt V-shaped limiting protrusions integrally formed with the seat frame support member 31, and their side surfaces are flat and can adapt to the edge of the first connecting member 35, making the limiting more stable and less prone to shaking and deformation.

[0084] Compared with the prior art in which the end of the second support member 33 away from the first support member 32 is hinged to the middle part of the third support member 34, in this embodiment, the end of the second support member 33 away from the first support member 32 is hinged to the second legrest connecting member 42 at the fourth hinge point 54, so that when the slider 73 moves the same distance, the extension speed of the extension component is reduced during the process of switching from the sitting state to the lying state, which can effectively avoid the feeling of weightlessness; and the driving component drives the extension component to move to make the process of switching the extension component from the lying state to the sitting state smoother.

[0085] When the extension component is in the sitting state and the TV state, the telescopic length of the back spring 100 is a1, and when the extension component is in the lying state, the telescopic length of the back spring 100 is a2, and the ratio of a1 to a2 is in the range of 0.7 to 0.9. In this embodiment, a back spring 100 is provided in the extension component, a1:a2=0.84, in the sitting state, the length of the back spring 100 is 105.22mm, when the extension component is extended, the leg extension unit 4 is extended first, and the back unit 2 is rotated; when the extension component is extended to the lying state, the back spring 100 is stretched to the longest, and the length is 125.02mm at this time; when the extension component is folded, the back unit 2 is rotated back first, and the leg extension unit 4 is folded. During the folding process, the contraction force of the back spring 100 makes the folding process natural and smooth, and the folding is easier.

[0086] Furthermore, two seat frame mounting members 8 are provided on the outer side of the seat frame support member 31 for mounting a seat cushion. In this embodiment, a seat frame mounting member 8 is provided on the outer side of the first seat frame member 311 and the outer side of the second seat frame member 312, respectively. The included angles between the lower side surfaces of the two seat frame mounting members 8 of the same seat frame support member 31 and the base 1 are B1 and B2 respectively. Figure 4 As shown, when the extension component is in a lying position, the values ​​of B1 and B2 are both 13° to 23°; this conforms to the ergonomic structure, thereby making the lying position flatter and achieving a zero-gravity posture for the human body, which is more comfortable.

[0087] Obviously, the above 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. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

[0088] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0089] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. A sofa seat stretching device, comprising a base (1) and arranged on the base (1): An extension component, the extension component comprising a backrest unit (2), a seat frame unit (3) and a leg extension unit (4) which are symmetrically arranged at both ends of the base (1) in the width direction, and the front and rear ends of the seat frame unit (3) are respectively hinged to one end of the backrest unit (2) and the leg extension unit (4); A driving assembly, the driving assembly comprising a linear driving unit (71), the linear driving unit (71) being a linear motor, used for driving the two extension assemblies to synchronously extend or retract along the front-back direction so that the extension assemblies can switch between a sitting position, a TV position and a lying position; It is characterized in that The leg extension unit (4) comprises a first legrest connecting member (41) and a second legrest connecting member (42), wherein the middle portion of the first legrest connecting member (41) and the middle portion of the second legrest connecting member (42) are hinged at a third hinge point (53); The seat frame unit (3) comprises a seat frame support member (31) hinged to one end of the second legrest connecting member (42) at a first hinge point (51), a first support member (32) rotatable relative to the seat frame support member (31), a second support member (33), and a third support member (34) hinged to one end of the seat frame support member (31) at a fifth hinge point (55); the other end of the third support member (34) is hinged to the first legrest connecting member (41), one end of the second support member (33) is hinged to one end of the first support member (32), and the other end of the second support member (33) is hinged to the second legrest connecting member (42) at a fourth hinge point (54), the fourth hinge point (54) is located between the first hinge point (51) and the third hinge point (53), and the first hinge point (51) is located in front of the fifth hinge point (55); The seat frame unit (3) further comprises a first connecting member (35), a second connecting member (36), a third connecting member (37), a fourth connecting member (38), a fifth connecting member (39) and a sixth connecting member (30); One end of the first connecting member (35) is hinged to the seat frame support member (31), the middle part of the first connecting member (35) is hinged to one end of the third connecting member (37), the other end of the first connecting member (35) is hinged to one end of the second connecting member (36), the other end of the second connecting member (36) is hinged to the front end of the base (1); the other end of the third connecting member (37) is hinged to the backrest unit (2); One end of the fourth connecting member (38) is hinged to the middle of the third supporting member (34), and the other end of the fourth connecting member (38) is hinged to one end of the sixth connecting member (30); the middle of the sixth connecting member (30) is hinged to 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); The first connecting member (35) is provided with a first limiting member (91) for limiting the movement of the third supporting member (34); the seat frame supporting member (31) is provided with a second limiting member (92) for limiting the folding of the extending member, and a third limiting member (93) for limiting the extension of the extending member; the second limiting member (92) and the third limiting member (93) are located on both sides of the first connecting member (35); When the extension assembly is in a lying state, the third limiting member (93) abuts against the first connecting member (35); When the extension assembly is in a sitting position, the second limiting member (92) abuts against the first connecting member (35), and the first limiting member (91) is sandwiched between the seat frame supporting member (31) and the third supporting member (34); The second legrest connecting member (42) is provided with a fourth limiting member (94) for limiting the upper end surface of the first legrest connecting member (41).

2. The sofa seat stretching device according to claim 1, characterized in that: The backrest unit (2) comprises 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); 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), and the other end of the lower portion of the first backrest connecting member (21) is hinged to the seat frame support member (31); 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 one end of the fourth backrest connecting member (24) at a tenth hinge point (50), the third backrest connecting member (23) is hinged to the seat frame support member (31), and the other end of the fourth backrest connecting member (24) is hinged to the rear end of the base (1).

3. The sofa seat stretching device according to claim 2, characterized in that: The third backrest connecting member (23) is connected to the seat frame supporting member (31) via a backrest spring (100); when the extension component is in a sitting position and a TV position, the telescopic length of the backrest spring (100) is a1; when the extension component is in a lying position, the telescopic length of the backrest spring (100) is a2; and the ratio of a1 to a2 is in the range of 0.7 to 0.

9.

4. The sofa seat stretching device according to claim 3, characterized in that: The seat frame support member (31) comprises a first seat frame member (311) having one end connected to the leg extension 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 a "√"-shaped seat frame support member (31); 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 stretching device according to claim 4, characterized in that: The angle between the side surface of the third support member (34) facing the base (1) when the extension member is in a sitting position and the rear side surface of the third support member (34) when the extension member is in a lying position is A; The tenth hinge point (50) is always located below the middle of the second seat frame member (312), so that 100°<A<110°.

6. The sofa seat stretching device according to claim 4, characterized in that: A seat frame mounting member (8) is respectively disposed on 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 sides of the two seat frame mounting members (8) on the same seat frame support member (31) and the base (1) are B1 and B2 respectively. When the extension assembly is in a lying state, B1 and B2 are both 13° to 23°.

7. The sofa seat stretching device according to claim 2, characterized in that: 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); When the extension assembly is in a sitting position, 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).

8. The sofa seat stretching device according to claim 7, characterized in that: The second limiting member (92) and the third limiting member (93) are both configured as V-shaped limiting protrusions integrally formed with the seat frame support member (31); The fourth limiting member (94), the first limiting member (91) and the fifth limiting member (95) are all configured as columnar structures.

9. The sofa seat stretching device according to any one of claims 1 to 8, characterized in that: The driving assembly comprises: A guide rail (72), wherein the guide rail (72) is provided with a slider (73) slidably connected thereto in a front-rear direction, and the slider (73) is connected to the third support members (34) of the two seat frame units (3) via a connecting unit; The output end of the linear drive unit (71) is fixedly connected to the slider (73).

10. The sofa seat stretching device according to any one of claims 1 to 8, characterized in that: The first hinge point (51), the fourth hinge point (54), the fourth limiter (94) and the third hinge point (53) are sequentially distributed along the extension direction of the second legrest connecting member (42).

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