Extension device for sofa frame, sofa frame and sofa

Abstract

The utility model belongs to the technical field of sofas, and particularly relates to a stretching device for a sofa frame, the sofa frame and a sofa. The seat frames are arranged on the two sides of the bottom frame, each seat frame is hinged to the bottom frame through a front supporting connecting rod and a rear supporting connecting rod, and the front end of each seat frame is hinged to a leg mechanism; the driving mechanism is suitable for driving the sofa frame to be at least switched between the sitting posture position and the lying posture position and comprises a front driving connecting rod, a rear driving connecting rod and an electric push rod, the two ends of the front driving connecting rod are connected with the corresponding leg mechanisms respectively, and the two ends of the rear driving connecting rod are connected with the corresponding rear supporting connecting rods respectively; according to the stretching device for the sofa frame, the sofa frame and the sofa, the electric push rod is adopted as a driving source, and the electric push rod is directly connected with the first rotating rod of the leg mechanism through the front driving connecting rod, so that the electric push rod obtains larger torque to push the first rotating rod to rotate so as to open the leg mechanism.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of sofa, concretely relates to a deck chair including a leg rest or a foot rest, and particularly relates to a stretching device for a sofa frame, a sofa frame and a sofa. BACKGROUND

[0002] At present, in order to improve the comfort, the posture of the sofa is designed to be adjustable, that is, a sofa frame is arranged in the sofa, so that the sofa frame is transformed between the sitting position and the lying position.

[0003] The sofa frame generally comprises at least a bottom frame, a seat frame, a leg mechanism and a driving mechanism, the length of the seat frame determines the seat depth of the sofa frame, when the seat depth needs to be lengthened, the driving position of the leg mechanism on the seat frame is farther away from the mounting position of the driving mechanism, so that the driving mechanism needs stronger driving force to push the leg mechanism to open.

[0004] In the related art, a sliding block push rod is generally used as a driving source, but in the case of such long-distance driving, the support force of the sliding block push rod on the leg mechanism is not enough, so that the leg mechanism is prone to retraction when stressed.

[0005] Therefore, how to solve the technical problem of low support force of the existing sliding block push rod on the leg mechanism in the sofa frame with lengthened seat depth is an urgent problem for those skilled in the art.

[0006] It should be noted that the above information disclosed in the background section is only used to understand the background of the present application, and therefore, the above description is not considered as information of the prior art. CONTENT OF THE UTILITY MODEL

[0007] The present disclosure provides at least a stretching device for a sofa frame, a sofa frame and a sofa.

[0008] In a first aspect, the embodiments of the present disclosure provide a stretching device for a sofa frame, comprising: a bottom frame; a pair of seat frames arranged on both sides of the bottom frame, each of the seat frames being hinged to the bottom frame through a front support link and a rear support link, and each of the seat frames being hinged at a front end portion to a leg mechanism; and a driving mechanism configured to drive the sofa frame to change between at least a sitting position and a lying position, and comprising: a front driving link, a rear driving link, and an electric push rod, two ends of the front driving link being connected to corresponding leg mechanisms respectively, two ends of the rear driving link being connected to corresponding rear support links respectively, and two ends of the electric push rod being connected to the front driving link and the rear driving link respectively; wherein in the sitting position, an included angle β between the electric push rod and the bottom frame ranges from 8° to 25°; and / or in the sitting position, a length H1 of the sofa frame ranges from 615 mm to 900 mm; and / or in the sitting position, a height H2 between a hinge point P of the electric push rod and the front driving link and a lower surface of the bottom frame ranges from 190 mm to 265 mm.

[0009] In an optional embodiment, a first rotating rod of the leg mechanism is hinged at a hinge point A to the front end portion of the seat frame, and the front driving link is connected at a connection point B to the first rotating rod; in the sitting position, a straight line L1 passing through the hinge point A and the connection point B forms an included angle α with a straight line L2 passing through the electric push rod, and the included angle α ranges from 70° to 110°.

[0010] In an optional embodiment, the leg mechanism further comprises: a second rotating rod hinged at a hinge point C to the front end portion of the seat frame; wherein the hinge point A is located in front of the hinge point C.

[0011] In an optional embodiment, the leg mechanism further comprises: a third leg link, a fourth leg link, and a footrest; wherein one end of the third leg link is hinged at a hinge point G to the first rotating rod, and the other end of the third leg link is hinged to the footrest; one end of the fourth leg link is hinged at a hinge point D to the second rotating rod, and the other end of the fourth leg link is hinged at a hinge point E to the footrest; wherein in the TV position and the lying position, the first rotating rod is located above the second rotating rod.

[0012] In an optional embodiment, a limiting column is arranged on the first rotating rod; wherein in the TV position and the lying position, the limiting column abuts against the fourth leg link at a limiting point F; a ratio of a distance L3 between the limiting point F and the hinge point D to a distance L4 between the hinge point D and the hinge point E is located between 1 / 7 and 1 / 5; and in the sitting position, the straight line L1 passing through the hinge point A and the connection point B forms the included angle α with the straight line L2 passing through the electric push rod, and the included angle α ranges from 70° to 85°.

[0013] In an alternative embodiment, a limiting post is arranged on the first rotating rod; wherein the ratio of the distance L5 between the hinge point G and the limiting post and the distance L6 between the hinge point G and the hinge point A is between 1 / 3 and 1 / 2; and in the sitting position, the angle a between the straight line L1 where the hinge point A and the connecting point B are located and the straight line L2 where the electric push rod is located ranges from 70 to 98 degrees.

[0014] In an alternative embodiment, a limiting post is arranged on the first rotating rod; wherein the ratio of the distance L5 between the hinge point G and the limiting post and the distance L6 between the hinge point G and the hinge point A is between 1 / 3 and 1 / 2; and in the sitting position, the angle a between the straight line L1 where the hinge point A and the connecting point B are located and the straight line L2 where the electric push rod is located ranges from 70 to 98 degrees.

[0015] In a second aspect, the embodiments of the present disclosure further provide a stretching device for a sofa frame, comprising: a bottom frame; a pair of seat frames arranged on both sides of the bottom frame, each of the seat frames being hinged to the bottom frame through a front support connecting rod and a rear support connecting rod, and the front end of each of the seat frames being hinged with a leg mechanism; and a driving mechanism adapted to drive the sofa frame to change between at least a sitting position and a lying position, and comprising: a front driving connecting rod, a rear driving connecting rod and an electric push rod, both ends of the front driving connecting rod being connected with corresponding leg mechanisms, both ends of the rear driving connecting rod being connected with corresponding rear support connecting rods, and both ends of the electric push rod being connected with the front driving connecting rod and the rear driving connecting rod; wherein the first rotating rod of the leg mechanism is hinged to the front end of the seat frame at a hinge point A, the first rotating rod of the leg mechanism is hinged to the third leg connecting rod of the leg mechanism at a hinge point G, and the front driving connecting rod is connected with the first rotating rod at a connecting point B; the ratio of the distance L7 between the connecting point B and the hinge point A and the distance L6 between the hinge point G and the hinge point A is between 1 / 3 and 1 / 2.

[0016] In an alternative embodiment, a limiting post is arranged on the first rotating rod; wherein the ratio of the distance L5 between the hinge point G and the limiting post and the distance L6 between the hinge point G and the hinge point A is between 1 / 3 and 1 / 2.

[0017] In an alternative embodiment, the front driving connecting rod is connected with the first rotating rod at the connecting point B; in the sitting position, the length H1 of the sofa frame ranges from 615 mm to 900 mm; and in the sitting position, the angle a between the straight line L1 where the hinge point A and the connecting point B are located and the straight line L2 where the electric push rod is located ranges from 70 to 110 degrees.

[0018] In an alternative embodiment, the leg mechanism further comprises: a second rotating rod, which is hinged with the front end of the seat frame at a hinge point C; wherein the hinge point A is away from the rear support connecting rod relative to the hinge point C; in the TV position and the lying position, the first rotating rod is above the second rotating rod; the included angle a is 85° or 98° or 105°.

[0019] In a third aspect, the embodiments of the present disclosure further provide a sofa frame, which comprises the sofa frame stretching device as described above.

[0020] In a fourth aspect, the embodiments of the present disclosure further provide a sofa, which comprises the sofa frame as described above.

[0021] The sofa frame stretching device, the sofa frame and the sofa of the present application have the following beneficial effects: the electric push rod is used as the driving source, and the electric push rod is directly connected with the first rotating rod of the leg mechanism through the front driving connecting rod, so that the included angle β between the electric push rod and the bottom frame is in the range of 8°-25° in the sitting position, thereby a greater torque can be obtained to drive the first rotating rod to rotate to open the leg mechanism, and the leg mechanism can obtain more stable supporting force.

[0022] Other features and advantages of the present application will be described in the following description, and some will become apparent from the description, or will be understood from the practice of the present application. The purpose and other advantages of the present application will be achieved and obtained by the structure specifically pointed out in the description and the drawings.

[0023] In order to make the above purpose, features and advantages of the present application more obvious and easy to understand, the preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0025] Figure 1 A structural schematic view of a sofa frame in a sitting position is provided for the embodiments of the present disclosure;

[0026] Figure 2 A side view structural schematic view of a sofa frame in a sitting position is provided for the embodiments of the present disclosure;

[0027] Figure 3This is a structural diagram of a sofa frame in the TV position according to an embodiment of the present disclosure;

[0028] Figure 4 This is a structural schematic diagram of a sofa frame in a reclining position, provided by an embodiment of the present disclosure;

[0029] Figure 5 This is a schematic diagram of the structure of a first rotating rod provided in an embodiment of this disclosure.

[0030] In the picture:

[0031] Bottom frame 1;

[0032] Seat frame 2, front support link 21, rear support link 22;

[0033] Leg mechanism 3, first rotating rod 31, limiting post 311, second rotating rod 32, third leg connecting rod 33, fourth leg connecting rod 34, footrest 35;

[0034] Drive mechanism 4, front drive linkage 41, rear drive linkage 42, electric push rod 43. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0036] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the figures, the thickness of parts may be exaggerated or reduced for the purpose of effectively depicting the technical content.

[0037] The following detailed description, with reference to the accompanying drawings, describes some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0038] like Figure 1 As shown, at least one embodiment provides an extension device for a sofa frame, comprising: a base frame 1; a pair of seat frames 2 disposed on both sides of the base frame 1, each seat frame 2 being hinged to the base frame 1 via a front support link 21 and a rear support link 22, and each seat frame 2 having a leg mechanism 3 hinged to its front end; and a drive mechanism 4 configured to drive the sofa frame to change at least between a sitting position and a reclining position.

[0039] In some embodiments, the driving mechanism 4 comprises a front driving link 41, a rear driving link 42 and an electric push rod 43, both ends of the front driving link 41 are connected with the corresponding leg mechanism 3 respectively, both ends of the rear driving link 42 are connected with the corresponding rear support link 22 respectively, both ends of the electric push rod 43 are connected with the front driving link 41 and the rear driving link 42 respectively.

[0040] As shown in the drawings, in some embodiments, in the sitting position, the length H1 of the sofa frame ranges from 615mm to 900mm. Figure 2

[0041] In the present embodiment, the length H1 of the sofa frame ranges from 615mm to 900mm; compared with the general sofa frame, the seat depth is longer, which can adapt to some people with higher height.

[0042] The inventor found that when the seat depth needs to be lengthened, the driving position of the leg mechanism 3 on the seat frame 2 is farther away from the mounting position of the driving mechanism 4, so that the driving mechanism 4 needs stronger driving force to push the leg mechanism 3 to open, but the driving mechanism 4 generally uses a sliding block push rod as the driving source, and in this case of super-long distance driving, the support force of the sliding block push rod on the leg mechanism 3 is not enough, so that the leg mechanism 3 is prone to retraction when stressed.

[0043] In order to solve the above problems, in some embodiments, an electric push rod 43 is used as the driving source, and the electric push rod 43 is directly connected with the first rotating rod 31 of the leg mechanism 3 through the front driving link 41.

[0044] In some embodiments, in the sitting position, the angle β between the straight line where the electric push rod 43 is located and the bottom frame 1 ranges from 8° to 25°; preferably, the angle β ranges from 15° to 20°; more preferably, the angle β is 17°.

[0045] In some embodiments, in the sitting position, the height H2 between the hinge point P of the electric push rod 43 and the lower surface of the bottom frame 1 ranges from 190mm to 265mm; preferably, the height H2 ranges from 210mm to 235mm.

[0046] In some embodiments, the first rotating rod 31 of the leg mechanism 3 is hinged with the front end of the seat frame 2 at the hinge point A, and the front driving link 41 is connected with the first rotating rod 31 at the connection point B.

[0047] In some embodiments, in the sitting position, the angle α between the straight line L1 where the hinge point A and the connection point B are located and the straight line L2 where the electric push rod 43 is located ranges from 70° to 110°, so as to obtain greater torque to push the first rotating rod 31 to rotate to open the leg mechanism 3; preferably, the angle α ranges from 85° to 95°; alternatively, the angle α is 85° or 98° or 105°.​

[0048] As shown in Figure 3 some embodiments, the leg mechanism 3 further comprises: a second rotating rod 32 hinged with the front end of the seat frame 2 at a hinge point C; wherein the hinge point A is located in front of the hinge point C.

[0049] In some embodiments, the leg mechanism 3 further comprises: a third leg link 33, a fourth leg link 34 and a footrest 35; wherein one end of the third leg link 33 is hinged with the first rotating rod 31 at a hinge point G, and the other end is hinged with the footrest 35; one end of the fourth leg link 34 is hinged with the second rotating rod 32 at a hinge point D, and the other end is hinged with the footrest 35 at a hinge point E; wherein in the TV position and the lying position, the first rotating rod 31 is located above the second rotating rod 32.

[0050] In the present embodiment, the front support link 21 is connected to the first rotating rod 31, and during the change of the sofa frame posture, the first rotating rod 31 is located above the second rotating rod 32, and in this state, the support force of the electric push rod 43 to the leg mechanism 3 is stronger.

[0051] As shown in Figure 4 some embodiments, a limiting column 311 is arranged on the first rotating rod 31; wherein in the TV position and the lying position, the limiting column 311 abuts against the fourth leg link 34 at a limiting point F; the ratio of the distance L3 between the limiting point F and the hinge point D to the distance L4 between the hinge point D and the hinge point E is between 1 / 7 and 1 / 5.

[0052] As shown in Figure 5 some embodiments, a limiting column 311 is arranged on the first rotating rod 31; wherein the ratio of the distance L5 between the hinge point G and the limiting column 311 to the distance L6 between the hinge point G and the hinge point A is between 1 / 3 and 1 / 2.

[0053] As shown in Figure 5 some embodiments, a limiting column 311 is arranged on the first rotating rod 31; wherein the ratio of the distance L7 between the connecting point B and the hinge point A to the distance L6 between the hinge point G and the hinge point A is between 1 / 3 and 1 / 2.

[0054] At least one of the embodiments also provides a sofa frame stretching device, which comprises a bottom frame 1, a pair of seat frames 2 arranged on both sides of the bottom frame 1, each seat frame 2 is hinged to the bottom frame 1 through a front support connecting rod 21 and a rear support connecting rod 22, and the front end of each seat frame 2 is hinged with a leg mechanism 3, and a driving mechanism 4 adapted to drive the sofa frame to change at least between a sitting position and a lying position, and comprising a front driving connecting rod 41, a rear driving connecting rod 42 and an electric push rod 43, both ends of the front driving connecting rod 41 are connected with the corresponding leg mechanism 3, both ends of the rear driving connecting rod 42 are connected with the corresponding rear support connecting rod 22, and both ends of the electric push rod 43 are connected with the front driving connecting rod 41 and the rear driving connecting rod 42; wherein the first rotating rod 31 of the leg mechanism 3 is hinged with the front end of the seat frame 2 at the hinge point A, the first rotating rod 31 of the leg mechanism 3 is hinged with the third leg connecting rod 33 of the leg mechanism 3 at the hinge point G, and the front driving connecting rod 41 is connected with the first rotating rod 31 at the connecting point B; the ratio of the distance L7 between the connecting point B and the hinge point A to the distance L6 between the hinge point G and the hinge point A is between 1 / 3 and 1 / 2.

[0055] In some embodiments, a limiting column 311 is arranged on the first rotating rod 31; wherein the ratio of the distance L5 between the hinge point G and the limiting column 311 to the distance L6 between the hinge point G and the hinge point A is between 1 / 3 and 1 / 2.

[0056] In some embodiments, the front driving connecting rod 41 is connected with the first rotating rod 31 at the connecting point B; in the sitting position, the included angle α between the straight line L1 where the hinge point A and the connecting point B are located and the straight line L2 where the electric push rod 43 is located ranges from 70° to 110°.

[0057] In some embodiments, the leg mechanism 3 further comprises a second rotating rod 32, which is hinged with the front end of the seat frame 2 at the hinge point C; wherein the hinge point A is away from the rear support connecting rod 22 relative to the hinge point C; in the TV position and the lying position, the first rotating rod 31 is above the second rotating rod 32.

[0058] At least one of the embodiments also provides a sofa frame, which comprises the sofa frame stretching device.

[0059] At least one of the embodiments also provides a sofa, which comprises the sofa frame.

[0060] In summary, the sofa frame stretching device, the sofa frame and the sofa adopt the electric push rod 43 as the driving source, and the electric push rod 43 is directly connected with the first rotating rod 31 of the leg mechanism 3 through the front driving connecting rod 41, so that in the sitting position, the included angle β between the electric push rod and the bottom frame ranges from 8° to 25°, thereby obtaining a larger torque to drive the first rotating rod 31 to rotate to open the leg mechanism 3.

[0061] In this document, when a first component is referred to as being "on" a second component, it can be directly on the second component or intervening components can be present. In contrast, when a first component is referred to as being "directly on" a second component, there are no intervening components present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0062] In this document, when an element or layer is referred to as being "on" another element or layer, it can be directly on the other element or layer, or intervening elements or layers can be present. In contrast, when an element is referred to as being "directly on" another element or layer, there are no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0063] In this document, example embodiments of the disclosure are described in more detail with reference to the accompanying drawings. As used herein, such as the expression "at least one of," when preceding a list of two or more items, modifies the entire list of items and does not modify the individual items of the list. For example, the expression "at least one of a, b, and c" should be understood as including only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0064] The terminology used herein is for the purpose of describing particular example configurations only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "includes," and "including" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order

[0065] As used herein, the phrases “in an embodiment,” “according to an embodiment,” “in some embodiments,” and the like generally mean the particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of the present disclosure. Thus, appearances of such phrases in various places in the specification do not necessarily all refer to the same embodiment. As used herein, the terms “example,” “for example,” and the like are utilized merely for the purpose of facilitating this description. Any embodiment, aspect, or design described herein as an “example” or “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments, aspects, or designs. Rather, the term “example” is intended to indicate a non-limiting example, and that other embodiments, aspects, or designs are possible.

[0066] In the description of the embodiments of the present application, unless specifically defined and limited otherwise, the terms “mounting”, “connected with”, “connection” should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, can be electrically connected; can be directly connected, can be indirectly connected through an intermediate medium, or can be internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0067] In the description of the present application, it should be explained that the terms “center”, “upper”, “lower”, “left”, “right”, “vertical”, “horizontal”, “inner”, “outer” and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, terms such as “first”, “second” and other numerical terms are used herein without implying a sequence or order unless the context clearly indicates otherwise. Therefore, the first element, component, region, layer or section discussed above can be referred to as the second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0068] Spatially relative terms, such as "inner," "outer," "beneath," "below," "lower," "above," "upper," and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms can be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0069] In the above discussion, unless otherwise stated, the terms "about," "approximately," "substantially" and the like mean a variation of + / - 10% when used to describe a numerical value.

[0070] With the above ideal embodiments according to the present application as the inspiration, through the above description, relevant personnel can certainly make various changes and modifications without deviating from the technical thought of the present application. The technical scope of the present application is not limited to the content in the specification, and must be determined according to the scope of claims.

Claims

1. A stretching device for a sofa frame, characterized in that The sofa frame stretching device comprises: a bottom frame (1); a pair of seat frames (2) arranged on both sides of the bottom frame (1), each of the seat frames (2) is hinged to the bottom frame (1) through a front support connecting rod (21) and a rear support connecting rod (22), and the front end of each of the seat frames (2) is hinged to a leg mechanism (3); and a driving mechanism (4) configured to drive the sofa frame to change at least between a sitting position and a lying position, and comprising a front driving connecting rod (41), a rear driving connecting rod (42) and an electric push rod (43), both ends of the front driving connecting rod (41) are connected to the corresponding leg mechanism (3), both ends of the rear driving connecting rod (42) are connected to the corresponding rear support connecting rod (22), and both ends of the electric push rod (43) are connected to the front driving connecting rod (41) and the rear driving connecting rod (42); wherein in the sitting position, the angle β between the electric push rod (43) and the bottom frame (1) ranges from 8° to 25°; and / or, in the sitting position, the length H1 of the sofa frame ranges from 615mm to 900mm; and / or, in the sitting position, the height H2 between the hinge point P of the electric push rod (43) and the front driving connecting rod (41) and the lower surface of the bottom frame (1) ranges from 190mm to 265mm.

2. The sofa frame stretching device according to claim 1, wherein the first rotating rod (31) of the leg mechanism (3) is hinged to the front end of the seat frame (2) at a hinge point A, and the front driving connecting rod (41) is connected to the first rotating rod (31) at a connection point B; in the sitting position, the angle α between the straight line L1 passing through the hinge point A and the connection point B and the straight line L2 passing through the electric push rod (43) ranges from 70° to 110°.

3. The sofa frame stretching device according to claim 2, wherein the leg mechanism (3) further comprises a second rotating rod (32) hinged to the front end of the seat frame (2) at a hinge point C; wherein the hinge point A is located in front of the hinge point C.

4. The sofa frame stretching device according to claim 3, wherein the leg mechanism (3) further comprises a third leg connecting rod (33), a fourth leg connecting rod (34) and a foot rest (35); wherein one end of the third leg connecting rod (33) is hinged to the first rotating rod (31) at a hinge point G, and the other end is hinged to the foot rest (35); one end of the fourth leg connecting rod (34) is hinged to the second rotating rod (32) at a hinge point D, and the other end is hinged to the foot rest (35) at a hinge point E; wherein, in the TV position and the lying position, the first rotating rod (31) is located above the second rotating rod (32).

5. The sofa frame stretching device according to claim 4, wherein a limiting column (311) is arranged on the first rotating rod (31); wherein in the TV position and the lying position, the limiting column (311) abuts against the fourth leg connecting rod (34) at a limiting point F. The ratio of the distance L3 between the limiting point F and the hinge point D and the distance L4 between the hinge point D and the hinge point E is between 1 / 7 and 1 / 5; and In the sitting position, the angle α between the straight line L1 where the hinge point A and the connecting point B are located and the straight line L2 where the electric push rod (43) is located is in the range of 70-85°.

6. The stretching device for sofa frame according to claim 4, characterized in that, A limiting column (311) is arranged on the first rotating rod (31); wherein The ratio of the distance L5 between the hinge point G and the limiting column (311) and the distance L6 between the hinge point G and the hinge point A is between 1 / 3 and 1 / 2; and In the sitting position, the angle α between the straight line L1 where the hinge point A and the connecting point B are located and the straight line L2 where the electric push rod (43) is located is in the range of 70-98°.

7. The stretching device for sofa frame according to claim 4, characterized in that, A limiting column (311) is arranged on the first rotating rod (31); wherein The ratio of the distance L7 between the connecting point B and the hinge point A and the distance L6 between the hinge point G and the hinge point A is between 1 / 3 and 1 / 2; and In the sitting position, the angle α between the straight line L1 where the hinge point A and the connecting point B are located and the straight line L2 where the electric push rod (43) is located is in the range of 82-105°. It comprises:

8. An extension device for a sofa frame, characterized in that a bottom frame (1); a pair of seat frames (2) arranged on both sides of the bottom frame (1), each of the seat frames (2) is hinged to the bottom frame (1) through a front support connecting rod (21) and a rear support connecting rod (22), and the front end of each of the seat frames (2) is hinged with a leg mechanism (3); and a driving mechanism (4) adapted to drive the sofa frame to change at least between the sitting position and the lying position, and comprising a front driving connecting rod (41), a rear driving connecting rod (42) and an electric push rod (43), both ends of the front driving connecting rod (41) are connected with the corresponding leg mechanism (3), both ends of the rear driving connecting rod (42) are connected with the corresponding rear support connecting rod (22), and both ends of the electric push rod (43) are connected with the front driving connecting rod (41) and the rear driving connecting rod (42); wherein the first rotating rod (31) of the leg mechanism (3) is hinged to the front end of the seat frame (2) at a hinge point A, the first rotating rod (31) of the leg mechanism (3) is hinged to the third leg connecting rod (33) of the leg mechanism (3) at a hinge point G, and the front driving connecting rod (41) is connected to the first rotating rod (31) at a connecting point B; The ratio of the distance L7 between the connecting point B and the hinge point A and the distance L6 between the hinge point G and the hinge point A is between 1 / 3 and 1 / 2.

9. The stretching device for sofa frame according to claim 8, characterized in that, A limiting column (311) is arranged on the first rotating rod (31); wherein The ratio of the distance L5 between the hinge point G and the limiting column (311) and the distance L6 between the hinge point G and the hinge point A is between 1 / 3 and 1 / 2. ​ 10. The stretching device for sofa frame according to claim 9, characterized in that, the length H1 of the sofa frame in the sitting position ranges from 615 mm to 900 mm; the front link (41) is connected to the first rotating rod (31) at a connection point B; in the sitting position, the included angle a between the straight line L1 passing through the hinge point A and the connection point B and the straight line L2 passing through the electric push rod (43) ranges from 70° to 110°.

11. The stretching device for sofa frame according to claim 10, characterized in that, the leg mechanism (3) further comprises a second rotating rod (32) hinged to the front end of the seat frame (2) at a hinge point C; wherein the hinge point A is away from the rear support link (22) relative to the hinge point C; in the TV position and the lying position, the first rotating rod (31) is above the second rotating rod (32); the included angle a is 85° or 98° or 105°.

12. A sofa frame, characterized by A sofa frame comprising the stretching device according to any one of claims 1-11.

13. A sofa, characterized in that A sofa frame comprising the stretching device according to claim 12.

Images