FOLDABLE SEAT FRAME

Abstract

A foldable seat frame includes a plurality of supporting bars and a plurality of crossing-bar pairs. Each crossing-bar pair is disposed between and pivotally connected to two adjacent supporting bars. Each crossing-bar pair includes first and second crossing bars pivotally coupled to each other at their middle portions. Each of the first and second crossing bars of one or more crossing-bar pairs includes a substantially flat surface for enhancing stability, enhancing ease of use and installation, improving durability, or reducing folded size of the foldable seat frame.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to Chinese Patent Application No. 202422945207.8 filed Nov. 29, 2024. Moreover, the present application is a continuation-in-part of U.S. patent application Ser. No. 18/184,487 filed Mar. 15, 2023, which claims priority to Chinese Patent Application No. 202220617720.2 filed on Mar. 16, 2022. Further, the present application is a continuation-in-part of U.S. patent application Ser. No. 29/880,833 filed Jul. 27, 2023, which claims priority to Chinese Patent Application No. 202330120459.5 filed Mar. 15, 2023 and is a continuation-in-part of U.S. patent application Ser. No. 18/184,487 filed Mar. 15, 2023, which claims priority to Chinese Patent Application No. 202220617720.2 filed on Mar. 16, 2022. The disclosure of each and every application is incorporated herein for all purposes by reference in its entirety.

FIELD OF THE INVENTION

The present invention generally relates to foldable seat frames and in particular to foldable seat frames with enhanced stability, enhanced ease of use and installation, improved durability, and/or reduced folded size.

BACKGROUND

Foldable chairs are widely used for their portability and space-saving advantages, making them ideal for various applications such as outdoor activities, event seating, and temporary seating arrangements. These chairs typically feature a foldable frame, allowing them to be easily stored and transported more easily than non-foldable alternatives.

However, existing foldable chair frames often present several challenges in terms of stability, usability, durability, and/or storage efficiency. One common issue is the complexity of installation. Another drawback is their susceptibility to twisting. Twisting can weaken the frame over time, leading to instability and reducing the overall service life of the frame and thus the chair. In addition, despite being foldable, many existing frames remain relatively bulky when folded, making them difficult to carry, transport, or store in limited spaces.

Given the current state of the art, there remains a need for foldable frames and foldable chairs that address the abovementioned issues.

The information disclosed in this Background section is provided for an understanding of the general background of the invention and is not an acknowledgement or suggestion that this information forms part of the prior art already known to a person skilled in the art.

SUMMARY OF THE INVENTION

The present disclosure provides foldable seat frames with enhanced stability, improved durability, enhanced ease of use, and/or reduced folded size.

In various exemplary embodiments, the present disclosure provides a foldable seat frame including a plurality of supporting bars, a plurality of lower connectors, a plurality of upper connectors, and a plurality of pairs of crossing bars. The plurality of supporting bars includes a pair of front supporting bars disposed at a front side of the foldable seat frame and a pair of rear supporting bars disposed at a rear side of the foldable seat frame when the foldable seat frame is unfolded. Each front supporting bar in the pair of front supporting bars has a first length adjustable between an expanded length and a contracted length. Each rear supporting bar in the pair of rear supporting bars has a second length equal to or greater than the first length. Each of the plurality of lower connectors is disposed at a lower end portion of a supporting bar in the plurality of supporting bars. Each of the plurality of upper connectors is disposed at a supporting bar in the plurality of supporting bars above the lower end portion thereof. The plurality of upper connectors includes a pair of front upper connectors each disposed at an upper end portion of a front supporting bar in the pair of front supporting bars and a pair of rear upper connectors each disposed at a rear supporting bar in the pair of rear supporting bars and movable along the rear supporting bar. Each of the plurality of pairs of crossing bars includes a first crossing bar and a second crossing bar pivotally coupled to each other at middle portions thereof and is disposed between two adjacent supporting bars in the plurality of supporting bars. For each pair in the plurality of pairs of crossing bars, each of the first and second crossing bars has a lower end portion pivotally connected to the lower connector disposed at one of the two adjacent supporting bars and an upper end portion pivotally connected to the upper connector disposed at the other of the two adjacent supporting bars. For each of one or more pairs in the plurality of pairs of crossing bars, each of the first and second crossing bars has a substantially flat bar surface, and the substantially flat bar surfaces of the first and second crossing bars face each other, thereby enhancing stability, enhancing ease of use and installation, improving durability, or reducing folded size of the foldable seat frame.

In some embodiments, a first pair in the plurality of pairs of crossing bars is disposed between the pair of front supporting bars. A first bar extension is connected to or integrally formed with the upper end portion of the first crossing bar of the first pair, and a second bar extension is connected to or integrally formed with the upper end portion of the second crossing bar of the first pair. When the foldable seat frame is unfolded, the first bar extension extends upward, outward, or upward and outward beyond the upper connector disposed at a first front supporting bar in the pair of front supporting bars, and the second bar extension extends upward, outward, or upward and outward, beyond the upper connector disposed at a second front supporting bar in the pair of front supporting bars.

In some embodiments, for each of the one or more pairs in the plurality of pairs of crossing bars, the substantially flat bar surface of each of the first and second crossing bars extends across substantially an entire length of the first or second crossing bar.

In some embodiments, for each of the one or more pairs in the plurality of pairs of crossing bars, each of the first and second crossing bars has a substantially D-shaped cross section.

In some embodiments, corresponding to each of the one or more pairs in the plurality of pairs of crossing bars: the lower connector disposed at a first supporting bar in the two adjacent supporting bars includes a first lower connecting surface facing the substantially flat bar surface of the first crossing bar; the lower connector disposed at a second supporting bar in the two adjacent supporting bars includes a second lower connecting surface facing the substantially flat bar surface of the second crossing bar; the upper connector disposed at the first supporting bar in the two adjacent supporting bars includes a first upper connecting surface facing the substantially flat bar surface of the second crossing bar; the upper connector disposed at the second supporting bar in the two adjacent supporting bars includes a second upper connecting surface facing the substantially flat bar surface of the second crossing bar; and each of the first lower connecting surface, the second lower connecting surface, the first upper connecting surface and the second upper connecting surface are substantially flat, thereby further enhancing stability, enhancing ease of use and installation, improving durability, or reducing folded size of the foldable seat frame.

In some embodiments, the one or more pairs in the plurality of pairs of crossing bars includes each of the plurality of pairs of crossing bars.

In some embodiments, a respective lower connector in the plurality of lower connectors includes a first connecting member, a second connecting member, and a third connecting member. The first connecting member is connected to the lower end portion of a corresponding supporting bar in the plurality of supporting bars. The second connecting member is pivotally connected to the lower end portion of a crossing bar in a pair of crossing bars that is disposed at a first side of the corresponding supporting bar. The third connecting member is pivotally connected to the lower end portion of a crossing bar in another pair of crossing bars that is disposed at a second side of the corresponding supporting bar.

In some embodiments, the first connecting member of the respective lower connector and the lower end portion of the corresponding supporting bar are connected to each other by snap-fitting or interference-fitting.

In some embodiments, the first connecting member of the respective lower connector is in a form of a socket for receiving the lower end portion of the corresponding supporting bar.

In some such embodiments, a first coupling member is disposed in the socket and configured to couple with a second coupling member disposed at the lower end portion of the corresponding supporting bar.

In some embodiments, the first connecting member of the respective lower connector and the lower end portion of the corresponding supporting bar have matching non-circular cross sections to prevent rotation of the respective lower connector relative to the corresponding supporting bar.

In some such embodiments, the matching non-circular cross sections are substantially D-shaped.

In some embodiments, the respective lower connector further includes a base member, wherein the first, second and third connecting members extend from the base member in a direction substantially perpendicular to the base member.

In various embodiments, the present disclosure provides a foldable seat frame including a plurality of supporting bars, a plurality of lower connectors, a plurality of upper connectors, and a plurality of pairs of crossing bars. Each of the plurality of lower connectors is disposed at a lower end portion of a supporting bar in the plurality of supporting bars. Each of the plurality of upper connectors is disposed at a supporting bar in the plurality of supporting bars above a lower end portion thereof. Each of the plurality of pairs of crossing bars includes a first crossing bar and a second crossing bar pivotally coupled to each other at middle portions thereof and is disposed between two adjacent supporting bars in the plurality of supporting bars. For each pair in the plurality of pairs of crossing bars, each of the first and second crossing bars has a lower end portion pivotally connected to the lower connector disposed at one of the two adjacent supporting bars and an upper end portion pivotally connected to the upper connector disposed at the other of the two adjacent supporting bars. For each of one or more pairs in the plurality of pairs of crossing bars, each of the first and second crossing bars has a substantially flat bar surface, and the substantially flat bar surfaces of the first and second crossing bars face each other, thereby enhancing stability, enhancing case of use and installation, improving durability, or reducing folded size of the foldable seat frame. In addition, corresponding to each of the one or more pairs in the plurality of pairs of crossing bars: the lower connector disposed at a first supporting bar in the two adjacent supporting bars includes a first lower connecting surface facing the substantially flat bar surface of the first crossing bar; the lower connector disposed at a second supporting bar in the two adjacent supporting bars includes a second lower connecting surface facing the substantially flat bar surface of the second crossing bar; the upper connector disposed at the first supporting bar in the two adjacent supporting bars includes a first upper connecting surface facing the substantially flat bar surface of the second crossing bar; the upper connector disposed at the second supporting bar in the two adjacent supporting bars includes a second upper connecting surface facing the substantially flat bar surface of the second crossing bar; and each of the first lower connecting surface, the second lower connecting surface, the first upper connecting surface and the second upper connecting surface are substantially flat, thereby further enhancing stability, enhancing ease of use and installation, improving durability, or reducing folded size of the foldable seat frame.

In some embodiments, for each of the one or more pairs in the plurality of pairs of crossing bars, the substantially flat bar surface of each of the first and second crossing bars extends across substantially an entire length of the first or second crossing bar.

In some embodiments, for each of the one or more pairs in the plurality of pairs of crossing bars, each of the first and second crossing bars has a substantially D-shaped cross section.

In some embodiments, the one or more pairs in the plurality of pairs of crossing bars include each of the plurality of pairs of crossing bars.

In some embodiments, the plurality of supporting bars includes two front supporting bars and two rear supporting bars, and the plurality of pairs of crossing bars includes four pairs. When the foldable seat frame is unfolded, the two front supporting bars are disposed at a front side of the foldable seat frame and the two rear supporting bars are disposed at a rear side of the foldable seat frame.

In some embodiments, the plurality of supporting bars includes three front supporting bars and three rear supporting bars, and the plurality of pairs of crossing bars includes seven pairs. When the foldable seat frame is unfolded, the three front supporting bars are disposed at a front side of the foldable seat frame and the three rear supporting bars are disposed at a rear side of the foldable seat frame.

In some embodiments, the plurality of supporting bars includes four front supporting bars and four rear supporting bars, and the plurality of pairs of crossing bars includes ten pairs. When the foldable seat frame is unfolded, the four front supporting bars are disposed at a front side of the foldable seat frame and the four rear supporting bars are disposed at a rear side of the foldable seat frame.

The frames and chairs of the present disclosure have other features and advantages that will be apparent from, or are set forth in more detail in, the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of exemplary embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more exemplary embodiments of the present disclosure and, together with the Detailed Description, serve to explain the principles and implementations of exemplary embodiments of the invention.

FIG. 1 is a perspective view illustrating an exemplary frame in an unfolded state in accordance with some exemplary embodiments of the present disclosure.

FIG. 2 is a perspective view illustrating the exemplary frame of FIG. 1 in a folded state in accordance with some exemplary embodiments of the present disclosure.

FIG. 3 is a partially dissembled view illustrating some components of the exemplary frame of FIG. 1 in accordance with some exemplary embodiments of the present disclosure.

FIG. 4 is a cutout view illustrating some components of the exemplary frame of FIG. 1 in accordance with some exemplary embodiments of the present disclosure.

FIG. 5 is another partially dissembled view illustrating some components of the exemplary frame of FIG. 1 in accordance with some exemplary embodiments of the present disclosure.

FIG. 6 is a perspective view illustrating an exemplary crossing-bar pair in an open state in accordance with some exemplary embodiments of the present disclosure.

FIG. 7A is a side view illustrating the exemplary crossing-bar pair of FIG. 6 in a closed state in accordance with some exemplary embodiments of the present disclosure.

FIG. 7B is a top view illustrating the exemplary crossing-bar pair of FIG. 6 in a closed state in accordance with some exemplary embodiments of the present disclosure.

FIG. 8 is a perspective view illustrating an exemplary connector in accordance with some exemplary embodiments of the present disclosure.

FIG. 9 is another perspective view illustrating the exemplary connector of FIG. 8 in accordance with some exemplary embodiments of the present disclosure.

As will be apparent to those of skill in the art, the components illustrated in the figures described above are combinable in any useful number and combination. The figures are intended to be illustrative in nature and are not limiting.

DETAILED DESCRIPTION

Reference will now be made in detail to implementations of exemplary embodiments of the present disclosure as illustrated in the accompanying drawings. The same reference indicators will be used throughout the drawings and the following detailed description to refer to the same or like parts. Those of ordinary skill in the art will understand that the following detailed description is illustrative only and is not intended to be in any way limiting. Other embodiments of the present disclosure will readily suggest themselves to such skilled persons having benefit of this disclosure.

In the interest of clarity, not all of the routine features of the implementations described herein are shown and described. It will be appreciated that, in the development of any such actual implementation, numerous implementation-specific decisions are made in order to achieve the developer's specific goals, such as compliance with application-and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure.

Many modifications and variations of the exemplary embodiments set forth in this disclosure can be made without departing from the spirit and scope of the exemplary embodiments, as will be apparent to those skilled in the art. The specific exemplary embodiments described herein are offered by way of example only, and the disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled.

Embodiments of the present disclosure are described in the context of foldable seat frames. A foldable seat frame generally includes a plurality of supporting bars and a plurality of pairs of crossing bars connected to each other by a plurality of lower connectors and a plurality of upper connectors. The supporting bars, crossing bars, lower connectors, and/or upper connectors are configured to enhance stability, enhance case of use and installation, improve durability, simplify machining and assembly, reduce folded frame size and/or other characteristics of the frame.

Referring now to FIGS. 1 and 2, there is depicted an exemplary foldable seat frame 100 in accordance with some exemplary embodiments of the present disclosure. Frame 100 includes a plurality of supporting bars, such as supporting bars 110-1, 110-2, 110-3 and 110-4. In some embodiments, the plurality of supporting bars includes a pair of front supporting bars, such as supporting bars 110-1 and 110-2, and a pair of rear supporting bars, such as supporting bars 110-3 and 110-4. When the foldable seat frame is unfolded, the pair of front supporting bars is disposed at a front side of the foldable seat frame (e.g., a side facing a user when in use), and the pair of rear supporting bars disposed at a rear side of the foldable seat frame (e.g., a side facing away from a user when in use). It should be noted that front supporting bars can be but do not have to be identical or symmetric to each other. Similarly, rear supporting bars can be but do not have to be identical or symmetric to each other. In addition, a bar (e.g., a supporting bar or other bar disclosed herein) or a portion of it can be solid or hollow.

In some embodiments, each front supporting bar in the pair of front supporting bars has a first length and each rear supporting bar in the pair of rear supporting bars has a second length that is equal to or greater than the first length of the front support. That is, the rear supporting bars are generally longer than the front supporting bars so that upper portions of the rear supporting bars can be used to support a backrest (e.g., a fabric or panel connected to the upper portions of the rear supporting bars). In some embodiments, each front supporting bar in the pair of front supporting bars is adjustable in length, e.g., the first length is adjustable between an expanded length (e.g., the length when the frame is folded as illustrated in FIG. 2) and a contracted length (e.g., the length when the frame is unfolded as illustrated in FIG. 1). In some embodiments, each front supporting bar in the pair of front supporting bars includes two or more bar segments (e.g., bar segments 111 and 112) telescopically connected to each other, thereby allowing each front supporting bar to change its length when folding and unfolding the frame.

Frame 100 also includes a plurality of lower connectors, such as lower connectors 120-1, 120-2, 120-3 and 120-4. In some embodiments, each lower connector is disposed at (e.g., coupled with) a lower end portion of a supporting bar in the plurality of supporting bars. For instance, in the illustrated embodiment, lower connector 120-1 is disposed at the lower end portion of supporting bar 110-1, lower connector 120-2 is disposed at the lower end portion of supporting bar 110-2, lower connector 120-3 is disposed at the lower end portion of supporting bar 110-3, and lower connector 120-4 is disposed at the lower end portion of supporting bar 110-4. Lower connectors can be but do not have to be identical or symmetric to each other.

In some embodiments, a lower connector in the plurality of lower connectors includes a first connecting member, a second connecting member and a third connecting member. For instance, as a non-limiting example, FIGS. 8 and 9 illustrate a lower connector (e.g., lower connector 120-1, 120-2, 120-3 or 120-4) including first connecting member 121, second connecting member 122, and third connecting member 123. In some embodiments, the lower connector is a monolithically molded plastic component (e.g., the first, second and third connecting members are integrally molded together). In an exemplary embodiment, the second and third connecting members are branched from (e.g., joined with) the first connecting member. In some embodiments, the lower connector further includes a base member, such as base member 124, configured to abut a ground when the frame or chair is in use. In some such embodiments, the first, second and third connecting members extend from the base member in a direction substantially perpendicular to the base member.

The first, second, and third connecting members of a lower connector can be of any suitable shapes. As a non-limiting example, FIG. 8 illustrates the first connecting member in a form of a socket (e.g., having a cavity) with a substantially D-shaped cross section, and each of the second and third connecting members in a form of a mounting block, wall, bracket or the like. However, the present disclosure is not limited thereto. For instance, the cross section of the first connecting member can be of polygonal, elliptical, or other non-circular shapes (regular or irregular, smooth or non-smooth). In some embodiments, the first connecting member includes a first coupling member, such as first coupling member 125, provided in the socket. The second connecting member has a first connecting surface, such as first connecting surface 126, and the third connecting member has a second connecting surface, such as second connecting surface 127. In some embodiments, each of the first and second connecting surfaces of the lower connector, or at least a portion of it, is substantially flat. In an exemplary embodiment, the first and second connecting surfaces of the lower connector are substantially perpendicular to each other.

Referring back to FIGS. 1 and 2, frame 100 includes a plurality of upper connectors, such as upper connectors 130-1, 130-2, 130-3 and 130-4. In some embodiments, each upper connector is disposed at a supporting bar in the plurality of supporting bars above its lower end portion (e.g., the portion at which a lower connector is disposed). In some embodiments, the plurality of upper connectors includes a pair of front upper connectors (e.g., upper connectors 130-1 and 130-2), and a pair of rear upper connectors (e.g., upper connectors 130-3 and 130-4). Front upper connectors can be but do not have to be identical or symmetric to each other. Similarly, rear upper connectors can be but do not have to be identical or symmetric to each other. In some embodiments, each front upper connector is disposed at an upper end portion of a front supporting bar in the pair of front supporting bars. For instance, in the illustrated embodiment, upper connector 130-1 is disposed at the upper end portion of supporting bar 110-1, and upper connector 130-2 is disposed at the upper end portion of supporting bar 110-2. In some embodiments, each rear upper connector is disposed at a rear supporting bar in the pair of rear supporting bars and movable along the rear supporting bar. For instance, upper connector 130-3 is disposed at supporting bar 110-3 and movable along supporting bar 110-3. Similarly, upper connector 130-4 is disposed at supporting bar 110-4 and movable along supporting bar 110-4.

In some embodiments, an upper connector is configured substantially the same as a lower connector disclosed herein or similar to a lower connector disclosed herein with minor modification. For instance, in some embodiments, a front upper connector includes first, second and third connecting member substantially the same as or similar to those of substantially the same as a lower connector disclosed herein. In some embodiments, a rear upper connector includes a second connecting member and a third connecting member similar to second connecting member 122 and third connecting member 123 of a lower connector disclosed herein, and a first connecting member in a form of a through-hole (instead of a socket) to allow the rear upper connector to slide onto the corresponding rear supporting bar.

Frame 100 further includes a plurality of pairs of crossing bars (or a plurality of crossing-bar pairs), such as crossing-bar pairs 140-1, 140-2, 140-3, and 140-4. As used herein, a pair of crossing bars is interchangeably with a crossing-bar pair. Cross-bar pairs can be but do not have to be identical or symmetric to each other. In some embodiments, each crossing-bar pair in the plurality of crossing-bar pairs is disposed between two adjacent supporting bars in the plurality of supporting bars and connected to the two adjacent supporting bars by the lower and upper connectors disposed at the two adjacent supporting bars. For instance, crossing-bar pair 140-1 is disposed between supporting bars 110-1, 110-2 and connected to supporting bars 110-1, 110-2 by lower connectors 120-1, 120-2 and upper connectors 130-1, 130-2, which are disposed at supporting bars 110-1, 110-2. Similarly, crossing-bar pair 140-2 is disposed between supporting bars 110-2, 110-3 and connected to supporting bars 110-2, 110-3 by lower connectors 120-2, 120-3 and upper connectors 130-2, 130-3, which are disposed at supporting bars 110-2, 110-3. Crossing-bar pair 140-3 is disposed between supporting bars 110-3, 110-4 and connected to supporting bars 110-3, 110-4 by lower connectors 120-3, 120-4 and upper connectors 130-3, 130-4, which are disposed at supporting bars 110-3, 110-4. Crossing-bar pair 140-4 is disposed between supporting bars 110-4, 110-1 and connected to supporting bars 110-4, 110-1 by lower connectors 120-4, 120-1 and upper connectors 130-4, 130-1, which are disposed at supporting bars 110-4, 110-1.

Each crossing-bar pair in the plurality of crossing-bar pairs includes a first crossing bar and a second crossing bar pivotally coupled to each other at middle portions thereof. For instance, as a non-limiting example, FIGS. 6, 7A and 7B illustrate a crossing-bar pair (e.g., crossing-bar pair 140-1, 140-2, 140-3 or 140-4) including first crossing bar 141 and second crossing bar 142 pivotally connected to each other at pivotal point 143, which is located at middle portions of the first and second crossing bars. The first crossing bar has a first crossing bar surface, such as first crossing bar surface 144, at a side facing the second crossing bar, and a second crossing bar surface, such as second crossing bar surface 145, at a side facing away from the second crossing bar. Similarly, the second crossing bar has a third crossing surface, such as third crossing bar surface 146, at a side facing the first crossing bar, and a fourth crossing bar surface, such as fourth crossing bar surface 147, facing away from the first crossing bar. In some embodiments, the first crossing bar surface of the first crossing bar and the third crossing bar surface of the second crossing bar are substantially flat across at least a portion of the first or second crossing bar in the length direction of the first or second crossing bar. In some embodiments, the substantially flat bar surface of each of the first and second crossing bars extends across substantially the entire first or second crossing bar in its length direction.

By configuring the first and second crossing bars to have substantially flat bar surfaces, the frame of the present disclosure has several advantages over existing seat frames that typically do not have crossing-bar pair with flat bar surfaces facing each other. For instance, the substantially flat bar surfaces of the first and second crossing bars allow for controlled pivot motion and prevent unwanted rotation around the pivotal point. This ensures a more stable and controlled pivoting motion, making folding and unfolding of the frame (and thus a chair that uses the frame) easy and smooth. Moreover, the substantially flat bar surfaces of the first and second crossing bars provide larger contact area and better contact at the pivotal point, reducing the risk of slippage, improving load distribution and/or reducing stress concentration. This leads to better durability and less wear. Further, the substantially flat bar surfaces of the first and second crossing bars are self-aligning. This makes alignment of the bars and assembly of the frame easy and simple, enhancing case of use and installation. Furthermore, with the substantially flat bar surfaces of the first and second crossing bars, a crossing-bar pair is more compact. This reduces the size of the frame when folded.

The second crossing bar surface of the first crossing bar or the fourth crossing bar surface of the second crossing bar can be angled (e.g., having multiple flat surface segments), curved, or a combination thereof. In some embodiments, the second crossing bar surface of the first crossing bar and the fourth crossing bar surface of the second crossing bar are substantially curved. For instance, in some embodiments, one or each of the first and second crossing bars has a substantially D-shaped cross section or the like. The angled or curved crossing bar surfaces of the first and second crossing bars ensure the crossing-rod pair with sufficient bending and torsion strength for its use.

In some embodiments, for each of one or more crossing-bar pairs in the plurality of crossing-bar pairs, each of the first and second crossing bars has a substantially flat bar surface, and the substantially flat bar surfaces of the first and second crossing bars face each other. In some embodiments, for each crossing-bar pair in the plurality of crossing-bar pairs, each of the first and second crossing bars has a substantially flat bar surface, and the substantially flat bar surfaces of the first and second crossing bars face each other.

Referring to FIGS. 1-5, in some embodiments, for each crossing-bar pair in the plurality of crossing-bar pairs, each of the first and second crossing bars has (i) a lower end portion pivotally connected to the lower connector disposed at one of the two adjacent supporting bars and (ii) an upper end portion pivotally connected to the upper connector disposed at the other of the two adjacent supporting bars. For instance, in the illustrated embodiment, the first crossing bar of crossing-bar pair 140-1 has (i) a lower end portion pivotally connected to lower connector 120-1 disposed at supporting bar 110-1 and (ii) an upper end portion pivotally connected to upper connector 130-2 disposed at supporting bar 110-2. The second crossing bar of crossing-bar pair 140-1 has (i) a lower end portion pivotally connected to lower connector 120-2 disposed at supporting bar 110-2 and (ii) an upper end portion pivotally connected to upper connector 130-1 disposed at supporting bar 110-1.

In some embodiments, frame 100 includes one or more bar extensions connected to or integrally formed with one or more crossing bars of one or more crossing-bar pairs. For instance, in some embodiments, for a first crossing-bar pair disposed between the pair of front supporting bars (e.g., crossing-bar pair 140-1), a first bar extension, such as first bar extension 151, is connected to or integrally formed with the upper end portion of the first crossing bar of the first crossing-bar pair and a second bar extension, such as second bar extension, is connected to or integrally formed with the upper end portion of the second crossing bar of the first crossing-bar pair. In some such embodiments, when the foldable seat frame is unfolded, the first bar extension extends upward, outward, or upward and outward beyond the upper connector (e.g., upper connector 130-2) disposed at a first front supporting bar (e.g., supporting bar 110-2) in the pair of front supporting bars, and the second bar extension extends upward, outward, or upward and outward, beyond the upper connector (e.g., upper connector 130-1) disposed at a second front supporting bar (e.g., supporting bar 110-1) in the pair of front supporting bars. In an exemplary embodiment, the first and/or second bar extensions are configured to support or serve as an armrest.

In some embodiments, for a respective lower connector in the plurality of lower connectors, the first connecting member is connected to the lower end portion of a corresponding supporting bar in the plurality of supporting bars, the second connecting member is pivotally connected to the lower end portion of a crossing bar in a pair of crossing bars that is disposed at a first side of the corresponding supporting bar, and the third connecting member is pivotally connected to the lower end portion of a crossing bar in another pair of crossing bars that is disposed at a second side of the corresponding supporting bar. For instance, as a non-limiting example, FIGS. 3 and 4 illustrates a respective lower connector (e.g., lower connector 120-2) having first connecting member 121 connected to the lower end portion of a corresponding supporting bar (e.g., supporting bar 110-2), second connecting member 122 pivotally connected to the lower end portion of a crossing bar in a pair of crossing bars (e.g., second crossing bar 142 of crossing-bar pair 140-1) that is disposed at a first side of the corresponding supporting bar, and third connecting member 123 pivotally connected to the lower end portion of a crossing bar in another pair of crossing bars (e.g., first crossing bar 141 of crossing-bar pair 140-2) that is disposed at a second side of the corresponding supporting bar.

In some embodiments, the first connecting member of a respective lower connector (e.g., lower connector 120-2) and the lower end portion of the corresponding supporting bar (e.g., supporting bar 110-2) are connected to each other, for instance, by snap-fitting, interference-fitting, fastener(s), or the like. For instance, as a non-limiting example, FIGS. 3 and 4 illustrates a second coupling member, such as second coupling member 113, disposed at the lower end portion of the corresponding supporting bar. The second coupling member is configured to couple (e.g., snap-fitted) with first coupling member 125 of the respective lower connector. In an exemplary embodiment, the second coupling member is configured in a form of a tongue oblique to the length direction of the corresponding supporting bar. The oblique tongue allows insertion of the lower end portion of the corresponding supporting bar into the respective lower connector, making it easy to assemble the parts. Once coupled with the first coupling member of the respective lower connector, the oblique tongue prevents the lower end portion of the corresponding supporting bar from disengaging with the respective lower connector.

In some embodiments, the first connecting member of the respective lower connector and the lower end portion of the corresponding supporting bar have matching non-circular cross sections to prevent rotation of the respective lower connector relative to the corresponding supporting bar. A non-circular cross-section can be polygonal, elliptical, or other regular, irregular, smooth, or non-smooth shape. In an exemplary embodiment, the matching non-circular cross sections are substantially D-shaped.

In some embodiments, corresponding to each of one or more crossing-bar pairs in the plurality of crossing-bar pairs (e.g., 1, 2, 3, or all of the crossing-bar pairs): the lower connector disposed at a first supporting bar in the two adjacent supporting bars includes a first lower connecting surface facing the substantially flat bar surface of the first crossing bar, and the lower connector disposed at a second supporting bar in the two adjacent supporting bars includes a second lower connecting surface facing the substantially flat bar surface of the second crossing bar. Moreover, the upper connector disposed at the first supporting bar in the two adjacent supporting bars includes a first upper connecting surface facing the substantially flat bar surface of the second crossing bar, and the upper connector disposed at the second supporting bar in the two adjacent supporting bars includes a second upper connecting surface facing the substantially flat bar surface of the second crossing bar. For instance, crossing-bar pair 140-1 is disposed between supporting bars 110-1 and 110-2. Corresponding to crossing-bar pair 140-1, lower connector 120-1 and upper connector 130-1 are disposed at supporting bar 110-1, and lower connector 120-2 and upper connector 130-2 are disposed at supporting bar 110-2. Each of lower connector 120-1 and upper connector 130-2 has a connecting surface (e.g., connecting surface 126 or 127) facing bar surface 144 of crossing bar 141. Each of lower connector 120-2 and upper connector 130-2 has a connecting surface facing bar surface 146 of crossing bar 142.

In some embodiments, each of the first lower connecting surface, the second lower connecting surface, the first upper connecting surface and the second upper connecting surface are substantially flat. Like the substantially flat bar surfaces of a respective crossing-bar pair that provide better pivot motion between the first and second crossing bars of the respective crossing-bar pair, these substantially flat bar surfaces allow for better pivot motion between the crossing bars and connectors. As a result, this further enhances stability, enhances case of use and installation, improves durability, reduces folded size, and/or enhances other performances of the foldable seat frame.

While 4 supporting bars, 4 lower connectors, 4 upper connectors and 4 crossing-bar pairs are illustrated, it should be noted that this is by way of example and the present disclosure is not limited thereto. The plurality of supporting bars can include 3, 4, 5, 6, 7, 8 or more than 8 supporting bars. Similarly, the plurality of lower connectors can include 3, 4, 5, 6, 7, 8 or more than 8 lower connectors, the plurality of upper connectors can include 3, 4, 5, 6, 7, 8 or more than 8 upper connectors, or the plurality of crossing-bar pairs can include 3, 4, 5, 6, 7, 8 or more than 8 crossing-bar pairs. For instance, in an embodiment, a frame of the present disclosure includes 6 supporting bars (e.g., 3 front supporting bars and 3 rear supporting bars) and 7 crossing-bar pairs each disposed between two adjacent supporting bars. Such a frame resembles a combination of two frames 100 (with no bar extension or a single bar extension) placed side by side and sharing a front support, a rear support, and a crossing-bar pair. It can be used, for instance, to make a loveseat. In another embodiment, a frame of the present disclosure includes 8 supporting bars (e.g., 4 front supporting bars and 4 rear supporting bars) and 10 crossing-bar pairs each disposed between two adjacent supporting bars. Such a frame resembles a combination of a combination of two frames 100 (with no bar extension or a single bar extension) placed side by side and connected by two additional crossing-bar pairs. It can be used, for instance, to make a sofa.

The terminology used herein is for the purpose of describing particular implementations only and is not intended to be limiting of the claims. As used in the description of the implementations and the appended claims, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be understood that the terms “top” or “bottom”, “lower” or “upper”, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. It will be understood that, although the terms “first,” “second,” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first portion could be termed a second portion, and, similarly, a second portion could be termed a first portion, without changing the meaning of the description, so long as all occurrences of the “first portion” are renamed consistently and all occurrences of the “second portion” are renamed consistently.

As used herein, the term “and/or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

As used herein, the term “about” or “approximately” or “substantially” can mean within an acceptable error range for the particular value as determined by one of ordinary skill in the art, which can depend in part on how the value is measured or determined, e.g., the limitations of the measurement system. For example, “about” can mean within 1 or more than 1 standard deviation, per the practice in the art. “About” can mean a range of ±20%, ±10%, ±5%, or ±1% of a given value. Where particular values are described in the application and claims, unless otherwise stated, the term “about” means within an acceptable error range for the particular value. The term “about” can have the meaning as commonly understood by one of ordinary skill in the art. The term “about” can refer to ±10%. The term “about” can refer to ±5%.

When a reference number is given an “i^th” denotation, the reference number refers to a generic component, set, or embodiment. For instance, a “unit i” refers to the i^th unit in a plurality of units.

Claims

1. A foldable seat frame comprising: a plurality of supporting bars comprising: a pair of front supporting bars disposed at a front side of the foldable seat frame when the foldable seat frame is unfolded, wherein each front supporting bar in the pair of front supporting bars has a first length adjustable between an expanded length and a contracted length; anda pair of rear supporting bars disposed at a rear side of the foldable seat frame when the foldable seat frame is unfolded, wherein each rear supporting bar in the pair of rear supporting bars has a second length equal to or greater than the first length;a plurality of lower connectors, each disposed at a lower end portion of a supporting bar in the plurality of supporting bars;a plurality of upper connectors, each disposed at a supporting bar in the plurality of supporting bars above the lower end portion thereof, wherein the plurality of upper connectors comprises: a pair of front upper connectors, each disposed at an upper end portion of a front supporting bar in the pair of front supporting bars; anda pair of rear upper connectors, each disposed at a rear supporting bar in the pair of rear supporting bars and movable along the rear supporting bar; anda plurality of pairs of crossing bars, each comprising a first crossing bar and a second crossing bar pivotally coupled to each other at middle portions thereof and disposed between two adjacent supporting bars in the plurality of supporting bars, wherein: for each pair in the plurality of pairs of crossing bars, each of the first and second crossing bars has a lower end portion pivotally connected to the lower connector disposed at one of the two adjacent supporting bars and an upper end portion pivotally connected to the upper connector disposed at the other of the two adjacent supporting bars; andfor each of one or more pairs in the plurality of pairs of crossing bars, each of the first and second crossing bars has a substantially flat bar surface, and the substantially flat bar surfaces of the first and second crossing bars face each other, thereby enhancing stability, enhancing ease of use and installation, improving durability, or reducing folded size of the foldable seat frame.

2. The foldable seat frame of claim 1, wherein: a first pair in the plurality of pairs of crossing bars is disposed between the pair of front supporting bars;a first bar extension is connected to or integrally formed with the upper end portion of the first crossing bar of the first pair, the first bar extension extending upward, outward, or upward and outward beyond the upper connector disposed at a first front supporting bar in the pair of front supporting bars when the foldable seat frame is unfolded; anda second bar extension is connected to or integrally formed with the upper end portion of the second crossing bar of the first pair, extending upward, outward, or upward and outward, beyond the upper connector disposed at a second front supporting bar in the pair of front supporting bars when the foldable seat frame is unfolded.

3. The foldable seat frame of claim 1, wherein for each of the one or more pairs in the plurality of pairs of crossing bars, the substantially flat bar surface of each of the first and second crossing bars extends across substantially an entire length of the first or second crossing bar.

4. The foldable seat frame of claim 1, wherein for each of the one or more pairs in the plurality of pairs of crossing bars, each of the first and second crossing bars has a substantially D-shaped cross section.

5. The foldable seat frame of claim 1, wherein corresponding to each of the one or more pairs in the plurality of pairs of crossing bars: the lower connector disposed at a first supporting bar in the two adjacent supporting bars comprises a first lower connecting surface facing the substantially flat bar surface of the first crossing bar;the lower connector disposed at a second supporting bar in the two adjacent supporting bars comprises a second lower connecting surface facing the substantially flat bar surface of the second crossing bar;the upper connector disposed at the first supporting bar in the two adjacent supporting bars comprises a first upper connecting surface facing the substantially flat bar surface of the second crossing bar;the upper connector disposed at the second supporting bar in the two adjacent supporting bars comprises a second upper connecting surface facing the substantially flat bar surface of the second crossing bar; andeach of the first lower connecting surface, the second lower connecting surface, the first upper connecting surface and the second upper connecting surface are substantially flat, thereby further enhancing stability, enhancing ease of use and installation, improving durability, or reducing folded size of the foldable seat frame.

6. The foldable seat frame of claim 1, wherein the one or more pairs in the plurality of pairs of crossing bars comprise each of the plurality of pairs of crossing bars.

7. The foldable seat frame of claim 1, wherein a respective lower connector in the plurality of lower connectors comprises: a first connecting member connected to the lower end portion of a corresponding supporting bar in the plurality of supporting bars;a second connecting member pivotally connected to the lower end portion of a crossing bar in a pair of crossing bars that is disposed at a first side of the corresponding supporting bar; anda third connecting member pivotally connected to the lower end portion of a crossing bar in another pair of crossing bars that is disposed at a second side of the corresponding supporting bar.

8. The foldable seat frame of claim 7, wherein the first connecting member of the respective lower connector and the lower end portion of the corresponding supporting bar are connected to each other by snap-fitting or interference-fitting.

9. The foldable seat frame of claim 7, wherein the first connecting member of the respective lower connector is in a form of a socket for receiving the lower end portion of the corresponding supporting bar.

10. The foldable seat frame of claim 9, wherein a first coupling member is disposed in the socket and configured to couple with a second coupling member disposed at the lower end portion of the corresponding supporting bar.

11. The foldable seat frame of claim 7, wherein the first connecting member of the respective lower connector and the lower end portion of the corresponding supporting bar have matching non-circular cross sections to prevent rotation of the respective lower connector relative to the corresponding supporting bar.

12. The foldable seat frame of claim 11, wherein the matching non-circular cross sections are substantially D-shaped.

13. The foldable seat frame of claim 7, wherein the respective lower connector further comprises a base member, wherein the first, second and third connecting members extend from the base member in a direction substantially perpendicular to the base member.

14. A foldable seat frame comprising: a plurality of supporting bars;a plurality of lower connectors, each disposed at a lower end portion of a supporting bar in the plurality of supporting bars;a plurality of upper connectors, each disposed at a supporting bar in the plurality of supporting bars above a lower end portion thereof; anda plurality of pairs of crossing bars, each comprising a first crossing bar and a second crossing bar pivotally coupled to each other at middle portions thereof and disposed between two adjacent supporting bars in the plurality of supporting bars,wherein:for each pair in the plurality of pairs of crossing bars, each of the first and second crossing bars has a lower end portion pivotally connected to the lower connector disposed at one of the two adjacent supporting bars and an upper end portion pivotally connected to the upper connector disposed at the other of the two adjacent supporting bars;for each of one or more pairs in the plurality of pairs of crossing bars, each of the first and second crossing bars has a substantially flat bar surface, and the substantially flat bar surfaces of the first and second crossing bars face each other, thereby enhancing stability, enhancing ease of use and installation, improving durability, or reducing folded size of the foldable seat frame; andcorresponding to each of the one or more pairs in the plurality of pairs of crossing bars: the lower connector disposed at a first supporting bar in the two adjacent supporting bars comprises a first lower connecting surface facing the substantially flat bar surface of the first crossing bar;the lower connector disposed at a second supporting bar in the two adjacent supporting bars comprises a second lower connecting surface facing the substantially flat bar surface of the second crossing bar;the upper connector disposed at the first supporting bar in the two adjacent supporting bars comprises a first upper connecting surface facing the substantially flat bar surface of the second crossing bar;the upper connector disposed at the second supporting bar in the two adjacent supporting bars comprises a second upper connecting surface facing the substantially flat bar surface of the second crossing bar; andeach of the first lower connecting surface, the second lower connecting surface, the first upper connecting surface and the second upper connecting surface are substantially flat, thereby further enhancing stability, enhancing ease of use and installation, improving durability, or reducing folded size of the foldable seat frame.

15. The foldable seat frame of claim 14, wherein for each of the one or more pairs in the plurality of pairs of crossing bars, the substantially flat bar surface of each of the first and second crossing bars extends across substantially an entire length of the first or second crossing bar.

16. The foldable seat frame of claim 14, wherein for each of the one or more pairs in the plurality of pairs of crossing bars, each of the first and second crossing bars has a substantially D-shaped cross section.

17. The foldable seat frame of claim 14, wherein the one or more pairs in the plurality of pairs of crossing bars comprise each of the plurality of pairs of crossing bars.

18. The foldable seat frame of claim 14, wherein: the plurality of supporting bars comprises two front supporting bars and two rear supporting bars;the plurality of pairs of crossing bars comprises four pairs; andwhen the foldable seat frame is unfolded, the two front supporting bars are disposed at a front side of the foldable seat frame and the two rear supporting bars are disposed at a rear side of the foldable seat frame.

19. The foldable seat frame of claim 14, wherein: the plurality of supporting bars comprises three front supporting bars and three rear supporting bars;the plurality of pairs of crossing bars comprises seven pairs; andwhen the foldable seat frame is unfolded, the three front supporting bars are disposed at a front side of the foldable seat frame and the three rear supporting bars are disposed at a rear side of the foldable seat frame.

20. The foldable seat frame of claim 14, wherein: the plurality of supporting bars comprises four front supporting bars and four rear supporting bars;the plurality of pairs of crossing bars comprises ten pairs; andwhen the foldable seat frame is unfolded, the four front supporting bars are disposed at a front side of the foldable seat frame and the four rear supporting bars are disposed at a rear side of the foldable seat frame.