A folding chair backrest unfolding and folding mechanism

Abstract

This utility model relates to an unfolding and folding mechanism for a folding chair backrest, including a backrest rod and a rear cross rod assembly. The rear cross rod assembly includes a first main cross rod and a second main cross rod. One end of the first and second main cross rods is hinged to the upper part of the two backrest rods, and the other end is movably connected to the lower part of the backrest rods or to the chair frame. A support rod assembly is also provided between the first and second main cross rods. The support rod assembly includes a left support rod hinged to the first main cross rod and a right support rod hinged to the second main cross rod. The left and right support rods are hinged through a connecting block. When the rear cross rod assembly is unfolded, the ends of the left and right support rods abut against the connecting block. The first and second main cross rods, the left and right support rods, and the connecting block are located in the same plane. The structure of this utility model can reduce the deformation of the rods, improve the service life, and reduce the packaging volume after folding.

Description

Technical Field

[0001] This utility model relates to the field of folding chair technology, specifically to a folding and unfolding mechanism for the backrest of a folding chair, which is particularly suitable for outdoor camping chairs, leisure chairs, and other scenarios that require frequent folding and unfolding and have high requirements for load-bearing stability. Background Technology

[0002] Folding chairs are widely used in outdoor activities, impromptu meetings, and home settings due to their portability and high space utilization. Some high-end folding chairs use multiple sets of rods hinged in different planes to improve support strength. For example, in conventional folding chairs, the support rod assembly is placed on the outside of the cross tube. When the backrest is under stress, the support rod assembly will deform backward, and the deformation will be severe. The stress will be concentrated on the connecting fasteners. This multi-plane hinge structure not only makes the mechanism work unevenly, but also affects the service life of the fasteners. In addition, when the mechanism is folded, the rods cannot be completely closed, resulting in a large storage volume and reduced portability. Utility Model Content

[0003] In order to solve the above-mentioned technical problems, the purpose of this utility model is to provide a folding mechanism for the backrest of a folding chair, which has a more even force distribution and a smaller volume after folding.

[0004] To achieve the above-mentioned objectives, this utility model adopts the following technical solution:

[0005] A folding chair backrest unfolding and folding mechanism includes backrest rods and a rear crossbar assembly disposed between two backrest rods. The rear crossbar assembly includes a first main crossbar and a second main crossbar that cross each other. One end of the first and second main crossbars is hinged to the upper part of the two backrest rods, and the other end of the first and second main crossbars is movably connected to the lower part of the backrest rods or to the chair frame. A support rod assembly is also provided between the first and second main crossbars. The support rod assembly includes a left support rod hinged to the first main crossbar and a right support rod hinged to the second main crossbar. The left and right support rods are hinged together by a connecting block. When the rear crossbar assembly is unfolded, the ends of the left and right support rods abut against the connecting block. The first and second main crossbars, the left and right support rods, and the connecting block are located in the same plane.

[0006] As a preferred embodiment, the left support rod is hinged to the first main cross rod via a connector, and the right support rod is also hinged to the second main cross rod via a connector.

[0007] As a preferred embodiment, the connector is fixedly installed with the first main crossbar and / or the second main crossbar.

[0008] As a preferred embodiment, one side of the connector is a U-shaped opening and the other side is a closed collar. The U-shaped opening is hinged to the left or right support rod, and the closed collar is fitted and fixed on the first or second main cross rod.

[0009] As a preferred embodiment, the other ends of the first main crossbar and the second main crossbar are respectively hinged to a first auxiliary connecting rod and a second auxiliary connecting rod, and the first auxiliary connecting rod and the second auxiliary connecting rod are hinged to the lower part of the two backrest rods.

[0010] As a preferred embodiment, the first main crossbar includes two rod segments fixedly connected by a connecting limiting member, and the limiting connecting member has an elongated through hole, through which the second main crossbar passes.

[0011] As a preferred embodiment, the rods at both ends of the connecting limiting member are staggered.

[0012] As a preferred embodiment, the handle is also provided with a through hole for easy gripping.

[0013] As a preferred embodiment, the through hole is circular, rectangular, triangular, or elongated.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0015] This invention significantly improves the load-bearing capacity of the backrest by setting a support rod assembly on the rear cross rod assembly. When unfolded, the end of the support rod abuts against the connecting block to form a rigid support, preventing the backrest from folding back unexpectedly. In addition, the support rod assembly, the first main cross rod, and the second main cross rod are arranged in the same plane to form an eccentric connection. When the backrest is under force, the support rod assembly receives the force more directly and evenly, distributing the force on the connecting parts, reducing the degree of deformation of the rods, and improving the overall service life. Moreover, all rods (main cross rods, support rods, and connecting blocks) are located in the same plane, and the components move synchronously when folded, avoiding the jamming problem caused by multi-plane hinges. At the same time, it can also reduce the packaging volume after folding. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute a limitation thereof.

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0018] Figure 2 This is a side view of the structure of this utility model;

[0019] Figure 3 This is a structural diagram of a folding chair that adopts the structure of this utility model;

[0020] Figure 4 This is a schematic diagram of another folding chair that adopts the structure of this utility model.

[0021] The attached figures are labeled as follows: 1. Backrest rod; 2. First main cross rod; 3. Second main cross rod; 4. First auxiliary connecting rod; 5. Connecting block; 50. Through hole; 6. Left support rod; 7. Right support rod; 8. Connector; 9. Connecting limiter; 10. Second auxiliary connecting rod; 11. Front support leg tube; 12. Rear support leg tube; 13. Armrest; 14. Seat tube; 15. Front cross tube assembly. Detailed Implementation

[0022] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] Furthermore, in the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more, unless otherwise expressly defined.

[0026] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0029] like Figure 1 and Figure 2 As shown, a folding mechanism for the backrest of a folding chair includes a backrest rod 1 and a rear crossbar assembly disposed between two backrest rods 1. The rear crossbar assembly includes a first main crossbar 2 and a second main crossbar 3 that are arranged in a cross manner. One end of the first main crossbar 2 and the second main crossbar 3 are respectively hinged to the upper part of the two backrest rods 1, and the other end of the first main crossbar 2 and the second main crossbar 3 are respectively movably connected to the backrest rod 1, or directly movably connected to the chair frame.

[0030] like Figure 3 As shown, the other ends of the first main cross rod 2 and the second main cross rod 3 are respectively hinged to the first auxiliary connecting rod 4 and the second auxiliary connecting rod 10. The first auxiliary connecting rod 4 and the second auxiliary connecting rod 10 are hinged to the lower parts of the two backrest rods 1. In other embodiments, the first main cross rod 2 and the second main cross rod 3 can be directly slidably connected to the lower parts of the two backrest rods 1.

[0031] Figure 3The chair frame includes a front support leg tube 11, a rear support leg tube 12, an armrest 13, a seat tube 14, and a front cross tube assembly 15. The upper ends of the front support leg tube 11 and the rear support leg tube 12 are hinged to the armrest 13. The seat tube 14 is rotatably connected to the front support leg tube 11, and its rear end is movably connected to the rear support leg tube 12. The upper part of the front cross tube assembly 15 is hinged to the front ends of the seat tubes 14 on both sides, and the lower part of the front cross tube assembly 15 is hinged to the lower end of the front support leg tube 11. The backrest rod 1 is rotatably connected to the armrest 13 and the seat tube 14.

[0032] like Figure 4 The diagram shows another type of chair frame structure of this utility model. The chair frame includes a front support leg tube 11, a rear support leg tube 12, an armrest 13, a seat tube 14, a backrest rod 1, and a front cross tube assembly 15. The front cross tube assembly 15 is movably connected to the two front support leg tubes 11. The upper end of the front support leg tube 11 is movably connected to the armrest 13. The middle part of the backrest rod 1 is movably connected to the armrest 13, and the lower end is hinged to the lower end of the front support leg tube 11. One end of the seat tube 14 is movably connected to the front support leg tube 11, and the other end is movably connected to the backrest rod 1. The upper end of the rear support leg tube 12 is movably connected to the backrest rod 1. The other ends of the first main cross rod 2 and the second main cross rod 3 are respectively hinged to the lower parts of the two rear support leg tubes 12.

[0033] A support rod assembly is also provided between the first main cross rod 2 and the second main cross rod 3. The support rod assembly includes a left support rod 6 hinged to the first main cross rod 2 and a right support rod 7 hinged to the second main cross rod 3. The left support rod 6 and the right support rod 7 are hinged together by a connecting block 5. When the cross rod assembly is opened, the ends of the left support rod 6 and the right support rod 7 abut against the connecting block 5. The support rod assembly forms a rigid lock in the unfolded state (abutting against the connecting block 5), avoiding accidental folding caused by external impact. The overall reliability and safety are high.

[0034] The left support rod 6 is hinged to the first main cross rod 2 via a connector 8, and the right support rod 7 is also hinged to the second main cross rod 3 via a connector 8. The first main cross rod 2, the second main cross rod 3, the left support rod 6, the right support rod 7, and the connecting block 5 are located in the same plane. The connector 8 is perpendicularly fixed to the first main cross rod 2 and / or the second main cross rod 3.

[0035] The connector 8 can be made of two metal connecting pieces, which respectively hinge the left support rod 6 to the first main cross rod 2 from both sides, or the right support rod 7 to the second main cross rod 3. In order to improve assembly efficiency, this embodiment adopts a connector with the following structure: one side of the connector 8 is a U-shaped opening and the other side is a closed collar. The U-shaped opening is hinged to the left support rod 6 or the right support rod 7, and the closed collar is sleeved and fixed on the first main cross rod 2 or the second main cross rod 3.

[0036] The aforementioned connector 8 adopts a composite structure of a U-shaped opening and a closed collar. The U-shaped opening is hinged to the strut, and the closed collar is fitted and fixed on the main cross bar. This structure simplifies the assembly process, reduces assembly complexity, and improves production efficiency and maintenance convenience; at the same time, it allows the strut to rotate freely around the main cross bar, ensuring smooth folding action.

[0037] The first main crossbar 2 comprises two rod segments fixedly connected by a connecting limiting member 9. The limiting connecting member 9 has an elongated through hole, through which the second main crossbar 3 passes, and the second main crossbar 3 is hinged to the connecting limiting member 9. The rod segments at both ends of the connecting limiting member 9 are staggered, ensuring that the two rod segments are parallel and not on a straight line.

[0038] During folding, the second main cross rod and the first main cross rod move closer to each other, and at the same time drive the first auxiliary connecting rod 4 and the second auxiliary connecting rod 10 to rotate downwards until all the rods are finally bundled together. The misalignment space between the rods at both ends of the connecting limit piece 9 on the first main cross rod allows the second main cross rod and the first main cross rod to be placed side by side and close together after folding, reducing the volume after folding. The entire folding process is convenient to operate and runs smoothly.

[0039] The connecting block 5 is designed in the shape of a handle, and the handle also has a through hole 50 for easy gripping. The through hole 50 is circular, rectangular, triangular, or elongated. The handle of the above structure not only serves as the hinge point of the support rod, but also has a through hole. The shape of the through hole can be designed according to needs, taking into account both grip comfort and lightweight. This structure improves portability, and the folding operation can be completed with one hand, making it suitable for quick storage scenarios.

[0040] In summary, through the above structure, this utility model significantly improves the stress resistance of the folding chair backrest and reduces the volume after folding without adding complex components.

[0041] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0042] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A folding and unfolding mechanism for a folding chair backrest, comprising a backrest rod (1) and a rear crossbar assembly disposed between two backrest rods (1), the rear crossbar assembly comprising a first main crossbar (2) and a second main crossbar (3) arranged in a cross configuration, one end of the first main crossbar (2) and the second main crossbar (3) being hinged to the upper part of the two backrest rods (1) respectively, and the other end of the first main crossbar (2) and the second main crossbar (3) being movably connected to the lower part of the backrest rod (1) or movably connected to the chair frame; characterized in that: A support rod assembly is provided between the first main cross rod (2) and the second main cross rod (3). The support rod assembly includes a left support rod (6) hinged to the first main cross rod (2) and a right support rod (7) hinged to the second main cross rod (3). The left support rod (6) and the right support rod (7) are hinged together by a connecting block (5). When the rear cross rod assembly is opened, the ends of the left support rod (6) and the right support rod (7) abut against the connecting block (5). The first main cross rod (2), the second main cross rod (3), the left support rod (6), the right support rod (7) and the connecting block (5) are located in the same plane.

2. The folding and unfolding mechanism for a folding chair back as described in claim 1, characterized in that, The left support rod (6) is hinged to the first main cross rod (2) via a connector (8), and the right support rod (7) is also hinged to the second main cross rod (3) via a connector (8).

3. The folding and unfolding mechanism for a folding chair back as described in claim 2, characterized in that, The connector (8) is fixedly installed with the first main crossbar (2) and / or the second main crossbar (3).

4. The folding and unfolding mechanism for a folding chair back as described in claim 2, characterized in that, One side of the connector (8) is a U-shaped opening and the other side is a closed collar. The U-shaped opening is hinged to the left support rod (6) or the right support rod (7), and the closed collar is sleeved and fixed on the first main cross rod (2) or the second main cross rod (3).

5. The folding and unfolding mechanism for a folding chair back as described in claim 1, characterized in that, The other ends of the first main cross rod (2) and the second main cross rod (3) are respectively hinged to the first auxiliary connecting rod (4) and the second auxiliary connecting rod (10), and the first auxiliary connecting rod (4) and the second auxiliary connecting rod (10) are hinged to the lower part of the two backrest rods (1).

6. The folding and unfolding mechanism for a folding chair back as described in claim 1, characterized in that, The first main cross rod (2) includes two rod segments fixedly connected by a connecting limiting member (9). The limiting connecting member (9) has an elongated through hole, and the second main cross rod (3) passes through the elongated through hole.

7. The unfolding and folding mechanism for a folding chair back as described in claim 6, characterized in that, The rods at both ends of the connecting limiting member (9) are staggered.

8. The unfolding and folding mechanism for a folding chair back as described in claim 1, characterized in that, The handle (5) is also provided with a through hole (50) for easy gripping.

9. The unfolding and folding mechanism for a folding chair back as described in claim 8, characterized in that, The through hole (50) is circular, rectangular, triangular or elongated.

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