Folding Mechanism of Sofa Bed and Sofa Bed

This application claims priority to Chinese patent application number 202410403698.5, filed on Apr. 3, 2024, and Chinese patent application number 202510070172.4, filed on Jan. 16, 2025. Chinese patent application number 202410403698.5 and Chinese patent application number 202510070172.4 are incorporated herein by reference.

The present disclosure relates to furniture, and more particularly to a sofa bed.

As living standards gradually improve, residents' demands for furniture products have become increasingly diversified. Among these, sofa beds have emerged as a popular furniture product. Existing sofa beds suffer from several drawbacks. For example, transitions between the two states (sofa and bed) of conventional sofa beds are not smooth, making it difficult for users with limited strength to operate independently, the sofa configuration of existing sofa beds may lack stability, as the angle between the seat and backrest may shift, compromising comfort, and furthermore, the folding mechanisms of current foldable beds are relatively simplistic and fail to meet diverse user needs.

Even if the aforementioned issues were resolved, current sofa beds still exhibit shortcomings in detailed design. For instance, cushions and elastic layers tend to shift relative to each other during use, the base support structure cannot adequately support both the sofa-configuration frame and bed-configuration frame, the mounting method between the bed frame and bed panels in the main frame is suboptimal, disassembly and folding of sofa bed components remain unachievable, and where spring modules are employed, their installation methods are often structurally unsound.

The primary technical problem addressed by the present disclosure is to provide a folding mechanism of a sofa bed. The folding mechanism has a simple structure and a reasonable position, making it convenient for users to adjust.

In order to solve the above technical problems, the present disclosure provides a folding mechanism of a sofa bed. The folding mechanism comprises a left armrest, a right armrest, a bed frame, and a locking mechanism. The bed frame comprises a first bed frame and a second bed frame arranged in sequence along a width direction of the left armrest and the right armrest, and the first bed frame is fixedly connected to and located between the left armrest and the right armrest. The second bed frame is rotatably connected to and located between the left armrest and the right armrest, and each of the left armrest and the right armrest is disposed with a folding hinge to enable the left armrest and the right armrest to be rotatably connected to the second bed frame. The folding hinge comprises a first supporting arm and a second supporting arm, and a first end of the first supporting arm and a first end of the second supporting arm is pivotally connected to each other. A second end of the first supporting arm is fixedly connected to a corresponding one of the left armrest or the right armrest, and a second end of the second supporting arm is fixedly connected to the second bed frame. The locking mechanism is configured to lock the first bed frame and the second bed frame in one or more relative positions.

In some embodiments, the locking mechanism comprises a ratchet disposed on one of the first supporting arm or the second supporting arm and a pawl disposed on the other one of the first supporting arm or the second supporting arm. The ratchet has at least two ratchet teeth arranged circumferentially, and the pawl is configured to engage one of the at least two ratchet teeth to lock the second bed frame at different positions.

In some embodiments, the second bed frame is configured to be in a first position and a second position relative to the first bed frame. When the second bed frame is in the first position, an angle between the first bed frame and the second bed frame is 180°. When the second bed frame is in the second position, the angle between the first bed frame and the second bed frame is less than 180°.

In some embodiments, the left armrest and the right armrest are fixedly connected by a lateral rod.

In some embodiments, the lateral rod comprises one or more position-provided recesses. When the second bed frame is in the first position, one or more parts of the second bed frame that abut the lateral rod are disposed in the one or more position-provided recesses.

The present disclosure provides a sofa bed, and the sofa bed comprises a bed board, a cushion layer, an elastic layer, and the folding mechanism. The bed board is respectively connected to the first bed frame and the second bed frame.

In some embodiments, the first bed frame comprises a plurality of first insertion holes located on two first side frames of the first bed frame along a length direction of the sofa bed. The second bed frame comprises a plurality of second insertion holes located on two second side frames of the second bed frame along the length direction of the sofa bed, and the plurality of first insertion holes and the plurality of second insertion holes are configured to fix the bed board.

In some embodiments, a first one of the two first side frames of the first bed frame and a first one of the two second side frames of the second bed frame facing away from each other respectively comprises a first inner surface and a second inner surface on which a plurality of first insertion holes and a plurality of second insertion holes are respectively located at intervals. A second one of the two first side frames of the first bed frame and a second one of the two second side frames of the second bed frame facing each other respectively comprises a first upper surface and a second upper surface on which a second set of plurality of first insertion holes and a second set of the plurality of second insertion holes are respectively located at intervals.

In some embodiments, the bed board comprises a plurality of grid-shaped bed board units, and a first side of each of the plurality of grid-shaped bed board units comprises a first set of a plurality of first insertion pins extending along a horizontal direction. A second side of each of the plurality of grid-shaped bed board units comprises a second set of the plurality of second insertion pins extending along a height direction.

In some embodiments, the bed board is divided into a first bed board connected to the first bed frame and a second bed board connected to the second bed frame.

In some embodiments, each of the left armrest and the right armrest extends in a direction in which the left armrest and the right armrest face each other to form a supporting rod for supporting the first bed frame. The supporting rod comprises a first connecting groove, and the first bed frame comprises one or more first connecting columns configured to be matched with the first connecting groove.

In some embodiments, the first connecting groove is divided into a first portion and a second portion which are in communication with each other, and a distal end of each of the one or more first connecting columns radially extends outward to form a flange. A diameter of the first portion is larger than a diameter of the flange, and a diameter of the second portion is smaller than the diameter of the flange.

In some embodiments, the first bed frame and the second bed frame are connected to the first bed board and the second bed board by screws respectively.

In some embodiments, an end of the second supporting arm away from the first supporting arm extends to form a supporting surface for supporting the second bed board. The supporting surface comprises a second connecting groove, and the second bed frame comprises one or more second connecting columns configured to be matched with the second connecting groove.

In some embodiments, the second connecting groove is divided into a first portion and a second portion which are in communication with each other, and a distal end of each of the one or more second connecting columns radially extends outward to form a flange. A diameter of the first portion is larger than a diameter of the flange, and a diameter of the second portion is smaller than the diameter of the flange.

In some embodiments, the bed board comprises a third bed board connected to the first bed board, and the third bed board is connected to a side of the first bed board adjacent to the second bed board. The third bed board is arranged at an obtuse angle relative to the first bed board, and a distal end of the third bed board is connected to a first group of a plurality of elastic units on the first bed board adjacent to the second bed board.

In some embodiments, the bed board comprises at least one set of two sub-bed boards, and the two sub-bed boards are pivotally connected to each other, so that the bed board has an unfolded state and a folded state.

In some embodiments, one or more middle legs are provided for supporting the two sub-bed boards, and opposite sides of the two sub-bed boards are each disposed with one or more connecting lugs. When the bed board is in the unfolded state, two sets of the one or more connecting lugs that respectively belong to the two sub-bed boards are misaligned with each other in a height direction so that connecting holes respectively on the two sets of the one or more connecting lugs are aligned with each other. The one or more middle legs have pins passing through the connecting holes to fix the first bed board in the unfolded state.

In some embodiments, a surface of the bed board is disposed with a plurality of connecting assemblies configured to be connected to the elastic layer and spaced apart from each other, and a side of the elastic layer facing the bed board comprise one or more connecting matching assemblies configured to be matched with the plurality of connecting assemblies.

In some embodiments, the plurality of connecting assemblies are I-shaped protrusions extending in a height direction.

In some embodiments, each of the plurality of connecting assemblies comprises a fixed tapered upper cover and a fixed tapered lower cover, and the fixed tapered upper cover and the fixed tapered lower cover are respectively disposed on an upper side and a lower side of the bed board in a thickness direction of the bed board. The fixed tapered lower cover passes through the bed board and is fixedly connected to the fixed tapered upper cover, and the fixed tapered upper cover is tapered. The one or more connecting matching assemblies are one or more tapered holes.

In some embodiments, the elastic layer comprises a plurality of first connecting members spaced apart from each other in a circumferential direction of the elastic layer, and a lower surface of the cushion layer comprises a plurality of second connecting members spaced apart from each other in a circumferential direction of the cushion layer. The plurality of first connecting members are connected to the plurality of second connecting members through one or more intermediate connecting members.

In some embodiments, the plurality of first connecting members and the plurality of second connecting members are insertion slots, and the one or more intermediate connecting members are respectively connected to the plurality of first connecting members and the plurality of second connecting members.

In some embodiments, each of the one or more intermediate connecting members comprises a connecting belt and two insertion blocks disposed at two ends of the connecting belt.

In some embodiments, the elastic layer comprises a plurality of elastic units arranged in an array arrangement, and adjacent elastic units of the plurality of elastic units are connected together to form the elastic layer.

In some embodiments, each of the plurality of elastic units is disposed with a correspond set of the plurality of first connecting members respectively located on two first sides of a corresponding one of the plurality of elastic units in a transverse direction of the array arrangement and two second sides of the corresponding one of the plurality of elastic units in a longitudinal direction of the array arrangement. Adjacent two first connecting members of the plurality of first connecting members that respectively belong to adjacent two elastic units of the plurality of elastic units are connected by a corresponding one of the one or more intermediate connecting members.

In some embodiments, the cushion layer is fixedly connected to the bed frame.

Compared with the existing techniques, the technical solution has the following advantages. The first bed frame and the second bed frame are arranged between the left armrest and the right armrest. The left armrest and right armrest are respectively rotatably connected to the second bed frame via the folding hinges, and the locking mechanism is provided to form the folding mechanism. This design enables the second bed frame to be folded at an angle vertically, allowing the sofa bed to switch between sofa and bed configurations. The folding mechanism is simple in structure, reasonably positioned, and convenient for user adjustment.

The technical solutions of the embodiments of the present disclosure will be described in detail below with reference to the drawings. It should be understood that the embodiments described are only part of the embodiments of the present disclosure, and not all possible embodiments. All other embodiments that would be apparent to a person skilled in the art based on the teachings of the present disclosure, without requiring any inventive step, are within the scope of the present disclosure's protection.

In the description of the present disclosure, it should be noted that terms such as “upper”, “lower”, “inner”, “outer”, “top”, “bottom”, and the like, refer to positions or positional relationships based on the orientations shown in the drawings. These terms are used for convenience in describing the present disclosure and simplifying the description, and should not be interpreted as limiting the present disclosure. The device or element in question does not necessarily have to be constructed or operated in a specific orientation or position. Additionally, the terms “first”, “second”, and similar terms are used for descriptive purposes only and do not imply any relative importance or ranking.

In the description of the present disclosure, unless otherwise clearly stated or limited, terms such as “installed”, “provided with”, “mounted/connected”, “connected”, etc., should be understood in their broadest sense. For example, “connection” can refer to a wall-mounted connection, a detachable connection, or an integral connection. It may refer to a mechanical or electrical connection, direct or indirect connection, or an internal connection between components. The specific meaning of these terms will be understood by those skilled in the art based on the particular context of the disclosure.

Referring to, this embodiment provides a foldable sofa bed. A backrest portion of the sofa bed can be laid flat so that the backrest portion and a seat cushion can be combined to form a flat bed, and the backrest portion can form an angle less than 180° with the seat cushion to achieve a function of a normal sofa.

To this end, the sofa bed comprises a structural frame, a cushion layer, and an elastic layer. The structural frame is used to support the elastic layerand the cushion layer.

Specifically, the structural frame comprises a left armrest, a right armrest, a bed frame, and a bed board. The bed frame comprises a first bed frameand a second bed framearranged in sequence along a width direction of the left armrestand the right armrest. The first bed frameis fixedly connected to and located between the left armrestand the right armrest, and the second bed frameis rotatably connected to and located between the left armrestand the right armrest. The bed board is respectively connected to the first bed frameand the second bed frame.

After the above settings, the first bed frameis fixedly connected to the left armrestand the right armrest, and the first bed frameis correspondingly used as a first supporting frame of the seat cushion. The second bed framecan be rotated relative to the left armrestand the right armrest, thereby changing an angle relative to the first bed frame, and the second bed frameis correspondingly used as a second supporting frame of the backrest portion.

By limiting a rotation range of the second bed frame, the second bed frameis configured to be in a first position and a second position relative to the first bed frame. When the second bed frameis in the first position, the angle between the first bed frameand the second bed frameis 180°. When the second bed frameis in the second position, the angle between the first bed frameand the second bed frameis less than 180°.

In this embodiment, to achieve a rotating connection of the second bed framerelative to the left armrestand the right armrest, each of the left armrestand the right armrestis disposed with a folding hingeto enable the left armrestand the right armrestto be rotatably connected to the second bed frame. The folding hingecomprises a first supporting armand a second supporting arm. A first end of the first supporting armand a first end of the second supporting armare pivotally connected to each other. A second end of the first supporting armis fixedly connected to a corresponding one of the left armrestor the right armrest, and a second end of the second supporting armis fixedly connected to the second bed frame.

In this embodiment, the second bed frameneeds to be locked in the second position to achieve the function of the normal sofa. To this end, a locking mechanism is provided. The locking mechanism is configured to lock the first bed frameand the second bed framein one or more relative positions. Specifically, the locking mechanism comprises a ratchetmounted on one of the first supporting armor the second supporting arm, and a pawlmounted on the other one of the first supporting armor the second supporting arm. The ratchethas ratchet teeth arranged circumferentially, and the pawlis configured to engage one of the ratchet teeth to lock the second bed frameat its current position.

To achieve multi-position adjustment of an angle of the backrest portion, a number of ratchet teeth can be increased, so that when the pawlis engaged with different ratchet teeth, a position of the second bed framecan be changed, thereby achieving the multi-position adjustment of the angle of the backrest portion.

In order to increase stability of the structural frame, the left armrestand the right armrestare fixedly connected by a lateral rod. The lateral rodis arranged on a side of the left armrestand the right armrestadjacent to the backrest portion. A supporting legextends downward from a middle of the lateral rodalong a height direction, and the supporting legabuts ground to provide an additional supporting point.

Since the second bed frameand the first bed frameare in a coplanar configuration when the second bed frameis in the first position, the lateral rodis configured to avoid interference with a rotation of the second bed frame. To this end, the lateral rodcomprises one or more position-provided recesses. When the second bed frameis in the first position, one or more parts of the second bed framethat abut the lateral rodare disposed in the one or more position-provided recesses, thereby avoiding interference between the lateral rodand the second bed frame.

In this embodiment, each of the second bed frameand the first bed frameis formed by connecting two rectangular frames along a length direction of the foldable sofa bed. Therefore, the second bed frameincludes a longitudinal beamin a middle of the second bed frame, in addition to all sides of a rectangular frame of the second bed frame. Therefore, the one or more position-provided recessesare three position-provided recesses, and the three position-provided recessescorrespond to two sides of the rectangular frame of the second bed frameand the longitudinal beam.

Since the first bed frameand the second bed frameare merely frames and cannot support the elastic layerand the cushion layer, the bed board needs to be mounted on the first bed frameand the second bed frame. In order to mount the bed board, the first bed framecomprises a plurality of first insertion holeslocated on two first side frames of the first bed framealong the length direction of the foldable sofa bed, and the second bed framecomprises a plurality of second insertion holeslocated on two second side frames of the second bed framealong the length direction of the foldable sofa. The plurality of first insertion holesand the plurality of second insertion holesare configured to fix the bed board.

To ensure stability of the bed board, positions of each of the plurality of first insertion holesand the plurality of second insertion holesare different, so that a position of the bed board can be inhibited from moving in the height direction and in a horizontal direction, thereby ensuring the stability of the bed board. Specifically, a side frame of the first bed frameand a side frame of the second bed framefacing away from each other respectively comprises a first inner surface and a second inner surface on which a first set of the plurality of first insertion holesand a first set of the plurality of second insertion holesare respectively located at intervals. A side frame of the first bed frameand a side frame of the second bed framefacing each other respectively comprises a first upper surface and a second upper surface on which a second set of the plurality of first insertion holesand a second set of the plurality of second insertion holesare respectively located at intervals.

Correspondingly, the bed board comprises a plurality of grid-shaped bed board units. A first side of each of the plurality of grid-shaped bed board unitscomprises a plurality of first insertion pinsextending along the horizontal direction, and a second side of each of the plurality of grid-shaped bed board unitscomprises a plurality of second insertion pinsextending along the height direction. By inserting the plurality of first insertion pinsand the plurality of second insertion pinsextending in different directions into the plurality of first insertion holesand the plurality of second insertion holesextending in different directions, the bed board can be stably fixed on the first bed frameand the second bed frame.