Patent ID: 12220058

DETAILED DESCRIPTION OF EMBODIMENTS

Specific embodiments of the present prevention will now be described in detail with reference to the figures. What are described here are only preferred embodiments according to the present invention. Those skilled in the art can implement other embodiments of the present invention on the basis of the preferred embodiments, and said other embodiments also fall within the scope of the present invention.

The invention provides a sofa bed.FIG.1-FIG.63show at least partial structures of some preferred embodiments of the present invention. First, it needs be appreciated that “transverse direction” and “longitudinal direction” mentioned in the present invention are two directions perpendicular to each other, and they are relative directions relative to a rectangle formed by a seat portion, a backrest portion and even a unit frame; the transverse direction is shown by X in the figures, and the longitudinal direction is shown by Y in the figures; a height direction mentioned in the text is an absolute vertical direction and shown by Z in the figures.

FIG.1-FIG.63show some preferred embodiments of the present invention.

Referring toFIG.1throughFIG.4, a sofa bed in the preferred embodiment comprising a main body frame100which includes a seat portion4, a backrest portion3, a seat portion connecting rod41, a backrest portion connecting rod31, and two armrest frames2. The seat portion4and the backrest portion3are both formed as a rectangular structure, which may be a rectangular frame structure or a rectangular plate-shaped structure. A longitudinal edge of the seat portion4and a longitudinal edge of the backrest portion3are butted together.

The seat portion connecting rod41is fixed on a transverse edge of the seat portion4, the backrest portion connecting rod31is fixed on a transverse edge of the backrest portion3, and the seat portion connecting rod41and the backrest connecting rod31are connected together in a way that they are pivotable relative to each other. When the seat portion connecting rod41and the backrest portion connecting rod31pivot relative to each other, an angle therebetween increases or decreases. It needs to be appreciated that the “angle” mentioned in the present invention refers to an angle less than or equal to 180°.

The two armrest frames2are provided at both ends of the seat portion4and the backrest portion3in the longitudinal direction, and each armrest frame2is provided with a slideway that opens toward the backrest portion3and the seat portion4and partially extends in the transverse direction. In the present embodiment, the slideway is a sliding groove211, and a rear end211bof the sliding groove211is lower than a front end211aof the sliding groove211.

The exploded schematic view of the pivotal connection of the seat portion4and the backrest portion3is shown inFIG.5. Referring toFIG.5, the seat portion connecting rod41and the backrest portion connecting rod31are engaged by a hinge mechanism34, and the hinge mechanism34has a pin341protruding from a side facing the armrest. The front end211aof the sliding groove211is provided with an upward opening, so that the pin341can enter the sliding groove211from the front end211aof the sliding groove211and slide in the sliding groove211. A special-shaped gear and a gear matching claw are provided at the hinge mechanism34, and respectively disposed on the seat portion connecting rod41and the backrest portion connecting rod31. The special-shaped gear is for example a ratchet342. An edge of the ratchet342is provided with a recessed portion that is recessed in a radial direction of the ratchet342. The gear matching pawl is provided with a protruding portion that mates with the recessed portion. The recessed portion and the protruding portion are positioned such that when the backrest portion3and the seat portion4are at a predetermined obtuse angle, the protruding portion is embedded in the recessed portion to achieve locking. The seat portion4is provided with a seat portion insertion sleeve42for accommodating the seat portion connecting rod41, and the backrest portion3is provided with a backrest portion insertion sleeve32for accommodating the backrest portion connecting rod31.

Furthermore, each armrest frame2includes an armrest frame main body22(i.e. the outer frame of the armrest frame) and a reinforcing cross beam21, the sliding groove211is disposed on the reinforcing cross beam21, and an extension direction of the reinforcing cross beam21coincides with that of the sliding groove21, i.e., the rear end211bof the reinforcing cross beam21is also lower than the front end211aof the reinforcing cross beam21. The armrest frame main body22further includes two upright columns extending in the vertical direction and a body cross beam connected to the top of the two upright columns. The reinforcing cross beam is connected to the middle of the two upright columns and is parallel to the main body cross beam.

In addition to the armrest frame2, the supporting and fixing structure of the sofa bed further includes a bottom supporting structure24which is disposed under the backrest portion3and the seat portion4and is fixedly connected to the two armrest frames2. The bottom supporting structure24for example includes a bottom supporting structure longitudinal beam, a bottom supporting structure transverse beam23, and legs25. The sofa bed further includes a driven beam26whose one end is pivotally connected to the armrest frame2, and whose the other end is pivotally connected to the backrest portion3.

FIG.6A-FIG.6Fshow a process in which the main body frame100transitions from a first in-use position (in which the sofa bed is used as a bed) to a second in-use position (in which the sofa bed is used as a sofa) and then back to the first in-used position.

First, referring toFIG.6A, when the main body frame100is in the first in-use state, the backrest portion3and the seat portion4are both horizontal, and the angle therebetween is a straight angle. The angle between the backrest portion connecting rod31and the seat portion connecting rod41is also substantially a straight angle, and the pivot of the hinge mechanism34is substantially located nearby the front end211aof the sliding groove211. At this time, the backrest portion connecting rod31and the seat portion connecting rod41are not locked, which allows the seat portion4to be operated to pivot toward a position where the angle between the seat portion4and the backrest portion3is reduced. The direction of the pivoting is shown by the arrow inFIG.6A.

When the main body frame100needs to be adjusted to the second in-use state, the seat portion4can be pivoted in the direction shown by the arrow inFIG.6A, to the position shown inFIG.6B. At the position shown inFIG.6B, the pivoting between the backrest portion connecting rod31and the seat portion connecting rod41is locked. Specifically, for example, the hinge mechanism34may be provided with a special-shaped ratchet342and a special-shaped pawl. At the position shown inFIG.6B, the special-shaped ratchet342and the special-shaped pawl are shaped to snap fit together to stop the seat portion4from further rotating relative to the backrest portion3. At this time, the angle between the seat portion4and the backrest portion3is a, which is an obtuse angle. The “predetermined obtuse angle” mentioned in the present invention may be understood as a inFIG.6B.

At this time, the pin341at the hinge mechanism34can enter the sliding groove211from the front end211aof the sliding groove211. Then, as shown inFIG.6C, the seat portion4may be pressed down along an arc-shaped arrow, and meanwhile the pin341can drive the combination of the backrest portion3and the seat portion4to slide in a direction indicated by a straight arrow inFIG.6C. After this operation, the combination of the backrest portion3and the seat portion4can reach the second in-use state as shown inFIG.6D.

In the structure shown inFIG.6BthroughFIG.6D, the backrest portion connecting rod31and the seat portion connecting rod41are locked to each other at the hinge mechanism34, and the angle between the backrest portion3and the seat portion4is always a.

When it is necessary to change the main body frame100from the second in-use position to the first in-use position, the seat portion4can be manually operated to further pivot toward the backrest portion3in the direction indicated by the arrow as shown inFIG.6D. The action for example can make the protruding portion of the pawl disengage from the recessed portion of the ratchet, thereby releasing the locking between the seat portion connecting rod41and the backrest portion connecting rod31.

Referring toFIG.6E, after the seat portion4is pivoted in the direction indicated by arrow A, the locking between the seat portion connecting rod41and the backrest portion connecting rod31is released. After the locking is released, the pin341is allowed to slide in the sliding groove211toward the front end211ain the direction indicated by the arrow B, thereby driving the backrest portion3and the seat portion4to reach the position shown inFIG.6F, so that the main body frame100returns to the first in-use state.

To sum up, it can be seen that the sofa bed of the present invention includes the hinge mechanism, and the hinge mechanism includes a first section (e.g., the combination of the seat portion insertion sleeve42and the seat portion connecting rod41in the above embodiments), a second section (e.g., the combination of the backrest portion insertion sleeve32and the backrest portion connecting rod31in the above embodiments) and a third section (e.g., the driven beam26in the above embodiments) which are sequentially connected pivotally relative to one another. The first section is fixed to a side of the seat portion, the second section is fixed to a side of the backrest portion, and the protruding portion (e.g., pin341) is provided at a position where the first section is connected with the second section. The slideway is disposed on the armrest frame for engaging and guiding the protruding portion, an end of the third section opposite to the second section (i.e., an end of the driven beam opposite to the backrest portion connecting rod31) is pivotally connected with the armrest frame.

In addition to the above embodiments, the hinge mechanism of the present invention may also have other preferred arrangements.

For example, referring toFIG.7andFIG.8, the hinge mechanism234includes a first section2341, a second section2342and a third section2343. The first section2341includes a first section rod2341band a first section sleeve2341a, the first section sleeve2341ais provided with an opening toward the seat portion, the first section rod2341bis placed in the first section sleeve2341a, and the opening of the first section sleeve2341aand the seat portion are fixed together to encapsulate the first section rod2341btherein. The first section rod2341band the first section sleeve2341amay be further fastened together by bolts. The second section2342includes a second section rod2342band a second section sleeve2342a, the second section sleeve2342ais provided with an opening towards the backrest portion, the second section rod2342bis placed in the second section sleeve2342a, and the opening of the second section sleeve2342aand the backrest portion are fixed together to encapsulate the second section rod2342btherein. The first section rod2341band the second section rod2342bmay also be pivotally connected. The second section rod2342band the second section sleeve2342amay also be further fastened together by bolts. One end of the third section2343is pivotally connected to the second section sleeve2342a, and the other end of the third section2343is pivotally connected to the armrest frame202.

The mounting and connection relationship between the hinge mechanism and the bottom supporting structure210is shown inFIG.11-FIG.13. As shown in the figure, an armrest frame202has a reinforcing beam201, and a slideway2011having an opening2011ais formed on the reinforcing beam. A protruding portion2344at the connection of the first section2341and the second section2342can extend from the opening2011ainto the slideway2011of the armrest frame202and can slide in the slideway2011. Specifically, the protruding portion2344slides in the slideway2011in a case where an angle between the first section2341and the second section2342is locked.

FIG.9andFIG.10are schematic views of another hinge mechanism of the sofa bed according to the present invention. Referring toFIG.9, a first section2351, a second section2352and a third section2353are sequentially and pivotably connected, wherein, the first section2351is a one-piece member, and the second section is also a one-piece member. If the first section2351and the second section2352are sectioned with a plane perpendicular to a direction in which the first section2351and the second section2352are pivoted relative to each other, it can be seen that the sections of the first section2351and the second section2352are L-shaped. In order to make the first section2351and the second section2352which are L-shaped in cross section have better stability, reinforcing portions2355are provided at an angle of the two walls forming the L shape, and reinforcing portions2355comprise a plurality of reinforcing portions and are disposed in an extending direction of the first section2351and the second section2352. A protrusion2354capable of engaging with the slideway is disposed at the connection between the first section2351and the second section2352.

FIG.14-FIG.22illustrate another preferred embodiment according to the present invention.

Referring toFIG.14andFIG.15, the sofa bed includes a main body frame200and an armrest frame202, and the seat portion204and the backrest portion203of the main body frame200can transition between a sofa configuration and a bed configuration.

FIG.16shows a schematic view of a bottom supporting structure210of the sofa bed inFIG.14andFIG.15after the main body frame200is detached. The bottom supporting structure210includes a support pipe203extending substantially in a transverse direction, and the number of support pipe203may be one, two or more. In the present embodiment, the support pipe serves as a bracket, while in other embodiments the bracket may have other forms. The support pipe203is provided with a first supporting structure and a second supporting structure, wherein the first supporting structure is configured to support the position where the seat portion204and the backrest portion203are connected when the main body frame200is in the bed configuration; the second supporting structure is configured to support both the seat portion204and the backrest portion203when the main body frame200is in the sofa configuration.

Referring toFIG.17, in the present embodiment, a main body2031of the support pipe extends in the transverse direction of the seat portion204and the backrest portion203, and the main body2031of the support pipe includes a first support pipe section2031a, a second support pipe section2031band a third support pipe section2031cwhich are connected sequentially, the main body2031of the support pipe is provided with a support block2032, a lower end of the support block2032may have a U-shaped opening2032a, and the U-shaped opening2032acan be snapped on the main body2031of the support pipe, and the support block2032may have a riveting hole for engaging with the main body2031of the support pipe, and the support block2032may be mounted on the main body of the support rod by welding or riveting.

Referring to the state in which the main body frame200is in the bed configuration as shown inFIG.18andFIG.19, the support block2032is located below the position where the seat portion204and the backrest portion203are connected (the hinge mechanism234is disposed at the longitudinal end of the connection position) and supports the seat portion204and the backrest portion203simultaneously, so that the main body frame200is stably located in the bed configuration. That is, in the present embodiment, the support block2032constitutes the first supporting structure of the support rod.

Referring to the state when the main body frame200is in the sofa configuration as shown inFIG.20andFIG.21, it can be seen that the first section2031aof the support pipe203abuts against and supports a bottom surface of the seat portion204, and the second section2031bof the support pipe203abuts against and supports a surface of the backrest section203facing away from the seat portion204, that is, the surfaces of the support rod first section2031aand the support rod second section2031bof the support pipe203facing the main body frame200jointly form the second supporting structure for the support rod.

Preferably, further referring toFIG.20, the backrest portion203and the seat portion204each include a plurality of longitudinal beams220extending in the longitudinal direction. Referring toFIG.22, the support block2032is configured to be positioned forward of a longitudinal beam220of the seat portion204to limit the forward slide of the seat portion204when the main body frame200is in the bed configuration. Referring toFIG.18andFIG.19, when the main body frame200is in the bed configuration, the longitudinal beam of the backrest portion203closest to the seat portion204and the longitudinal beam of the seat portion204closest to the backrest portion203are in close contact with each other, and the support block2032contact sand supports the two longitudinal beams.

As a comparison with the present invention,FIG.23shows a limiting supporting structure of a conventional sofa bed. It can be seen that in this structure, a limiting and fixing device205′ is provided on the leg230′ to support a bed plate204′ in a sofa configuration, but the supporting structure cannot support the bed plate when the bed plate is in a bed configuration. The present invention overcomes this defect. In the present invention, the support pipe as shown inFIG.17is provided, and the sofa bed in the present invention needn't be provided with the traditional limiting and fixing structure as shown inFIG.23. Certainly, the present invention can also be provided with a limiting supporting structure as shown inFIG.23.

Preferably, turning back toFIG.16andFIG.17, the bottom supporting structure210includes two longitudinal bottom supporting structure pipes located at two transverse outermost edges respectively; both ends of the main body2031of the support pipe are respectively provided with downward-opened and U-shaped portion2033; when the support pipe203is mounted on the bottom supporting structure210, the two longitudinal bottom supporting structure pipes are respectively embedded in the two U-shaped portions2033of the support pipe203.

FIG.24-FIG.29illustrate another preferred embodiment according to the present invention. Referring toFIG.24, the sofa bed includes a main body frame composed of a seat portion203and a backrest portion204, and an armrest frame202. Both the seat portion203and the backrest portion204include a mesh panel structure.

FIG.25may be a separate schematic view of the seat portion203or the backrest portion204inFIG.24, wherein the seat portion203and the backrest portion204may both include main body units205. By way of an example,FIG.25shows the seat portion203ofFIG.24. The seat portion203includes two main body units205arranged in the longitudinal direction, and each main body unit205includes a unit frame301and a unit mesh panel302. Referring toFIG.26, the unit frame301is provided with a step3011around an inner edge of the unit frame301and integrally disposed around the main body of the unit frame301. The step3011may be disposed intermittently or continuously. The unit mesh panel302includes an edge rib around its edge. The unit mesh panel302is detachably mounted on the unit frame301and the edge rib fits on the step3011.

FIG.27andFIG.28show schematic views after the unit mesh panel302is removed from the unit frame301, andFIG.29shows a schematic view showing the unit mesh panel302mounted on the unit frame301. As can be seen fromFIG.28andFIG.29, the unit frame301is further mounted with a toggle piece303which is configured to be operable to move between a first position (as shown inFIG.29) where the toggle piece303stops at a top of the edge rib to prevent the unit mesh panel302from disengaging from the unit frame301and a second position (shown inFIG.28) that the toggle piece303allows the unit mesh panel302to disengaging from the unit frame301.

Preferably, the toggle piece303is configured to be connected to the unit frame301via a pin304perpendicular to an overall extension direction of the main body unit205and to be rotatable about the pin304.

Also preferably, each of the main body units205is a polygonal structure, and each corner of the polygonal structure is provided with the toggle piece303. In the present embodiment, each main body unit205is rectangular.

As shown inFIG.24, the seat portion203and the backrest portion204are each formed into a rectangular structure. Respective longitudinal edges of the seat portion203are butted together with respective longitudinal edges of the backrest portion204, and the seat portion203and the backrest portions204each include two main body units205arranged in the longitudinal direction thereof. That is to say, the sofa bed includes four main body units205arranged in an array, wherein a pair of main body units205arranged side by side in the longitudinal direction constitute the seat portion203, and another pair of main body units205arranged side by side in the longitudinal direction constitute the backrest portion204.

FIG.30-FIG.37illustrate another preferred embodiment according to the present invention.

Referring toFIG.30andFIG.31, the armrest frame202of the sofa bed can be detached from the sofa bed main body, and the armrest frame202itself can further be disassembled. The armrest frame202includes a substantially U-shaped armrest frame main body and a reinforcing beam201detachably connected between two legs of the armrest frame main body, wherein both ends of the reinforcing beam201are provided with tongues2012which are respectively detachably engaged with the two legs. A slideway2011is formed on the reinforcing beam201.

In order to facilitate the positioning and installation of the reinforcing beam201on the armrest frame main body, the armrest frame main body is further provided with a catching hole2021, and each end of the reinforcing beam201may be provided with a small protrusion which can engage with the catching hole2021to achieve positioning.

Preferably, referring toFIG.32-FIG.34, the armrest frame main body can be further disassembled and/or folded. That is to say,FIG.32-FIG.34show two storing modes that can be realized on the same armrest frame main body at the same time.

The armrest frame main body includes a plurality of sections202aconnected in sequence, one section202aof any two adjacent sections202ahas an opening at the end, and the end of the other section202aextends into the opening to connect the two adjacent sections202a. Each section202ais disassembled and stored in one of two storing modes.

The legs are connected to a connecting section by a pivot shaft203a, and the armrest frame main body is configured so that the two legs can be pivotally folded relative to the connecting section between the two legs to make the armrest frame main body is in a folded state as shown inFIG.34. Referring toFIG.33, the connection between the section202cof the leg and the section202cof the connecting section specifically includes a shaft202f, a washer202e, and a plastic cover202dthat encapsulates the shaft202fand washer202e. The legs and the connecting section being pivotally thus to be stored is the other mode of the two storing modes.

The structure of the armrest frame adapting the second storing mode other than the first storing mode is shown inFIG.34.

Referring toFIG.36andFIG.37, a cross-section of the leg is rectangular, a cross-section of the tongue2012is L-shaped, and the tongue2012fits with two adjacent side surfaces of the leg. Furthermore, the sofa bed further includes the bottom supporting structure210positioned and supported under the main body frame. The bottom supporting structure210includes a bottom supporting structure longitudinal beam connected between the two armrest frames202. Furthermore, the tongue2012of each of the armrest frames202includes a first portion of the tongue2012facing the other armrest frame202and fitted on the leg. The bottom supporting structure longitudinal beam is connected to the armrest frame202by being fixed on the first portion of the tongue2012by a bolt2014.

As an alternative to the tongue with the L-shaped cross-section,FIG.35shows another reinforcing beam201on which a slideway2011is provided. The cross section of the tongue2013of the reinforcing beam201is U-shaped, and the tongue2013can fit on two adjacent side surfaces of the leg and a surface between the two adjacent side surfaces.

FIG.38A-FIG.47show schematic views of another preferred embodiment of the present invention. The sofa bed may further include a plurality of elastic modules mounted in an array on the seat portion and the backrest portion.

FIG.39shows an exploded schematic view of an elastic module400. Each elastic module400includes a conical spring403and a spring bracket402that accommodates the conical spring. The spring bracket402includes a bottom portion401that can fit with the main body frame of the sofa bed. The spring bracket of each of the elastic modules includes a base having a spring mounting seat405, wherein each spring mounting seat405has a spring fixing portion for fixing an end of the conical spring. An end cap407is disposed opposite to a corresponding spring mounting seat405. Flexible straps408are spaced apart from each other and evenly arranged between a corresponding pair of the spring mounting seat and end cap.

In the present embodiment, the seat portion204and the backrest portion203may each constitute a main body frame, or both of them may jointly constitute a main body frame. The main body frame is formed with a slide rail that can be engaged with the bottom of the spring bracket, so that the plurality of elastic modules400can slide in the slide rails, and the main body frame can be folded in half along a fold-in-half line perpendicular to an extending direction of the slide rail to switch between a folded state and an in-use state. When the main body frame is in the folded state, the slide rail forms a slide rail opening53at the fold line; when the main body frame is in the in-use state, the slide rail opening53is closed. The slide rails on the main body frame are configured so that the plurality of elastic modules400can be mounted to the slide rails from the outside of the main body frame via the slide rail openings53and slide toward the ends of the slide rails when the main body frame is folded, so that the plurality of elastic modules400are densely arranged on the side facing the user.

It should be appreciated that the “folded state” mentioned herein refers to a position where the main body frame is folded in half along the fold-in-half line to expose the opening53of the slide rail. When the main body frame is in the folded state, the sofa bed cannot be used. As this time, the sofa bed is not used as a bed nor as a sofa. The “in-use state” mentioned herein refers to a position where the main body frame is flattened so that the opening53of the slide rail is closed, and the sofa bed can be used in the in-use state. At this time, the sofa bed can be used as a sofa or a bed.

FIG.40shows a possible structure of the seat portion204or the backrest portion203. For an illustration purpose,FIG.40shows the seat portion204. Each of the slide rails of the seat portion204extending in the longitudinal direction is mounted with an odd number of elastic modules400, and the fold line is offset from an intermediate position of the main body frame in the longitudinal direction.FIG.41-FIG.46are schematic views of a process of mounting the elastic modules400on the main body frame to finally obtain the structure shown inFIG.40.

Referring toFIG.41, the main body frame is folded in half along the fold-in-half line, and the two folded portions50folded in half with each other, namely, a first folded portion50aand a second folded portion50b, have different longitudinal dimensions (i.e., dimensions of extension along their respective longitudinal directions). Taking the first folded portion50aas an example, the first folded portion50aincludes a plurality of longitudinal beams52(i.e., rail beams), and any two adjacent longitudinal beams52together form a slide rail, each slide rail has an opening53at a position wherein the first folded portion50aand the second folded portion50bare folded in half.

Referring toFIG.42, the elastic module400can be mounted into the slide rail from the opening53of the slide rail and slide on the slide rail. The bottom of the elastic module400matches with the slide rail, so that the elastic module400can not only slide on the slide rail, but also won't disengage from the slide rail from other positions except the opening53. A state after one slide rail of the first folded portion50ais covered with the elastic modules400is shown inFIG.43, and a state after all slide rails of the first folded portion50aare covered with the elastic modules400is shown inFIG.44. InFIG.44, the second folded portion50bis not yet mounted with spring modules, and the second folded portion50balso has a plurality of longitudinal beams52, and any two adjacent longitudinal beams52form a slide rail.

FIG.45shows a schematic view showing one slide rail of the second folded portion50bbeing covered with the elastic modules400. It can be seen that the elastic modules400are also mounted into the slide rail from the opening53of the slide rail of the second folded portion50b. A state in which the second folded portion50bis covered with the elastic modules400is shown inFIG.46. InFIG.46, the first folded portion50aand the second folded portion50bare both covered with the elastic modules400, the seat portion204can be flattened again by folding the first folded portion50aand the second folded portion50bin a direction indicated by the arrows in the figure; the openings53of the slide rails will be closed after the flattening, and the elastic modules400cannot be taken out from the seat portion204.

It can be seen fromFIG.46that at maximum 7 elastic modules400can be mounted on each slide rail of the first folded portion50a, and at maximum 6 elastic modules400can be mounted on each slide rail of the second folded portion50b. The maximum number of the elastic modules400that can be mounted on each slide rail of the first folded portion50ais only one more than the maximum number of the elastic modules400that can be mounted on each slide rail of the second folded portion50b. In this way, finally the maximum number of the elastic modules400that are received in a complete slide rail (jointly formed by butting a slide rail of the first folded portion50awith a slide rail of the second folded portion50b) of the seat portion204is certainly an odd number. Such an arrangement can minimize the longitudinal dimension of the main body frame (i.e., the longitudinal dimension of the first folded portion50a) when the main body frame is in the folded state, so that the main body frame in the folded state occupies the smallest area when being stored. Certainly, without considering the occupied area in the folded state, it is possible to set a larger difference between the maximum numbers of elastic modules that can be carried on the slide rails of the first folded portion50aand the second folded portion50b.

Turning back toFIG.40, respective transversely-extending beams of any two adjacent folded portions in at least two folded portions in the longitudinal direction are butted together and are pivotal relative to each other about a transversely-extending shaft so that the two adjacent folded portions are folded relative to each other. Furthermore, the slide rail beams of the two adjacent folded portions are aligned in the longitudinal direction, but the fold-in-half lines may be spaced apart (certainly there may not be a spacing). A size of the spacing is configured in a way that the elastic modules400are not allowed to disengage from the slide rail from the spacing in the fold-over state.

FIG.47shows a further possible configuration of the seat portion or the backrest portion. For an exemplary purpose,FIG.47shows a seat portion with an even number of elastic modules400mounted on each longitudinally-extending slide rail of the seat portion. Referring toFIG.47, the fold-in-half line51is located at a middle position in the longitudinal direction, that is, the longitudinal dimensions of the two folded portions50folded in half along the fold-in-half line51are equal.FIG.48shows a state after the main body frame inFIG.47is folded in half along the fold-in-half line51. It can be seen that each folded portion50includes a plurality of longitudinal beams52, and two adjacent longitudinal beams52together form a slide rail, each slide rail forms an opening53at the position of the fold-in-half line51, and the elastic modules400can be mounted into the slide rail from the opening53.

FIG.49shows a schematic view after the main body frame inFIG.48are covered with elastic modules400, and each slide rail of each of the two folded portions50folded in half along the fold-in-half line51can receive up to 7 elastic modules400. That is to say, the maximum number of elastic modules400that can be received on each slide rail of the two folded portions50folded in half along the fold-in-half line51is equal. In this way, finally the maximum number of the elastic modules400that are received in a complete slide rail (jointly formed by butting a slide rail of the first folded portion50with a slide rail of the second folded portion50) of the seat portion204is certainly an even number. Such an arrangement can minimize the longitudinal dimension of the main body frame (i.e., the longitudinal dimension of the first folded portion50) when the main body frame is in the folded state, so that the main body frame in the folded state occupies the smallest area when received. Certainly, regardless of the occupied area in the folded state, it is possible to set different numbers of elastic modules in the slide rails of the first folded portion50and the second folded portion50.

Although the main body frame in the embodiments shown inFIG.40-FIG.49includes only two folded portions50, the main body frame may include a plurality of folded portions50arranged in the longitudinal direction in other embodiments not shown. Any two adjacent folded portions50can be folded in half relative to each other so that the opening53of the slide rail is opened, and be flattened relative to each other so that the opening53of the slide rail is closed. That is to say, if there are a plurality of folded portions50, the structures of any two adjacent folded portions50can be similar to the structures shown inFIG.40-FIG.49.

FIG.50-FIG.63illustrate other possible implementations for mounting elastic modules.

Referring toFIG.50, the sofa bed includes a main body frame and a plurality of elastic modules400. The main body frame may include a seat portion and/or a backrest portion. The main body frame may in turn include a plurality of main body units50a. Specifically, the seat portion includes two main body units50aarranged in the longitudinal direction, and the backrest portion also includes two main body units50aarranged in the longitudinal direction. Each main body unit50aincludes a plurality of longitudinal beams extending in the longitudinal direction, and the longitudinal beams may also be referred to as rail beams. Any two adjacent slide rail beams52can jointly form a slide rail. Furthermore, the two slide rail beams52of each slide rail are provided with a first snap structure extending along the entirety thereof, the bottom of the spring bracket is provided with a second snap structure404, and the elastic modules400can be mounted in the slide rail in a way of being pressed perpendicular to a plane jointly defined by extension directions of the two slide rail beams. When the elastic modules400are mounted on the slide rail, the first snap structure and the second snap structure404are snap-fitted with each other to only allow the elastic modules400to move relative to the slide rail beam52in a sliding manner along the slide rail.

It can be understood that in the process of mounting the elastic modules400in the slide rail by pressing them perpendicular to the plane jointly defined by extension directions of the two slide rail beams (i.e., pressing them downward), a portion of a base401of the elastic module400in contact with the slide rail beams52will be slightly deformed, and the deformation will disappear after completion of the mounting, so that the elastic module400cannot disengage from the slide rails. In other words, when the elastic module400is not mounted on the slide rails, the base401of the elastic module400is structured to interfere with the slide rail beams52. If a downward pressure is not applied to the elastic module400to deform it, the elastic module400cannot be mounted on the slide rails.

Preferably, referring toFIG.53, the first snap structure includes a groove52athat is on a top surface of the slide rail beam52and extends along the slide rail beam52(i.e., extends in a direction perpendicular to the paper ofFIG.53), and the second snap structure404comprises a protrusion404aprotruding outward from the top surface of the base401of the elastic module400and toward the groove52a.

Preferably, further referring toFIG.53, the first snap structure further includes a bottom surface52bof the slide rail beam, the second snap structure404includes an extension structure protruding downward from the base401, and a bottom of the extension structure is provided with an outwardly protruding snap hook404b. The snap hook404bis configured to snap onto the bottom surface52bof the slide rail beam. Furthermore, two said extension structures and the protrusion52alocated between the two extension structures are provided on a side of the base401which is engaged with the slide rail beam52.

More preferably, referring simultaneously toFIG.53,FIG.55andFIG.56, the width of the groove52ais configured to receive two protrusions404aside by side, so that respective protrusions404aof two elastic modules400on both sides of each of the slide rail beams52can slide in the grooves52aindependently relative to each other. That is, the slide rail beam52is configured so that the first snap structure can simultaneously engage the second snap structures404of the two elastic modules400on both sides of the slide rail beam52, and in the engaged state, the two elastic modules400on both sides of the slide rail beam52can slide along their respective rails independently relative to each other.

The cross-sectional configuration of the slide rail beam52may also have other preferred configurations. For example, referring toFIG.54BandFIG.54C, the bottom surface52bof the slide rail beam is also provided with a groove52a, and the snap hook404bis configured to hook into the groove52a. Furthermore, the grooves52aon the bottom surface52band the grooves52aon the top surface of the slide rail beam52are arranged symmetrically, and the slide rail beam52is simultaneously configured to be symmetrical about a plane defined by the bottommost end of the groove52aon the top surface of the slide rail beam52and the topmost end of the groove52aon the bottom surface52bof the slide rail beam. As shown inFIG.54C, left and right side surfaces of the slide rail beam52are planes, or as shown inFIG.54B, the left and right side surfaces of the slide rail beam52are convex arc surfaces, and a portion of the base401of the elastic module400corresponding to the convex arc surface is a concave arc surface.

Alternatively, in other embodiments not shown, the first snap structure includes a protrusion52aextending along the slide rail beam52on the top surface of the slide rail beam52, and the second snap structure404includes a groove52aprovided at an edge of the top surface of the base401of the elastic module400and facing the protrusion52a.

FIG.57-FIG.63show schematic views of a process of mounting the elastic modules400on the bed frame of the sofa bed. First, an elastic module400is pressed down to the slide rail formed by a pair of slide rail beams52. After the elastic module400is mounted on the slide rail, the elastic module400can slide on the slide rail in the longitudinal direction. Afterwards, subsequent elastic modules400can be mounted on the slide rail, as shown inFIG.58-FIG.59. Referring toFIG.61, while the elastic modules400are mounted on one slide rail, the elastic modules400can be simultaneously mounted on the other slide rails by being pressed. Furthermore, although the elastic modules400on adjacent slide rails engage with the same slide rail beam52, the elastic modules400on adjacent slide rails can slide independently relative to each other, and their respective sliding do not affect each other.FIG.62shows a schematic view in which all the elastic modules400are already mounted on one main body unit50aof the seat portion or backrest portion, andFIG.63shows a schematic view in which two main body units50aof the seat portion or backrest portion are already mounted with all the elastic modules400.

It should be appreciated that all the embodiments mentioned in the present invention can be combined, and the technical solutions obtained by combining any two or more embodiments fall within the scope of protection of the present invention. For example, there may be a sofa bed that has a bracket as shown inFIGS.16-23as well as the unit structure composed of the mesh panel and the unit frame as shown inFIGS.24-26, as well as the foldable and detachable armrest frame as shown inFIGS.30-37, and furthermore the elastic modules can be mounted in the manner shown inFIG.38A-FIG.49, and/or the elastic modules can be mounted in the manner shown inFIG.50-FIG.63. It should be further appreciated that the elastic module-mounting manner shown inFIG.38A-FIG.49and the elastic module-mounting manner shown inFIG.50-FIG.63do not conflict with each other and they may coexist, that is to say, the elastic modules can be mounted on the sofa bed in two manners.

The switching of the sofa bed provided by the present invention between two in-use states can be easily achieved with convenient operations. Furthermore, in the predetermined switching process and the predetermined use process, the angle between the seat portion and the backrest portion can be locked to improve the reliability of the operation; in the switching operation, with the pin sliding in the sliding groove in an extension direction having a transverse component and a vertical component, the user's operation burden can be reduced, and the switching operation can be achieved quickly and easily. In order to realize the switching of the main body frame between the sofa configuration and the bed configuration, a hinge in the form of three sections is provided at the connection between the backrest portion and the seat portion; the bottom supporting structure of the sofa bed is further provided with a support pipe, which can not only support the main body frame when the sofa bed is used as a sofa, but also support the main body frame when the sofa bed is used as a bed; the main body frame may include a bed plate frame and a steel mesh plate, which can be engaged and disengaged well; the armrest frame can also be detached and folded for easy storage and transportation. Furthermore, the sofa bed may be provided with a plurality of detachable elastic modules, the mounting of the elastic modules is relatively simple and easy to operate, and the user can manually mount the elastic modules to obtain a sofa bed with better comfort. In order to mount the elastic modules, the main body frame is set to be foldable in half, and the slideway for mounting the elastic modules is opened at the fold-in-half position to allow the elastic modules to enter the slideway, and the opening is closed when the main body frame is flattened to thereby prevent the elastic modules from disengaging; the elastic modules may also be configured to be pressed directly from top to bottom onto the rail, and such an arrangement may prevent adjacent elastic modules from interfering with each other.

The above depictions of various embodiments of the present invention are provided to those having ordinary skill in the art for a depiction purpose, and are not intended to exclude other embodiments from the present prevention or limit the present prevention to a single disclosed embodiment. As described above, various alternatives and modifications of the present prevention will be apparent to those of ordinary skill in the art. Accordingly, although some alternative embodiments have been described in detail, those having ordinary skill in the art will understand or readily develop other embodiments. The prevention is intended to cover all alternatives, modifications and variations of the present prevention described herein, as well as other embodiments falling within the spirit and scope of the present prevention described herein.