Foldable Supporting Device

Abstract

A foldable supporting device includes first and second supporting frames, first and second movable elements, a first foldable structure, and first and second rotatable elements. The first supporting frame includes a first upper part and a first lower part. The second supporting frame includes a second upper part and a second lower part. The first movable element and the second movable elements are respectively movable along the first lower part and the second lower part. The first foldable structure connects to the first movable element and the second movable element. The first rotatable element is connected to the first supporting frame and the first foldable structure. The second rotatable element is connected to the second supporting frame and the first foldable structure. The first rotatable element and the second rotatable element are respectively rotatable with respect to the first supporting frame and the second supporting frame.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to a foldable supporting device.

Description of the Related Art

U.S. Pat. No. 6,581,223 discloses a conventional foldable supporting structure. When extended, the supporting structure can be used for supporting, for example, a mattress. For storage, the supporting structure can be folded. When folded, however, the supporting structure becomes higher and occupies a storage space that is somewhat large.

U.S. Pat. No. 8,348,207 discloses another conventional foldable support structure. The supporting structure, when folded, does not become higher. The storage space of the supporting structure is reduced. However, extension of the supporting structure is not smooth because of the upright rods sliding within the supporting frames.

BRIEF SUMMARY OF THE INVENTION

The invention provides a foldable supporting device that can be extended and folded smoothly. The storage space of the foldable supporting device is reduced. The foldable supporting device in accordance with an exemplary embodiment of the invention includes first and second supporting frames, first and second movable elements, a first foldable structure, and first and second rotatable elements. The first supporting frame includes a first upper part and a first lower part disposed opposite to the first upper part. The second supporting frame includes a second upper part and a second lower part disposed opposite to the second upper part. The first movable element and the second movable elements are respectively movable along the first lower part and the second lower part. The first foldable structure connects to the first movable element and the second movable element and is foldable from a first extended position to a first folded position so as to change a distance between the first supporting frame and the second supporting frame. The first rotatable element is connected to the first supporting frame and the first foldable structure. The second rotatable element is connected to the second supporting frame and the first foldable structure. The first rotatable element and the second rotatable element are respectively rotated with respect to the first supporting frame and the second supporting frame when the first foldable structure is folded from the first extended position to the first folded position.

In another exemplary embodiment, the first supporting frame further includes a first side part connecting the first upper part and the first lower part. The second supporting frame further includes a second side part connecting the second upper part and the second lower part. The first rotatable element is rotatably connected to the first side part and is fixed to the first foldable structure. The second rotatable element is rotatably connected to the second side part and is fixed to the first foldable structure.

In yet another exemplary embodiment, the first foldable structure includes two crossing elements that are rotatable with respect to each other. The crossing elements include a first end rotatably connected to the first movable element, a second end rotatably connected to the second movable element, a third end fixed to the first rotatable element, and a fourth end fixed to the second rotatable element.

In another exemplary embodiment, the first rotatable element has a first hole for receiving the third end of the crossing elements and a second hole for receiving the fourth end of the crossing elements.

In yet another exemplary embodiment, the first hole and the second hole are extended perpendicular to each other.

In another exemplary embodiment, the foldable supporting device further includes a third movable element, a third rotatable element and a connecting member. The third movable element is movable along the second lower part. The third rotatable element is rotatably connected to the first supporting frame. The connecting member is rotatably connected to the third movable element and fixed to the third rotatable element.

In yet another exemplary embodiment, the first supporting frame further includes a side part connecting the first upper part and the first lower part. The third rotatable element is rotatably connected to the side part.

In another exemplary embodiment, the foldable supporting device further includes a third supporting frame, a third movable element, a fourth movable element, a second foldable structure, a third rotatable element and a fourth rotatable element. The third supporting frame includes a third upper part and a third lower part disposed opposite to the third upper part. The third movable element is movable along the second lower part. The fourth movable element is movable along the third lower part. The second foldable structure connects to the third movable element and the fourth movable element and is foldable from a second extended position to a second folded position so as to change a distance between the second supporting frame and the third supporting frame. The third rotatable element is connected to the second supporting frame and the second foldable structure. The fourth rotatable element is connected to the third supporting frame and the second foldable structure. The third rotatable element and the fourth rotatable element are respectively rotated with respect to the second supporting frame and the third supporting frame when the second foldable structure is folded from the second extended position to the second folded position.

In yet another exemplary embodiment, the foldable supporting device further includes a third movable element, a fourth movable element, a third rotatable element and a fourth rotatable element. The third movable element is movable along the first lower part. The fourth movable element is movable along the second lower part. The third rotatable element is rotatably connected to the first supporting frame and the first foldable structure. The fourth rotatable element is rotatably connected to the second supporting frame and the first foldable structure. The first foldable structure includes two crossing elements that are rotatable with respect to each other. The crossing elements include a first end rotatably connected to the first movable element, a second end rotatably connected to the second movable element, a third end rotatably connected to the third movable unit, and a fourth end rotatably connected to the fourth movable unit.

In another exemplary embodiment, the first rotatable piece is rotatably connected to the first upper part and the crossing elements. The second rotatable piece is rotatably connected to the second upper part and the crossing elements. The third rotatable piece is rotatably connected to the first upper part and the crossing elements. The fourth rotatable piece is rotatably connected to the second upper part and the crossing elements.

In yet another exemplary embodiment, the foldable supporting device further includes a stopper disposed between the first movable element and the third movable element and fixed to the first lower part of the first supporting frame.

In another exemplary embodiment, the foldable supporting device further includes a first joint and a side structure. The side structure is rotatably connected to the first supporting frame through the first joint. The side structure includes a connecting rod, a second joint and a leg. The connecting rod is connected to the first joint. The connecting rod and the leg are connected through the second joint. The second joint includes a channel and a roller disposed in the channel.

The invention also provides an apparatus that includes a foldable supporting device described above, a coupling element and an object. The object is fixed to the foldable supporting device through the coupling element. The coupling element includes a first portion, a second portion, and a connecting portion connecting the first portion and the second portion. The first portion is fixed to the object. The second portion is detachably connected to the foldable supporting device.

In an exemplary embodiment, the object is an inflatable product that includes a first sheet and a second sheet fused to contain the first portion of the coupling element. The foldable supporting device further includes a groove along which the connecting portion is moved when the second portion is connected to the foldable supporting device.

The invention also provides an apparatus that includes a foldable supporting device described above and an object. The object is supported by the foldable supporting device. The foldable supporting device further includes an auxiliary support to support the object. The auxiliary support includes a sleeve. The foldable supporting device further includes a hook that penetrates through the sleeve.

In an exemplary embodiment, the auxiliary support is a weaving strap.

In another exemplary embodiment, the foldable supporting device includes a plurality of supporting structures, a foldable structure and a plurality of rotatable elements. The supporting structures include upper parts and lower parts disposed opposite to the upper parts. The foldable structure is connected to the lower parts of the supporting structures and is foldable from an extended position to a folded position. The rotatable elements connect the supporting structures and the foldable structure. When the foldable structure is folded, external forces from the lower parts of the supporting structures are transmitted to the upper parts of the supporting structures with the rotatable elements cooperating to rotate, thereby moving the supporting structures close to each other.

In yet another exemplary embodiment, the foldable supporting device further includes movable elements that are connected to the foldable structure and are movable along the lower parts of the supporting structures, wherein a distance between the supporting structures is determined by an extent of extending of the foldable structure and positions of the movable elements.

In another exemplary embodiment, the foldable supporting device includes a plurality of supporting structures, a foldable structure and a plurality of rotatable elements. The supporting structures include upper parts and lower parts disposed opposite to the upper parts. The foldable structure is connected to the lower parts of the supporting structures and is foldable from an extended position to a folded position. The rotatable elements connect the supporting structures and the foldable structure. During extension of the foldable supporting device, external forces from the upper parts of the supporting structures are transmitted to the foldable structure with the rotatable elements cooperating to rotate, thereby extending the foldable structure and moving the supporting structures apart from each other.

A detailed description is given in the following embodiments with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:

FIG. 1A shows a foldable supporting device in a folded state in accordance with a first embodiment of the invention.

FIG. 1B shows the foldable supporting device of FIG. 1A in an extended state.

FIG. 1C is an explored view of the foldable supporting device of FIG. 1B.

FIG. 2A is a perspective view of a rotatable element of the foldable supporting device of FIG. 1B.

FIG. 2B is a perspective view of another rotatable element of the foldable supporting device of FIG. 1B.

FIG. 3A shows a canvas basket disposed in the foldable supporting device of FIG. 1A.

FIG. 3B shows the canvas basket of FIG. 3A when the foldable supporting device is extended.

FIG. 4A shows an inflatable infant mattress disposed in the foldable supporting device of FIG. 1A wherein the inflatable infant mattress is not inflated yet.

FIG. 4B shows the inflatable infant mattress of FIG. 4A after the inflatable infant mattress is inflated and the foldable supporting device is extended.

FIG. 5 shows an inflatable chair fixed to the foldable supporting device of FIG. 1B.

FIG. 6 shows a foldable supporting device in accordance with a second embodiment of the invention.

FIG. 7 shows an inflatable chair fixed to the foldable supporting device of FIG. 6 that is sized for three people to sit.

FIG. 8 shows an inflatable chair fixed to a foldable supporting device that is sized for two people to sit.

FIG. 9A shows a foldable supporting device in an extended state in accordance with a third embodiment of the invention.

FIG. 9B is an explored view of the foldable supporting device of FIG. 9A.

FIG. 9C depicts a modified foldable supporting device of FIG. 9A.

FIG. 10 shows a foldable supporting device in an extended state in accordance with a fourth embodiment of the invention.

FIG. 11A shows a foldable supporting device in a folded state in accordance with a fifth embodiment of the invention.

FIG. 11B shows the foldable supporting device of FIG. 11A in an extended state.

FIG. 11C shows a side structure of the foldable supporting device of FIG. 11A in a folded state.

FIG. 11D shows the side structure of FIG. 11C in an extended state.

FIG. 12A shows an inflatable infant mattress disposed in the foldable supporting device of FIG. 11A wherein the inflatable infant mattress is not inflated yet.

FIG. 12B shows the inflatable infant mattress of FIG. 12A after the inflatable infant mattress is inflated and the foldable supporting device is extended.

FIG. 13 shows a foldable supporting device in accordance with a sixth embodiment.

FIG. 14A shows a foldable supporting device in a folded state in accordance with a seventh embodiment of the invention.

FIG. 14B shows the foldable supporting device of FIG. 14A in an extended state.

FIG. 15A shows the foldable supporting device of the seventh embodiment that carries an inflatable mattress.

FIG. 15B is a local view of the inflatable mattress of FIG. 15A, wherein an auxiliary chamber after inflation is expanded to raise and support the backrest of the inflatable mattress.

FIG. 15C is a perspective view of a coupling element, a joint of the foldable supporting device of the seventh embodiment, and a weaving strap.

FIG. 15D is a side view of the coupling element of FIG. 15C.

DETAILED DESCRIPTION OF THE INVENTION

A foldable supporting device of the invention may includes one or plural supporting units. For example, FIGS. 1A-1C show a foldable supporting device that includes one supporting unit 100, and FIG. 6 show a foldable supporting device that includes three supporting units 100′, 100, 100′.

FIGS. 1A, 1B and 1C show a foldable supporting device in accordance with a first embodiment of the invention, wherein the foldable supporting device includes two supporting frame 110, 120, a foldable structure 130, two movable elements 134, 135, and two rotatable elements 143, 146.

The supporting frame 110 includes an upper part 111, a lower part 112 disposed opposite to the upper part 111 in a vertical direction, and two side parts 113, 114 connected to the upper part 111 and the lower part 112 through connectors 150, 160. The upper part 111 and the lower part 112 are horizontally disposed, while the side parts 113, 114 are vertically disposed. In the first embodiment, the upper part 111, the lower part 112 and the side parts 113, 114 are rods.

The supporting frame 120 includes an upper part 121, a lower part 122 disposed opposite to the upper part 121 in a vertical direction, and two side parts 123, 124 connected to the upper part 121 and the lower part 122 through connectors 150, 160. The upper part 121 and the lower part 122 are horizontally disposed, while the side parts 123, 124 are vertically disposed. In the first embodiment, the upper part 121, the lower part 122 and the side parts 123, 124 are rods.

The movable element 135 is movably disposed on the lower part 112 of the supporting frame 110. The movable element 134 is movably disposed on the lower part 122 of the supporting frame 120.

The rotatable element 143 is flat and trapezoidal. Referring to FIG. 2A, the rotatable element 143 has holes 1431, 1432. The hole 1431 is extended vertically and has a round cross section to receive the side part 113 of the supporting frame 110. Therefore, the rotatable element 143 can be rotated with respect to the supporting frame 110. The hole 1432 is extended horizontally and has a rectangular cross section.

The rotatable element 146 is also flat and trapezoidal. Referring to FIG. 2B, the rotatable element 146 has holes 1461, 1462. The hole 1461 is extended vertically and has a round cross section to receive the side part 123 of the supporting frame 120. Therefore, the rotatable element 146 can be rotated with respect to the supporting frame 120. The hole 1462 is extended horizontally and has a rectangular cross section.

The foldable structure 130 includes two crossing elements 131, 132 that cross and are pivoted to each other. In the first embodiment, the crossing elements 131, 132 are rods and have rectangular cross sections. The crossing element 131, 132 has a first end rotatably connected to the first movable element 135, a second end rotatably connected to the movable element 134, a third end fitted into the hole 1432 of the rotatable element 143, and a fourth end fitted into the hole 1462 of the rotatable element 146.

FIG. 1A shows the foldable supporting device in a folded state. A user can manually extend the foldable supporting device. Specifically, the user can grasp the upper parts 111, 121 of the supporting frames 110, 120 and move them away from each other, wherein forces applied to the upper parts 111, 121 of the supporting frames 110, 120 are transmitted to the foldable structure 130 so as to spread apart the crossing elements 131, 132. Thanks to the rotatable elements 143, 146, the supporting frames 110, 120 can keep upright (without tilting) during extension of the foldable supporting device. Accordingly, the foldable supporting device of the invention can be extended smoothly with less effort.

Further, during extension of the foldable supporting device, the movable element 135 is moved along the lower part 112 of the supporting frame 110, the movable element 134 is moved along the lower part 122 of the supporting frame 120, the rotatable element 143 is rotated with respect to the side part 113 of the supporting frame 110, and the rotatable element 146 is rotated with respect to the side part 123 of the supporting frame 120. By means of movement of the movable elements 135, 134 and rotation of the rotatable elements 143, 146, forces from the upper parts 111, 121 are transmitted to the foldable structure 130 so as to spread apart the crossing elements 131, 132. FIG. 1B shows the foldable supporting device in an extended state.

When the foldable supporting device is folded from an extended position to a folded position, external forces from the lower parts 112, 122 of the supporting frames 110, 120 are transmitted to the upper parts 111, 121 of the supporting frames 110, 120 with the rotatable elements 143, 146 cooperating to rotate, thereby moving the supporting frames 110, 120 close to each other.

The foldable supporting device can be used to carry an object. As shown in FIG. 3A, for example, a canvas basket 300 is fixed to the foldable supporting device. A handle 170 and wheels 172 can be additionally provided that facilitates the user to drag the foldable supporting device. When the foldable supporting device is extended as shown in FIG. 3B, the canvas basket 300 can be loaded.

In another example, an inflatable infant mattress 310 is fixed to the foldable supporting device as shown in FIG. 4A, wherein the infant mattress 310 is not inflated yet. It is noted that the foldable supporting device is in a folded state, with the infant mattress 310 sagging between the supporting frames 110, 120. When inflated, the infant mattress 310 is expanded as shown in FIG. 4B. The foldable supporting device can be automatically extended by means of expansion of the inflatable infant mattress 310. Thanks to the rotatable elements 143, 146, the supporting frames 110, 120 can keep upright (without tilting) during extension of the foldable supporting device. Accordingly, the foldable supporting device can be extended smoothly.

In another example, an inflatable chair 320 is fixed to the foldable supporting device as shown in FIG. 5, wherein the inflatable chair 320 includes a backrest 321, an armrest 322 and a cup holder 324 disposed on a seat cushion 323. The inflatable chair 320 is sized for one person to sit. When inflated, the inflatable chair 320 is expanded and the foldable supporting device can be automatically extended by means of expansion of the inflatable chair 320.

FIG. 6 shows a foldable supporting device in accordance with a second embodiment of the invention, wherein the foldable supporting device includes three supporting units 100′, 100, 100′ that are combined together. It is worth noting that the supporting unit 100 and the supporting unit 100′ use a supporting frame in common. The supporting unit 100 of the second embodiment is identical to or similar with that of the first embodiment. The supporting unit 100′ differs from the supporting unit 100 in that the supporting unit 100′ further includes a connecting member 137, a movable element 138 and a rotatable element 149. The movable element 138 is movable along the lower part 122 of the supporting frame 120. The rotatable element 149 is rotatably connected to the side part 114 of the supporting frame 114. The connecting member 137 has an end rotatably connected to the movable element 138, and another end fixed to the rotatable element 149. When the foldable supporting device is extended, the movable element 138 is moved along the lower part 122 of the supporting frame 120 and the rotatable element 149 is rotated with respect to the side part 114 of the supporting frame 114. The connecting member 137 is provided to promote the structural strength and stability of the foldable supporting device.

As shown in FIG. 7, an inflatable chair, sized for three people to sit, can be fixed to the foldable supporting device of FIG. 6.

FIG. 8 shows an inflatable chair sized for two people, wherein the foldable supporting device includes two supporting units 100, 100.

FIGS. 9A and 9B show a foldable supporting device in accordance with a third embodiment of the invention, wherein the foldable supporting device includes two supporting frame 210, 220, a foldable structure 230, four movable elements 233, 234, 235, 236, and four rotatable elements 241, 242, 244, 245.

The supporting frame 210 includes an upper part 211, a lower part 212 disposed opposite to the upper part 211 in a vertical direction, and two side parts 213, 214 connected to the upper part 211 and the lower part 212 through connectors 250, 260. The upper part 211 and the lower part 212 are horizontally disposed, while the side parts 213, 214 are vertically disposed. In the third embodiment, the upper part 211, the lower part 212 and the side parts 213, 214 are rods.

The supporting frame 220 includes an upper part 221, a lower part 222 disposed opposite to the upper part 221 in a vertical direction, and two side parts 223, 224 connected to the upper part 221 and the lower part 222 through connectors 250, 260. The upper part 221 and the lower part 222 are horizontally disposed, while the side parts 223, 224 are vertically disposed. In the third embodiment, the upper part 221, the lower part 222 and the side parts 223, 224 are rods.

The movable elements 235, 233 are movably disposed on the lower part 212 of the supporting frame 110. The movable elements 234, 236 are movably disposed on the lower part 222 of the supporting frame 220.

The foldable structure 230 includes two crossing elements 231, 232 that cross and are pivoted to each other. The crossing element 231, 232 has a first end rotatably connected to the first movable element 235, a second end rotatably connected to the movable element 234, a third end rotatably connected to the movable element 233, and a fourth end rotatably connected to the movable element 236.

In the third embodiment, the rotatable elements 241, 242, 244, 245 are flat strips. Each of the rotatable elements 241, 242 has an end rotatably connected to the upper part 211 of the supporting frame 210, and another end rotatably connected to one of the crossing elements 231, 232. Similarly, each of the rotatable elements 244, 245 has an end rotatably connected to the upper part 221 of the supporting frame 220, and another end rotatably connected to one of the crossing elements 231, 232.

From a folded state to an extended state, the crossing elements 231, 232 are spread apart, the movable elements 233, 235 are moved away from each other along the lower part 212 of the supporting frame 210, the movable elements 234, 236 are moved away from each other along the lower part 222 of the supporting frame 220, the rotatable elements 241, 242 are rotated with respect to the upper part 211 of the supporting frame 210 and the crossing elements 231, 232, and the rotatable elements 244, 245 are rotated with respect to the upper part 221 of the supporting frame 220 and the crossing elements 231, 232.

The foldable supporting device of FIG. 9A can be modified as shown in FIG. 9C, wherein at least one stopper 271 is additionally disposed between the movable elements 233, 235 and fixed to the lower part 212 of the supporting frame 210, for respectively limiting the travel distances of the movable elements 233, 235 when the foldable supporting device is extended. Similarly, another stopper 272 may be additionally disposed between the movable elements 234, 236 and fixed to the lower part 222 of the supporting frame 220, for respectively limiting the travel distances of the movable elements 234, 236 when the foldable supporting device is extended.

In a fourth embodiment, the rotatable elements 241, 244 are removed and the movable elements 233, 236 are replaced with fixed elements 233′, 236′ that are respectively fixed to the lower parts 212, 222 of the supporting frames 210, 220 as shown in FIG. 10. When the foldable supporting device is extended, the crossing elements 231, 232 can be still spread apart, wherein the movable elements 235, 234 are moved along the lower parts 212, 222 of the supporting frames 210, 220, and the rotatable elements 242, 245 are rotated with respect to the supporting frames 210, 220 and the crossing elements 231, 232.

FIGS. 11A and 11B show a foldable supporting device in accordance with a fifth embodiment, wherein the foldable supporting device includes a supporting unit 200 and two side structures 202, 202 disposed at opposite sides of the supporting unit 200. The supporting unit 200 further includes weaving straps 270 that connect the supporting frames 210, 220 through the connectors 250 for functioning as an auxiliary support.

The side structure 202 includes connectors 264, connecting rods 263, joints 262, legs 261 and a weaving strap 265. The weaving strap 265 is connected between the joints 262, 262 for functioning as an auxiliary support. The connector 250 and the connectors 264 are assembled to be a joint 272 in which a torsion spring 268 (shown in FIG. 11C) is provided. The connecting rod 263 is connected to the connector 264. The leg 261 is connected to the connecting rod 263 through the joint 262.

As shown in FIG. 11A, in a folded state, the side structure 202 is flipped over to the top of the supporting unit 200. Referring to FIG. 11C, the joint 262 has a channel 269 and a roller 266 disposed in the channel 269. When the foldable supporting device is extended by an external force, the side structure 202 is rotated with respect to the joint 272 as indicated by arrow A, the torsion spring 268 in the joint 272 is twisted, and the leg 261 is spread as shown in FIG. 11D. Since the side structure 202 is rotated, the joint 262 is inverted with the roller 266 located at the top of the channel 269. After the rotation of the side structure 202 is finished, the leg 261 of the side structure 202 is spread and the roller 266 falls to the bottom of the channel 269 by virtue of gravity and is stuck thereto for keeping the leg 261 in position.

In an example of the foldable supporting device that carries an inflatable mattress, the foldable supporting device can be extended by inflation of the mattress. Specifically, as shown in FIG. 12A, an inflatable mattress 400 before inflation is disposed in the foldable supporting device and has some locations where the inflatable mattress is fixed to the foldable supporting device. By such arrangement, the mattress 400 can be inflated to expand and the foldable supporting device is forced to be extended because of expansion of the inflatable mattress as shown in FIG. 12B. When the foldable supporting device is extended, the side structure 202 is rotated, the leg 261 of the side structure 202 is spread, the torsion spring 268 in the joint 272 is twisted, and the roller 266 falls to the bottom of the channel 269 by virtue of gravity and is stuck thereto. When the mattress is deflated and shrinks, the side structure 202 is reversely rotated back to the top of the supporting unit 200 by virtue of the restoring force of the torsion spring 268.

FIG. 13 shows a foldable supporting device in accordance with a sixth embodiment. The sixth embodiment differs from the fifth embodiment mainly in that the side structures 202′ of the sixth embodiment further includes connecting rods 263′ that connect the legs 261′ and the supporting frames 210, 220 through connectors 260′.

FIGS. 14A and 14B show a foldable supporting device in accordance with a seventh embodiment, wherein the foldable supporting device includes three supporting units 100 of the first embodiment and six side structures 202′ of the sixth embodiment.

FIG. 15A shows a foldable supporting device of the seventh embodiment that carries an inflatable mattress 500. As shown in FIG. 15B, during inflation, an auxiliary chamber 540 is expanded to raise and support the backrest of the inflatable mattress 500. The inflatable mattress 500 is fixed to the foldable supporting device through the coupling elements 510 shown in FIG. 15C. The coupling element 510 has two enlarged portions 511, 512 and a connecting portion 513 connecting the enlarged portions 511, 512. The joint 262′ (or connector 250′) of the foldable supporting device has an L-shaped groove 2621′ on the top surface, and a C-shaped hook 2622′ and an opening 2623′ on a side surface. A weaving strap 265 has an end formed into a sleeve 2651 through which the hook 2622′ can penetrate to fix the weaving strap 265. Specifically, the C-shaped hook 2622′ has two arms 2624′, 2626′ and a gap 2625′ formed between the arms 2624′, 2626′. An end 2652 of the sleeve 2651 is passes through the gap 2625′ to contain the arm 2624′, and another end 2653 of the sleeve 2651 is passes through the gap 2625′ to contain the arm 2626′, thereby fixing the weaving strap 265 to the joint 262′ (or connector 250′). Referring to FIG. 15D, the inflatable mattress 500 has a bottom sheet 520 and a supplemental sheet 530 that are fused to contain the enlarged portion 511 of the coupling element 510. During assembly, the coupling element 510 is coupled to the joint 262′ (or connector 250′), wherein the connecting portion 513 is moved along the L-shaped groove 2621′ when the enlarged portion 512 enters the interior of the joint 262′ (or connector 250′) through the opening 2623′ thereof. Thus, the inflatable mattress 500 is fixed to the foldable supporting device through the coupling element 510.

By the coupling element 510, the inflatable mattress 500 can be connected to and disconnected from the foldable supporting device of the invention rapidly.

While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.

Claims

1. A foldable supporting device, comprising: a first supporting frame comprising a first upper part and a first lower part disposed opposite to the first upper part;a second supporting frame comprising a second upper part and a second lower part disposed opposite to the second upper part;a first movable element that is movable along the first lower part;a second movable element that is movable along the second lower part;a first foldable structure which connects to the first movable element and the second movable element and is foldable from a first extended position to a first folded position so as to change a distance between the first supporting frame and the second supporting frame;a first rotatable element connected to the first supporting frame and the first foldable structure;a second rotatable element connected to the second supporting frame and the first foldable structure;wherein the first rotatable element and the second rotatable element are respectively rotated with respect to the first supporting frame and the second supporting frame when the first foldable structure is folded from the first extended position to the first folded position.

2. The foldable supporting device as claimed in claim 1, wherein: the first supporting frame further comprises a first side part connecting the first upper part and the first lower part;the second supporting frame further comprises a second side part connecting the second upper part and the second lower part;the first rotatable element is rotatably connected to the first side part and is fixed to the first foldable structure;the second rotatable element is rotatably connected to the second side part and is fixed to the first foldable structure.

3. The foldable supporting device as claimed in claim 1, wherein: the first foldable structure comprises two crossing elements that are rotatable with respect to each other;the crossing elements comprise a first end rotatably connected to the first movable element, a second end rotatably connected to the second movable element, a third end fixed to the first rotatable element, and a fourth end fixed to the second rotatable element.

4. The foldable supporting device as claimed in claim 3, wherein the first rotatable element has a first hole for receiving the third end of the crossing elements and a second hole for receiving the fourth end of the crossing elements.

5. The foldable supporting device as claimed in claim 4, wherein the first hole and the second hole are extended perpendicular to each other.

6. The foldable supporting device as claimed in claim 1, further comprising: a third movable element movable along the second lower part;a third rotatable element rotatably connected to the first supporting frame;a connecting member rotatably connected to the third movable element and fixed to the third rotatable element.

7. The foldable supporting device as claimed in claim 6, wherein: the first supporting frame further comprises a side part connecting the first upper part and the first lower part;the third rotatable element is rotatably connected to the side part.

8. The foldable supporting device as claimed in claim 1, further comprising: a third supporting frame comprising a third upper part and a third lower part disposed opposite to the third upper part;a third movable element that is movable along the second lower part;a fourth movable element that is movable along the third lower part;a second foldable structure which connects to the third movable element and the fourth movable element and is foldable from a second extended position to a second folded position so as to change a distance between the second supporting frame and the third supporting frame;a third rotatable element connected to the second supporting frame and the second foldable structure;a fourth rotatable element connected to the third supporting frame and the second foldable structure;wherein the third rotatable element and the fourth rotatable element are respectively rotated with respect to the second supporting frame and the third supporting frame when the second foldable structure is folded from the second extended position to the second folded position.

9. The foldable supporting device as claimed in claim 1, further comprising: a third movable element that is movable along the first lower part;a fourth movable element that is movable along the second lower part;a third rotatable element rotatably connected to the first supporting frame and the first foldable structure;a fourth rotatable element rotatably connected to the second supporting frame and the first foldable structure;wherein the first foldable structure comprises two crossing elements that are rotatable with respect to each other;wherein the crossing elements comprise a first end rotatably connected to the first movable element, a second end rotatably connected to the second movable element, a third end rotatably connected to the third movable unit, and a fourth end rotatably connected to the fourth movable unit.

10. The foldable supporting device as claimed in claim 9, wherein: the first rotatable piece is rotatably connected to the first upper part and the crossing elements;the second rotatable piece is rotatably connected to the second upper part and the crossing elements;the third rotatable piece is rotatably connected to the first upper part and the crossing elements;the fourth rotatable piece is rotatably connected to the second upper part and the crossing elements.

11. The foldable supporting device as claimed in claim 9, further comprising a stopper disposed between the first movable element and the third movable element and fixed to the first lower part of the first supporting frame.

12. The foldable supporting device as claimed in claim 1, further comprising: a first joint;a side structure rotatably connected to the first supporting frame through the first joint;wherein the side structure comprises a connecting rod, a second joint and a leg;wherein the connecting rod is connected to the first joint;wherein the connecting rod and the leg are connected through the second joint;wherein the second joint comprises a channel and a roller disposed in the channel.

13. An apparatus comprising: a foldable supporting device as claimed in claim 1;a coupling element;an object fixed to the foldable supporting device through the coupling element;wherein the coupling element comprising a first portion, a second portion, and a connecting portion connecting the first portion and the second portion;wherein the first portion is fixed to the object;wherein the second portion is detachably connected to the foldable supporting device.

14. The apparatus as claimed in claim 13, wherein: the object is an inflatable product that comprises a first sheet and a second sheet fused to contain the first portion of the coupling element;the foldable supporting device further comprises a groove along which the connecting portion is moved when the second portion is connected to the foldable supporting device.

15. An apparatus comprising: a foldable supporting device as claimed in claim 1;an object supported by the foldable supporting device;wherein the foldable supporting device further comprises an auxiliary support to support the object;wherein the auxiliary support comprises a sleeve;wherein the foldable supporting device further comprises a hook that penetrates through the sleeve.

16. The apparatus as claimed in claim 15, wherein the auxiliary support is a weaving strap.

17. A foldable supporting device, comprising: a plurality of supporting structures comprising upper parts and lower parts disposed opposite to the upper parts;a foldable structure which is connected to the lower parts of the supporting structures and is foldable from an extended position to a folded position;a plurality of rotatable elements which connect the supporting structures and the foldable structure;wherein when the foldable structure is folded, external forces from the lower parts of the supporting structures are transmitted to the upper parts of the supporting structures with the rotatable elements cooperating to rotate, thereby moving the supporting structures close to each other.

18. The foldable supporting device as claimed in claim 17, further comprising movable elements that are connected to the foldable structure and are movable along the lower parts of the supporting structures, wherein a distance between the supporting structures is determined by an extent of extending of the foldable structure and positions of the movable elements.

19. A foldable supporting device, comprising: a plurality of supporting structures comprising upper parts and lower parts disposed opposite to the upper parts;a foldable structure which is connected to the lower parts of the supporting structures and is foldable from an extended position to a folded position;a plurality of rotatable elements which connect the supporting structures and the foldable structure;wherein during extension of the foldable supporting device, external forces from the upper parts of the supporting structures are transmitted to the foldable structure with the rotatable elements cooperating to rotate, thereby extending the foldable structure and moving the supporting structures apart from each other.

20. The foldable supporting device as claimed in claim 19, further comprising movable elements that are connected to the foldable structure and are movable along the lower parts of the supporting structures, wherein a distance between the supporting structures is determined by an extent of extending of the foldable structure and positions of the movable elements.