SPACE-SAVING MATTRESS SUPPORT

Abstract

A mattress support (10) consisting of longitudinal beams (11a, 11b) extending at a distance from each other, transverse beams (12a, 12b) rigidly connected at or near the ends of the longitudinal beams, a flexible support material (14) stretched between the longitudinal beams that is situated at a distance above the underside of the longitudinal beams, and at least one rotatable bracing element (13a, 13b) under the flexible support material surface that is loaded under pressure by the flexible support material surface. The rotatable bracing element can be rotated between an unfolded operational position in which the rotatable bracing element extends downwards at right angles to the flexible support material surface to allow for elastic deformation of the flexible support material surface, and a folded rest position. The rotatable bracing element (13a, 13b) including the rotation means (15a, 15b) can be at least partially enclosed within the space defined between the underside of the flexible support material, the underside of the longitudinal beams and the inner surfaces of the longitudinal beams facing each other.

Claims

1. A mattress support, comprising: longitudinal beams, which extend next to and at a distance from each other; transverse beams that are rigidly connected to the longitudinal beams at or near to the ends of the longitudinal beams, and which together with the longitudinal beams form a main frame; a flexible surface material elastically stretched between the longitudinal beams and located at a level distance above a level of an underside of the longitudinal beams; a rotatable bracing element located below the flexible support material, which is configured to hold the longitudinal beams apart at a constant transverse width, and rotatable coupling means provided at both ends of the rotatable bracing element, which connect the rotatable bracing element to the longitudinal beams, around an axis of rotation that is orthogonal to the longitudinal beams and parallel to the flexible support material; wherein the rotatable bracing element is provided with a plastic deformation extending in a direction perpendicular to the axis of rotation, and wherein the rotatable bracing element is pivotally mounted around the axis of rotation between: a first extended operational position in which the plastic deformation of the rotatable bracing element extends away from the flexible support material downwards under the level of the underside of the main frame to allow for elastic deformation of the flexible support material, and a second folded rest position in which the rotatable bracing element is completely above the level of the underside of the main frame.

2. The mattress support according to claim 1, wherein the rotatable bracing element extends between the longitudinal beams over the transverse width, wherein a central part of the plastic deformation of the rotatable bracing element forms an area which, in the unfolded position of use, is situated below the level of the underside of the main frame and which, in the direction of extension relative to the axis of rotation, is situated at a central internal distance, and wherein a ratio R/Y between the central internal distance and the transverse width satisfies 1/20R/Y1/10.

3. The mattress support according to claim 1, wherein the plastic deformation of the rotatable bracing element has a curved or kinked concave shape, which is preferably mirror symmetric with respect to a plane orientated orthogonally to the axis of rotation and located at the centre of the rotatable bracing element.

4. The mattress support according to claim 3, wherein the rotatable bracing element is bent away from the axis of rotation near the ends by a component along the deformation direction, and further towards a central part is bent back by an opposite component along the deformation direction, so that a central portion of the rotatable bracing element lies parallel to the axis of rotation.

5. The mattress support according to claim 1, wherein the rotatable coupling means comprises an axial bearing, a thrust bearing or a pivot bearing.

6. The mattress support according to claim 5, wherein a rotatable bracing element is in the form of a shaped tube or rod defined capped by mutually parallel end faces, wherein the end faces are orthogonal to the axis of rotation and wherein the axial bearing, thrust bearing or pivot bearing is incorporated between each end face of the rotatable bracing element and the adjacent longitudinal beam.

7. The mattress support according to claim 1, whereby the rotatable bracing element is equipped with blocking devices for blocking the rotatable bracing element in the extended use position and/or in the folded rest position.

8. The mattress support according to claim 5, wherein one end of the rotatable bracing element has a end face and the corresponding longitudinal beam carries a counter surface, in which end face and counter surface interact as a sliding pivot bearing, and in which end face and counter surface have recesses or protrusions, respectively, which engage in a blocking manner in the folded rest position and/or in the folded use position of the rotatable bracing element.

9. The mattress support according to claim 1, whereby the rotatable bracing element has a maximum width orthogonal to the direction of plastic deformation and orthogonal to the axis of rotation, and the rotatable coupling means has a width orthogonal to the direction of plastic deformation and orthogonal to the axis of rotation, whereby both the rotatable bracing element width and the rotatable coupling means width are smaller than the distance between the underside of the flexible support material and the underside of the main frame.

10. The mattress support according to claim 1, wherein the rotatable bracing element in the unfolded position of use is at least partially and preferably completely accommodated in an internal space determined between the underside of the flexible support material, the underside of the main frame and the inward facing side surfaces of the longitudinal beams.

11. The mattress support according to claim 1, wherein the rotatable bracing element viewed perpendicularly to the axis of rotation has a rotatable bracing element height defined in a radial direction away from the axis of rotation and has a rotatable bracing element width defined in a direction orthogonal to both the height and the axis of rotation, and wherein the height is greater than the width.

12. The mattress support according to claim 1, whereby the axis of rotation of the rotatable bracing element intersects the longitudinal beams at a position essentially midway between the underside of the longitudinal beams and the underside of the flexible support material.

13. The mattress support according to claim 1, comprising ground support elements connected to the longitudinal beams, and provided with one or more ground support bodies and movable between an operative ground support position, projecting downwards in relation to the main frame, and a folded position in which the ground support elements are at least partially accommodated in the internal space defined between the underside of the flexible support material, the underside of the main frame and the inward facing side surfaces of the longitudinal members, preferably a folded position in which the ground support elements are wholly accommodated in the internal space defined between the underside of the flexible support material, the level of the underside of the main frame and the inward facing side surfaces of the longitudinal members.

14. The mattress support according to claim 13, wherein the ground support element also comprises a ground support bracing element.

15. The mattress support according to claim 13, wherein at least one ground support bracing element is provided between a ground support body of the ground support element and a longitudinal beam, in which the ground support bracing element and the longitudinal beam together have a stop for determining the extended position of the ground support body.

16. The mattress support according to claim 15, wherein the ground support bracing element is rotatably connected to the ground support body and slidably cooperates with a sliding track provided on the longitudinal beam.

17. The mattress support according to claim 13, whereby the ground support elements are equipped with blocking devices for blocking the ground support bodies in their folded position.

18. The mattress support according to claim 13, wherein a ground support element and two slide block rails provided at its ends form a substructure that is attached to the longitudinal beams.

19. The mattress support according to claim 1, wherein the flexible support material comprises an elastic material, such as, for example, a network of elastic yarns or interwoven helical springs, or a perforated breathable sheet of rubber with an inlay.

20. The mattress support according to claim 1, wherein in relation to the top or underside of the main frame protrusions are provided, and in relation to the underside or top of the main frame recesses are provided, where in the recesses are so arranged as to interlock with the protrusions of a second, identical, mattress support, if the second mattress support is stacked on top in the correct orientation, for the purpose of stabilising stacked mattress supports.

21.-23. (canceled)

Description

SHORT DESCRIPTION OF THE FIGURES

[0032] The following non-limiting examples of the invention will be described in light of the accompanying schematic drawings of FIGS. 1-9. In the figures, corresponding parts are indicated by corresponding reference symbols. Multiple representations of a part may be indicated by an additional letter in their reference symbol. For example, two representations of a component 20 may be indicated by 20a and 20b. The reference symbol may be used without the additional letter (e.g. 20) to refer generally to an unspecified representation or to all representations of that part, while the reference symbol will contain an additional letter (e.g. 20a) to refer to a specific representation of the part.

[0033] FIG. 1 shows a perspective view of a mattress support in the position of use according to one embodiment;

[0034] FIG. 2 shows a partial cross-section of a rotatable bracing element along its axis of rotation according to the design in FIG. 1;

[0035] FIG. 3 shows a combination of stacked mattress supports in collapsed resting positions according to an embodiment;

[0036] FIGS. 4a-c show views of another embodiment of a mattress support in the use position;

[0037] FIGS. 5a-c show views of the mattress support from FIGS. 4a-c, in the folded rest position;

[0038] FIGS. 6a-c show views of a rotatable bracing element in a mattress support according to an alternative embodiment.

[0039] FIGS. 7a-c show various positions of the ground support elements of the mattress support depicted in FIG. 1.

[0040] FIGS. 8a-b show a preferable embodiment of the invention, with FIG. 8a depicting a ground support element in isolation and FIG. 8b depicting the mattress support in a folded rest position in which the two rotatable bracing elements and the two ground support elements are completely above the level of the underside of the main frame.

[0041] FIGS. 9a-b show a preferable embodiment of the invention, with FIG. 9a depicting a mattress support in a first extended operational position in which the plastic deformation of the two rotatable bracing elements extend away from the flexible support material downwards under the level of the underside of the main frame to allow for elastic deformation of the flexible support material. FIG. 9b depicts three inverted mattress supports from an imaginary perspective to show how the ground support bracing element is rotatably connected to the ground support body and slidably cooperates with a sliding track provided on the longitudinal beam of the mattress support.

[0042] The drawings are for illustrative purposes only and do not serve to limit the scope of protection conferred by the claims.

DESCRIPTION OF THE EMBODIMENTS

[0043] FIG. 1 shows a perspective view of a mattress support 10 in an unfolded use position according to one embodiment. The mattress support 10 depicted comprises a main frame 29, which is formed by two longitudinal beams 11a, 11b that are substantially parallel and spaced apart, and two transverse beams 12a, 12b that are rigidly connected to ends of the longitudinal beams 11a-b. These longitudinal beams 11a-b extend in a longitudinal direction X. The transverse beams 12a-b extend mainly along a transverse direction Y which is perpendicular to the longitudinal direction X. Perpendicular to both the longitudinal direction X and the transverse direction Y, a vertical direction Z is defined. During use of the mattress support 10 in the unfolded state, the longitudinal and transverse directions X, Y are primarily aligned with a supportive surface (in so far as the surface permits i.e. uneven ground), and the vertical direction Z is preferably along (i.e., opposite to) the direction of gravity as much as possible.

[0044] The main frame 29 of the mattress support 10 in this example also includes two rotatable bracing elements 13a, 13b. Furthermore, the mattress support 10 has an elastic flexible support material surface 14 which is elastically deformed by stretching between the two longitudinal beams 11a-b. For the sake of clarity, the flexible support material surface 14 is only partially depicted. In this example, the tensile stress on the elastic support material 14 is about 1002 Newtons in the transverse directions Y (outward relative to the respective longitudinal beam 11) per centimeter in the longitudinal direction X. As a result of this tensile stress, the cross members 13 are loaded under pressure (by bearing a load) which acts primarily in the inward transverse directions Y.

[0045] Each of the rotatable bracing elements 13 are attached to the longitudinal beams 11 by its two ends. The rotatable bracing elements 13 of this embodiment are positioned according to a mirror symmetrical distribution with respect to the centre of the longitudinal beams 11 in the longitudinal direction X, in order to be able to absorb the transverse tension of the stressed flexible support material surface 14 with an even distribution of rotatable bracing elements in the X direction. In this example, the two rotatable bracing elements 13 are positioned at about and of the length of the longitudinal beams 11. The rotatable bracing elements 13 are fixed at both ends to the longitudinal beams 11a-b by rotation means 15a-d. The rotation means 15 enable the respective rotatable bracing element 13 to be rotated relative to the main frame 29 around the its axis of rotation A.

[0046] In their operational position, the rotatable bracing elements 13a-b have a downward curving shape which determines a plastic deformation 16a-b. In FIG. 1, the direction of plastic deformation for the rotatable bracing element 13b is indicated by Rb, and in FIG. 2 the direction of plastic deformation is indicated by R. This plastic deformation 16 is shaped in such a way that the flexible support material surface 14 is not hindered from making a (limited) downward elastic deformation. The shape of the plastic deformation 16 of each rotatable bracing element 13 can be described by a function for the radially outward shape deviation from the respective axis of rotation A, which depends on the transverse position along the axis of rotation A between two opposite ends of the rotatable bracing element 13. In this example, each rotatable bracing element 13 is bent away from the axis of rotation A near the ends by a component along the deformation direction +R, and further towards a central part bent back by an opposite (i.e. negative) component along the deformation direction R. As a result, both the ends of the traverse 13 and the central portion of the traverse 16 in this example run substantially parallel to the axis of rotation A. The resulting bowed shape of the plastic deformation 16 therefore corresponds to a deformation that monotonically increases between the first end and the central portion of the rotatable bracing element 13, and monotonically decreases between the central portion and the other end of the rotatable bracing element 13, with displacement from the axis of rotation in the central portion of the rotatable bracing element. The resulting curved shape in this example is mirror symmetric with respect to a plane orientated orthogonally to the axis of rotation and located at the centre of the rotatable bracing element.

[0047] In the illustrated embodiment, the mattress support 10 is also provided with two ground support element 30a, 30b, with pivoting ground support bodies 31a, 31b. These ground support bodies 31 enable, in the unfolded state, the main frame 29 to be positioned stably and at a non-zero support height Z0 in relation to a supporting ground surface. In this example, a height Z1 of the main frame 29 with longitudinal beams 11a, 11b and transverse beams 12a, 12b is in the order of a few tens of millimeters, for example about 50 millimeters. In addition, the support height Z0 in this example is of the order of a few hundred millimetres, for example about 250 millimetres. In the unfolded state, the rotatable bracing elements 13 extend in relation to the nominal lower surface of the main frame 29, with a distance in the centre of the order of several tens of millimetres.

[0048] The example in FIG. 1 shows that the main frame 29 is provided with recesses 28 at the top of the main frame 39 and protrusions 27 at the bottom of the main frame 18. The recesses 28 of the mattress support are configured to interlock with the protrusions of a second, identical, mattress support, if the second mattress support is stacked on top in the correct orientation.

[0049] FIG. 2 shows a cross-sectional view of a rotatable bracing element 13 in the mattress support 10 according to FIG. 1. In this example, the rotation means 15 are provided with a bearing 20. This bearing 20 is formed from a plug 21 attached to the rotatable bracing element 13, a pin 41 fixed in the longitudinal beam 11 and extending inwardly thereof towards the internal space 40, and a counter piece 22 lying like a collar around the pin 41. The plug 21 has a blind hole 42 in which the pin 41 is rotatably incorporated and an end face 23 which cooperates with and lies flat against a counter surface 24 of the counter piece 22. Due to the influence of the tension of the flexible surface 14 (and resulting elastic returning force F), the end face 23 and the counter surface 24 are held firmly together in the transverse directions Y. By using a suitable plastic (or metal) with a low friction coefficient, or interstitial lubricating agent, the rotatable bracing element 13 can nevertheless be easily rotated around the axis of rotation A and relative to the main frame 29. In doing so, the walls of the blind hole 42 and the pivot pin 41 incorporated therein work together to prevent the end face 23 from moving in transverse directions (here X and Z) relative to the axis of rotation A. In alternative embodiments, the pivot means may be designed differently, for example, by using a through hole instead of a blind hole, by reversing the pin and hole, and/or by using roller bearings instead of glide bearings.

[0050] The end face 23 and the counter surface 24 have protrusions 25 or recesses 26 which, under the influence of the force exerted by the flexible support material, mutually engage, both in the operating position shown in FIG. 2 and in the rest position. The recesses 26 and the protrusions 25 can engage in a blocking manner in the retracted rest position and/or in the deployed operational position of the rotatable bracing element 13, and act as a blocking means for blocking the rotatable bracing element 13 in these positions. Thus, a stable position of the rotatable bracing element 13 is achieved in both cases.

[0051] The flexible support material 14 is stretched between the longitudinal beams 11, and is situated with a lower surface 17 at a plane distance Z2 above a plane aligned with the underside (lower surface) 18 of the longitudinal beams 11. A block or plate-shaped internal space 40 is formed between the lower surface 17 of the flexible support material 14, the plane aligned with the underside 18 of the longitudinal beams 11, and inward facing (opposing) sides of the longitudinal beams 11. This internal space 40 provides enough space to accommodate the folded rotatable bracing element 13, such that in its resting position it does not project beneath to the plane aligned with the undersides 18 of the longitudinal beams 11.

[0052] FIG. 3 shows a combination of similarly shaped mattress supports 10a-10f in collapsed rest positions. When these mattress supports 10 are stacked on top of each other, the protrusions 27 of an upper mattress support 10(i) can be stably accommodated in the recesses 28 of the immediately underlying mattress support 10(i1). Thus, a stable stack from mattress supports 10 is obtained.

[0053] Both the rotatable bracing elements 13 and the ground support bodies 31 of each mattress support 10 in the stack are, when collapsed, completely contained in the internal space 40 between the lower surface of the flexible support material 14 and the plane aligned with underside 18 of the longitudinal beams 11 of the corresponding mattress support. As a result, it is possible to stack a plurality of the shown mattress supports 10 flat on top of each other, with the stack having a relatively low total height Zt. This total height Zt is only equal to the sum of the thicknesses Z1 of the longitudinal beams 11 and/or the transverse beams 12 of the mattress supports 10 stacked on top of each other, whichever the greater. FIG. 2 illustrates that the flexible support material 14 is at approximately the same height as the top sides 39 of the longitudinal beams 11, so that the vertical internal space 40 is as large as possible.

[0054] When the ground support elements (30) are connected to the longitudinal beams (11), and provided with one or more ground support bodies (31) and movable between an operative ground support position, projecting downwards in relation to the main frame (29), and a folded position in which the ground support elements are at least partially accommodated in the internal space (40) defined between the underside (17) of the flexible support material (14), the underside (18) of the main frame (29) and the inward facing side surfaces (19) of the longitudinal members (11), this confers the advantage of providing a compact design, which by extension, facilitates protection of moving components during transport. Preferably all the ground support elements (30) are connected to the longitudinal beams (11), and provided with one or more ground support bodies (31) and movable between an operative ground support position, projecting downwards in relation to the main frame (29), and a folded position in which the ground support elements are at least partially accommodated in the internal space (40) defined between the underside (17) of the flexible support material (14), the underside (18) of the main frame (29) and the inward facing side surfaces (19) of the longitudinal members (11).

[0055] In a preferable embodiment, the ground support elements (30) a movable between an operative ground support position, projecting downwards in relation to the main frame (29), and a folded position in which the ground support elements are wholly accommodated in the internal space (40) defined between the underside (17) of the flexible support material (14), the level of the underside (18) of the main frame (29) and the inward facing side surfaces (19) of the longitudinal members (11). Preferably, all the ground support elements (30) a movable between an operative ground support position, projecting downwards in relation to the main frame (29), and a folded position in which the ground support elements are wholly accommodated in the internal space (40) defined between the underside (17) of the flexible support material (14), the level of the underside (18) of the main frame (29) and the inward facing side surfaces (19) of the longitudinal members (11). By wholly accommodating the ground support elements (30) in the internal space (40), this confers the further advantage of providing a yet more compact design, which by extension, facilitates yet greater protection of moving components during transport. Since no movable part is outside of the internal volume 40 in this second folded position, they are protected from accidental or unavoidable impact which may occur during shipping or handling a mattress support according to the present disclosure.

[0056] FIGS. 4a-4c and 5a-5c show views of another embodiment of a mattress support 110 in the unfolded use position and the folded rest position, respectively. Elements and features of the above-described embodiment of the mattress support 10 (see FIGS. 1-3) may also be present in the mattress support 110 shown in FIGS. 4a-5c, and are not revisited here. Similar elements are indicated by similar reference numerals (same last two digits), but preceded by a 1 to distinguish the embodiment.

[0057] FIG. 4a shows a top view of a mattress support 110 in the in-use position, FIG. 4b shows a side view, and FIG. 4c shows an end-on side view. Similarly, FIG. 5a shows the top view of the mattress support 110 in the folded rest position, FIG. 5b shows a side view, and FIG. 5c shows the end-on side view.

[0058] As shown in FIGS. 4a and 5a, the rotatable bracing elements 113 extend between the longitudinal beams 111 over a transverse width Y. The rotatable bracing elements 113 are located below the flexible support material 114, and under the influence of the tension of the flexible support material 114, are pressure loaded to hold the longitudinal beams 111 apart at this transverse width Y. For such a mattress support 110 formed for carrying one person, the transverse width Y is preferably in a range of about 700 millimetres to 1000 millimetres.

[0059] Unlike in the embodiment according to FIGS. 1-3, this mattress support is not provided with ground support elements, and the shape of the plastic deformation 116 of each rotatable transverse member 113 in this example is single curved concave. Here, the elongated body of the respective rotatable transverse member 113 has a deflection in the deformation direction R as a function of the transverse direction Y. As shown in FIGS. 4c and 5a, the maximum shape deformation R also lies in the central portion of the rotatable transverse member 113 in this example. This central part of the plastic deformation 116 forms an area which, in the unfolded position of use, is lower than the level of the underside 118 of the main frame 129. This central inner distance R lies in a range of about 50 millimeters to 70 millimeters. As a result, a ratio R/Y between the central inner distance R and the traverse width Y for this mattress support 110 lies in a range of 1/20R/Y1/10. As can be seen further in FIGS. 4c and 5a, the traverse already deviates from the axis of rotation A with a non-zero component near the ends, in contrast to the multiple-curved concave shape of the traverse from FIGS. 1 and 2.

[0060] Each rotatable bracing element 113a, 113b is rotatable with respect to the main frame 29 around a corresponding axis of rotation Aa, Ab and in a corresponding direction of rotation da, @b. In the resting position of the mattress support 110 shown in FIGS. 5a-c, the rotatable bracing elements 113 are rotated through 90 with respect to the use position shown in FIGS. 4a-c such that they lie entirely within the (internal) space 140 defined between the underside 117 of the flexible support material 114, the nominal plane orientated along the underside 118 of the longitudinal beams 111 and the opposing internal side surfaces 119 of those longitudinal beams 111. This block-shaped or plate-shaped internal space 140 provides enough space to accommodate the collapsed rotatable bracing elements 113 in such a way that they do not protrude downwards relative to the nominal plane orientated along the underside 118 of the longitudinal beams 111 (e.g. they do not extend beneath the plane). This makes it possible to stack a plurality of the mattress supports 110 shown flat on top of each other (similar to FIG. 3).

[0061] FIGS. 6a-6c show views of a rotatable bracing element 213 in a mattress support 210 according to an alternative embodiment, with elements and features similar to those of the mattress support 10 according to FIGS. 1-3. Again, the rotatable bracing elements 213 are rotatable around their respective axes of rotation A, with respect to the main frame 229, but each of the rotatable bracing elements 213 is formed with an asymmetric cross section perpendicular to the axis of rotation A. Similar elements are indicated by similar reference numerals (same last two digits), but preceded by a 2 to distinguish the embodiments.

[0062] FIG. 6b shows a cross-sectional view of one of the rotatable bracing elements 213, near the rotation means 215 where the rotatable bracing element 213 is rotationally coupled to the longitudinal beam 211. Depicted here is the operating position, in which the rotatable bracing element 213 is has been extended by rotating through an angle of 90 from the resting position, and extends downward relative to the main frame 229. FIG. 6b also depicts the linear protrusions 225 and recesses 226 in the top surface and counter surface of the rotation means 215, which, in the unfolded position of the rotatable bracing element 213, align and interlock to increase resistance to rotation, thereby temporarily locking the rotatable bracing element in this configuration. In this position, the width D1 of the rotatable bracing element 213 is defined along X (which is orientated orthogonal to both the axis of rotation A and the direction of radial plastic deformation), while the height H of the rotatable bracing element 213 is defined along Z (orientated along the direction of radial plastic deformation and lies orthogonal to the axis of rotation A). Here the height H is greater than the thickness D1. For example, in a practical example, D1 can be equal to 25 millimetres and H can be equal to 40 millimetres. The cross-sectional elongation in the direction of radial deformation increases the mechanical resistance of the rotatable bracing element 213 to bending or buckling under loads encountered when the mattress support is used, where an increased inward force component is orientated along the axis of rotation A (through the mass of a mattress and or a person lying on a mattress acting on the flexible support material 214). The cross-sectional elongation of the rotatable bracing element along H is preferentially applied along the entire length Y of the rotatable bracing element 213, including in the central part of the rotatable bracing element 213 which is plastically deformed away from axis of rotation A in a radial direction as a result of the plastic deformation 216 (not shown in FIG. 6b).

[0063] The rotatable transverse member 213 is in this example embodied as a hollow tube formed of flat and interconnected walls, which together have a rectangular shape with rounded corners, seen in cross-sections perpendicular to the longitudinal direction of the rotatable bracing element 213. In this example, the thickness dimension D1 is defined as the distance between the outward surfaces of the two side walls 243, 244. In cross sections near the rotation means 215, the axis of rotation A is located in the middle between these walls 243, 244, and also at approximately equal distance from top wall 245 (i.e., at distance 1/2-D1 from each of these walls 243-245). Here, the diagonal distance D3 from the axis of rotation A to corner 246 (where walls 243 and 245 merge) is sufficiently small to fit within the available height between the axis of rotation A and the underside of the flexible support material 214, if the rotatable transverse member 213 is rotated from the use position to the rest position. In alternative embodiments, the rotatable transverse member may also have other flattened cross-sectional shapes and/or may be solid.

[0064] In the rest position shown in FIG. 6c, the rotatable bracing element 213 is rotated through an angle of +90 in relation to the operational position such that the rotatable bracing element 213 with its width D1 falls entirely within (is enclosed within) the internal space 240 which is vertically bounded between the underside of the flexible support material 214 and the nominal plane aligned with the underside of the longitudinal beams 211. Due to the 90 rotational symmetry of the protrusions 225 and recesses 226 around axis of rotation A, when the rotatable bracing element 213 is collapsed (placed in a storage position), they align and mutually engage, which serves to increase the resistance to rotation out of this position.

[0065] FIGS. 6b-6c further show that the rotation means 215 in this example is positioned at the end of the rotatable bracing element 213, such that the axis of rotation A is shifted upwards in the direction of the height H. As a result, the additional height H-D1 of the rotatable bracing element 213 deforms in only one radial direction relative to the axis of rotation A, and this asymmetrical cross-sectional deformation of the rotatable bracing element along the direction of the height H can be applied close to the rotatable coupling means 215 in the rotatable bracing element 213.

[0066] FIGS. 7a-7c show further details of the ground support elements 30 from FIG. 1. The slide block rails 34 are each formed as a rigid elongated recessed channel extending straight along the longitudinal direction X. Each ground support element 30 also includes ground support bracing element 32 and slide blocks 33. Each ground support bracing element 32 is rotatably connected at one end to an associated ground support body 31, and rotatably connected at another end to associated slide block 33. The slide block 33 is slidably incorporated in a slide track 37 of the slide block rail 34. The slide block rails 34 are further provided with couplings for securing the respective ground support elements 30 to two longitudinal beams. The ground support body 31 is rotatably attached via the fixed mounting 35, which has a fixed position in the slide block rail 34. In the extended position of the ground support body 31, the slide block 33 along the slide track 37 comes to rest against the fixed mounting 35. In the suspension of the ground support body 31 to the fixed mounting 35, there is a blocking means for blocking the ground support body 31 in its retracted position. This blocking means may also be provided with recesses and matching protrusions on adjacent and mutually rotatable top surfaces, similar to those in the rotatable bracing elements rotation means shown in FIG. 2.

[0067] FIGS. 8a-b show a preferable embodiment of the invention. FIG. 8a depicts a ground support element (330) in isolation, wherein the ground support element (330) comprises two ground support bracing elements (332), with one located at each end of the ground support element (330). The ground support element (330) and ground support bracing elements are primarily composed of 12 mm diameter solid steel tubes.

[0068] FIG. 8b depicts the mattress support (310) in a folded rest position in which the two rotatable bracing elements (313), the two ground support elements (330) and the four ground support bracing elements (332) are all completely above the level of the underside (318) of the main frame (329). The four ground support bracing elements (332) are provided between the ground support bodies (331) of the ground support elements (330) and the longitudinal beams (311). The ground support bracing elements (332) are rotatably connected to the ground support body (331) and slidably cooperate with sliding tracks (337) provided on the longitudinal beams (311). The ground support bracing elements (332) and the longitudinal beams (311) together have a stop for determining the extended position of the ground support body (331) (not depicted).

[0069] FIGS. 9a-b show the same preferable embodiment of the invention as FIGS. 8a-b, with FIG. 9a depicting a mattress support (310) in a first extended operational position in which the plastic deformations (316) of the two rotatable bracing elements (313) extend away from the flexible support material (314) downwards under the level of the underside (318) of the main frame (329) to allow for elastic deformation of the flexible support material (314). FIG. 9b depicts three inverted mattress supports (310) from an imaginary perspective to show how the ground support bracing element (332) is rotatably connected to the ground support body (331) and slidably cooperates with a sliding track (337) provided on the longitudinal beam (311) of the mattress support (310).

[0070] It will be understood that the above-described embodiments are only described by way of example and not in any limiting sense, and that various modifications and adaptations are possible without going beyond the scope of the invention and that the scope is only determined by the appended claims. For instance, the ground support elements (30) may be provided as interconnected rods that form parallelepipeds, wherein two opposite faces of each parallelepiped are parallel with the plane of the upper side of the main frame of the mattress support. Herein, the rods are rotatably attached to the mainframe so as to allow the parallelepiped to be moved from a first position in which the parallelepiped is in a flattened form and accommodated wholly in the internal space (40) defined between the underside (17) of the flexible support material (14), the underside (18) of the main frame (29) and the inward facing side surfaces (19) of the longitudinal members (11) to a second operative (downward extended) ground support position in which the parallelepiped is arranged so that the rods defining the lowest face of the parallelepiped may engage the ground. Other geometries may be readily envisaged, such as wire frames defining a pyramid (those with a triangular base are typically called Eiffel legs, through the Eames DSR chair of 1951) or a frustum (square, hexagonal, etc).

[0071] In the examples in FIGS. 1-5c, the main frames of the mattress supports were fitted with two rotatable bracing elements, but mattress supports in alternative designs may be fitted with only one rotatable bracing element, or with more than two rotatable bracing element. In this case, it is preferable that the rotatable bracing elements are distributed evenly along the longitudinal direction and mirror-symmetrically in relation to the centre of the longitudinal beams, in order to provide equal resistance to the inward force exerted by the flexible support material. In the case of mattress supports with an odd number of rotatable bracing elements, one of the rotatable bracing element is preferably always positioned at the centre of the longitudinal beams, seen in the longitudinal direction X. In the case of a mattress support with three rotatable bracing elements, these rotatable bracing elements can, for example, be mirror-symmetrically positioned along the main frame at positions corresponding to th, th and th of the length of the longitudinal beams.

[0072] Furthermore, the mattress supports in the examples shown in FIGS. 1-3 included rotatable bracing elements and support frames with ground support elements that were coupled to the longitudinal beams of the main frame of the mattress support by means of additional longitudinal profiles. In alternative designs, the longitudinal trunks may also be integrally formed with coupling parts for the pivotally coupling of transoms and/or ground support elements directly to these longitudinal trunks. The longitudinal beams themselves may be formed, for example, as flexurally rigid extruded profiles in which/to recessed chambers, coupling ridges, etc. are provided for the traverses and/or the support organs.

[0073] The reference figures in the claims are for illustrative purposes only and should not be regarded as limiting for the interpretation of the claims. For the sake of brevity, similar reference numbers corresponding to similar elements of described embodiments are indicated in the claims only by their last two digits (i.e. without hundreds) where correspondences with multiple embodiments apply. This does not suggest that these claim elements refer only to elements of the description that correspond to a last two digits. For example, the reference numeral (13) in the claims should be read as (13; 113; 213) where this correspondence is applicable. The applicability of several similar reference figures in the claims follows from a comparison with the figures and the description. In cases where a claim focuses on a specific embodiment, specific reference numbers with hundreds are used in the claims (e.g. 213).

LIST OF REFERENCE MARKS

[0074] Similar reference numbers used in the description to indicate similar elements (but only differences in hundreds) are implicitly included. [0075] 10 mattress support [0076] 11 longitudinal beam [0077] 12 transverse beam [0078] 13 rotatable bracing element [0079] 14 flexible support material [0080] 15 rotatable coupling [0081] 16 plastic deformation [0082] 17 underside of support material [0083] 18 underside main frame [0084] 19 inward facing faces of longitudinal beam [0085] 20 bearing [0086] 21 plug [0087] 22 counterpart [0088] 23 end face [0089] 24 counter surface [0090] 25 protrusion [0091] 26 recess [0092] 27 protrusion [0093] 28 recess [0094] 29 main frame [0095] 30 ground support element [0096] 31 ground support body (e.g. support leg or bracket) [0097] 32 ground support bracing element [0098] 33 slide block [0099] 34 slide block rail (e.g. channel) [0100] 35 fixed mounting [0101] 37 track configured for slide block [0102] 39 top of main frame [0103] 40 internal space [0104] 41 pin [0105] 42 blind hole [0106] 243 sidewall [0107] 244 sidewall [0108] 245 upper wall [0109] 246 corner [0110] A axis of rotation [0111] X first direction (e.g. longitudinal direction) [0112] Y second direction (e.g. transverse direction) [0113] Z third direction (e.g. vertical direction) [0114] R plastic deformation direction [0115] direction of rotation [0116] D1 rotatable bracing element width [0117] D2 rotatable coupling width [0118] D3 the distance of corner from the axis of rotation A [0119] H rotatable bracing element height [0120] Y transverse width [0121] Z0 support height [0122] Z1 height of main frame [0123] Z2 Inter plane distance [0124] Zt main frame stack height [0125] R central internal distance of crossbar