Technical field

The invention relates to a mattress support. Further, the invention relates to a method for stacking mattress supports.

State of the Art

Mattress supports with folding legs and a rigid base, such as a steel base plate are well known. Such mattress supports are intended for use in emergency situations or temporary applications in emergency shelters. The disadvantage of these well-known mattress supports is that, due to the rigid nature of the steel base plate, a relatively thick top mattress must be used in order to provide sufficient comfort.

Another type of mattress support is known, for example, from patent document GB532573A. This describes a stretcher that is constructed from longitudinal and transverse beams formed from angle irons that are interconnected to form a frame, and between which a flexible support surface is attached. Attached to the frame are legs that can be rotated between an extended position in which the legs extend below the frame to position it at a height relative to a lower surface, and a collapsed position in which the legs are virtually contained within the vertical space of the frame. The two legs in a single pair are connected near their ends by a crossbar to facilitate simultaneous rotation of these legs.

The robustness of this type of foldable stretcher against deformation is low. In particular, resistance to warping of the frame members inwards due to high tension loads applied by or through a flexible support surface appears to be low (for example, when the mattress support is loaded with a heavy load, it is to be expected that the frame bends inwards). It is therefore desirable to provide a mattress support that can provide both a high degree of shape retention and comfort and can be stacked in a reliable and stable manner.

An alternative approach in the art is to obviate the combination of a support and mattress entirely, for example, from patent document FR 2666730. The stackable relaxation couch disclosed therein is a piece of furniture wherein the essential characteristics are as follows: it is rigid and resistant so that an enveloping canvas, tightly stretched below the frame by means of short elastics crossing eyelets, replaces slats plus usual mattresses, for supposed comfort. The stackable relaxation couches comprise rigid, immobile ground support elements that render such articles needlessly bulky and their ground support element vulnerable to incidental damage.

It remains an outstanding challenge to provide emergency use mattress supports that are lightweight and hence easy to manhandle, whilst also being comfortable to use and finally being able to be stored or transported in a volume efficient manner so that a large number of mattress supports can be transported in one aid truck. Brief Description of the Invention

For this purpose, according to a first aspect, the invention provides a mattress support with longitudinal beams, transverse beams, a flexible support material, rotatable coupling means, and at least one rotatable bracing element. The longitudinal beams extend next to and at a distance from each other, preferably orientated parallel to one another. The transverse beams are rigidly connected to the longitudinal beams at or near to the ends of the longitudinal beams, and together with the longitudinal beams form a main frame. The flexible support material is pre-stressed or stretched between the longitudinal beams so that it defines a surface corresponding to the upper surface of the frame. At least one rotatable bracing element is located under the flexible support material surface. As the flexible support medium is elastically deformed (stretched) towards the longitudinal beams, the flexible support medium exerts an inward force on the longitudinal beams and the rotatable bracing element or elements are configured so as to bear the stress resulting from this inward force along its length and keep the longitudinal beams apart at a constant rotatable element length. The rotatable coupling means are provided at both ends of the rotatable bracing element, and connect the rotatable bracing element to the longitudinal beams in a rotating manner around an axis of rotation directed transversely to the longitudinal beams and parallel to the flexible support material surface. The rotatable bracing element comprises a plastic deformation that extends in a direction perpendicular to the axis of rotation. The plastic deformation can be rotated around the axis of rotation between an unfolded operational position, in which the projection protrudes at right angles to the flexible support material, below the plane of the nominal bottom surface of the main frame to allow for deformation of the flexible support medium when the mattress support medium is in use (i.e. deformation due to the flexible support medium bearing the weight of a person), and a folded rest position, in which the projection is completely contained within a volume defined by the main frame (i.e. does not project below the bottom surface defined by the main frame).

The term "rotatable bracing element" here denotes a rigid elongated body positioned between the two longitudinal beams of the mattress support, rotatably connected to these longitudinal beams at or near two opposite ends of the rotatable bracing element, preferably extending along a centre line running between the two longitudinal beams, and preferably primarily perpendicular to the longitudinal direction of the longitudinal beams. A beam has a high stiffness (mechanical resistance) to forces acting inward along the centre line at the ends of the beam. The rotatable bracing element therefore provides a high resistance to transverse (inward) forces applied to the longitudinal beams by the stretched flexible support material and prevents the longitudinal beams from bending inwards when the flexible support material is under high stress. The expression "constant transverse length" in this context refers to a transverse distortion of the longitudinal beams that remains very small in relation to the total length of the main frame due to the presence of the rotatable bracing element(s). The resulting inward displacement is at most a few % (e.g. maximum 1%) of the length of the main frame.

In contrast to a rotatable bracing element, a support element, such as a foot or other leg assembly, is configured to support the main frame when the supporting element is in a support position, in which the major portion of the support element is extended beyond the volume defined by the main frame. A transverse connection between two legs, preferably near the free ends of a pair of legs (such as the transverse bars in document GB532573A), facilitates simultaneous rotation of pairs of legs, and can serve to hold the two legs together in the transverse direction when in the support position (i.e. when unfolded). However, a transverse connection between legs is far from an axis of rotation located directly between the longitudinal beams when the legs are in a support position (i.e. when unfolded), and thus provides little resistance to the inward compression forces exerted by a tensioned flexible support material on the longitudinal beams in the transverse direction towards each other.

According to this aspect of the invention, the rotatable bracing element is rotatable and extends almost directly between the longitudinal members, in both the folded and the unfolded state of the mattress support. According to this aspect, the rotatable bracing element is provided with a relatively small plastic deformation. The term "plastic deformation" here refers in a broad sense to a relatively small degree of displacement of a central area of the rotatable bracing element in a direction radially outward from the axis of rotation of the rotatable bracing element, with respect to the two opposite ends of the rotatable bracing element which are nearly coincident with the axis of rotation. Due to the presence of such a plastic deformation, the rotatable bracing element may have a slightly curved and/or radially displaced shape such that the radial displacement from the axis of rotation of the rotatable bracing element is greatest half-way between the two ends of the rotatable bracing element, and the radial displacement of the rotatable bracing element from the axis of rotation becomes progressively smaller for positions closer to the ends of the rotatable bracing element that are rotationally attached to the longitudinal members. Due to this plastically deformed shape, when the rotatable bracing element is in the unfolded position, there is additional space for the flexible support material to be displaced downwards (i.e. towards the axis of rotation) as compared to the folded position. This additional displacement of the flexible support material could be caused when the flexible support material bears a load, such as a person resting on the mattress support. The plastic deformation of the rotatable bracing element therefore confers the advantage that the flexible support material can deform more when in use, and consequently a thinner mattress can be used to confer the same degree of comfort as would be required by a stiffer mattress support material (such as a steel plate). Preferably, the rotatable bracing element possesses mirror symmetry with respect to a plane orthogonal to the axis of rotation of the rotatable bracing element.

The shape of the rotatable bracing element can be described by a function for the radially outward displacement from the axis of rotation of the rotatable bracing element, which depends on the transverse position along the axis of rotation between the two opposite ends of the rotatable bracing element. Preferably, this form function has a (not necessarily strictly) monotonic rising character between the first rotationally attached end and the central part of the rotatable bracing element, and a (not necessarily strictly) monotonic falling character between the central part and the other rotationally attached end of the rotatable bracing element. For example, the rotatable bracing element may have a curved or kinked concave shape. Alternatively, the traverse may be curved or kinked near the ends by a component in a direction of expansion away from the axis of rotation, and may be curved or kinked further towards the central part by a component in the opposite direction of expansion, such that the central part runs at a distance and almost parallel to the turning centre line.

The rotatable bracing element(s) span(s) a transverse width AY between the longitudinal beams. A central part of the rotatable bracing element forms an area which, in the unfolded operating position, is furthest below the level of the underside of the main frame, at a central internal distance AR along the bracing direction and in relation to the axis of rotation. In order to provide a good balance between sufficient space for vertical displacement of the flexible support material and sufficient compression stiffness of the rotatable bracing element, a ratio AR/AY between the central inner distance and the transverse width should satisfy 0 < AR/AY < 1/10, and preferably 1/20 < AR/AY < 1/10.

The rotatable bracing element with plastic deformation can be rotated to the folded rest position, in which case it is completely contained within the internal volume of the main frame of the mattress support. As a result, the extension of the turned folded rotatable bracing element does not project below the top or bottom surface of the main frame. Preferably, the rotation angle of the rotatable bracing element between the unfolded and the folded positions is 90°. Because of the position of the rotatable bracing element in the folded position above the nominal plane tangent to the underside of the frame, which coincides with the level of the underside of the frame, several mattress supports can be stacked on top of each other. This advantageously results in a compact and stable stack of stacked mattress supports with a minimum stacking height. The underside of the main frame is determined by the underside of the longitudinal beams and/or the transverse beams. The underside of the main frame is further determined by the fact that this underside fulfils a support function when stacking mattress supports with the crossbeams folded down. The mattress supports can be configured so that both the longitudinal and transverse beams support the weight of a mattress support stacked above them. Alternatively, the mattress supports can be configured so that only some of the longitudinal or transverse beams support the weight of a mattress support stacked above them, for instance if both the longitudinal beams bear the weight of the mattress support stacked above them or both the transverse beams bear the weight of a mattress support stacked above them. The mattress supports can be stacked on top of each other with the longitudinal beams and/or their transverse beams, if necessary, enclosing the edges of the supporting surface and the corresponding fasteners with which the supporting surface is stretched between the longitudinal trusses.

The mattress support according to this first aspect is therefore robust in the state of use but stably stackable with low stacking height in the folded state. Such a robust stackable mattress support is excellently (but not exclusively) suited for temporary use, such as in emergency rooms in case of calamities. It can also be used for other temporary applications, such as large events, military or emergency service units and so on. The mattress support is ideally suited for mobile applications. The mattress supports can be kept ready in storage and transported while stacked. After all, the volume of a stack of such mattress supports is relatively low, while the stacks are also easy to move because of the stable shape of the stack. Due to the highly elastic nature of the flexible support material, user comfort is ensured even with relatively thin upper mattresses. This results in a further advantage: not only are the mattress supports themselves stackable in a relatively small volume when collapsed, but also these relatively thin upper mattresses. The total volume of mattress supports and top mattresses is therefore considerably smaller than the total volume of the known mattress supports and relatively thick top mattresses. This is density of mattress supports and upper mattresses is particularly advantageous when shipping aid supplies, where the limiting logistical factor is often available ship, air-freight or truck volume. According to a further embodiment, the flexible support material extends at the level of the upper sides of the longitudinal beams in such a way that the longitudinal beams and the flexible support material are directly adjacent on their upper sides to the same nominal upper surface. This facilitates the placing of the upper mattress and optimises the available vertical space between the undistorted support and a nominal lower surface that touches the longitudinal beams at their lower ends. In a further embodiment, the longitudinal beams, the transverse beams, and the flexible support material surface are all adjacent to the same nominal upper surface on their upper sides, and the longitudinal beams and the transverse beams are adjacent to the same nominal lower surface on their lower sides. This allows the height of a stack of mattress supports to be minimised.

The rotatable coupling means can comprise a glide bearing, a slide bearing, an axial bearing, a thrust bearing, or a pivot bearing, respectively. These bearings may be ball or roller bearings. Preferably, the axial bearing, thrust bearing, or pivot bearing is provided as a slide bearing. Here, the rotatable bracing element is preferably in the form of a shaped tube or rod or profile capped by mutually parallel end faces, wherein the end faces are orthogonal to the axis of rotation (A). The axial bearing, thrust bearing or pivot bearing is arranged between each end face of the cross member and the adjacent longitudinal beam.

Preferably, the rotatable bracing element is provided with blocking means for temporarily blocking the rotatable bracing element in the unfolded use position and/or in the folded storage position. In particular, one end of the rotatable bracing element can have an end face and the corresponding longitudinal beam can have a counter surface, which end face and counter surface interact as a sliding pivot bearing. In connection with securing the rotatable bracing element in its blocked positions, the end face and the counter surface may have recesses or depressions which engage in a blocking manner in the storage position and/or in the working position of the rotatable bracing element.

According to one embodiment, the rotatable bracing element and the rotation means have a maximum thickness in a direction transverse to the centre of rotation and transverse to the direction of plastic displacement R have maximum thickness dimensions which are no more than the inter-plane distance between the underside of the flexible support surface and the underside of the main frame.

Because of the limited maximum dimension of the rotatable bracing element mentioned, it is sufficiently thin that it can be fully enclosed in the space bounded by the aforementioned nominal flat surface along the underside of the longitudinal beams, by the flexible support material surface, which is at rest or not deformed, and by the inner side walls of the longitudinal beams, which are oriented towards each other (i.e. facing inwards). This relatively thin block-shaped or plate-shaped space proves to be sufficiently high or thick to accommodate the rotatable bracing element, at least when arranged in the stacking position. The rotatable bracing elements can be completely folded in. In this case, the rotatable bracing elements do not form an obstacle when stacking the mattress supports.

In a further embodiment, the rotatable bracing element seen in a cross-section perpendicular to the axis of rotation has a height dimension defined in the direction of deformation (i.e. radial direction away from the axis of rotation), and the height dimension is greater than the above defined thickness dimension. By increasing the height with respect to the thickness, the stiffness of the transverse beam against bending loads along the radial direction can be increased, without reducing the stowability of the folded transverse beam inside the above space.

In a further embodiment, the axis of rotation of the rotatable bracing element can intersect the longitudinal beams at a position essentially midway between the underside of the longitudinal beams and the flexible support material surface. This facilitates complete enclosure of the transverse beam within the space underneath the bearing surface and above the underside of the longitudinal beams.

According to one embodiment, the longitudinal beams of the mattress support may be provided with ground support elements that are connected to the longitudinal beams. Such a ground support element may be provided with one or more supporting devices (such as ground support legs or ground support frames) that are movable between an operative position, projecting downward in relation to the main frame (i.e. toward the ground), and a collapsed position in which the one or more ground support devices are wholly contained within the space determined between the flexible support material surface, the level of the underside of the main frame (or, in other words, by a plane along the underside of the main frame), and the inward facing surfaces of the longitudinal beams.

The ground support element may also include a transverse connecting beam. The rotatable bracing element and the ground support element(s) may be offset by their respective pivot axes in the longitudinal direction of the longitudinal beams, the distance between them being greater than the sum of the internal central distance of the rotatable bracing element and the length of the ground support element. A ground support body constructed in this way may also be included entirely within the said space under the load-bearing surface.

The ground support element may be equipped with blocking devices for blocking the support bodies in their folded position.

An embodiment is conceivable in which the ground support element(s) and two profile sections fitted at the ends of the ground support element are attached to the longitudinal beams.

According to a further embodiment, at least one ground support bracing element (e.g. a strut) may be provided between a ground support element of the ground support device and a longitudinal beam. This ground support bracing element (e.g. a strut) and the longitudinal beam together may have a stop for determining the extended position of the support body. Furthermore, the strut may be rotatably connected to the ground support element and may cooperate in a sliding manner with a sliding track provided on the longitudinal beam.

The flexible support material surface extends along a plane enclosed by the main frame of the longitudinal and transverse beams and is elastically stretched in a direction parallel to that of the transverse beams between the longitudinal beams in such a way that it can support a mattress and a person lying or sitting on it. This flexible support material surface is elastically deformable in all directions along the stretched surface and is elastically deformed by stretching of the surface in outward directions along the surface and orthogonal to the longitudinal beams. This ability to deform elastically along the stretched surface confers the advantage of providing dynamic comfort during use, avoiding excessive hardness in any one area or sagging in others. The presence of rotatable bracing elements according to the invention makes it possible to place the supporting surface under high stress. According to one embodiment, the elastic support material is elastically deformed by an applied force in the direction parallel to the transverse beams towards the longitudinal beams, fixed to the longitudinal beams and the applied force removed. This results in a mattress support in which the elastically deformed mattress support material exerts a total inward force equal to the force applied to elastically deform the support material, in an inward direction parallel to the transverse beams and orthogonal to the direction of the longitudinal beams. Preferably the inward force is between 200 and 40000 N, more preferably between 1000 and 30000 N, yet more preferably between 10000 and 27500 N and most preferably between 20000-25000 N. The transverse force with which the longitudinal beams are pulled towards each other by the flexible support material may increase further when a person rests on this flexible supporting surface. The relatively high horizontal pre-tensioning of the mattress support material limits the vertical downmovement of the mattress support material when a load is loaded onto the matters support material (i.e. a person of 120 kg). This confers the advantage of providing superior macro-comfort for a person using the mattress support with a thin mattress (<100 mm thickness), both in a resting position and in dampening the impact of forcefully sitting down on the mattress support. The flexible support material surface is preferably formed by a network of interlocking helical springs. More preferably, the flexible support material is formed by a network of interlocking helical springs in which the direction of coil progression is orthogonal to the longitudinal beams. Such a network, when elastically deformed/stretched across the longitudinal beams exerts an inward force on the longitudinal beams. The rotatable bracing elements are excellent at bearing this inward force, in particular when rotatably connected to the longitudinal beams by slide bearings. Other elastic sheet-shaped flexible support materials can also be used, such as a prestressed elastic fabric (for example, from a network of elastic yarns) or elastic sheet (for example, a perforated breathable sheet of rubber with an inlay). The rotatable bracing elements are preferably configured to bear a load of 50 to 20000 N, more preferably 250 to 15000 N, yet more preferably 2500 to 13750 N, even more preferably 5000 to 12500 N and most preferably 5500 to 7500 N.

Preferably, the flexible support material surface is air permeable. Air permeability is defined as "the volume of air in cubic centimetres (cm ³ ) which is passed through in one second through 100 cm ² of the fabric at a pressure difference of 10 cm head of water". Air permeability is measured using the Frazier test method in accordance with ASTM D737 (2018).

According to one embodiment, the top or bottom of the main frame may have protrusions that protrude from the top or bottom of the entablature. In addition, the underside or top of the main frame may feature recesses that are recessed relative to the top or bottom of the main frame. The protrusions and recesses of mattress supports stacked directly on top of each other can be configured to cooperatively stabilize stacked mattress supports and prevent lateral displacement of stacked mattress supports. Preferably, these protrusions and recesses are configured to interlock. More preferably these protrusions and recesses are suitably shaped and smoothly curved, to reduce the risk of damage to the contact surfaces.

In one embodiment, the longitudinal and transverse beams are made of extruded aluminium profiles, and the rotatable bracing elements are formed of bent aluminium tubing. In an alternative embodiment, the beams and rotatable bracing elements are made of steel.

According to a second aspect and in accordance with the advantages and effects described above, the invention provides a combination of at least two mattress supports according to the first aspect. This combination can be formed by means of a process for forming a stack from at least a first mattress support and second mattress support, wherein the process comprises: - rotating the rotatable bracing elements about the corresponding axes of rotation to bring the first and second mattress bearers into the folded stacking positions, and - placing the second mattress support with a lower side of the main frame on top of an upper side of the main frame of the first mattress support. In the resulting combination of mattress supports, the underside of the main frame of an upper mattress support rests on an underlying mattress support, such as on the upper side of the main frame of an underlying mattress support. However, it is also possible that the underside of an upper frame rests on elements that are still above the upper side of the underlying main frame, such as the attachment elements of the support.

Short Description of the Figures

The following non-limiting examples of the invention will be described in light of the accompanying schematic drawings of Figures 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.

Figure 1 shows a perspective view of a mattress support in the position of use according to one embodiment;

Figure 2 shows a partial cross-section of a rotatable bracing element along its axis of rotation according to the design in Figure 1 ;

Figure 3 shows a combination of stacked mattress supports in collapsed resting positions according to an embodiment;

Figures 4a-c show views of another embodiment of a mattress support in the use position;

Figures 5a-c show views of the mattress support from figures 4a-c, in the folded rest position;

Figures 6a-c show views of a rotatable bracing element in a mattress support according to an alternative embodiment.

Figures 7a-c show various positions of the ground support elements of the mattress support depicted in Figure 1 .

Figures 8a-b show a preferable embodiment of the invention, with Figure 8a depicting a ground support element in isolation and Figure 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.

Figures 9a-b show a preferable embodiment of the invention, with Figure 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. Figure 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.

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

Figure 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, 11 b 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.

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 100±2 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.

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 1/3 and 2/3 of the length of the longitudinal beams 11 . The rotatable bracing elements 13 are fixed at both ends to the longitudinal beams 11 a-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.

In their operational position, the rotatable bracing elements 13a-b have a downward curving shape which determines a plastic deformation 16a-b. In Figure 1 , the direction of plastic deformation for the rotatable bracing element 13b is indicated by RD, and in Figure 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.

In the illustrated embodiment, the mattress support 10 is also provided with two ground support element 30a, 30b, with pivoting ground support bodies 31 a, 31 b. 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 AZO in relation to a supporting ground surface. In this example, a height AZ1 of the main frame 29 with longitudinal beams 11 a, 11 b 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 AZO 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.

The example in Figure 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.

Figure 2 shows a cross-sectional view of a rotatable bracing element 13 in the mattress support 10 according to Figure 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. 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 Figure 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.

The flexible support material 14 is stretched between the longitudinal beams 11 , and is situated with a lower surface 17 at a plane distance AZ2 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.

Figure 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(i-1 ). Thus, a stable stack from mattress supports 10 is obtained.

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 AZt. This total height AZt is only equal to the sum of the thicknesses AZ1 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. Figure 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.

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).

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.

Figures 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 abovedescribed embodiment of the mattress support 10 (see Figures 1-3) may also be present in the mattress support 1 10 shown in Figures 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.

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

As shown in Figures 4a and 5a, the rotatable bracing elements 113 extend between the longitudinal beams 111 over a transverse width AY. 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 AY. For such a mattress support 110 formed for carrying one person, the transverse width AY is preferably in a range of about 700 millimetres to 1000 millimetres.

Unlike in the embodiment according to Figures 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 1 13 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 Figures 4c and 5a, the maximum shape deformation AR 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 AR lies in a range of about 50 millimeters to 70 millimeters. As a result, a ratio AR/AY between the central inner distance AR and the traverse width AY for this mattress support 110 lies in a range of 1/20 < AR/AY < 1/10. As can be seen further in Figures 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 Figures 1 and 2.

Each rotatable bracing element 113a, 1 13b is rotatable with respect to the main frame 29 around a corresponding axis of rotation Aa, Ab and in a corresponding direction of rotation <t>a, <t>b. In the resting position of the mattress support 1 10 shown in Figures 5a-c, the rotatable bracing elements 113 are rotated through 90° with respect to the use position shown in Figures 4a-c such that they lie entirely within the (internal) space 140 defined between the underside 117 of the flexible support material 1 14, 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 Figure 3).

Figures 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 Figures 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.

Figure 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 <t> of -90° from the resting position, and extends downward relative to the main frame 229. Figure 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 AY 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 Figure 6b).

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 %-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.

In the rest position shown in Figure 6c, the rotatable bracing element 213 is rotated through an angle <t> 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.

Figures 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.

Figures 7a-7c show further details of the ground support elements 30 from Figure 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 Figure 2.

Figures 8a-b show a preferable embodiment of the invention. Figure 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.

Figure 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).

Figures 9a-b show the same preferable embodiment of the invention as Figures 8a-b, with Figure 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). Figure 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).

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). In the examples in Figures 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 1 /4th, 1/2th and 3/4th of the length of the longitudinal beams.

Furthermore, the mattress supports in the examples shown in Figures 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.

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

Similar reference numbers used in the description to indicate similar elements (but only differences in hundreds) are implicitly included.

10 mattress support

11 longitudinal beam

12 transverse beam

13 rotatable bracing element

14 flexible support material

15 rotatable coupling

16 plastic deformation

17 underside of support material

18 underside main frame

19 inward facing faces of longitudinal beam

20 bearing

21 plug

22 counterpart

23 end face

24 counter surface

25 protrusion

26 recess

27 protrusion

28 recess

29 main frame

30 ground support element

31 ground support body (e.g. support leg or bracket)

32 ground support bracing element

33 slide block

34 slide block rail (e.g. channel)

35 fixed mounting

37 track configured for slide block

39 top of main frame

40 internal space

41 pin

42 blind hole

243 sidewall

244 sidewall

245 upper wall

246 corner

A axis of rotation

X first direction (e.g. longitudinal direction) Y second direction (e.g. transverse direction)

Z third direction (e.g. vertical direction)

R plastic deformation direction

<t> direction of rotation

D1 rotatable bracing element width

D2 rotatable coupling width

D3 the distance of corner from the axis of rotation A

H rotatable bracing element height

AY transverse width

AZO support height

AZ1 height of main frame

AZ2 inter plane distance

AZt main frame stack height

AR ce ntra I i nte rn a I d ista n ce of cross ba r