The invention relates to a self-adjusting bed including at least two frame cheeks, attached to which there are sheaves supporting an elongated element, for example a belt or a rope, extending in the longitudinal direction of each of the frame cheeks mentioned, a plurality of transverse slats and at least one supporting device for supporting the transverse slats.

The purpose of the self-adjusting bed is to provide support for the body in such a way that the spine is unloaded as much as possible when the person is lying. From earlier, various mattresses adapted for adjusting to the body and providing support, adjustable beds and self-adjusting beds exist.

The Norwegian patent application No. 19853483 discloses a self-adjusting lathed base, for example for beds and chairs, the lathed base including at least two frame cheeks to which rope sheaves are attached with bearings, running over which sheaves, there are ropes supporting interconnected laths by means of other rope sheaves and supporting parts.

Nottinblu is an Italian make of bed supplying self-adjusting beds, among other things, in which a hydraulic circuit is used, wherein the slats of the lying surface are connected to a series of interconnected cylinders balancing and evenly supporting the body by distributing the weight.

The Swiss patent publication CH 663339 A5 discloses a bed in which transverse boards/slats are connected to sheaves which are positioned in vertical grooves in two longitudinal cheeks, so that the transverse slats can be lifted and lowered in said vertical grooves.

DE 3827476 Al discloses an under-mattress having a frame which is spanned in the transverse direction by a multiplicity of slats which are supported on the frame at their two ends in each case via at least one device which runs along the frame, holds a plu- rality of slat ends and is flexible in the direction of the loading of the under-mattress.

WO 2011/032251 Al discloses a base for bed mattress having slats, where each slat end is attached to a frame and each slat is connected to a first end of a rod at the centre of the slat. The rod is, at its second end, connected to a dynamic pulley.

DE 3815098 Al discloses a mattress base which is based on a frame and resilient slats. Both CH 684779 A5 and EP 0575630 Al disclose bed bottoms where slats are arranged such that they can move vertically when loaded.

It is a drawback of the prior art that the transverse slats of the slat set can only be moved in the vertical direction when the bed and the bed bottom are placed in the normal position of application. Further, it may be unfortunate that the transverse slats of the prior-art slat set are only individually movable. This may result in gaps between the slats of the slat set, which may give increased wear on the overlying mattress, possible pinching hazard and an uneven lying surface.

The invention has for its object to remedy or reduce at least one of the drawbacks of the prior art or at least provide a useful alternative to the prior art.

The object is achieved through features which are specified in the description below and in the claims that follow.

The invention relates to a self-adjusting bed including a bed frame, a slat set and a supporting device connecting the bed frame and the slat set in such a way that the slat set is flexible and self-adjusting under the influence of pressure from above, such as when a person is lying down on the bed. A self-adjusting bed according to the invention will give reduced pressure strain for the user of the bed as the load will be evenly spread over the entire contact zone between the body and the bed. Further, a bed according to the invention will allow movement of the slats of the slat set in both vertical and horizontal directions, to a limited extent though, and will thus give greater flexibility and better adaptation to the user.

The invention relates, more specifically, to a bed which includes:

- at least two frame cheeks, attached to which there are sheaves supporting an elongated element extending in the longitudinal direction of each of said frame cheeks,

- a plurality of transverse slats, and

- at least one supporting device for supporting the transverse slats, characterized by:

- the supporting device including at least two struts and a roller, each strut being fixedly connected to said roller at its proximal end, the roller of the supporting device being arranged to be able to move slidingly and/or rollingly along and in contact with said elongated element,

- at least one pair of straps extending, in opposite orders, over and under the transverse slats,

- there being, formed from the plurality of transverse slats, at least one group of at least two adjacent slats, two or more of the slats of the group being connected to the same supporting device via the distal ends of the struts.

By frame cheeks are meant, here, cheeks or beams in the longitudinal direction of the bed. On the frame cheeks a plurality of sheaves have been positioned in the longitudinal direction of the frame cheeks by means of fixing means. An elongated element, such as a belt, a chain, a rope or the like, which, for the sake of simplicity, is called a belt in what follows, is attached to a fixed point, for example a sheave, a bolt, a pin, a pipe or the like at the head end of the bed and to a fixed point near the foot end of the bed, for example a sheave, bolt, pin, pipe or even to the supporting device nearest to the foot end of the bed, for example to a strut connected to a foot plate. Between said fixing points, said belt lies loose on top of said sheaves. The sheaves may be provided with a safety device which prevents the belt from sliding off the sheaves. Said safety device may be a hook or edge, for example. The fact that the belt is loosely connected to the sheaves contributes to increased flexibility as the belt can move freely over the sheaves. Positioned between the at least two frame cheeks, there are a plurality of transverse slats. The transverse slats are interconnected by means of two pairs of straps, one pair of straps being placed relatively closer to one of the frame cheeks than the other pair of straps which in its turn is placed relatively closer to the other one of the frame cheeks. Said straps of a pair of straps extend alternately over and under the transverse slats in opposite orders, so that each of the transverse slats has one strap over and one strap under. Together with the straps, the transverse slats thus form a continuous slat set which may in its turn form the base for a mattress, or a flexible lying surface as it is. The slat set is connected to the belt of the bed frame by means of one or more supporting devices. Said supporting devices may have an angular shape, in which each of the the sides of the angle is formed of a strut which is fixedly connected to one of the slats of the slat set, and in which there is a roller or its equivalent placed at the vertex of the angle, resting against the belt of the bed frame. The supporting device may further be provided with an attachment device extending from one end face of the roller, under the belt and up to the second end face of the roller. Said attachment device ensures that the belt does not lose connection with the supporting device. The struts of the supporting device are movably connected to the roller of the supporting device, so that the struts are free to move relative to each other as the slats are differently loaded.

The fact that the rollers of the supporting devices are arranged to be able to move along and in contact with the belts entails the possibility of a horizontal movement in addition to the vertical movement resulting from the slats of the slat set being pressed down as somebody lies down on the bed. It must be understood that the roller of the supporting device may be formed of any body on which the struts of the supporting device can be movably arranged and which are arranged to move slidingly and/or rollingly along said belt.

Said straps extending, in opposite orders, over and under the transverse slats connect the slats to each other so that they form a continuous slat set. Further, the straps help to prevent the slats from rubbing against each other, and in those cases in which one or more slats are not supported by a supporting device it is the straps that hold the slats in position.

The fact that one or more groups are formed from two or more adjacent slats, each slat group being connected to a supporting device, has the effect of the movement of the slats being a coordinated and sliding one.

From the plurality of transverse slats, at least one group of three or more adjacent slats may have been formed, each slat group consisting of two edge slats and one or more intermediate slats, the two edge slats being fixedly connected to the distal end of a respective one of the struts, or the sides of the angle, of a supporting device.

Having more than two slats in each slat group connected to one supporting device means that one or more slats will not be directly connected to one of the struts of the supporting device, but will be hanging exclusively on the straps. This means a simpler structure as fewer supporting devices are needed, thus resulting in a more inexpensive production. In addition, the structure will be less rigid.

The at least two frame cheeks may include two pairs of frame cheeks. It is conceivable that one pair of frame cheeks is placed on either side of the bed, the two cheeks of the same pair being spaced apart so that said sheaves can be attached to bolts or their equivalents, for example axles, which are fixed to both cheeks of the pair. A solution like that may result in a more stable and robust attachment of the sheaves and increased support to the belts and the slat set itself.

For each slat group, two supporting devices may be provided, the rollers of the sup- porting groups each being arranged to move along and in contact with a respective one of the belts. Two supporting groups for each slat group will mean greater stability than just one supporting device for each slat group and prevent a possible tilting of the slats transversely to the longitudinal direction of the slat set.

The roller may be connected to two sets of struts with two or more struts in each set. A solution is conceivable, in which one end of the roller of the supporting device is resting against the belt connected to one frame cheek, and in which the roller is of such an extent that its other end is resting against the belt connected to the other frame cheek, the two sets of struts thus being connected to a common roller.

The plurality of transverse slats may be divided into groups with three slats in each group, the two edge slats being connected to struts in the supporting device, and there being, between the groups, at least one slat which does not belong to any group.

The transverse slats may have a substantially trapeziform end cross section, the upper base of the end cross section being longer than the lower base of the end cross section. By substantially trapeziform is meant here a cross section which is trapeziform, but which has rounded edges. It must be understood that it is not necessary for all the slats to have the same cross section. The slats may also be of different sizes. The possibility of varying the cross sections and sizes of the slats makes it easier to adapt the bed to the size and needs of the user. The substantially trapeziform end cross section of the slats prevents the slats from rubbing against each other and/or stopping against each other. Rounding the corners reduces wear on the straps holding the slat set together and prevents the possibility of sharp edges causing discomfort to the user. The fact that the slats may be of different sizes, that is to say different widths, gives the possibility of good adaptation of the slat set to the user. Narrow slats give a slat set with better adaptation and flexibility, whereas broader slats give a somewhat stiffer set. In this way, the slat set may also be divided into zones. It may be appropriate, for reasons of economy and production, to have zones with broader slats, for example in the foot part of the slat set, in the area for the user's legs.

The bed may further include a leg plate. The leg plate is connected to said belt and when the slat set is loaded, the leg plate will be raised slightly. This has the purpose of keeping the legs at a certain level relative to the body. The effect of such an adjustment is that the spine is kept straight, that is to say in its natural, curved shape, without any unnatural kinks and without any straining pressure. Said leg plate may be provided with a strut, arranged to lift the leg plate when the bed is loaded, the strut of the leg plate being connected to said belt. A preloading mechanism connected to the leg plate is arranged in such a way that the slat set will automatically be extended again when the load is removed.

In what follows, an example of a preferred embodiment is described, which is visualized in the accompanying drawings, in which :

Figure 1 is a perspective view of a bed;

Figure 2 is a perspective view of the bed of figure 1, but in which the outermost frame cheeks have been removed for reasons of illustration;

Figure 3 is a plan view of the bed of figure 2 viewed from the side;

Figure 4 is a plan view of the bed of figure 3 viewed from the side, but the bed is under load;

Figure 5 is a partially transparent perspective view showing one embodiment of a supporting device; and

Figure 6 shows a supporting device in detail.

Reference is first made to figure 1 which shows a bed 1 according to the invention. The bed 1 includes at least two frame cheeks 2; in the embodiment shown, the bed 1 includes two frame cheeks 2 on either side of the bed, that is to say four frame cheeks 2 altogether. The frame cheeks 2 are spaced apart. Further, two transverse boards 21 which do not directly have any influence on the embodiment of the invention, but which contribute to the aesthetic expression of the bed 1. The transverse boards 21 will further have a bracing effect on the bed 1. A plurality of transverse slats 3 are placed over the at least two frame cheeks 2. A head plate 4 and a leg plate 5 are shown as well. Further, two pairs of straps 31 can be seen, the two straps 31 of each pair extending, in opposite orders, over and under the transverse slats 3. The head plate 4 is shown here as fixedly connected to four supporting legs 41. Supporting devices 6 support the slat set of transverse slats 3, whereas the leg plate 5 is loosely supported by supporting legs 51 while being connected to a movable strut bar 52 at the same time.

In figure 2, the bed 1 of figure 1 is shown, but the outermost frame cheeks 2 and the transverse boards 21 have been removed for reasons of illustration. It is shown how the transverse slats 3 are connected to supporting devices 6 comprising at least two struts 61 and a roller 62. The supporting devices 6 are arranged to support the transverse slats 3 and connect them to a belt 22 resting on sheaves 23. The sheaves 23 are fixedly connected to the frame cheeks 2.

Further, figure 2 shows the shape of the transverse slats 3 which, in the embodiment shown, have a cross section differing from a rectangular shape in that the two short sides are bevelled in such a way that the side of the slat facing upwards in the position of application is larger than the side of the slat facing downwards in the position of application. The cross section of the transverse slats 3 may thus be substantially tra- peziform, preferably with rounded corners. The transverse slats 3 may be of different widths and different cross sections.

In the embodiment shown in figure 1, the at least two frame cheeks 2 comprise four frame cheeks 2 altogether, the frame cheeks 2 being placed in pairs with one pair on each longitudinal side of the bed 1. The sheaves 23 are attached with through bolts or axles 24 (see figure 2) to two frame cheeks 2. It must be understood that in other embodiments, the sheaves 23 may be attached only to one frame cheek 2. The sheaves 23 may further be arranged to prevent the belt 22 from sliding off, for example by the sheaves 23 being provided with hooks or edges projecting upwards.

The strut bar 52 of the leg plate 5 is attached to the belt 22, and the strut 52 is further spring-loaded by a spring 53 which is connected to the upper portion of the strut 52 and to the frame cheek 2.

Figure 3 and figure 4 show the bed 1 in a plan view, seen from the side, in the non- loaded state and the loaded state, respectively. When comparing these two figures, it clearly appears how the rollers 62 of the supporting devices 6 move both vertically and horizontally when the transverse slats 3 are being loaded. It is also shown that when loaded, in figure 4, the leg plate 5 is tilted up. The belt 22 may be attached in various ways, and a difference in the figures 3 and 4 is that in figure 3, the belt 22 is shown attached in connection with the sheave 23 nearest to the head end of the bed, whereas in figure 4, the belt 22 is shown attached in connection with an attachment mechanism 25 in the form of a bolt, pin or some equivalent.

In figure 5 is shown, at an angle from above, in a partially transparent sketch, how one embodiment of a supporting device 6 (figure 2) may be formed. In this embodiment, a supporting device 6 consists of two pairs of struts 61, the two struts 61 of each pair being connected to each other at the upper, or distal, end via a bracket 63 and at the lower, or proximal, end via the roller 62. The two pairs of struts 61 are connected to the same roller 62 but to different brackets 63. And the respective brackets 63 are attached to respective ones of the transverse slats 3. The struts 61 are movable relative to each other around the roller 62.

Figure 6 shows a detail of a supporting device 6, in which one strut 61 includes an extension 611 at its lower end, so that the strut 61 has an extent down past the roller 62, thus functioning as a guard against the belt 22 possibly getting outside the roller 62. Further, a stop device 612 is shown, here in the form of a pin projecting inwards, preventing the belt from losing connection to the supporting device 6 as the supporting device moves upwards on lower loading.