Background Art More and more efforts are made to make beds more comfortable. For example, it is becoming more and more common to have adjustable beds of the type where the bed- stead bottom in the longitudinal direction of the bed is divided into two or more segments which are articulated to one another, where the angle between the segments can be adjusted as desired by the user. Thus, the bed can be easily adapted for different purposes, such as sitting in when reading, working, eating etc., lying on when sleep- ing or resting, placing one's legs or head high in con- nection with certain disorders and illnesses, etc.

Beds of the type mentioned by way of introduction are already known from, for example, WO 97/30614 and EP 0604240. These known beds comprise four segments which can be arranged at various angles relative to one another by means of adjusting means. However, one problem with these prior-art constructions is that the construction which allows adjustability makes it more difficult to in- sert other types of comfort, such as massage devices.

Furthermore, one problem is that there is often A con- flict in making a bed comfortable in both the outer posi-

tions, i. e. in a sitting position and in a lying down po- sition. Since the lying down position has to be given priority, this means that the bed does not become as com- fortable to sit in as furniture directly adapted for this position.

It is further known to arrange areas that are verti- cally adjustable to vary the distance between the bed- stead bottom and the upper mattress layer and, thus, vary the hardness and/or the height of the mattress and, for example, to serve as a curve support. This is, for in- stance, known from US 3806968. This document discloses an expandable element having two plates between which the distance can be varied, which element is placed between two mattress layers. However, one problem with this solu- tion is that it is a relatively expensive and complicated solution that is also difficult to control automatically.

In addition, another problem is that it is difficult to properly attach the element thoroughly to the mattress.

Moreover, it is known from US 3551924 to make por- tions of the bedstead bottom vertically adjustable. How- ever, this solution is even more complicated and expen- sive to manufacture.

Besides, both these solutions are unsuitable to use in, for example, adjustable beds of the type discussed above.

As a further measure, it is known to arrange massage devices in beds. Such prior-art devices usually comprise a vibration unit which produces vibrations. However, one problem with such known devices are that they must be placed at a distance from the user, which makes them fairly inefficient since a large amount of inertial mass of the bed has to be vibrated, which will only to a small degree be good for the user.

Object of the Invention An object of the present invention is thus to pro- vide a bed which wholly or at least partly solves the above-mentioned problems of prior-art technique and, thus, provides a more comfortable and/or less complicated bed construction.

This object is achieved by means of a bed as claimed in the appended claims.

Summary of the Invention According to a first aspect of the invention, it comprises a bed which comprises a relatively rigid bed- stead bottom and at least one resilient layer arranged thereon and at least one part which is movable relative to the bedstead bottom for local variation of the hard- ness and/or the height of the resilient layer, which mov- able part is articulated to the bedstead bottom and is lockable in different positions which are raised relative to the hinge.

This construction provides a bed where the hardness of the bed can be locally increased, which is useful es- pecially to provide an improved curve support. At the same time the movable part obtains support and stability from the bedstead bottom, which renders it possible to make the construction simple and inexpensive at the same time as it is rugged and durable. This is especially suitable for adjustable beds, where a simple and light construction is particularly preferred.

Moreover, it is particularly preferred that the bed comprises a displacement means for automatic displacement of the movable part between different raised positions, which displacement means preferably acts against that side of the movable part which is opposite to the resil- ient layer. Owing to the stable construction of the mov- able part, both the displacement means and the connection between the same and the movable part can be made easily

and inexpensively since relatively low loads are pro- vided.

In addition, it is preferred that the movable part has a surface which is convex towards the resilient layer and, above all, that the convex surface has a bend which increases in a direction away from the articulated con- nection between the movable part and the bedstead bottom.

This causes a relatively even increase of the load even when the movable part is in a raised position.

According to another aspect of the present inven- tion, it comprises a bed having a relatively rigid bed- stead bottom and at least one resilient layer arranged thereon, and at least one massage device comprising a vi- bration unit which via a vibration retarding connection is connected to the bedstead bottom on that part of the same which is opposite to the resilient layer, and vibra- tion transmitting means connecting the vibration unit to the part of the resilient layer that is opposite to the bedstead bottom.

Thus, the vibrations do not affect the bedstead bot- tom but are directly transmitted to the upper part of the resilient layer. Consequently, unnecessary inertial mass does not need to be vibrated but only those parts of the mattress which are in contact with and directly affect the person lying on the same. This makes on the one hand the massage more efficient and, on the other, the vibra- tion unit can be made simpler and less expensive. In its turn, this also leads to noise and generation of heat be- ing reduced.

The vibration retarding connection preferably com- prises distance elements of vibration absorbing material, preferably of rubber material.

Furthermore, the vibration transmitting means pref- erably comprise a relatively inelastic and preferably bendable connecting means, such as straps.

It is more advantageous to use two or more massage devices, which preferably are adapted to produce vibra-

tions with different frequencies, and further preferably are separated from one another, and preferably separated in the longitudinal direction of the bed. Thus, interfer- ence between the vibrations which are transmitted from the massage devices results in massaging vibrations being obtained also between the massage devices, which makes the massaging effect more efficient.

A bed is especially preferred having a combination of the above-mentioned aspects of the invention.

Furthermore, the two above-mentioned aspects of the invention are each separately, or in combination, par- ticularly suited for beds of the type where the bedstead bottom in the longitudinal direction of the bed is di- vided into at least two segments which are articulated to one another, and adjusting means for adjusting the angle between the segments.

Moreover, the two above-mentioned aspects of the in- vention are each separately, or in combination, espe- cially suited for beds where the resilient layer com- prises at least one layer of elastic springs.

Further characteristics and advantages of the pre- sent invention will be evident from the following de- scription of preferred embodiments and from the appended claims.

Brief Description of the Drawings The invention will now be described in more detail by way of example and with reference to the accompanying drawings, in which Fig. 1 is a partly cross-sectional perspective view of a bed according to one embodiment of the invention, the adjusting means not being shown, Fig. 2 is a partly exploded cross-sectional side view of the bed in Fig. 1 in a first, lowered position, Fig. 3 is a partly exploded cross-sectional side view of the bed in Fig. 1 in a second raised position,

Fig. 4 is a cross-sectional perspective side view of a curve support according to one embodiment of the inven- tion shown in a lowered position, Fig. 5 is a cross-sectional perspective side view of the curve support in Fig. 4 shown in a raised position, and Fig. 6 is a cross-sectional perspective side view of a massage device according to one embodiment of the in- vention.

Description of Preferred Embodiments A bed according to a preferred embodiment of the in- vention as shown in Figs 1-3 comprises a bed frame 1 which supports a bedstead bottom 2. At least one resil- ient layer 3, preferably an elastic spring layer, is ar- ranged on the bedstead bottom. Bed constructions without a separate bed frame, where the bedstead bottom is self- supporting, are, however, also possible. The aspects of the invention are especially suited for adjustable beds, but are also usable in a large number of other conven- tional bed types.

Adjustable Bed The bedstead bottom is as shown in Figs 1-3 divided into segments, preferably four segments, in the longitu- dinal direction of the bed: one headboard segment 21, a base segment 22, an upper footboard segment 23 and a lower footboard segment 24. These segments are adjustable in such a manner that the headboard can be raised rela- tive to the base segment as a back-rest, and so that the lower footboard segment can be raised.

In the preferred embodiment, an adjusting means 4 for adjusting the inclination between the headboard seg- ment and the base segment comprises a pivot pin 41 ex- tending in the transverse direction of the bed. The pivot pin is affected directly, or preferably via one or more link arms, by a piston assembly 42. Other ways of auto-

matically or manually rotating the pivot pin 41 are also possible.

The pivot pin further comprises rigid protruding arms 43 which abut against a sliding surface 44 of the headboard. By rotating the pivot pin 41, the arms 48 thus press the headboard segment 21 upwards. Advantageously, also rolls 45 or the like can be arranged at the end of the arms which abut against the bedstead bottom in order to thus further reduce the friction.

In the preferred embodiment, an adjusting means 5 for the upper and lower footboard segments comprises a pivot pin 51 extending in the transverse direction of the bed. The pivot pin is affected directly, or preferably via one or more link arms, by a piston assembly 52. Other ways of automatically or manually rotating the pivot pin 51 are also possible.

In addition, the pivot pin comprises rigid protrud- ing arms 53 which abut against a sliding surface 54 of the upper footboard segment. Advantageously, rolls 55 or the like can also be arranged at the end of the arms which abut against the bedstead bottom in order to thereby reduce the friction further.

Moreover, link arms 56 are arranged between the bed frame and the lower footboard segment below the pivot pin. By rotating the pivot pin 51, the arms 53 thus turn the upper footboard segment 23 upwards, whereby the lower footboard segment 24 is raised.

However, a plurality of variants of the adjusting means are possible as is known within the field of the invention. For example, other drive means instead of pis- ton assemblies can be used; other transmitting means in- stead of the link arms and the like that have been de- scribed above can be used, etc.

Advantageously, the adjustable bed as described above can also be equipped with means for displacing the bedstead bottom 2 relative to the bed frame 1 when rais- ing the headboard segment 21, so that the distance in the

longitudinal direction of the bed between the headboard segment 21 and the headboard of the end of the bedstead during raising remains constant or at least is not changed to any appreciable extent. This can be provided by the adjusting means and the bedstead bottom together being displaceably connected to the bed frame. For in- stance, the bedstead bottom and the adjusting means can be arranged on two bars 81 extending adjacent to the bed frame and essentially parallel to the longitudinal direc- tion of the bed. These bars are in a slidable manner con- nected to and supported by the bed frame 1 via attach- ments 82 in the bed frame. Preferably, roller bearings 83 or the like can be arranged between the attachments 82 and the bars 81. In addition, that part of the bed which is displaceably arranged relative to the bed frame is ad- vantageously connected to the headboard of the bed frame via a link arm system 84, which preferably is connected to the pivot pin 41. Consequently, the displaceable part of the bed is automatically pulled towards the headboard of the bed when the head end is raised.

Instead of the piston assemblies mentioned above, other types of linear actuators can be used.

Furthermore, the bed is advantageously equipped with covering means 12 which are arranged between the bed frame and at least one of the movable segments. The cov- ering means are intended to cover the gap which is formed between the segment of the bedstead bottom and the bed frame when the segments are in the raised position. For example, such covering means can advantageously be ar- ranged in the footboard and/or headboard of the bed as in the preferred embodiment. Preferably, the covering means comprise textile material which is extensible and has a tensioning function which automatically tightens slacken- ing parts of the material. This can be provided, for ex- ample, by the material in one end being wound on a spring-loaded roll 13, where the spring acts to wind the material on the roll.

Covering means as mentioned above reduce the risk of injury caused by squeezing and the like. Besides, the bed becomes more aesthetically attractive.

Curve support As especially shown in Figs 3-4, the bed according to the invention also comprises at least one part 6 which is movable relative to the bedstead bottom for local variation of the hardness and/or the height of the resil- ient layer 3 by varying the distance between the bedstead bottom 2 and the resilient layer. The movable part 6 is articulated to the bedstead bottom via a pivot pin 61, such as one or more hinges. Preferably, the pivot pin 61 is arranged in the transverse direction of the bed. Ad- vantageously, such a movable part can be arranged in a position corresponding to the curve portion of the person lying down and, thus, function as a curve support. This is particularly important when the bed is used to sit in.

Alternatively, or as a complement, portions with the pur- pose of varying hardness and height can, however, be ar- ranged also at other locations in the bed.

In addition, the movable part is lockable in differ- ent positions which are raised relative to the hinge.

This is preferably provided by displacement means 62 for automatic displacement of the movable part between dif- ferent raised positions, which displacement means also retains the movable part in the position taken. The dis- placement means can advantageously be a piston assembly, but other variants, such as an electric motor or the like, are also possible.

Preferably, the displacement means 62 acts against that side of the movable part which is located opposite to the resilient layer, and also advantageously articu- lated to the movable part via a pivot hinge 63.

Besides, the movable part is advantageously formed with a convex surface 64 facing the resilient layer in order to allow easy and at the same time comfortable

raising of the resilient layer. The convex surface 64 is suitably bent in the longitudinal direction of the bed, and perpendicular to the pivot pin of the movable part.

In addition, it is preferred for the convex surface to have a bend which increases in a direction away from the articulated connection between the movable part and the bedstead bottom, so that those parts which during pivot- ing of the movable part are moved the most have the larg- est radius of curvature. Advantageously, the movable part can be made of a plate of, for example, sheet metal or a hard plastic material.

Massage part Above all, Fig. 6 shows that the bed according to the invention further comprises a massage device 7 having a vibration unit 71. Advantageously, the vibration unit can be an electric motor that drives an unbalanced rotat- ing body, and can further advantageously be encapsulated in a casing. However, other vibration units can also be used and are already known within the field of the inven- tion.

The vibration unit 71 is connected to the bedstead bottom 2 via a vibration retarding connection. This con- nection can, for example, comprise distance elements 72 of rubber or some other vibration absorbing material.

Preferably, the vibration unit is fixedly arranged on a plate 73 which, in its turn, via the distance elements 72 is attached to the bedstead bottom 2.

The vibration unit is further directly or indirectly connected to vibration transmitting means 74 which trans- mit vibrations from the vibration unit to that part of the resilient layer 3 which is opposite to the bedstead bottom. The vibration unit is preferably arranged at the opposite side of the bedstead bottom, the vibration transmitting means being extended through openings 75 in the bedstead bottom or extended past the same in some other suitable manner.

Advantageously, the vibration transmitting means can be a relatively inelastic and preferably bendable con- necting means, such as a strap 74 of a relatively inelas- tic material. Moreover, the massage device preferably comprises at least two such transmitting means. The straps are thus at one end attached to the vibration unit 71 or to the supporting plate 73, and extend through the openings 75 in the bedstead bottom. At the other end, they are attached at one or more points in the resilient layer, preferably at a height corresponding to at least half of the resilient layer, and most preferably in the surface layer of the same.

In addition, the vibration transmitting means can advantageously be pretensioned or comprise tightening means with the purpose of avoiding slacking when the re- silient layer is compressed when in use.

The massage device as described above can advanta- geously be arranged in the middle of the bed, for example adjacent to the base segment 22 of the bedstead bottom.

However, it is also possible to arrange massage devices in other positions of the bed, and it is especially pre- ferred to use at least two massage devices. Consequently, by being adapted, for instance, to produce vibrations at different frequencies, the massage devices can give a massage effect not only in their direct positions but also therebetween due to the interference phenomenon.

When several massage devices are used, it is thus pre- ferred for them to be arranged separated from one an- other, preferably separated in the longitudinal direction of the bed.

Summary The invention has now been described by way of exam- ple. However, it is understood that many other variants of the invention are possible. Especially, the different aspects of the invention described above can be used separately, although a combination is to be preferred.

Thus, the massage device, the curve support, the basic construction for the adjustable bed etc. can be used in- dependently of one another in other contexts and in other types of beds.

In addition, several variants of the respective parts are conceivable and many such variants are also mentioned above. Such related variants should be consid- ered to be within the scope of the invention as defined in the appended claims.