Beds take up considerable room space. The trend is towards wider beds, whilst, at the same time, confined living in smaller apartments located in densely built-up areas increases. It is therefore desirable to be able to utilise the floor space taken up by the bed, when the bed is not in use. The floor area taken up by the bed can be utilised by moving the bed. This enables rooms that have a small floor area to be used as a bedroom in which the bed would otherwise take up an excessive portion of the floor space.

This problem is usually solved with the aid of a bed cupboard, where the bed is tipped from a horizontal to a vertical position. This is a time-consuming task, since it is necessary, among other things, to secure the bed clothes before raising and lowering the bed. Moreover a vertically positioned bed also occupies floor space such that space saving will not be at an optimum.

Another way of obtaining more floor space is to mount the bed slightly be- neath the ceiling, so-called attic bed. Access to the bed, however, is restricted since the user needs to climb onto the bed, which is strenuous and requires the user to be physically fit.

Another way of obtaining free floor space, mentioned in AT 402 003 B, is to lift the bed in a retained horizontal position, by lifting the bed at all four corners.

The four corners of the bed are connected to a counterweight with the aid of a wire system. Two guide rails take up solely dynamic forces acting in the horizontal plane.

DE 8304830 U teaches another known bed structure in which the bed can be raised and lowered along two vertical rails placed along one side of the bed,

while keeping the bed horizontal. The force required to achieve such vertical movement is obtained pneumatically.

The two constructions described above are not optimal with respect to saving space, due to the complicated arrangements required for lowering and rais- ing the bed. The complexity of these arrangements also adds to the cost of the constructions.

The object of the present invention is to provide a simplified construction of the aforesaid kind for raising and lowering the bed while keeping the bed hori- zontal.

This object is achieved with a bed of the kind described in the introduction that has the characteristic features set forth in claim 1.

The present invention thus provides a considerably simplified and therewith less expensive construction, which also alleviates other deficiencies of earlier known solutions, such as time-consuming handling of te bed, poor access and non-optimal space saving.

According to the invention, a bedstead can also be moved vertically along a vertical rail while keeping the bed horizontal, said bedstead being mounted on a cantilever which is guided in all degrees of freedom with the exception of vertical movement, wherein the cantilever is connected to a counterweight to achieve con- stant equilibrium in the direction of vertical movement.

According to one advantageous embodiment of the inventive bed, the rail is comprised of telescopic profile sections for adaptation to different ceiling heights.

According to another advantageous embodiment of the inventive bed, the profile sections of the telescopic construction can be locked relative to one another in desired positions, therewith allowing the full weight of the arrangement to sup- port against the floor. This means that the upper attachment will not be loaded by vertically acting forces and allows the requirement of the ceiling attachment to be kept at level attainable in the home.

According to another advantageous embodiment of the inventive bed, the profile sections are C-profiles, within which the cantilever wheels run. This solution enables the bedstead and the counterweight to be guided by one single rail.

According to another advantageous embodiment of the inventive bed that part which transmits a moment of force from the bedstead to the rail is such that the spot loads from the cantilever wheels are kept low and of equal magnitude be- tween said wheels. This enables the rail to be comprised of a thin material and the total weight of the solution to be kept to a minimum.

According to another advantageous embodiment of the inventive bed, one end of the inner profile of the telescopic construction is provided with wedges and the wheel peripheries are given a planar surface and a V-shaped surface part, said planar surface of respective wheels running against the inside of the profiles, wherein the wedges and the V-shaped surface part of respective wheels are mu- tually adapted so that the wheels will run smoothly over the junction between two profile sections of mutually different dimensions in the telescopic construction. This means that the otherwise pronounced or proud passage over said junctions will not be noticed to any great extent when handling the bed.

According to further advantageous embodiments of the inventive bed, the cantilever profile is pivotally mounted on a round profile arranged in the longitudi- nal direction of the cantilever profile and fastened to the cantilever attachment, wherein locking means are provided for locking the cantilever profile in a desired position of rotation relative to the round profile, and adjustment means are pro- vided for rotating the cantilever profile round a horizontal rotational axis at right angles to the cantilever profile for adjustment of the position of said profile. This will readily ensure that at least three of the legs of the bed will rest on the floor when the bedstead is moved to its lowered position.

With the intention of explaining the invention more specifically, a chosen embodiment of the inventive bed will now be described by way of example with reference to the accompanying drawings, on which Figure 1 is a side view of one embodiment of the bed mounted between the floor and ceiling of a room, Figure 2 is an overview of those parts of the bed that are shown in more detail in the follow- ing Figures, Figure 3: 1 is a side view of the telescopic construction of said rail,

Figure 3: 2 is a sectional view taken through the plane A-A in Figure 3: 1, Figure 4: 1 illustrates locking of two profiles relative to one another, and Figure 4: 2 is a sec- tional view taken through the plane D-D in Figure 4: 1, Figure 5: 1 is a cross- sectional view of the inner profile and cross-sectional views B-B and C-C in the Figure, Figure 5: 2 shows longitudinal junctions between the two rail profiles, Fig- ure 5: 3 illustrates the design of the wheels that support the cantilever in the rail, Figure 6 is a view similar to that in Figure 1 and illustrates forces and moments occurring in the bed construction, Figure 7: 1 and 7: 2 illustrate mounting of the can- tilever in the rail, from one side and from above respectively, Figure 8: 1 is a sec- tional view taken on the line F-F in Figure 8: 2, Figure 8: 2 is a view from above, Figure 9: 1 is a side view of the cantilever and illustrates the possibility of adjusting the position of the bedstead on the cantilever, Figure 9: 2 is a view taken through the line G-G in Figure 9: 1, Figure 10 is a side view illustrating the counterweight device in the inventive bed, Figures 11: 1 and 11: 2 illustrate respectively the coun- terweight holder with loose weights, and Figure 12 shows the counterweight holder with loose weights moveably mounted on the rail in the inventive bed.

The inventive bed includes a framework comprised of profile sections that are partially inserted into one another to form a telescopic construction 1, which is intended to be fastened to floor 25 and ceiling 22 of a room, see Figure 1. The rail functions to guide a wheeled cantilever 2, on which a bedstead 3 having legs 23 is mounted, in all directions with the exception of the vertical direction. The tele- scopic construction enables the bed to be installed in rooms of arbitrary ceiling height. Since the profile sections of the telescopic constructions are rigid and since the entire construction supports against the floor 25, the floor 25 and the ceiling 22 attachments can be kept at a level achievable in the home. The framework is suitably mounted adjacent a wall 24 so that the largest possible floor space will be exposed when the bedstead is raised. The guided cantilever 2 may be connected to a counterweight 4 by means of a chain and via a guide roller for instance. The counterweight 4 is guided by the rail in all directions except in the vertical direction and enables the bedstead 3 to be moved from floor 25 to ceiling 22 with the aid of only a small external force from the user.

Figure 2 is an overview of those regions concerned in the description of structural solutions.

The telescopic construction comprises two profile sections 5 and 6 (see Figure 3: 2), which are sufficiently rigid to take up all bending moments exerted by the bedstead. The profiles 5 and 6 have mutually different dimensions and are in- serted partially into one another (see Figure 3: 1). The upper profile 5 is mounted to the ceiling with the aid of a ceiling-mounted attachment. The lower profile 6 is mounted on a floor-mounted attachment. The two profiles are fastened together partly by being inserted into one another and partly by being screwed together with the aid of a screw tab 9 shown in Figures 4: 1 and 4: 2.

One of the profiles includes grooves and the other holes for fitting screw tabs. The length of the grooves is chosen with respect to the pitch of the holes, therewith enabling the length of the telescopic construction to be varied smoothly.

As will be seen from Figure 5: 1, one end of the inner profile 5 is provided with wedge-shaped elements. The purpose of these elements is to reduce the prominence of the junction between adjacent profiles which is equal to the thick- ness of the inner profile 5 and which needs to be overcome by the wheels 7. By forming wedges in the material of the inner profile 5 while retaining the thickness of said material in accordance with Figure 5: 2 and by allowing wheels having V- shaped grooves in accordance with Figure 5: 3 to roll over the wedges the other- wise abrupt thickness junction will be spread over the length of the wedges.

Sixteen wheels 7 are mounted on a cantilever attachment 11, see Figures 7: 1 and 7: 2. The wheels 7 respectively include a planar surface and a V-shaped groove, see Figure 5: 3. The planar part of the wheels run against the insides of the profile in all positions, with the exception of the junction between the different pro- files, see Figure 5: 2, where the wheels run smoothly between the internal meas- urements of both profiles. This means that the wheels will run over the joints in a manner that will scarcely be noticed by the person handling the bed.

After installation, when the screw tab 9 according to Figure 4: 2 has been fitted, the profiles will butt against one another at their joins. All vertical forces in the rail 1, F4 in Figure 6, caused by the mass Fi and the mass F5 of the counter- weight 4 will be taken up by the lower floor attachment. The upper attachment, and therewith the ceiling 22, will thus be loaded solely by horizontal forces F2, see Fig- ure 6, therewith reducing requirements regarding the ceiling attachment. The lower

attachment is also subjected to a horizontal load F3. Neither the lower nor the up- per attachment is able to take up bending moments caused by Fi in any direction in other words the attachment moments M1 and M2 are zero, see Figure 6.

The cantilever attachment 11 comprises, among other things, sixteen wheels 7, shown in Figures 7: 1 and 7: 2. In the case of the Figure 7: 1 embodiment, these sixteen wheels 7 transmit to the rail 1 the forces F6 and F7 exerted by the mass of the bedstead 3 and the cantilever 2, see Fi in Figure 6. Vertical move- ment is enabled at the same time.

The sixteen wheels 7 are fitted in pairs on a respective horizontal shaft 8.

Each of the shafts 8, eight in number, is loaded by a respective spring 10, so as to distribute the load between the shafts, see Figure 7: 1. As will be seen from Figure 7: 2, all eight shafts 8 are pivotally mounted on spring 10, in order to distribute the load between the two wheels carried on a respective shaft. The shafts are guided solely for pivotal movement around the spring and for movement in the direction of the spring action.

As will be seen from Figures 8: 1 and 8: 2, transverse wheels 12 are mounted on the cantilever attachment and guide said attachment vertically in the rail together with the aforesaid wheels 7.

The torque caused by a non-optimally loaded cantilever 2, for instance re- sulting from a non-optimally mounted bedstead 3, is transmitted to the rail by the forces F8 and Fg via the transverse wheels.

In order to achieve a fully satisfactory function, it is most important that most of the legs 23 of the bedstead will reach the floor 25 when the bedstead is lowered fully. If one leg 23 reaches the floor before the other legs, the expected equilibrium will not be achieved and the bedstead will rest on too few of its legs.

When the bedstead is used or subjected to some other load when the bedstead 3 rests on too few legs, the counterweight 4 and the bedstead 3 will move until the bedstead stands on several of its legs, which will be experienced as being nega- tive.

The bedstead is mounted on a cantilever profile having the cross-section shown in Figure 9: 2. The cantilever profile is inserted along a part of its length over a round tube which forms a part of the cantilever attachment 11 guided in said rail,

see Figure 9: 1. When installing the cantilever profile 13, it can be rotated about its longitudinal axis, i. e. around the tube on which said profile is inserted, prior to tightening the bolts 15. The cantilever profile can be adjusted vertically with the aid of setting screws 21 and thereby rotated around the shaft 14.

Subsequent to appropriate adjustment, i. e. when the majority of the legs of the bedstead reach the floor simultaneously, the bolts 15 are tightened, therewith fixating the cantilever profile 13 in all directions relative to the cantilever attach- ment 11.

The cantilever attachment 11 is connected to a counterweight 4 via two chains 17 which run over a guide roller 18 mounted at the upper end of the rail 1, see Figure 10. The position of the guide roller 18 in the rail 1 is chosen with regard to the aforesaid aim of minimising the forces acting in the ceiling attachment, and is thus mounted in the rail standing on the floor.

As will be seen from Figures 11: 1 and 11: 2, the counterweight is designed as a holder for a number of loose weights 19. These weights are placed in and fixed to the holder. The holder is covered with a casing when it has been filled with sufficient weights to provide an appropriate counterweight.

Figure 12 shows the weight holder 4 from above. The weight holder is guided in all directions around the rail, with the exception of the vertical direction, with the aid of two slide elements 20 in the upper and lower edge of the weight holder 4. These slide elements 20 are adapted to handle the size junction between said two profiles.

The mass of the loose weights 19, which are suitably equal in weight, is determined with reference to the internal friction of the system. The mass of each loose weight is adapted so that it is less than the hysteresis in the system which regard to friction. This enables the weight of the bedstead and correctly chosen counterweight to achieve equilibrium with the internal friction.

In the case of installations in rooms that have high ceilings, so that the bedstead is not readily accessed in its upper position, the counterweight may con- veniently be provided with a handle. In this case the bedstead can then be lowered by pulling on the handle with a force that exceeds said internal friction. When the bedstead is within reach, it can then be moved directly down onto the floor.