OKIN Gesellschaft fur Antriebstechnik mbH D-51645 Gummersbach

Lift bed with adjusting traction mechanism

The invention relates to a lift bed with a bed frame, comprising frame side elements extending in the longitudinal direction and frame cross-elements located transversely between the frame side elements for mounting a reclining plane, an adjustable subframe that forms at least part of the reclining plane and can be pivoted about a pivoting axis, from a starting position in the reclining plane to an angled position relative to the reclining plane, and a drive motor by means of which the adjustable subframe can be adjusted from a starting position in the reclining plane to an angled position relative to the reclining plane.

The bed frame, consisting of head and foot elements and side elements, is regularly of welded or bolted design. The cross- elements customarily form the head and foot elements of the lift bed.

The lift beds known from the prior art customarily display a rotary tube that is driven by the drive motor and forms the pivoting axis. A pivoting lever coupled to a linear motor is mounted on this rotary tube to transmit the necessary torque. To apply the necessary torque for adjusting a loaded adjustable subframe, this pivoting lever must display a certain minimum length, and a certain minimum distance between the pivoting lever and the drive motor is also required. The pivoting radius necessary for the pivoting lever necessitates a certain height

of the lift bed. Since the rotary tube extends between the frame side elements and is laterally mounted in them in rotating fashion, it is always dependent on the size of the lift bed. This necessitates a large number of versions and causes correspondingly high stock-keeping costs. Finally, the existing systems have the disadvantage that the rotary tube acts as a pressure rod, which is very sensitive to unilateral loads.

A further disadvantage of the existing lift beds consists in the fact that they cannot be divided in the middle for transport purposes owing to the centrally located drive motor, which is connected to the frame side elements via a tubular structure. Since the lift bed cannot be dismantled due to the system design, the transport of existing systems requires a relatively large amount of space and thus causes high transport costs.

Based on a lift bed of the kind indicated, the object of the invention is thus to at least partially avoid the disadvantages mentioned, and to provide a lift bed that is inexpensive, of simple design, and preferably also easy to transport. In addition, the object of the invention is to provide means with which an existing lift bed can easily be retrofitted with a drive unit for adjusting an adjustable subframe.

On a lift bed of the kind mentioned in the opening paragraph, this object is solved in that the adjustable subframe can be connected to the frame side elements in rotating fashion in the pivoting axis, in that at least one adjusting lever, extending transversely to the pivoting axis, is connected to the pivoting axis for transmitting a torque to the adjustable subframe, and in that the adjusting lever is coupled to the drive motor via a traction mechanism.

As a result of the design according to the invention, the ro- tary tube located in the pivoting axis between the frame side elements is thus eliminated. Instead, it is only necessary that

an adjusting lever, which can be coupled to a drive motor via a traction mechanism, be provided on the lateral fastening fittings for rotary mounting of the adjustable subframe in the frame side elements. Said drive motor can, for example, be mounted in the middle of the head rail and guide the traction mechanism to the adjusting lever via deflection pulleys and/or sliding guides at the head-end corners.

The traction mechanisms open to consideration include, for ex- ample, a cable pull, a Bowden cable, or also a chain. The cable pull preferably displays steel cables with a diameter of 2 to 3 mm.

A particularly attractive feature of the solution according to the invention is that the traction mechanism can be delivered in a standardised maximum length and then pretensioned after being connected to the adjusting lever during pre-assembly. The traction mechanism is then tightened until resistance occurs as a result of the dead weight of the lift bed. This resistance can be measured by a sensor, for example. At the same time, this first point of resistance defines the bottom dead centre or starting position of the adjustable subframe. As a result, a standardised traction mechanism with a uniform maximum length can be used that, independently of the dimensions of the bed, can be set to the respective dimensions of the lift bed. Not only the starting position, but also the maximum angled position is set in the same way during initial installation.

In order to reduce the space required, also on existing lift beds, it is particularly advantageous if the adjusting lever is mounted on the pivoting axis in pivoting fashion. In addition, coupling means are provided that transmit the torque of the adjusting lever to the adjustable subframe. The coupling means can, for example, comprise a stop on the adjustable subframe, against which the adjusting lever strikes. In another embodiment, the adjusting lever displays a bead or a shoulder, which

strikes against the adjustable subframe to transmit the torque. This pivoting design of the adjusting lever also greatly simplifies transport, since the adjusting lever can be folded for transport purposes, from the space-occupying working position, in which is it positioned at an angle relative to the plane of the adjustable subframe, into a transport position, in which the adjusting lever lies in the plane of the adjustable subframe. During final assembly, the adjusting lever then only has to be coupled to the drive motor via the traction mechanism, then striking against the adjustable subframe in the angled position for raising the adjustable subframe.

It is obvious to the person skilled in the art that the solution proposed so far already permits great simplification of the transport of lift beds, since the drive motor no longer has to be located in the middle of the bed frame, below the slatted bed base. Owing to the design according to the invention, it is now possible to divide the bed frame in the middle of the frame side elements, only connecting it on site during final assem- bly.

Preferably, one end of the adjustable subframe is provided with journals that can be inserted into corresponding bearing bushes on the frame side elements in rotating fashion. However, it is also within the scope of the invention for the journals to be provided on the frame side elements, engaging corresponding bearing bushes in the adjustable subframe.

The drive motor according to the invention preferably drives a cable winch for winding up the traction mechanism. The drive motor is preferably designed as a safety extra-low voltage DC motor.

The invention moreover relates to a retrofit kit for subsequent installation on a lift bed with a reclining plane mounted on frame side elements extending in the longitudinal direction and

frame cross-elements located transversely between the frame side elements, where the reclining plane encompasses an adjustable subframe that forms at least part of the reclining plane and can be pivoted from a starting position in the reclining plane into an angled position relative to the reclining plane. The retrofit kit according to the invention is intended to enable low-cost retrofitting and simple conversion of existing lift beds in order to avoid the disadvantages mentioned above.

According to the invention, the retrofit kit encompasses a drive motor that can be mounted on the lift bed and by means of which the adjustable subframe can be adjusted from the starting position to the angled position, at least one adjusting lever that can be mounted on the pivoting axis, and a traction mecha- nism for coupling the adjusting lever to the drive motor. The retrofit kit can furthermore comprise deflection means, such as a deflection pulley or a sliding guide, by means of which the traction mechanism can be deflected at the corners of the lift bed if the drive motor is mounted on the head end or the foot end and the adjusting lever is mounted on the frame side elements .

The adjusting lever can also be mountable in pivoting fashion on the pivoting axis. In this case, the torque is transmitted from the pivoting lever to the adjustable subframe via a driver that is provided either on the adjustable subframe or on the pivoting lever.

Preferably, the retrofit kit moreover displays sliding bushes that can be inserted into the frame side elements to accommodate journals that can be mounted on the adjustable subframe and define the pivoting axis.

Further details, advantages and characteristics of the inven- tion can be taken from the following part of the description, in which a preferred practical example of the lift bed accord-

ing to the invention is explained on the basis of seven drawings. The drawings show the following:

Fig. 1: A top view of the lift bed according to the invention,

Fig. 2: An enlarged view of section C according to Fig. 1,

Fig. 3: An enlarged view of section A according to Fig. 1,

Fig. 4: An enlarged view of section B according to Fig. 1,

Fig. 5: A lateral longitudinal section through the lift bed according to Fig. 1,

Fig. 6: An enlarged view of section A according to Fig. 5, and

Fig. 7: An enlarged view of section B according to Fig. 5.

Identical or identically acting parts are indicated by the same reference numbers.

According to the Figures, the lift bed according to the invention consists of a frame 2, which is formed by two frame side elements 4, extending parallel to each other, together with a frame head element 6 and a frame foot element 8, extending transversely between frame side elements 4. Frame 2 forms a reclining plane defined by a slatted bed base 10. In the present instance, frame side elements 4, frame head element 6 and frame foot element 8 are designed as hollow sections.

Part of this reclining plane 10 is an adjustable subframe 12. This adjustable subframe 12 consists of two subframe side elements 14, extending parallel to each other, and subframe cross- element 16 connecting these subframe side elements 14 at the head end.

At its end projecting towards the middle of the lift bed, adjustable subframe 12 is mounted in rotating fashion on journals 18, which define the pivoting axis of adjustable subframe 12, about which it can be pivoted from the starting position in the reclining plane into an angled position relative to the reclining plane. Sliding bushes are positioned around journals 18. Journals 18 are bolted to frame side elements 4 via fittings, their outer ends extending into frame side elements 4, which are designed as hollow sections.

Oblong adjusting levers 20 are mounted in pivoting fashion on the inner side of journals 18 passing through subframe side elements 14. The essentially rectangular adjusting levers 20 are rounded on one side on the end fastened to journals 18. In the present instance, adjusting levers 20 are made of steel sections .

Mounted on the inner side of subframe side elements 14 are pin- type stops 22, against which the peripheral edge of the fasten- ing end of adjusting lever 20 strikes when the latter is pivoted out of the transport position, which extends parallel to the plane of adjustable subframe 12, into the operating position, which extends transversely to this plane. In the operating position, rotation of adjusting lever 20 about journal 18 transmits the torque to adjustable subframe 12 in order to adjust its angled position.

Mounted at the head end of the lift bed is a drive motor 24. Via deflection pulleys 30, 32 in the corners of frame 2, cable pulls 26, 28 run from drive motor 24, parallel to subframe side and cross-elements 14, 16, and their ends are fastened to the lower end of adjusting levers 20. Rotary motion of drive motor 24 is thus converted into pivoting motion of adjustable subframe 12. Rotation of drive motor 24 in different directions makes it possible to set any desired angled position of adjustable subframe 12 relative to the reclining plane.

It is apparent that the system according to the invention requires only a very small height of the lift bed. This is due to the fact that adjusting lever 20, mounted on the pivoting axis in rotating fashion, can extend parallel to the plane of the adjustable subframe and need only be pivoted into a plane running transversely to the plane of adjustable subframe 12 for the operating position. However, only a substantially smaller adjusting lever 20 is required for transmitting the necessary torques than in the case of the prior art.

The subject matter of the present invention results not only from the subject matter of the individual Claims, but also from combination of the individual Claims with each other. All ob- jects and characteristics disclosed in the documentation - including the Abstract - particularly the spatial arrangements shown in the drawings, are claimed as being essential for the invention insofar as they are new compared to the prior art, either individually or in combination.

OKIN Gesellschaft fur Antriebstechnik mbH D-51645 Gummersbach

Lift bed with adjusting traction mechanism

List of reference numbers

2 Frame

4 Frame side element

6 Frame head element

8 Frame foot element

10 Slatted bed base

12 Adjustable subframe

14 Subframe side element

16 Subframe cross-element

18 Journal

20 Adjusting lever

22 Stop

24 Drive motor

26 Cable pull

28 Cable pull

30 Deflection pulley

32 Deflection pulley