AU4093800A - Support assembly means - Google Patents

Description

WO 00/66061 PCT/AUOO/00401 TITLE: SUPPORT ASSEMBLY MEANS FIELD OF THE INVENTION 5 The invention relates to a support assembly means which support means is adapted to conform to a range of configurations. In particular the present invention relates to a support assembly means for supporting a body held thereon in a range of different positions. Even more particularly the support assembly means finds specific application in relation to treatment of long term bed ridden patients. 10 WO 00/66061 PCT/AUOO/00401 -2 BACKGROUND OF THE INVENTION There are many problems faced by long term bed ridden patients substantially incapable of supporting their own movement. Persons who stay in contact with bed support for 5 long periods of time are prone to suffer from poor blood circulation and decubitus ulcers (bed sores) as a result of a generally immobile condition. Generally patients falling into this category have required in the past significant and repeated attention by hospital staff, person carers or relatives so as to avoid lying or sitting in a single position for extended periods of time. 10 Problems have often been exacerbated due to low hospital staffing levels and therefore failure to provide adequate frequency ofpatient position change. Even further difficulties are experienced when such adequate frequency of change requires disturbance of a patient day and night and labour intensity associated with frequent physical lifting of 15 patients generally undertaken by nursing staff. Particular occupational health and safety problems have been highlighted when repeated heavy lifting is required. There have been many attempts in the prior art to address the above problems. For example in GB 2045603 there is disclosed a bed in which a patient can be supported by 20 an open net mesh which is attached across a support frame, which is in turn supported by a base frame. The support frame consists of two spaced parallel longitudinal members which are adapted to fold inwards thus providing the net mesh to support a patients weight. The means by which a patient is rolled comprises a combination of tilting the support frame and tensioning the mesh net at various points, depending on what part of 25 a patients body the net is supporting. This type of bed is somewhat clumsy and requires presence of nursing staff so as to appropriately apply tension to the mesh net during the course of operating the bed. In EP 262771 there is disclosed a sub-bed mattress assembly adapted to roll a patient. 30 The sub-bed mattress consists of two leafs divided longitudinally and overlaying a respective lateral portion of a supporting base connected by hinges. There is disposed beneath each leaf bladders for independently raising each leaf so as to roll a bed occupant. When one bladder is inflated the overlaying mattress portion is raised and the WO 00/66061 PCT/AU0O/00401 -3 whole mattress moved sideways so that a person lying thereon is correspondingly rolled. This system is again cumbersome, expensive and cannot be used to form a cradle configuration. In this prior art there is inevitably a risk of a patient rolling out of the bed. 5 Other prior art such as that described in US Patent No. 3875598, while a cradle type configuration is adopted, in order for rocking motion to commence so as to roll a patient some patient motion is required to initiate rocking movement. In addition the cradle configuration is attained by providing multiple hinges, collapsing spring assemblies and telescoping components, which add to the complexity of this apparatus. 10 It is known that a conventional hospital bed can adopt a variety of positions found to be useful for aiding treatment or improving comfort of persons suffering certain medical conditions. The following positions for example the trendelenberg 15', reverse trend 15', cardiac chair, vascular and posture relaxation are known to persons skilled in the art. 15 A conventional hospital bed can be raised or lowered for convenience in any of the above positions, and can be tilted to some extent with difficulty. The applicant has found that prior art means of turning patients have suffered the drawback of not being able to do so in all available conventional positions. There has, 20 as previously mentioned, therefore been a long felt need to address this problem so as to provide a means of turning a patient in any combination of desired bed positions. The present invention intends to ameliorate at least one of the above disadvantages. 25 SUMMARY OF THE INVENTION There has been a long felt need in this art to provide an efficient and cost effective means of improving patient care and quality of life for long term immobile bed ridden patients. 30 Accordingly the present invention provides in a first aspect a bed assembly for altering the position of a person supported thereon including: a longitudinal support frame having a support surface for receiving a person thereon; WO 00/66061 PCT/AUOO/00401 -4 a longitudinal cradle means extending over the support surface, the cradle means being attached to the support surface substantially along a central axis in the longitudinal direction thereof, the cradle means further incorporating a recess extending along side portions of the cradle means in the longitudinal direction thereof adapted for receiving 5 and engaging an engaging means; a cradle support engaging means mounted to the support frame in close relation to said recess adapted to be extendable and retractable in engaged relation within said recess along said longitudinal side portions of said cradle means so as to promote change in 10 configuration of said cradle means; a first actuator mechanism disposed beneath the support frame in physical coupling relation to the engaging means for extending or retracting the engaging means; 15 wherein in a first condition the first actuator means causes the engaging means to extend towards and be received by said recess extending along said longitudinal side portions of the cradle means, thereafter causing the cradle means to move, in positive engagement with the engaging means, with extending movement of the engaging means between a position of rest and a substantially concave configuration about the central longitudinal 20 axis of the support surface and in a second condition the first actuator means causes the engaging means to retract so as to correspondingly promote movement of the cradle means from said substantially concave configuration to said resting position conforming with the support surface, the change in configuration of the cradle means between said first and second condition being controllably continuous, staggered or cyclicle so as to 25 aid movement of a person lying on said support surface. In a second aspect of the invention there is disclosed a bed assembly for altering the position of a person supported thereon including: 30 a longitudinal support frame having a support surface for receiving a person thereon; a base support on which the support is centrally pivotally mounted; WO 00/66061 PCT/AUOO/00401 -5 a longitudinal cradle means extending over the support surface, the cradle means being attached to the support surface substantially along a central axis in the longitudinal direction thereof, the cradle means further incorporating a recess extending along side portions of the cradle means in the longitudinal direction thereof adapted for receiving 5 and engaging an engaging means; a cradle support engaging means mounted to the support frame in close relation to said recess adapted to be extendable and retractable in engaged relation within said recess along said longitudinal side portions of said cradle means so as to promote change in 10 configuration of said cradle means; a first actuator mechanism disposed beneath the support frame in physical coupling relation to the engaging means for extending or retracting the engaging means; 15 a second actuator mechanism coupled between the base support, and longitudinal support frame for promoting independent pivot movement of the support frame about its longitudinal central axis; wherein in a first condition the first actuator means causes the engaging means to extend 20 towards and be received by said recess extending along said longitudinal side portions of the cradle means, thereafter causing the cradle support to move in positive engagement with the engaging means, with extending movement of the engaging means between a position of rest and a substantially concave configuration about the central longitudinal axis of the support surface and in a second condition the first actuator means causes the 25 engaging means to retract so as to correspondingly promote movement of the cradle means from said substantially concave configuration to said resting position conforming with the support surface, the change in configuration of the cradle support means between said first and second condition being controllably continuous, staggered or cyclicle; 30 and the second actuator mechanism is able to act upon the support frame so as to promote tilting movement thereof to one side or the other about the longitudinal axis of the support frame; WO 00/66061 PCT/AUOO/00401 -6 the change in configuration of the cradle means being independent of the tilting movement of the support frame so as to aid movement of a person lying thereon. It has been found by the applicant that a person lying on the bed assembly of the 5 invention is able to be moved by the change in configuration of the cradle means. Because the configuration of the cradle means is able to change either continuously or incrementally, the applicants have also found that a body can be moved with less manual physical labour intervention. The applicant has also found that the cradle means enables turning of patients in all known conventional bed positions. 10 PREFERRED ASPECTS OF THE INVENTION The present invention finds particular application to hospital beds, in particular for aiding movement of infirmed, invalid or bedridden patients incapable of moving themselves. 15 Preferably the cradle means is a sheet type material having a recess on each side portion said recess extending in a longitudinal direction thereof Preferably the sheet material is selected from thermoplastic or thermosetting plastics. 20 More preferably the material is a acrylomitrilebutadiene-styrene copolymer. Preferably the cradle means can be a single continuous sheet or can be a series of sheet sections adapted to correspond to divided sections of a support frame. 25 Preferably the cradle means has a series of slots evenly spaced extending in a direction transverse to the longitudinal axis. The purpose of such slots is to improve the flexibility of the sheet and its ability to contour so as to better support various body parts during turning. It is found by the 30 applicant that depending on the position of the patients body on the sheet, certain parts of the sheet will be under tension by virtue of weight distribution of a patient supported thereon, while other parts may remain loose.

WO 00/66061 PCT/AUOO/00401 -7 Preferably a central portion of the cradle means extending longitudinally along the support frame is securably attached to the support frame by means of screwing to the frame or by using a system of valcro. 5 Preferably the cradle means can further have a mattress placed thereon. Preferably the cradle support engaging means is a frame structure disposed beneath and extending across said support frame. 10 Preferably the frame structure includes a set of raising arms adapted to be extendable and retractable when said engaging means is acted upon by said first actuator mechanism. Preferably the raising arms are cantilevered so as to adopt a first folded position adjacent longitudinal sides of the support frame when retracted and a second perpendicular 15 position with respect to the support surface when extended. Preferably the frame includes apair of engagement transmission bars positioned on either side of the support frame and coupled to the raising arms so as to be raised and lowered with extended and retracted movement of the raising arms respectively. 20 Preferably the raising arms and transmission bars are able to be moved in unison. Preferably the support frame is divided into a plurality of sections or plates. 25 More preferably the support frame has at least two sections, most preferably there are three sections or plates adapted to be independently slidably or pivotally movable so as to be capable of adopting any number of conventional positions including for example a reclining position and other positions mentioned previously. 30 Preferably the support frame can be pivotally adjusted about a vertical plane passing through its centrally located longitudinal axis. Preferably the base support can be raised or lowered or tilted about a vertical axis.

WO 00/66061 PCT/AU0O/00401 -8 Preferably the first and second actuator means is a piston operated hydraulically or by compressed air or electronically. More preferably the actuator means can be operated by a remote sensor device. 5 Preferably the actuator means can be continuously operable. In this way the movement of the cradle support means can be performed with the support frame and base support in any desired combination of positions. The applicants have found that the bed assembly of the present invention can effectively 10 and efficiently support a body up to a weight of about 150kg. The applicants present invention is capable of continuous or intermittent independent actuation of side arms and rocking motion by means of a first and second actuator respectively. This means that a body being supported by the present invention can be turned repeatedly while passing through a central origin point. Turning of a patient can also be conducted while the 15 support frame is inclined at any angle to the base frame or at any predetermined height. In particular an advantage of the present invention is its capability of turning a patient with the bed in any desired combination of positions. Specific embodiments of this invention will now be described by way of non-limiting 20 example. DESCRIPTION OF THE DRAWINGS Figure 1 represents an end view of the support assembly in a flat horizontal position. 25 Figure 2 represents an end view of the support assembly showing the sheet in cradle configuration. Figure 3 represents a schematic view of the support assembly having disposed on the 30 sheet a mattress in cradle configuration conforming to the contour of the sheet. Figure 4 represents a schematic view of the support assembly in a reclined position.

WO 00/66061 PCT/AU0O/00401 -9 Figure 5 represents a schematic view of the support assembly in a flat horizontal position. Figure 6 represents a schematic view of the support assembly in a slightly inclined position with the sheet in cradle configuration. 5 Figure 7 represents a schematic side view of the support assembly in a flat horizontal position. Figure 8 represents a schematic view of the support assembly in a inclined position. 10 Figure 9 is a side view of a support assembly in a reclined angled forward position. Figure 10 is a side view of a support assembly in a reclined horizontal position. 15 Figure 11 is a side view of a support assembly in a reclined angled backward. Figures 12, 13, 14 and 15 represent an end view of the support assembly which shows the support frame in a number of tilting positions each with the sheet engaged in a cradle configuration. 20 Figure 16 shows a side view of the support assembly with support frame and sheet in horizontal and flat configuration respectively. Figure 17 is an end view of Figure 16. 25 Figure 18 is a side view of the support assembly as in Figure 16 with the sheet being engaged in cradle configuration. Figure 19 is a rear view of Figure 18. 30 WO 00/66061 PCT/AUOO/00401 -10 INTEGER LIST 1. Bed assembly 2. Short lever arm 5 3. First actuator mechanism 4. Cradle support engaging frame 5. Support frame 6. First actuator 7. Raising arm 10 7a. Second raising arm 8. Sheet 9. Securing means 10. Folded recess of sheet 12. Second actuator mechanism 15 14. Mattress 15. Base frame 19. Transmission bar 20. Sections of support surface 21. Pivotal attachment 20 22. Second end of raising arm 23. Support surface 24. Pivot connection point 25. Second actuator 26. First transverse axle 25 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT WITH REFERENCE TO THE DRAWINGS With reference to Figures 1 and 2 there is shown an end view of a bed assembly (1) of 30 the invention. The bed assembly comprises a base frame (15) which provides pivotal attachment support at pivot point (21) for a generally rectangular support frame (5). The support frame (5) has a support surface (23) on which a body may be positioned. The support surface incorporates at least two preferably three sections or plates (20) (shown WO 00/66061 PCT/AUOO/00401 - 11 in Figure 9) which can be moved independently into a variety of positions. For example in Figure 9 there is shown a support frame incorporating three sections (20) which sections are pivotally and lockably moveable in relation to the support frame. A reclining position is represented in Figure 9. 5 Also shown in Figures 1 and 2 is an ABS flexible sheet (8) securely attached to the support frame along a central point in a longitudinal direction by securing means (9) illustrated as a nut and bolt combination. 10 There is shown in Figure 2 a clear end view representation of raising arms (7) in raised position with elongate longitudinal transmission bars (19) attached thereto, the transmission bars are shown in engagement arrangement with folded recess (10) of flexible sheet (8) so as to form a concave configuration. In Figure 1 raising arms (7) are shown in a lowered arrangement in folded relation to support frame (5). In this condition 15 the cradle support sheet conforms to the support surface (23) of the support frame (5). There is shown clearly in Figures 3, 16 and 18 two raising arms (7) and (7a) which are securely attached at a first end (22) to an elongate longitudinal transmission bar (19) and pivotally attached at the other end (24) to a transverse cross member (26) extending 20 across and beneath the support frame (5) to be pivotally attached to a corresponding raising arm (7). The transmission bar (19) is represented engaging the recess folds (10) of the ABS sheet. A specific embodiment of the bed assembly is shown in reference to Figures 16 to 20. 25 Figures 16 and 18 illustrate a side view of the bed assembly (1) of the preferred embodiment fitted with a cradle sheet (8), a cradle support engaging frame (4) and a cradle support engaging frame raising mechanism (3). 30 It is to be understood that some of the components of the bed assembly have been removed for the purposes of illustrating with clarity the mechanism for achieving a change in configuration of the cradle support sheet.

WO 00/66061 PCT/AUOO/00401 - 12 In a first condition shown in Figure 16 the cradle support sheet (8) is supported in a flat horizontal arrangement on the supporting surface (23) of the bed assembly (1). In this condition the recessed folds (10) of the cradle support sheet (8) rest on the support surface in non-engaged relation with and adjacent to longitudinal transmission bars (19). 5 In order to raise the cradle sheet (8) from the flattened position, a first actuator mechanism (3) is bounded between the support frame (5) and cradle support engaging frame (4). The first actuator mechanism (3) comprises an electric actuator (6) such as an electric 10 screw motor which when activated enables extension and retraction of an extender arm. The extendable/retractable arm is coupled at one end of a short lever arm (2). The other end of lever arm (2) is pivotally coupled to the bottom edge of support frame (5) at pivot connection point (24) and the raising arm (7) is fastened at a first end to pivot together with short lever arm (2) at pivot point (24). A transverse axle (26) is also connected at 15 the pivotal connection point (24) extending across and underneath the support frame to join corresponding sets of components so as to enable the first electric actuator (6) to drive both sets of components through short lever arm (2). The second end (22) of raising arm (7) is connected to a longitudinal transmission bar 20 (19) which in turn is adapted to be received within the recess (10) of the cradle sheet (8). As shown the cradle support engaging frame (4) includes a second raising arm (7a) spaced apart from the first lever arm (7) and connected to a corresponding lever armyia a second transverse axle (not shown). The upper ends (22) of both lever arms (7) and (7a) are connected to the transmission bar (19). 25 As shown in Figure 16, when the actuator (6) is in a retracted position the cradle support sheet (8) lies in a flat and horizontal condition with pivotable arms (7) and transmission bar (19) positioned adjacent to longitudinal edges of the support frame (5). 30 As the actuator (6) is extended, the lever arms (7) and (7a) are acted upon by short lever arm (2) so as to cause the lever arms (7, 7a) and transmission bar (19) connected thereto to be moved and raised in unison.

WO 00/66061 PCT/AUOO/00401 - 13 As can be seen in Figure 18, in raised condition, the lever arms (7, 7a) have adopted a perpendicular orientation relative to the support surface enabling the transmission bar (19) to be raised and received in engaged relation within the recess folds (10) of the cradle support sheet (8). As a result the configuration of the cradle means (8) is altered 5 between a flattened position and a symmetrical concave orientation. The concave orientation is best seen in Figures 2, 6 and 19. The first actuating means (6) can be adapted to continuously or incrementally extend or retract so that movement of the longitudinal bar can cycle through a variety of positions 10 during the course of engagement and disengagement of sheet (8). In this way the sheet can adopt a variety of configurations depending on the tension applied to it by the extent of engagement with the longitudinal transmission bar. In Figures 12, 13, 14 and 15 there is shown in end view the support assembly with sheet 15 (8) adapted to be in concave cradle configuration, in various tilting positions, and in various height adjusted positions. The tilting of said support frame is achieved by a second actuator mechanism (12) which is disposed underneath said support frame and within the base support (15). The second actuator mechanism comprises an actuator (25) shown with an extendable/retractable piston arm attached to the support frame (5) at 20 pivot point (21). Tilting or rocking motion is caused by the second actuator by means of the piston arm either extending or retracting, causing the support frame (5) to pivot in relation to the base support at pivot point (21). The second actuating means can be adapted to continuously or incrementally cause 25 pivotal movement of the support frame in relation to the support base. A further advantage of the present invention not shown in the diagrams is that the cradle configuration of the cradle sheet can be adopted when the sections of the support frame are in gentle reclining position. Figure 4 shows three sections of the support frame in 30 gentle reclining position. The height of the support assembly can be varied by conventional adjustments to the base support (15). The base support is conventionally adapted to enable the support frame to WO 00/66061 PCT/AUOO/00401 - 14 be tilted at an angle about its transverse central axis. Figures 5 to 11 show the bed assembly of the invention in a range of readily achievable positions and combinations of positions. In each of these positions a mattress (14) is 5 illustrated conforming to the configuration of the support surface and cradle sheet so as to provide movement of a person lying thereon without the need for excessive labour. The claims, illustrations, photographs and drawings, if any, form part of the disclosure of this specification as does the description, claims, illustrations, photographs and 10 drawings of any associated provisional or parent specification or of any priority document, if any, all of which are imported hereinto as part of the record hereof. Finally it is to be understood that various alterations, modifications and/or additions may be incorporated into the various constructions and arrangements or parts without 15 departing from the spirit and ambit of the invention.

Claims (35)

1. A bed assembly for altering the position of a person supported thereon including: 5 a longitudinal support frame having a support surface for receiving a person thereon; a longitudinal cradle means extending over the support surface, the cradle means being attached to the support surface substantially along a central axis in the 10 longitudinal direction thereof, the cradle means further incorporating a recess extending along side portions of the cradle means in the longitudinal direction thereof adapted for receiving and engaging an engaging means; a cradle support engaging means mounted to the support frame in close relation 15 to said recess adapted to be extendable and retractable in engaged relation within said recess along said longitudinal side portions of said cradle means so as to promote change in configuration of said cradle means; a first actuator mechanism disposed beneath the support frame in physical 20 coupling relation to the engaging means for extending or retracting the engaging means; wherein in a first condition the first actuator means causes the engaging means to extend towards and be received by said recess extending along said 25 longitudinal side portions of the cradle means, thereafter causing the cradle means to move, in positive engagement with the engaging means, with extending movement of the engaging means between a position of rest and a substantially concave configuration about the central longitudinal axis of the support surface and in a second condition the first actuator means causes the engaging means to 30 retract so as to correspondingly promote movement of the cradle means from said substantially concave configuration to said resting position conforming with the support surface, the change in configuration of the cradle means between said first and second condition being controllably continuous, staggered or cyclicle so WO 00/66061 PCT/AUOO/00401 - 16 as to aid movement of a person lying on said support surface.

2. A bed assembly according to Claim 1 wherein the cradle means is a sheet type material having a recess on each side portion said recess extending in a 5 longitudinal direction thereof.

3. A bed assembly according to Claim 2 wherein the sheet material is selected from thermoplastic or thermosetting plastics, preferably the material is a acrylomitrilebutadiene-styrene copolymer. 10

4. A bed assembly according to any one of the preceding claims wherein the cradle means can be a single continuous sheet or can be a series of sheet sections adapted to correspond to divided sections of a support frame. 15

5. A bed assembly according to any one of the preceding claims wherein the cradle means has a series of slots evenly spaced extending in a direction transverse to the longitudinal axis.

6. A bed assembly according to any one of the preceding claims wherein a central 20 portion of the cradle means extending in a longitudinal direction is securably attached to the support frame by means of screwing to the frame or by using a system of valcro.

7. A bed assembly according to any one of the preceding claims wherein the cradle 25 means can further have a mattress placed thereon.

8. A bed assembly according to Claim I wherein the cradle support engaging means is a frame structure disposed beneath and extending across said support frame. 30

9. A bed assembly according to Claim 8 wherein the frame structure includes a set of raising arms adapted to be extendable and retractable when said engaging means is acted upon by said first actuator mechanism. WO 00/66061 PCT/AUOO/00401 - 17

10. A bed assembly according to Claim 9 wherein the raising arms are cantilevered so as to adopt a first folded position adjacent longitudinal sides of the support frame when retracted and a second perpendicular position with respect to the support surface when extended. 5

11. A bed assembly according to any one of Claims 9 or 10 wherein the frame further includes a pair of engagement transmission bars positioned on either side of the support frame and coupled to the raising arms so as to be raised and lowered with extended and retracted movement of the raising arms respectively. 10

12. A bed assembly according to any one of Claims 10 or 11 wherein the raising arms and transmission bars are able to be moved in unison.

13. A bed assembly according to Claim 1 wherein the support frame is divided into 15 a plurality of sections or plates.

14. A bed assembly according to Claim 13 wherein the support frame has at least two sections, most preferably there are three sections or plates adapted to be independently slidably or pivotally movable so as to be capable of adopting any 20 number of conventional positions including for example a reclining position and other positions mentioned previously.

15. A bed assembly according to Claim 1 wherein the support frame can be pivotally adjusted about a vertical plane passing through its centrally located longitudinal 25 axis.

16. A bed assembly according to Claim 1 wherein the base support can be raised or lowered or tilted about a vertical axis. 30

17. A bed assembly for altering the position of a person supported thereon including: a longitudinal support frame having a support surface for receiving a person thereon; WO 00/66061 PCT/AUOO/00401 - 18 a base support on which the support is centrally pivotally mounted; a longitudinal cradle support means extending over the support surface, the cradle means being attached to the support surface substantially along a central axis in 5 the longitudinal direction thereof, the cradle means further incorporating a recess extending along each side portion of the cradle means in the longitudinal direction adapted for receiving and engaging an engaging means; a cradle support engaging means extendably mounted to the support in close 10 relation to said recess adapted to be extendable and retractable in engaged relation within said recess along said each side portions so as to promote change in configuration of said cradle means; a first actuator mechanism disposed beneath the support in physical coupling 15 relation to the engaging means for extending or retracting the engaging means; a second actuator mechanism coupled between the base support and longitudinal support frame for promoting independent pivot movement of the support frame about its longitudinal central axis; 20 wherein in a first condition the first actuator means causes the engaging means to extend towards and be received by said recess extending along said each side portions of the cradle support means, thereafter causing the cradle support to move in positive engagement with the engaging means, with extending 25 movement of the engaging means between a position of rest and a substantially concave configuration about the central longitudinal axis of the support surface and in a second condition the first actuator means causes the engaging means to retract so as to correspondingly promote movement of the cradle support from said substantially concave configuration to said resting position conforming with 30 the support surface, the change in configuration of the cradle support means between said first and second condition being controllably continuous, staggered or cyclicle; WO 00/66061 PCT/AUO0/00401 - 19 and the second actuator mechanism is able to act upon the support frame so as to promote tilting movement thereof to one side or the other about the longitudinal axis of the support frame; 5 the change in configuration of the cradle support being independent of the tilting movement of the support frame so as to aid movement of a person lying thereon.

18. A bed assembly according to any one of the preceding claims wherein the first and second actuator means is a piston operated hydraulically or by compressed 10 air or electronically, preferably the actuator means can be operated by a remote sensor device.

19. A bed assembly according to Claim 16 wherein the actuator means can be continuously operable. 15

20. A bed assembly according to Claim 17 wherein the cradle means is a sheet type material having a recess on each side portion said recess extending in a longitudinal direction thereof. 20

21. A bed assembly according to Claim 20 wherein the sheet material is selected from thermoplastic or thermosetting plastics, preferably the material is a acrylomitrilebutadiene-styrene copolymer.

22. A bed assembly according to any one of Claims 17, 20 or 21 wherein the cradle 25 means can be a single continuous sheet or can be a series of sheet sections adapted to correspond to divided sections of a support frame.

23. A bed assembly according to any one of Claims 17, 20, 21 or 22 wherein the cradle means has a series of slots evenly spaced extending in a direction 30 transverse to the longitudinal axis.

24. A bed assembly according to any one of Claims 17, 20 to 23 wherein a central portion of the cradle means extending in a longitudinal direction is securably WO 00/66061 PCT/AUOO/00401 - 20 attached to the support frame by means of screwing to the frame or by using a system of valcro.

25. A bed assembly according to any one of Claims 17, 20 to 24 wherein the cradle 5 means can further have a mattress placed thereon.

26. A bed assembly according to Claim 17 wherein the cradle support engaging means is a frame structure disposed beneath and extending across said support frame. 10

27. A bed assembly according to Claim 26 wherein the frame structure includes a set of raising arms adapted to be extendable and retractable when said engaging means is acted upon by said first actuator mechanism. 15

28. A bed assembly according to Claim 27 wherein the raising arms are cantilevered so as to adopt a first folded position adjacent longitudinal sides of the support frame when retracted and a second perpendicular position with respect to the support surface when extended. 20

29. A bed assembly according to any one of Claims 27 or 28 wherein the frame further includes a pair of engagement transmission bars positioned on either side of the support frame and coupled to the raising arms so as to be raised and lowered with extended and retracted movement of the raising arms respectively. 25

30. A bed assembly according to any one of Claims 28 or 29 wherein the raising arms and transmission bars are able to be moved in unison.

31. A bed assembly according to Claim 17 wherein the support frame is divided into a plurality of sections or plates. 30

32. A bed assembly according to Claim 31 wherein the support frame has at least two sections, most preferably there are three sections or plates adapted to be independently slidably or pivotally movable so as to be capable of adopting any WO 00/66061 PCT/AUOO/00401 -21 number of conventional positions including for example a reclining position and other positions mentioned previously.

33. A bed assembly according to Claim 17 wherein the support frame can be 5 pivotally adjusted about a vertical plane passing through its centrally located longitudinal axis.

34. A bed assembly according to Claim 17 wherein the base support can be raised or lowered or tilted about a vertical axis. 10

35. A bed assembly substantially as hereinbefore described with reference to the drawings.