GB1579936A

GB1579936A - Bed having mattress support platform capable or multiple inclinations

Info

Publication number: GB1579936A
Application number: GB4594676A
Authority: GB
Original assignee: AVION ENG Pty Ltd
Current assignee: AVION ENG Pty Ltd
Priority date: 1977-09-22
Filing date: 1977-09-22
Publication date: 1980-11-26

Description

(54) AN IMPROVED BED HAVING MATTRESS SUPPORT PLATFORM CAPABLE OF MULTIPLE INCLINATIONS (71) We, AVION ENGINEERING PTY. Ltd.

formerly known as Avion Australia Pty.

Ltd., a Company incorporated in the State of Western Australia, of Corner Knutsford Avenue and Eyre Street, Belmont, in the State of Western Australia, Commonwealth of Australia, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to beds and in particular to beds having a mattress supporting platform capable of occupying a number of inclined positions.

It is already known to have beds with mattress support platforms capable of multiple inclinations where one portion of the platform is pivotally mounted with respect to another such as in the case of a Fowler back. However, in all cases where there is such a provision one portion of the mattress support platform is fixed to the bed support frame. As a result it is not possible to incline the bed support frame in total without also tilting the bed support frame.

There are distinct disadvantages with the known system in that a bed capable of multiple inclination positioning is not capable of being moved to a Trendelenburg or Reverse Trendelenburg without also inclining the bed support frame. A disadvantage of inclining the bed support frame is created by the fact that the castors on which the bed may be mounted only operate effectively when vertical. If the bed support frame is to be inclined special provision must be made to maintain the castors vertical if the bed is to be moved efficiently when in the inclined position. In addition if auxiliary equipment such as self-help poles, intravenous bottle supports, orthapaedic frame or the like are mounted to the bed support frame the inclining of the bed frame will also incline such equipment.The inclination of the auxiliary equipment not only can detract from the effective operation of such but may also result in such equipment protruding from the line of the bed to block access around the bed and damage surrounding structures.

It is an object of this invention to provide a bed having a mattress supporting platform capable of multiple inclinations and also capable of total inclination without causingresultant inclination of the support frame or structure of the bed.

According to the present invention there is provided a bed having a support frame, a mattress support platform, said platform being transversely divided into a plurality of pivotally interconnected portions, wherein the mattress support platform is mounted to the support frame exclusively via a plurality of articulated levers, each pivotally mounted at one end to the platform and at the other end to a shaft rotatably mounted to the support frame, said pivotal mountings being spaced longitudinally on the platform, and each associated with different portions of the platform, drive means connected to the shafts to selectively cause rotation of one of the shafts to induce a substantially vertical movement of the portion of the platform supported by the articulated lever mounted to said shaft, means being provided betwen two adjacent portions to limit the relative pivotal movement therebetween and locking means to selectively lock portions at a desired angular relationship to each other.

It is a preferred feature of the invention that the pivotal mounting of each articulated lever to the portions of the mattress supporting platform are located such that the loading on the portions of the mattress supporting platform are substantially balanced to each side of the mounting.

The invention will be more fully understood in the light of the following description of one specific embodiment. The description is made with reference to the accompanying drawings of which; Figure 1 is a sectional elevation of the bed of the embodiment with the mattress support platform in the normal position; Figure 2 is a sectional elevation of the bed of the embodiment with the mattress support platform in the reverse Trendelenburg position; Figure 3 is a sectional elevation of the bed of the embodiment with the mattress support platform in the Fowler position; and Figure 4 are line drawings showing some other positions of which the mattress support platform is capable.

The embodiment comprises a bed having a support frame 11 and a mattress support platform 13. The support frame has a substantially horizontal rectangular frame 15 supported by legs 17 and may also incorporate a height adjustment means to provide for height variation of the bed. The mattress support platform is rectangular in plan and when horizontal and coplanar with the horizontal rectangular frame 15 of the support frame lies within the perimeter of the frame and closely adjacent thereto. The form of mounting between the support frame 11 and mattress support platform comprises a pair of transverse operating shafts 19 rotatably mounted to the rectangular frame 15, each shaft having a pair of spaced radial arms 21 (only one arm in each pair shown) rigidly mounted thereto and extending radially therefrom.The arm pair 21 on one shaft 19 are interconnected via a pair of slotted linkage bars 23 (only one shown) to the arm pair 21 on the other operating shaft 19.

Each slotted linkage bar 23 has mounted thereto a drive means 25 in the form of a screw thread drive between the linkage bar and the rectangular frame 15. A handle is provided on the screw thread drive to operate the same. Each linkage bar is provided with elongated slots 27 towards each end and parallel to the longitudinal axis of the bar.

Each radial arm 21 is slidably engaged in the slots 27 provided in bar 23, via a sliding pivot joint, and is engaged by the innermost end of the corresponding slot 27 when the bed is in the normal position (Figure 1). On the operation of the drive to cause longitudinal movement of the linkage bar 23 only one of the interconnected pairs of radial arms 21 is caused to move with bar 23 to produce corresponding rotation of the operating shaft 19 carrying radial arms 21.

Each shaft 19 is also provided with a pair of radial arms 29 fixed thereto and extending radially therefrom, each arm 29 being pivotally connected at its outer end with a respective link arm 31 which is pivotally mounted at its free end to the underneath of of the mattress support platform 13. A solitary stabiliser bar 33 extends between the mounting of the link arms 31 with the mattress platforms and one of the operating shafts 19, the bar 33 being pivotally mounted to the shaft 19 at the head end of the bed (the left hand side in the Figures) and rigidly mounted to the platform frame towards the foot end of the bed (the right hand side in the Figures) at the pivotal mounting for arms 31. The action of the stabiliser bar is to prevent uncontrolled rotation of one transverse operating shaft in relation to the other.

With the rotation of one operating shaft the corresponding portion of the mattress support platform is caused to be raised substantially vertically while the portion of the mattress supporting platform connected to the other operating shaft remains substantially steady. Therefore with the longitudinal movement of the linkage bar 23 in either direction as induced by the drive means, one or the other end of the mattress support platform is raised from the horizontal position to occupy the Reverse Trendelenburg position (Figure 2) or Trendelenburg position (not shown).

The mattress support platform is transversely divided into two portions hinged together and comprising a head portion 35 and main portion 37. The head portion has pivotally mounted thereto a link arm 31 from one of the operating shafts 19. The location of the mounting is such that on the mattress supporting platform being loaded with bedding and an occupant, the loading at the mounting to the head portion 35 is substantially equally balanced to each side thereof. Similarly the mounting of the other link arm 31 to the mattress supporting platform is located at a point underneath the main portion 37 such that on the mattress support platform being loaded with bedding and an occupant the loading on the mounting is substantially balanced to each side thereof.

It is for this balancing effect that the link arms 31 are contoured in order that the loading on each portion 35 and 37 is substantially balanced and yet the loading on the support frame 11 is taken at points towards each end thereof.

The hinged mounting between the headportion 35 and main portion 37 is associated with a locking means 39. The locking means 39 comprises a plate fixed to one portion of the mattress supporting platform and having an arcuate slot therein. The other portion carries an extension member with a slide (not shown) received in the slot and supporting a releasable clamp, the engagement of which with the slot locks the two portions against relative rotation with respect to each other. The locking means 39 also serves to limit the relative pivotal movement between the portions 35 and 37.

As a result the mattress support platform can perform as a coplanar platform capable of tilt or as a biplanar platform also capable of a variety of inclinations since the hinge locking means 39 between the two portions and pivoting action of the two portions is completely independent of the means for tilting the mattress supporting platform. In addition the head portion 35 can serve as a Fowler back (see Fig. 4B) and also facilitates positions as shown at Figure 4A when required.

The main portion 37 of the mattress supporting platform is itself transversely divided into two portions 37A and 37B via a hinged interconnection located at the mounting to the link arm 31. The free end portion (or foot portion) 37B of the mattress support platform is prevented from rotating with respect to the central portion 37A by means of a downwardly depending support 41 pivotally mounted underneath the portion and supported in a multiposition bracket 43 located on the link arm 31 of the mounting for the mattress support platform. The multiposition support 43 provides a plurality of positions vertically spaced from each other to facilitate vertical transposition of the foot portion 37B.

As a result of the articulated nature of the main portion 37 of the mattress supporting platform 13 the platform can be made to take on a contoured configuration as shown at Figure 3 and 4C. In addition such contoured configuration is independent of the inclination drive system of the bed.

As a result of the embodiment a bed is produced which is capable of a simple tilt at both the head and the foot end, a coplanar contour, a biplanar contour and a triplanar contour and wherein the contour of the platform is independent of the inclination drive and where the orientation of the mattress support platform does not in any way affect the orientation of the bed support frame. In addition due to the balanced location of the lever linkage system mountings to the mattress support platform little effort is required to pivot the head and main portions to the required orientation. However despite such balanced mounting the loading on the support frame is such that the stability of the bed is not adversely affected despite the position or contour of the mattress support platform.

If it is preferred a counter balance system which may incorporate weights or a resilient assistance may be mounted with the inclination drive system for the mattress supporting platform. An example of one such system comprises use of an extension spring between the linkage bar 23 and the frame whereby the upward drive provided to the mattress support platform is assisted with a force at least equal to the downward force thereon produced by the bedding and occupant.

WHAT WE CLAIM IS: 1. A bed having a support frame, a mattress support platform, said platform being transversely divided into a plurality of pivotally interconnected portions, wherein the mattress support platform is mounted to the support frame exclusively via a plurality of articulated levers, each pivotally mounted at one end to the platform and at the other end to a shaft rotatably mounted to the support frame, said pivotal mountings being being spaced longitudinally on the platform, and each associated with different portions of the platform, drive means connected to the shafts to selectively cause rotation of one of the shafts to induce a substantially vertical movement of the portion of the platform supported by the articulated lever mounted to said shaft, means being provided between two adjacent portions to limit the relative pivotal movement therebetween and locking means to selectively lock portions at a desired angular relationship to each other.

2. A bed as claimed in claim 1, wherein the support frame comprises an uppermost rectangular horizontal frame and the mattress support platform when horizontal and coplanar lies vertically within the perimeter of the frame and closely adjacent thereto.

3. A bed as claimed in claim 1 or 2, wherein the connection between the operating shafts and the drive means comprises a linkage bar mounted between a radial arm extending from each operating shaft and the drive means is mounted between the frame and the linkage bar to cause longitudinal movement of the linkage bar.

4. A bed as claimed in claim 3, having a second radial arm on each shaft and wherein the articulated levers are each pivotally connected at one end to the second radial arm and pivotally connected at the other end to the mattress support platform.

5. A bed as claimed in claim 4, wherein a stabiliser rod is connected between the underneath of the mattress support platform and one of said second radial arms on one of said operating shafts.

6. A bed as claimed in any one of claims 1 to 5, wherein the mattress supporting platform is transversely divided into two portions.

7. A bed as claimed in claim 6 as dependent on claim 4, wherein the pivotal mounting of the articulated levers to the mattress supporting platform is located where the loading on the portion is substantially equally balanced to each side of the point when the mattress supporting platform carries bedding and an occupant.

8. A bed as claimed in claim 7, wherein the supporting shafts are located at symmetrically opposed locations on the support frame and the articulated levers are contoured to interconnect the second radial arms with the mattress supporting platform.

9. A bed as claimed in any one of the preceding claims, wherein one end portion of said portions of the mattress is transversely divided into two sub-portions via a pivotal connection and the outermost subportion is supported from the associated

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. Fowler back (see Fig. 4B) and also facilitates positions as shown at Figure 4A when required. The main portion 37 of the mattress supporting platform is itself transversely divided into two portions 37A and 37B via a hinged interconnection located at the mounting to the link arm 31. The free end portion (or foot portion) 37B of the mattress support platform is prevented from rotating with respect to the central portion 37A by means of a downwardly depending support 41 pivotally mounted underneath the portion and supported in a multiposition bracket 43 located on the link arm 31 of the mounting for the mattress support platform. The multiposition support 43 provides a plurality of positions vertically spaced from each other to facilitate vertical transposition of the foot portion 37B. As a result of the articulated nature of the main portion 37 of the mattress supporting platform 13 the platform can be made to take on a contoured configuration as shown at Figure 3 and 4C. In addition such contoured configuration is independent of the inclination drive system of the bed. As a result of the embodiment a bed is produced which is capable of a simple tilt at both the head and the foot end, a coplanar contour, a biplanar contour and a triplanar contour and wherein the contour of the platform is independent of the inclination drive and where the orientation of the mattress support platform does not in any way affect the orientation of the bed support frame. In addition due to the balanced location of the lever linkage system mountings to the mattress support platform little effort is required to pivot the head and main portions to the required orientation. However despite such balanced mounting the loading on the support frame is such that the stability of the bed is not adversely affected despite the position or contour of the mattress support platform. If it is preferred a counter balance system which may incorporate weights or a resilient assistance may be mounted with the inclination drive system for the mattress supporting platform. An example of one such system comprises use of an extension spring between the linkage bar 23 and the frame whereby the upward drive provided to the mattress support platform is assisted with a force at least equal to the downward force thereon produced by the bedding and occupant. WHAT WE CLAIM IS:

1. A bed having a support frame, a mattress support platform, said platform being transversely divided into a plurality of pivotally interconnected portions, wherein the mattress support platform is mounted to the support frame exclusively via a plurality of articulated levers, each pivotally mounted at one end to the platform and at the other end to a shaft rotatably mounted to the support frame, said pivotal mountings being being spaced longitudinally on the platform, and each associated with different portions of the platform, drive means connected to the shafts to selectively cause rotation of one of the shafts to induce a substantially vertical movement of the portion of the platform supported by the articulated lever mounted to said shaft, means being provided between two adjacent portions to limit the relative pivotal movement therebetween and locking means to selectively lock portions at a desired angular relationship to each other.

articulated lever such that it retains its position relative to the mattress supporting platform irrespective of the inclination thereof.

10. A bed as claimed at claim 9 as dependent on claim 8, wherein the outermost sub-portion is supported on the associated articulated lever via a multi-position bracket providing a plurality of vertically spaced support locations for the sub-portion.

11. A bed as claimed in any one of the preceding claims wherein a counterbalance is provided to counteract at least a portion of the total weight of the mattress supporting platform, bedding and occupant.

12. A bed substantially as herein described with reference to the accompanying drawings.