GB2287401A - Lifting device for beds - Google Patents

Abstract

A lifting device which can be used on a bed includes a backrest comprising a frame 20 mounted for pivotal movement about an axis 12 by an inflatable bag 24, and a flexible backrest panel tethered to the frame 20 for movement relative thereto about a further axis 21 so that as the backrest is raised and lowered the movement of the panel provides more comfortable support for the user, especially with respect to bending of the user's body about the hip axis (14, Fig 4). <IMAGE>

Description

LIFTING DEVICE This invention concerns devices for use on a bed as a backrest which can be controlled to raise a recumbent person to a sitting-up position on the bed.

US-A-3781928 discloses a device, for raising and lowering the head end and/or foot end of a mattress of a bed from a bedstead, comprising an inflatable pad positioned at the head end and/or foot end of the bedstead between the bedstead and the mattress to raise or lower the associated end of the mattress. The pad is mounted in a frame which is composed of upper and lower hinged U-shaped parts each of which includes a plate of thin rigid material fixedly attached to the parallel legs of the associated frame part. The pad is attached only to the plate of the bottom part and is free to slide on the plate of the upper part when the mattress is raised and lowered in the course of inflation and deflation of the pad.

In use, the known apparatus can give rise to considerable discomfort for such persons, because, for example, a thick resilient mattress is required above the rigid plate, so that the axis of the person 5 hips is spaced above the pivot axis of the frame which generates an uncomfortable, and sometimes painful, conflict of geometry during lifting which can only be partially mitigated by increasing the conformability of the mattress. As well as this problem of user discomfort, the apparatus imposes structurally harmful loads upon the mattress by bending it about a fixed axis at a small radius of curvature, thus giving rise to the problem of damage to the mattress and high replacement costs.

The present invention enables these problems to be avoided, or at least substantially reduced. The present invention provides a lifting backrest device which comprises: (a) a backrest frame in which a pair of limbs are connected by a transverse bar at or adjacent one end of the backrest frame, (b) a support, for attachment to a bed, having a pair of pivots connecting the support to the ends of the limbs remote from the bar, (c) a backrest panel located between said limbs, and (d) pneumatic lifting means located below said panel to raise and lower the backrest frame pivotally about the axis of said pivots; which device is characterised in that said backrest panel is connected to said backrest frame by connection means constructed to permit the panel to tilt relative to the frame so as not to be confined to movement about said axis.

The panel is preferably movable in a generally pivotal manner about the bar, and preferably extends longitudinally (in a direction transverse to said axis) beyond the backrest frame.

The present invention further provides a lifting backrest device comprising a support, for attachment to a bed, a backrest assembly and pneumatic lifting means for raising and lowering the backrest assembly, the backrest assembly comprising a stabilising frame pivotally connected at one end to the support, and a backrest panel connected by a flexible connection means to the stabilising frame; wherein the backrest panel is supported during lifting upon the pneumatic lifting means for movement relative to the stabilising frame within limits determined by the flexible connection means.

The panel is preferably flexible, and in preferred embodiments is provided with longitudinal stiffening or is otherwise constructed so as to be stiffer in the longitudinal direction than it is in the transverse direction.

The connection means preferably includes flexible connections between lateral margins of the panel and the limbs of the frame adjacent thereto.

The pneumatic lifting means preferably comprises a pneumatically inflatable bag tethered to the panel, preferably by a web connected to a lower end portion of the panel.

The support may comprise a U-shaped base frame, larger than the backrest or stabilising frame, provided with means to tether the base frame upon a mattress of a bed.

However, in operation upon double beds it has been found that the base frame may not be sufficiently stabilised by tethering.

In order to overcome this problem of stability, the U-shaped base frame is preferably vertically adjustable upon upstanding members of a cramp device, the cramp device further comprising an under frame connected to the upstanding members so that a mattress can be cramped between the base frame and the underframe.

The upright members preferably form part of a clamp adjusting frame, and the two frames of the cramp device are preferably pivotally connected for relative movement through a limited arc.

The connection between the cramp adjustment frame and the base is preferably provided by connection means arranged so that the forces exerted by the mattress upon the base frame tend to cause the connection means to resist upward movement of the base frame.

The connection means preferably comprises a pair of brackets welded to a transverse member of the base frame, each of which brackets is generally of a U-shaped configuration in which the ends of the limbs are welded to the transverse member and the base forms a loop around said upright members. Each bracket is preferably angularly offset relative to the general plane of the base frame so that the loop binds against said upright members when the base frame and underframe are parallel or approximately so.

Locking means is preferably provided to prevent upward movement of the base frame relative to the upstanding members.

The backrest device is preferably provided with a flexible cushioning overlay, e.g. of foamed or cellular resilient plastics material. The overlay may be washable and much lighter and thinner, e.g. about 5cm thick, than a usual bed mattress (commonly 15 to 20cm thick).

The invention will be described further, by way of example, with reference to the accompanying diagrammatic drawings, wherein FIGURE 1 is a simplified diagram showing parts of a known backrest device installed in a bed for raising a person reposing on the bed; FIGURES 2 and 3 are perspective views of an embodiment of backrest device of the invention installed on a bed; FIGURE 4 is a further simplified diagram showing parts of this embodiment when used for raising a person reposing on the bed; FIGURE 5 shows a general perspective view of a lifting device of the invention, with the lifting means omitted for the sake of clarity; FIGURE 6 shows an enlarged view of connection means employed in the device; ; FIGURE 7 shows a diagram of a cramp device forming part of the lifting device, and FIGURE 8 shows a simplified version of the cramp device with some parts of the lifting device.

Referring to FIGURE 1 and the aforementioned US-A37819298, in the known device the rigid backrest plate, shown in FIGURE 1 and referenced as 10 is disposed below the normal mattress 11 of the bed and is supported for pivotal movement about a fixed axis 12 to raise and lower an upper (head) end portion 13 of the mattress. As indicated in FIGURE 1 the axis 14 of the hips of a person reposing on the mattress is spaced well above the axis 12.

During lifting the device endeavours to raise the person's upper body about the axis 12, whereas a person raising himself naturally would tend to raise his upper body about the axis 14 when sitting-up in bed. The conflict of geometry which the device generates can impose painful loads upon the person's lower back and lower limbs.

Furthermore, movement about the fixed axis 12 forces the portion 15 of the mattress above the axis 12 to become severely compressed to the detriment of the structure of the mattress.

Referring to FIGURES 2 to 4, the apparatus of the invention is installed on top of the mattress and is constructed so that the person's back is supported during lifting by a panel 20 which is movable relative to the axis 12 generally about a further axis 21 offset from the axis 12 so as to conform approximately to the momentary attitude of the person's back, whereby to avoid or reduce the problems experienced with the aforementioned known device.

The lifting backrest device includes a backrest or stabilising frame 22, a support 23, and lifting means 24 for supporting and raising the panel 20.

The backrest frame 22 is generally of U-shape and comprises a pair of approximately parallel limbs 25 connected by a transverse bar 26 at one end of the frame.

The support 23 is in the form of a larger, U-shaped, base frame provided with straps or tethers 27 to fasten the support onto the mattress 11. The free end portions 28 of the base frame are connected by pivots 29 to the free ends of the limbs 25 so that the backrest frame 22 can be swung about the fixed axis 12 common to the pivots 29.

Referring to FIGURES 2 and 3, the backrest panel 20 comprises a web 30 of flexible material, such as a woven fabric, sewn or otherwise formed to incorporate connection means comprising lateral extensions 31 providing sleeves 32 to accept the limbs 25, and a transverse sleeve 33 to accept the bar 26 so that a head end portion 34 of the panel projects beyond the bar 26. The undersides of the head end portion 34 and the opposite end portion 35 are each provided with a row of pockets 36 to receive opposite ends of a row of six longitudinally extending stiffeners 37 in the form of flat-spring strips of a stiffly flexible or high flexural strength material such as glass fibre reinforced plastics. The opposite end portion 35 has a web extension 38 attached thereto and to the lifting means 24.

The latter comprises a pneumatically inflatable bag 40, which when fully inflated is of cylindrical form and which extends across the panel 20 between the extensions 31 so as to support all the stiffeners 37 to which the bag 40 is tethered by means of loops 41. A pipe 42 is provided for inflation and deflation of the bag.

In use, the backrest device is simply laid on top of the mattress so that the base frame 23 abuts or is proximal to the headboard 16, (the space between the bar 26 and the base frame 23 is sufficient to accept the portion 34 of the panel so that the device can be laid flat upon the mattress), and the straps 27 are passed beneath the mattress (or the bed) and tightened to hold the base frame to the mattress.

A thin resilient foam plastics overlay 43 is then laid over the mattress and the backrest device, which overlay 43 may be housed in or covered by a cover or sheet (not shown). The overlay or cover may be attached to the backrest frame.

Referring also to FIGURE 4, when a person is to be raised from a recumbent to a sitting-up position, the bag is progressively inflated. Initially the nearly flat bag urges a large area of the panel generally upwards without constraint by any axis so that the inherent flexibility of the panel allows it to conform generally to the shape of the person's undersurface reposing above the device.

During further inflation, as the person's body is raised the panel can tilt to swing about the axis 24 (generally that of the bar 26) as indicated by arrow A (as well as flexing as the person's body shape changes) so as to adapt to the person's posture as the person's body pivots about the hip axis 14, within limits dictated by the extensions 31. Also, the backrest frame is not lifted directly by the bag, but follows the lifting movement of the upper portion of the panel, and serves only as a stabiliser, e.g. to prevent the panel twisting to an unacceptable degree under transverse loads, by transferring such loads, via the pivots, to the base frame which stabilises the device.

In the lifting device shown in FIGURES 5 to 8 the support 23 further comprises a cramp device including a cramp underframe 50, a cramp adjusting frame 51 and connection means 55 to connect the adjusting frame to the transverse member 58 of the base frame of the support 23.

The cramping device is arranged so that the base frame and the cramp underframe 50 together constitute the two jaws of a cramp to embrace an end portion of a mattress 11 of a bed therebetween to effectively limit movement of the base frame about the central longitudinal axis 59 of the apparatus, about the transverse axis 53 of the transverse bar 58 of the base frame and about the axis 52 of a junction between the cramp underframe adjusting frames.

Both of these frames 50, 51 of the cramp device are of Ushaped form and are joined by hinges 54 at their free ends to allow, for storage, the cramp frame to be swung to a position alongside the clamp adjusting frame. The hinges 54 restrict movement of the frames relative to each other through an arc of approximately a right-angle so that in the in-use condition the two frames lie generally in mutually perpendicular planes.

The connection means 55 is shown in more detail in FIGURE 6 and comprises two brackets 60 each of which is generally of U-shape configuration having free ends 61 welded to the transverse bar 58. The base 62 of the Ushape is curved and extends around the upright limbs 57 of the cramp adjusting frame. The bracket is angularly offset from the general plane of the base frame so that when the base frame 23 is approximately perpendicular to the uprights 57 the bottom of the U-shape forcibly engages the upright and urges the upright into firm engagement with the transverse member 58 so that relative vertical movement of the base frame is resisted. However, when the base frame 23 is swung downwards about the axis 53 the bases 62 of the U-shaped brackets are swung away from the uprights 57 allowing the base frame 23 to be moved up and down the upright 57 quite freely. The connection means 55 also serves to allow the upright to be swung generally about the axis 53 so that the whole cramp device can lie approximately alongside and close to the same general plane as that of the base frame 23, as diagrammed generally in FIGURE 7.

In use, when a mattress is clamped between the jaws of the cramp the resilient force exerted by the mattress on the cramp tends to lift the base frame relative to the cramp underframe so as to tend to keep the connection means in a locked condition, and, in order to prevent vertical movement of the base frame relative to the uprights, locking means in the form of a collar having a screw or cam clamp 56 is fitted to each upright.

The invention is not confined to details of the foregoing example and many variations are possible within the scope of the invention. For example, in the variation shown in FIGURE 8 some dismantling may be required when the apparatus is being prepared for storage for transportation to achieve compactness, but cost savings can be achieved by making the clamp underframe and clamp adjustment frame integral and by merely clamping the member 58 to the uprights of the adjustment frame. The clamping may be achieved by releasably connected collar members serving as the connection means 55, of which one collar member has in it a screw or cam clamp 56, in order to prevent vertical movement of the connection means relative to the uprights.

The collar members, when released from each other e.g. by means of fasteners, not shown, may be parted to release the bar 58.

If required, the two frames 50, 51 could be joined by the hinges 54 instead of being made integral.

In use, the cramp use provides complete stability for the base of the lifting device, and the cramp adjustment frame, being of inverted U-form, offers, in some installations, a form of headboard or head-rail which is free of potentially harmful protrusions.

The invention is not confined to the details of the foregoing example, and many variations and modifications are possible within the scope of the invention as defined by the appended claims.

The invention also provides and includes within its scope any lifting backrest device having any novel part of operational feature or combination of parts or features disclosed herein or in the accompanying drawings.

As well as avoiding the aforementioned problems, the device of the invention has the further advantage that it can be used on one side of a double bed, leaving the other side undisturbed.

The invention further includes and provides lifting apparatus, or a cramping device for lifting apparatus, embodying any novel feature, part or functional attribute disclosed or shown herein or in the drawings, and includes any combination thereof shown or described herein.

Claims (13)

1. A lifting backrest device which comprises: (a) a backrest frame in which a pair of limbs are connected by a transverse bar at or adjacent one end of the backrest frame, (b) a support, for attachment to a bed, having a pair of pivots connecting the support to the ends of the limbs remote from the bar, (c) a backrest panel located between said limbs, and (d) pneumatic lifting means located below said panel to raise and lower the backrest frame pivotally about the axis of said pivots; which device is characterised in that said backrest panel is connected to said backrest frame by connection means constructed to permit the panel to tilt relative to the frame so as not to be confined to movement about said axis.

2. A device as claimed in Claim 1 wherein the panel is movable in a generally pivotal manner about the bar.

3. A device as claimed in Claim 1 or 2 wherein the panel extends longitudinally (in a direction transverse to said axis) beyond the backrest frame.

4. A lifting backrest device comprising a support, for attachment to a bed, a backrest assembly and pneumatic lifting means for raising and lowering the backrest assembly, the backrest assembly comprising a stabilising frame pivotally connected at one end to the support, and a backrest panel connected by a flexible connection means to the stabilising frame; wherein the backrest panel is supported during lifting upon the pneumatic lifting means for movement relative to the stabilising frame within limits determined by the flexible connection means.

5. A device as claimed in any preceding claim wherein the panel is flexible, and is provided with longitudinal stiffening or is otherwise constructed so as to be stiffer in the longitudinal direction than it is in the transverse direction.

6. A device as claimed in any preceding claim wherein the connection means includes flexible connections between lateral margins of the panel and the limbs of the frame adjacent thereto.

7. A device as claimed in any preceding claim wherein the pneumatic lifting means comprises a pneumatically inflatable bag tethered to the panel by a web connected to a lower end portion of the panel.

8. A device as claimed in any preceding claim wherein the support comprises a U-shaped base frame, larger than the backrest or stabilising frame, provided with means to tether or secure the base frame upon a mattress of a bed.

9. A device as claimed in any preceding claim wherein the base frame is vertically adjustable upon upstanding members of a cramp device, the cramp device comprising an underframe connected to the upstanding members so that a mattress can be cramped between the base frame and the underframe.

10. A device as claimed in Claim 9 wherein the upright members form part of a clamp adjusting frame, and the two frames of the cramp device are pivotally connected for relative movement through a limited arc.

11. A device as claimed in Claim 9 or 10 wherein the connection between the cramp adjustment frame and the base frame is provided by connection means arranged so that the forces exerted by the mattress upon the base frame tend to cause the connection means to resist upward movement of the base frame.

12. A device as claimed in Claim 12 wherein the connection means comprises a pair of brackets welded to a transverse member of the base frame, each of which brackets is generally of a U-shaped configuration in which the ends of the limbs are welded to the transverse member and the base forms a loop around said upright members.

13. A device substantially as hereinbefore described with reference to FIGURES 2 to 4, FIGURES 5 to 7 or FIGURE 8 of the accompanying drawings.