IE64231B1 - Invalid beds - Google Patents

Abstract

In an invalid bed 1, a head end lifting support 11 underlies the top end of the mattress. The support 11 is pivoted by pins 22 on base 2, 3 of the bed. Support 11 may be pivoted upwardly by operation of an actuator 24, mounted between a displaceable transverse member 23 of support 11 and a fixed transverse member 25 of the bed frame. The actuator linkage 29 includes an abutment feature such that positive drive of support 11 takes place only during an upward pivoting movement, and downward pivoting of support 11 takes place under the force of gravity only. The bed also comprises a leg-lifting member 34 for underlying the mattress in the vicinity of a patient's legs. Member 34 is supported by side members 32 and 33, pivoted in bearings 37 and 38 on frame 2, 3 of the bed. Upward displacement of leg-lifting bar 34 takes place during pivoting of frame 11 by camming engagement of arms 44, 45 of support 11 against regions 46, 47 of side members 32, 33 on the opposite side of pivots 37, 38 from bar 34. In a further embodiment of the invention, side members 32 and 33 may be defined by pivoted together side member portions, restrained against relative displacement in one direction by stops but displaceable in the opposite direction to be brought into the general plane of the bed frame, so as to enable the bed to be shipped or stored in a compact flat-pack disposition.

Description

Invalid beds This invention relates to beds incorporating lifting devices and intended particularly for persons suffering from disabilities necessitating extensive periods lying in bed or continuous lying in bed. In particular, the invention is directed to beds having devices for lifting patients lying in bed from a supine disposition into a reclining or sitting position.

Hospital beds are known which provide a multiplicity of movements for handling patients with facility. Beds of this kind are very satisfactory in meeting the various purposes which are required of them, but they are extremely expensive compared with a domestic bed, and, for some care, do not represent a practical proposition for acquisition by the average householder. Accordingly, it is an object of the invention to provide a relatively inexpensive bed incorporating a patient lifting device especially suited to the domestic environment.

According to the invention, thre is provided a bed comprising - 2 a lifting device having a support portion for underlying a portion of the mattress of the bed, said support portion being pivotable relative to a base portion of the bed, means for effecting pivotal displacement of said support portion relative to said base portion, and a further lifting portion in the form of a thigh or leg-lifting portion, said leg-lifting portion comprising a lifting member for underlying a further portion of the mattress of the bed and side members associatable with said lifting member, said side members being mounted on the base portion of the bed for pivotal displacement relative to said base poriton and being operatively associated with said support portion so that pivoting movement of said leg-lifting portion is effected by pivoting displacement of said support portion, said support portion comprising camming portions for camming engagement against said side members of the lifting portion during pivoting displacement of the support portion.

In a specially favoured structure, said lifting member of the leg-lifting portion is demountably and adjustably associated with said side members. Each said side member preferably comprises first and second side member portions, said side member portions being pivotally linked together, and stops being provided to limit relative rotation of said first and second side member portions in a first direction of relative rotation thereof. This division of the side members of the leg-lifting structure into two portions, pivotally connected together but constrained against relative rotation in one direction of such rotation, facilitates storage and transport of the bed of the invention by enabling it to be shipped in a flat-pack manner, the side member portions being rotated in the direction opposite to that constrained by the stops for transforming the product into a flat-pack configuration.

Said means for effecting pivotal displacement of said support portion may comprise a member abuttingly engageable against an abutment portion of said support portion for upward pivotal displacement of the support portion.

Said means for effecting pivotal displacement of said support portion suitably includes an expansible actuator, disposed between the base portion of the bed and said support portion. This actuator may be a hydraulic actuator or jack, or it may be electrically driven.

Said abuttingly engageable member may be a link pivotally connected at one end to said support portion and pivotally connected at its other end to said actuator. Said abutment portion of said support portion may be defined by a stop member and said link may be an abutment portion for engagement against said stop member of said support portion for effecting said upward pivotal displacement. Said link is suitably pivotally displaceable into a disposition in which said abutment portion of the link is spaced from said abutment portion of the support portion. This latter feature again enables the bed of the-invention to be shipped as a flat-pack, with said link swung upwardly substantially in line with the general plane defined by the bed.

In any construction of the invention, said base portion is suitably at least in part defined by a shaped single length of substantially flat metal bar.

Embodiments of the invention and variants thereon will now be described having regard to the accompanying drawings, in which, Figure 1 is a pictorial view of a bed incorporating a patient lifting device in accordance with the principles of the invention, Figure 2 is a pictorial view of the base of the bed of Figure 1, Figure 3 is a pictorial view of the support portion of the bed of Figure 1, Figure 4 is a pictorial view of the thigh-lifting frame of the bed of Figure 1, Figure 5 is a side view of the bed of Figure 1 in a lowered or dropped disposition, Figure 6 is a similar view to that of Figure 5, showing the bed of Figure 1 in a raised or lifted disposition, Figure 7 corresponds to Figure 5, showing the bed fitted with a mattress, mattress base and headboard, and in the dropped or lowered configuration of the lifting device, Figure 8 shows the complete bed assembly of Figure 7 in a raised or lifted configuration, Figure 9 is a side view of a bed incorporating a lifting device according to the invention activated by hydraulic means, the device being shown in a lowered disposition.

Figure 10 is a pictorial view of the main frame of another embodiment of bed according to the invention, Figure 11 is a pictorial view of the lifting frame for the bed of Figure 10, Figure 12 is a pictorial view of the leg lift arrangement for 20 the bed of Figure 10 and the manner of its co-operation with the head lifting frame of Figure 11, Figures 13, 14 and 15 are diagrammatic kinematic representations of the relative orientations of the moving members of the bed of Figures 10 to 12 in a lowered disposition (Figure 13), a pivoted raised disposition (Figure 14), and folded into flat pack configuration for transport and/or storage (Figure 15), Figure 16 is a side view of the interconnection region between the head lifting frame and the head lifting arrangement of the bed of Ficures 10 to 12, Figure 17 shows the actuator for the head lifting frame of Figure 11 in its closed disposition, Figure 18 shows the actuator of Figure 17 in a partially extended disposition, in which it serves to raise the head lifting frame of Figure 11, Figure 19 is a side view of the actuator link connector in its folded or flat pack disposition, and Figure 20 shows the connecting link of Figure 19 engaged against the lifting frame member in position for effecting a pivoting or lifting movement.

As shown in Figure 1, a bed 1 according to the invention has a base or frame defined by longitudinal side members 2 and 3 connected by transverse end members 4 and 5 and supported by legs 6, 7, 8 and 9 at the corner regions of the generally rectangular bed base or frame.

The lifting feature provided in accordance with the invention consists of a support 11 positioned to underlie the mattress of the bed in the region which supports the upper body portion of a patient lying on the bed. The support portion 11 is defined by a frame bounded by side members 12 and 13, these being bridged by a transverse end member 14 located in the vicinity of the head of the bed. The bottom or floor of the support 11 is closed off by means such as mesh 15 defining a floor region of the support portion 11.

At the ends of support portion side members 12 and 13 remote from transverse end member 14, i.e. the free ends of these side members, support portion pivot arms 15 and 17 extend downwardly and forwardly, i.e. towards the foot of the bed. The pivot arms 16 and 17 are fixedly connected to the free ends of side members 12 and 13.

Pivot arms 16 and 17 are pivotally mounted on upstanding pivot lugs 18 and 19 extending upwardly from the base side members 12 and 13 of the frame of bed 1 by means of pivot pins 21 and 22. Thus an axis of pivoting for support portion 11 is defined by pivot pins 21 and 22 which pivotally interconnect arms 16 and 17 to lugs 18 and 19.

The lower ends of pivot arms 16 and 17 extend below side members 2 and 3 of the frame of the bed 1 and the free lower ends of these arms are transversely interconnected by an actuator driven transverse member 23. Pivoting displacement of support portion 11 is effected by an actuator 24 mounted between transverse actuator driven member 23 and a transverse actuator reaction member 25, extending transversely across the frame of the bed 1 between the side members 2 and 3 towards the lower or foot end of the bed. The actuator 24 is suitably electrically powered and consists of a drive or cylinder portion 26 and a ram or extension portion 27. Pivotal connections 28 and 29 are provided between the actuator drive portion 26 and the frame reaction member 25, and between the ram extension portion 27 and the support portion actuator driven member 23 respectively. Each of these pivotal connections is most conveniently defined by means of an outwardly extending lug portion provided on the relevant transverse member 23 or 25 to which the appropriate ram portion 26 or 27 is pivotally connected by means of a lug-embracing fork, the fork and lug being then pivotally coupled by means of a pivot pin.

The thigh-lifting feature provided by the invention is achieved by means of a thigh-lifting frame 31 having side members 32 and 33 interconnected by a transverse mattress underlying bar member 34. On the underside of each side member 32 and 33, a plurality of lugs 35 and 36 are provided, a succession of pivot pin receiving regions being defined between successive pairs of lugs along each side member, so that each side member has a plurality of pivot pin receiving locations. The thigh-lifting frame 31 is mounted on the frame of the bed 1 for pivoting displacement relative to the bed frame by engaging a selected pair of the regions defined between lugs 35 and 36 on pivot lugs 37 and .38, fixedly mounted on side members 2 and 3 of the bed frame and extending upwardly therefrom. This pivotal mounting is effected by engaging the selected pivot regions on the side members 32 and 33 over pivot pins 39 and 41 provided on the thigh-lifting pivot lugs 37 and 38.

Pivotal displacement of the thigh-1 ifting frame 31 is effected during pivoting of the main support portion 11 by means of extension members 42 and 43 extending forwardly from and parallel to the side members 12 and 13 of the support portion 11. These extension members 42 and 43 thus represent part continuations of the side members 12 and 13 in the direction of the foot of the bed, and leading or free end regions 44 and 45 respectively of the extension members 42 and 43 are arranged to overlie free end regions 46 and 47 of the thigh-lifting frame side members 32 and 33. Preferably the leading regions 44 and 45 of the extension members 42 and 43 are provided with engaging portions 48 and 49 so that when the support portion 11 is tilted or pivoted and the free ends 44 and 45 of extension members 42 and 43 bear down on the free end regions 46 and 47 of the thigh-lifting frame side members 32 and 33, the engaging portions 48 and 49 of the extension members 42 and 43 urge said free end regions 46 and 47 downwardly to thus cause the transverse mattress underlying bar 34 to pivot upwardly. During this pivoting action, sliding movement of engaging portions 48 and 49 along the side members 32 and 33 also takes place, as further described in a subsequent paragraph. Preferably, the engaging portions 48 and 49 are of rounded cross-sectional profile to facilitate the pivotally-urging engagement and sliding relative displacement of extension members 42 and 43 and thigh frame arms 32 and 33.

The only remaining feature of Figure 1 requiring to be mentioned is the mattress stop frame 51 positioned at the foot of the bed, to prevent endwise displacement of the mattress during tilting of support portion 11 and/or thigh-lifting frame 31.

Figure 2 shows the frame of the bed 1, with the support portion 11, the thigh-lifting frame 31 and the various operating mechanisms of the lifting device removed. Apart from those features already described in regard to Figure 1, Figure 2 shows the bores 52 and 53 in pivot lugs 18 and 19, within which the support portion pivot pins 21 and 22 are received. Also depicted in Figure 2 is the pivotal connection lug 54 for the pivotal connection 28 of actuator drive portion 26 to the bed frame transverse actuator reaction member 25.

Figure 3 is a pictorial view of support portion or lifting member or frame 11, and again, the only item requiring further reference is the lug 55 by which the pivotal connection 29 of actuator ram or extension portion 27 to the transverse actuator driven member 23 of the support portion 1 is effected.

Figure 4 is a pictorial view of the thigh-lifting frame showing in particular, the manner in which the side frame lugs 35 and 36 define various fulcrum points for placement of the thigh-1ifting frame on the pins 39 and 40 of the pivot lugs 37 and 38, so that the lifting height and endwise disposition of the mattress-underlying bar 34 may be readily varied selectively by the user.

Figure 5 shows the assembly of Figure 1 in side view in a dropped or inoperative disposition, and in the absence of a mattress base, mattress and bed head. The disposition of the engaging portions 48 and 49 of the leading regions 44 and 45 of support portion extension members 42 and 43, overlying the free end regions 46 and 47 of thigh-1 ifting frame side members 32 and 33, may be noted, as may the absence of any positive pivotal connection between these members.

Pivoting displacement of the thigh-lifting frame is effected solely by the bearing down action of the end regions 48 and 49 of the extension members 42 and 43, as now described in regard to Figure 6. In this manner, it is possible to readily reposition the thigh-lifting frame for pivoting displacement about different fulcrum points, i.e. thereby defining a different axis of pivoting of the thigh frame. This downward engagement of portions 48 and 49 takes place against the free end regions 46 and 47 of the side members 32 and 33 located on the opposite side of the fulcrum points or axis of pivoting from the transverse mattress underlying bar 34, so that when the free ends 46 and 47 are urged downwardly, the transverse bar 34 is displaced upwardly by the pivoting action of the thigh-lifting frame.

The pivoted disposition of the support portion 11 and thigh-lifting frame 31 is illustrated in Figure 6, where the actuator 34 is extended by displacement of the ram portion 37 from the drive part 36. Extension of ram 37 drives the lower ends of the pivot arms 16 and 17 towards the head of the bed, thereby pivoting the support portion 11 upwardly about the axis of pivoting of this frame defined by pivot pins 21 and 22, at the upper ends of pivot lugs 18 and 19. This upward pivoting displacement results in a corresponding downward pivoting displacement of the extension members 42 and 43, extending towards the foot of the bed from the axis of pivoting, the upwardly pivoting side members 12 and 13 of support portion 11 extending towards the head of the bed. During this downward pivoting displacement of extension members 42 and 43, their engaging portions 48 and 49 bear down on the free end regions 46 and 47 of thigh-lifting frame side members 32 and 33, so that the transverse mattress-underlying bar 34 is displaced upwardly, the extent of its upward displacement depending on the particular fulcrum points or pivot axis selected by placement of particular inter-lug spaces defined between lugs 35 and 36 of side members 32 and 33 over the pivot pins 39 and 41 of the thigh-lifting frame pivot lugs 37 and 38. The greater the spacing of transverse bar 34 from the pivot axis defined in this way, the greater the uplift achieved by pivoting displacement of thigh-lifting frame 31.

Figures 7 and 8 correspond to Figures 5 and 6, with the addition of a mattress 56, a mattress base 57 which lies on the base or frame of the bed 1, and a headboard 58 located at the upper end of the bed. Figure 7 requires little comment, but Figure 8 shows the configuration achieved by activation of the device of the invention.

An upper portion or region 59 of the mattress has been swung upwardly by the pivoting action of support portion 11, to maintain a patient lying on the bed in an approximately reclining sitting disposition. A central region of the mattress designated by reference 61 has also been lifted by displacement of transverse bar 34 to underlie the patient's thighs in the vicinity of the knees, and thereby to prevent the patient from sliding downwardly along the raised portion 59, in the direction of the foot of the bed. The comfort and convenience of the patient is thereby greatly facilitated by this feature of the lifting device and bed of the invention.

The use of an electrically driven actuator device is favoured for the system of the invention. The actuator may be controlled by a variety of means, for example, switches located at the head of the bed, or by means of a wander lead and control unit, which may be used by the patients themselves. The central location of the actuator device underneath the frame of the bed provides a neat and unobtrusive construction, and also results in a uniform pivoting or displacing force being applied to the support and thigh-lifting frame portions of the device.

However, such central placement is not an essential feature of the invention, and the pivoting force may also be applied to a single side member of the support portion or frame without any deleterious effect on its operational performance. Such an arrangement is shown in Figure 9, in which all of the features of the invention are unchanged as compared with the embodiment of Figures 1 to 8, save only the manner of pivotal drive. In place of a centrally located actuator disposed beneath the frame of the bed and acting between the transverse member of the support portion 11 and a transverse member of the frame of the bed itself, there is substituted a hydraulic drive mechanism in the form of a manually operated jack 62, mounted on a jack frame 63 secured to side member 3 of the bed frame and extending downwardly therefrom. The cylinder 64 of the hydraulic jack is mounted on frame 63 and ram 65 is extended by use of manual operating lever 66. The upper end of ram 65 is pivotally connected to side member 13 of support portion 11, this pivotal connection being indicated by reference 67.

Activation of the lifting device in this variant of the invention takes place in precisely similar manner to that already described, save only that the jack 62 is extended by manual action of lever arm 66. Thus the ram 65 is pumped up, and the necessary pivoting movement imparted to support portion 11. For this purpose, the cylinder 64 is also pivotally mounted on the jack frame 63. The support portion may be lowered by use of a bleed valve on the hydraulic device, and the maximum rate of bleed may be limited or restricted, to prevent over-rapid descent of the raised support portion. An electrically driven actuator may also be substituted for the jack 62 and arranged to drive the single side member 13 of support portion 11.

The electrically powered central actuator 24 of the embodiment of Figures 1 to δ may also be replaced by a hydraulic unit, if preferred. Thus manual or motor powered activation of the lifting device of the invention is available in either the embodiment of Figures 1 to 3 or in the variant described in regard to Figure 9.

An especially favoured embodiment of the invention will now be described having regard to Figures 10 to 20. The mechanical functioning of this favoured embodiment is essentially similar to that of the construction already described, but the embodiment of Figures 10 to 20 also facilitates packing, transport and storage of the bed of the invention by providing a flat pack arrangement.

As shown in Figures 10, 11 and 12, the invalid bed of the invention comprises a frame 101, a head lifting portion 111 and a leg lift mechanism 131. Referring first to Figure 10, the frame 101 is made from a single length of flat bar of suitable dimensions, typically 50 mm x 8 mm, which is precision bent to define the required shape and secured by a single weld. This bar-form main frame is supported from the floor by legs 102 attached to the bed frame structure by brackets 103. The longitudinal sides of the bar frame 101 are linked by transversal members 104, 105, 106 and 107. The front legs 102 of the bed are secured to the front transverse member 107, while the rear legs 102 are secured to the transversely extending side portion of the bar frame 101 at the rear or bed-head end of the bed. A bed board 108 is provided at this end of the structure, while at the front or opposite end of the bed, a mattress retainer 109 is hinged on the front transverse portion of the bar frame 101, so as to be capable of being folded down substantially flush with the upper surface of the bar frame itself in the folded or flat-pack configuration of the bed. Transverse member 106 carries an actuator bracket 125 and is reinforced against leg-supporting transverse member 107 by means of a short longitudinal member extending centrally of the bed, designated by reference 124 in the drawings. The interior space within the bar frame 101 is closed off by means of wire mesh 112, on which the mattress of the bed is supported. No bed base is used and the bed unit is of all steel construction. The mattress sits directly on the steel mesh, which is recessed slightly from the top of the main frame. The upper periphery of the main frame thus defines a circumferential wall defining a retaining well to hold the mattress securely in position.

Figure 11 shows the head lifting frame 111 of the bed of Figure 10. Frame 111 is again defined by a bent-around portion of flat steel bar, formed into a U-shape and welded at the ends of the Us ΙΠ to a transverse pivot member 114. The interior space within the bar frame of the lifting portion is closed off by wire mesh 112 to provide the mattress-supporting surface at the upper or head end of the bed. Pivot member 114 has end spigots 115, each of which is received in a respective pivot bearing 115 located on the inner side of the longitudinally extending portions of the bar-form main frame 101.

Thus frame 111 is mounted by means of the spigots 115 and the pivot bearings 116 within the bar frame 101 so as to be capable of pivoting between a first disposition in which it lies with its upper surface as defined by mesh 112 substantially flush with that defined within the bar frame by mesh 112 of the main frame and an upwardly pivoted disposition in which the head end of the mattress is raised. A pivotably mounted mattress retainer 113 is provided at the head end of the lifting frame, again to facilitate storage, packing and transport of the unit in its flat-pack disposition.

Pivot stops 117 on the sides of the U-shaped frame 111 limit downward pivoting of the frame beyond the flush disposition. Leg lift drive members 118 extend forwardly from the pivot member 114 and are rigidly affixed to the pivot member, essentially defining linear forward continuations of the side parts of frame 111. The co-operating interaction of these members with the leg lift arrangement will be described in regard to Figure 12, but it will be apparent from Figure 11 that when the head end of frame 111 pivots upwardly, the leg lift drive members 118 will swing downwardly, so that their abutment or camming end portions 119 may engage against corresponding portions of the leg lifting structure to drive the leg lift in a complementary pivoting movement. Drive of lifting frame 111 itself takes place by means of an actuator mechanism to be described, connected to an actuator bracket 121 on pivot member 114 by means of an actuator link · 122. The actuator bracket 121 incorporates a stop member 123 enabling link 122 to be freely moved in one direction of pivoting but to abut against the stop member and thereby drive lifting frame 111 in a pivoting motion when link 122 pivots in the opposite direction.

The leg lift mechanism and its manner of association with the lifting frame is shown in Figure 12. The mechanism 131 comprises first pivoting side members 132 which are fixedly secured to a pivot shaft 133. The lateral ends of pivot shaft 133 are supported in pivot bearings 134, again located on the inside surfaces of the longitudinal sides of frame 101, in similar manner to the lifting frame pivot bearings 116. The free ends of the side members 132 are engaged by the drive abutments 119 of the leg lift drive members 118 extending forwardly from lifting frame pivot member 114. Thus when frame 111 is pivoted upwardly, drive abutments 119 force side members 132 downwards, to pivot about shaft 133. Second lateral members 135 of the lifting frame structure are pivoted to first side members 132 between the pivot shaft 133 and the points of engagement of the drive abutment portions 119. The pivot points between the first members 132 and the second lateral members 135 are designated by references 136 in Figure 12.

Stop members 137 provided on first side members 132 limit relative pivoting of the side members 132 and 135 to one direction of pivoting only. The reason for this manner of interconnection will be explained having regard to subsequent Figures.

The non-pivoted ends of the side members 135 are bridged by a transverse bar 141, on which leg lift bar 138 is mounted by means of adjustable rods 139. Thus the spacing between the transverse bars 138 and 141 may be adjusted by relocating securing bolts by which the vertical members 139 are secured to the transverse bar 141 from a particular alignment hole to a different one. This feature enables the height of the leg supporting bar 138 which underlies the mattress in the same manner as previously described in regard to Figures 1 to 8 to be varied to give, for example, up to four lift positions or indeed for the bed to function without any leg lift displacement whatever.

The kinematic interaction of the lifting frame and leg lifting arrangements is shown in Figures 13, 14 and 15. Referring first to Figure 13, the lifting frame 111 is shown in a flat disposition, in which condition the weight of the leg lift bar 138 and the transverse bar 141 cause the leading or second side members 135 to be pivoted downwardly, so that the free ends of these members on the opposite side of pivot points 136 from the leg lift bar engage against the stops 137 which are integrally secured to the first side or lateral members 132. Thus side members 132 are also urged into an upward disposition in which their free ends engage against the abutment drive portions 119 of frame leg lift drive members 118. Actuator link 122 engages against actuator stop 123, which is fixedly associated with the head lifting frame 111, but no force is exercised by the actuator itself, designated by arrow 151.

In Figure 14, the lifting frame 111 has been pivoted to raise the head end of the bed by actuator 151 (arrow 151) being driven so that link 122 is forced against actuator stop 123 to thereby swing the frame 111 upwardly. Drive members 118 in turn pivot downwardly, so that their portions 119 force the free ends of side members 132 downwardly. The lift member stops 137 engage the free ends of the second pair of lateral members 135, so that these are effectively integral with side members 132 as they pivot downwardly. The relative dispositions of the inter-side member pivot points 136 with respect to the pivot shaft 133 for side members 132 is such that the downward pivoting swing of side members 132 causes the leading or lift bar ends 138 of the second side members 135 to be swung or displaced upwardly, and thereby to carry the leg lift bar 138 upwardly through a distance determined by the actuator movement. It will be immediately apparent that by adjusting the bolts securing bars 139 to transverse member 141, the actual final vertical disposition of the leg lift bar 138 relative to the upper surface of the main frame 101 of the bed may be varied.

It is a particular feature of the invention that the kinematic structure facilitates folding the entire mechanism into a substantially flat pack. This disposition is shown in Figure 15. The head frame 111 and the leg lift members 132 occupy the orientations shown - 16 previously for Figure 13. However, actuator link 122 has been swung forwardly away from engagement against actuator stop 123 and aligned substantially axially with the longitudinal direction of head frame 111. For this displacement, actuator 151 is disconnected from link 122. Similarly, the second side members 135 have been swung upwardly relative to the first side members 132 about the pivot points 136, so that again these side members extend generally coaxially with side members 132. When moved into this disposition, the ends of the second side members 135 which abut against the stops 137 of the first side members 132 are displaced from these stops 137. Thus in this disposition of the unit, side members 135 do not engage against the abutment stops 137. It will thus be seen that all of the various component members of the mechanism can be substantially brought into a single plane or envelope of relatively shallow depth.

Thus in a flat-pack configuration, the bed in its folded disposition will fit into a box approximately 100 mm deep. For accommodation in such a package for shipping purposes, the power unit or actuator 151 is separately boxed and shipped. The flat-pack arrangement is achieved by all of the parts of the bed being designed to hinge flat. Thus the two mattress retainers 109 and 113 hinge flat against the top of the lifting frame. The power lever or link 122 rotates to lie parallel with the main frame in the boxed configuration. The U-shaped structure defined by side members 135 and tranverse member 141 rotates away from stops 137 so that it lies flush against the main frame for packaging in a transport container. The lift bar 138 and its mounting tubes 139 are dismantled and packaged separately within the overall container for shipping purposes, but within the overall flat-pack dimensional envelope.

Figure 16 is a side view of the linkage between the lift frame and the leg lifting mechanism. The stops 137 are suitably defined by angle members welded to the first side members 132 of the leg lifting structure. The ability of the second side members 135 to be swung upwardly into line with the underside of the bed frame is also apparent, as is the inter-relationship between the drive abutments 119 and the first side members 132 which bring about the upward displacement of the leg lift bar 138 in use of the bed.

Figures 17 and 18 show operation of actuator 151 to effect lifting of head frame 111. It will be appreciated that in these Figures, as in Figure 16, components of the structure other than those under current discussion are omitted from the drawings, for clarity of representation. In Figure 17, the actuator is shown in a closed or retracted disposition, with actuator link 122 pivoted to some degree upwardly in the anti-clockwise direction. When actuator 151 is extended, as shown in Figure 18, link 122 is pivoted downwardly towards the head of the bed, to engage against stop 123 and thereby pivot frame 111 upwardly.

Figures 19 and 20 show further detail of the actuator link and the actuator bracket 121 in which it is pivotably mounted on the lifting frame 111. Bracket 121 is, as previously noted, rigidly affixed such as by welding to transverse lifting frame pivot member 114. The actuator stop 123 may be provided by a transverse welded-on bar or bar portion, indicated by reference 123, and, as shown, of circular cross-section, with the end of actuator link 122 which is received in bracket 121 being suitably profiled for engagement against this transverse member. Thus in the disposition shown in Figure 19, link 122 has been swung upwardly substantially into its flat-pack position substantially in line with the sides of frame 101, while in the active disposition of Figure 20, the snaped abutment end of link 122 has engaged against stop 123, so that continued movement in the clockwise direction, as shown in this Figure, will bring about a pivoting movement of frame 111.

The embodiment of Figures 10 to 20 offers a number of worthwhile advantages. Firstly, the unit is of all steel construction and no bed base is necessary. The mattress sits directly on the steel mesh, which is recessed slightly from the top of the main frame, for the front end of the bed. The surface defined by the mesh of the lifting frame, for the head end of the bed, is likewise recessed relative to the main bar frame. Thus a lip is provided and the structure functions as a retaining well to hold the mattress securely in position.

Secondly, manufacture of the main frame from the single length of flat bar bent and secured by a single weld provides a novel construction of considerable strength but relatively light weight.

The manner of interconnection of the members of the leg lifting structure enables the bed of the invention to be transformed into a flat-pack configuration of relatively shallow depth, in conjunction with the bar frame. So far as the actuator link is concerned, the flat-pack configuration is achieved by swinging the link into the general plane of the bar frame. For transport of the unit, the actuator itself is disconnected but may be readily placed in position and pivotably connected to the remainder of the structure at the point of use by a simple bolt arrangement.

The one-way pivoting feature of the actuator link provided by its mounting for abutment against a stop to undertake a driving or pivoting operation also provides a useful safety feature. Thus the head lifting frame is pivoted upwardly under power, but is lowered under gravity. There is no positive downward driving of the head frame of the bed. Accordingly if the head frame encounters an obstruction, such as for example a limb caught between the lifting frame and the main frame of the bed, downward displacement of the lifting frame will cease. There is no positive force exercised against the blocking object or member. Accordingly, while bruising or pinching may be suffered by someone whose arm or hand is caught in this manner, the actual crushing action which may result where positive drive is in question is obviated by the present invention in this - 19 embodiment by virtue of the one-way hinging of the power lever or actuator link so far as driving action is concerned.

In any of the arrangements described, the sides of the bed may be sheathed or screened to close off the working parts from access and view. The bed and device of the invention may also be fitted or associated with other features, such as, for example, a pivotallymounted table or tray, for use by the patient as required, but easily displaceable into an inoperative or storage disposition.

The invention may be provided in a variety of different forms. In first instance, an integrated unit consisting of a bed equipped with a lifting device incorporating the principles of the invention may be provided in its entirety. The lifting device may alternatively be fitted to or mounted on an existing bed, the bed being modified as required to accommodate the central actuator unit. The lifting device may also be supplied as a kit of parts incorporating the support portion and thigh-lifting arrangement described in regard to the drawings, together with the actuator unit, whether for central location or side mounting, as well as whatever additional members require securing to the bed to cooperate with the lifting system. The invention thus provides a comprehensive array of possibilities for easing the lot of invalid or bed-ridden patients, whether in the domestic environment, in nursing homes or in hospitals, at relatively modest cost compared with traditional hospital beds.

Claims (11)

1. A bed comprising a lifting device having a support portion for underlying a portion of the mattress of the bed, said support portion being pivotable relative to a base portion of the bed, means for effecting pivotal displacement of said support portion relative to said base portion, and a further lifting portion in the form of a thigh or leg-lifting portion, said leg-lifting portion comprising a lifting member for underlying a further portion of the mattress of the bed and side members associatable with said lifting member, said side members being mounted on the base portion of the bed for pivotal displacement relative to said base portion and being operatively associated with said support portion so that pivoting movement of said leg-lifting portion is effected by pivoting displacement of said support portion, said support portion comprising camming portions for camming engagement against said side members of the lifting portion during pivoting displacement of the support portion.

2. A bed according to Claim 1, wherein said lifting member of the leg-lifting portion is demountably and adjustably associated with said side members.

3. A bed according to Claim 1 or Claim 2, wherein each said side member comprises first and second side member portions, said side member portions being pivotally linked together, and stops being provided to limit relative rotation of said first and second side member portions in a first direction of relative rotation thereof.

4. A bed according to any preceding claim, wherein said means for effecting pivotal displacement of said support portion comprises a member abuttingly engageable against an abutment portion of said support portion for upward pivotal displacement of the support portion.

5. A bed according to Claim 4, wherein said means for effecting pivotal displacement of said support portion includes an expansible actuator, disposed between the base portion of the bed and said support portion. 5

6. A bed according to Claim 5, wherein said abuttingly engageable member is a link pivotally connected at one end to said support portion and pivotally connected at its other end to said actuator.

7. A bed according to Claim 6, wherein said abutment portion of 10 said support portion is defined by a stop member and said link has an abutment portion for engagement against said stop member of said support portion for effecting said upward pivotal displacement.

8. A bed according to Claim 7, wherein said link is pivotally displaceable into a disposition in which said abutment portion of the 15 link is spaced from said abutment portion of the support portion.

9. A bed according to any preceding claim, wherein said base portion is at least in part defined by a shaped single length of substantially flat metal bar.

10. A bed substantially as described herein with reference to 20 and as shown in Figures 1 to 8 of the accompanying drawings, or these Figures as modified by Figure 9.

11. A bed substantially as described herein with reference to and as shown in Figures 10 to 20 of the accompanying drawings.