IES62531B2 - "Lifting beds" - Google Patents

Abstract

In a lifting bed (1), a base frame (2) supports the bed frame (6) by way of a sub-frame (5). A parallel linkage mechanism (7, 8, 9) driven by a power unit enables the spacing between the base frame (2) and the bed frame (6) to be varied so that the bed frame (6) may be located at any desired spacing above the floor (4) carrying the base frame (2), within predetermined limits. In order to provide a tilt feature, the bed frame (6) is pivoted (15) on the sub-frame (5) and two tilt legs (11) are pivotably mounted (17) on the base frame (2) for interposition between a portion of the bed frame (6) and an abutment defined by the upper surface of the base frame (2), so that when the sub-frame (5) is lowered relative to the base frame (2), the bed frame (6) is tilted by virtue of a fixed spacing being maintained between the portion of the bed frame engaged by the roller-equipped uper end (13) of the tilt arms (11) and the base frame (2).

Description

LIFTING BEDS11 This invention relates to lifting and hospital beds. The invention is especially directed to providing a tilting facility for a lifting bed or a portion of a lifting bed and to lifting or hospital beds comprising a feature for tilting the entire bed or a portion of the bed.

Tilting arrangements and devices at present provided on lifting beds or hospital beds are typically manual and require a physical lifting operation by the user to be brought into effect. In addition, many such arrangements provide only a limited number of incremental or step locations, so that only a limited number of angles of tilt are available. It is a particular objective of the invention to provide an arrangement enabling a power tilting feature to be provided on a power-operated high/low lifting bed, whether hvdraulicallv or electrically operated, and it is a further particular objective of the invention to provide such an arrangement in which an infinitely variable tilt angle is possible within predefined limits or a prescribed range. - 2 According to the invention, there is provided a lifting bed comprising a base frame, a bed frame for supporting a mattress, and means for varying the spacing between the base frame and the bed frame so that the bed frame may be located at any desired spacing above a floor carrying the base frame within a predetermined range of height adjustment, wherein strut means are provided for interposition between a portion of the bed frame and an abutment region, so that a desired fixed spacing may be maintained between said portion of the bed frame and said abutment region when the spacing between the reminder of the bed frame and the base frame is reduced.

In a first and favoured embodiment of the invention, said abutment region is defined by one or more stop portions of the base frame» Said strut means is suitably then pivotably mounted on the base frame. In an especially preferred arrangement, said bed frame is supported on a sub-frame for pivotal movement of the bed frame relative to the sub-frame, and said means for varying the spacing between the base frame and the bed frame is operative between the bed frame and the sub-frame for height adjustment of the bed frame, said strut means comprising two tilt legs having free ends for engagement against undersurfaces of said bed frame, and the other ends of said tilt legs being interconnected for pivotal movement in unison of said tilt legs about a common axis of pivoting. Said tilt legs are then preferably cranked in the vicinity of said common axis of pivoting for engagement of the cranked regions of said tilt legs against said stop portions.

In an alternative adaptation of the invention, said abutment region is defined by an end portion of the strut means engaging a floor carrying the base frame. Placement of the strut means between a portion of the bed frame and the floor engaged by the abutment region end portion of the strut means enables the bed to be tilted by then lowering the bed frame until the weight of said portion of the bed frame is taken up by the strut means rather than carried by the base frame. In a favoured configuration of the invention, a separate said strut means is provided at each end of the bed frame, so that either the head or the foot of - 3 the bed may be selectively tilted by engagement of the appropriate one of said strut means between the bed frame and the floor. Suitably, the or each said strut means comprises a tilt frame pivoted to the bed frame and displaceable between an operative disposition in which lower ends of tilt frame members engage the floor and an inoperative disposition in which said members of the frame means extend substantially parallel to the longitudinal plane of the bed frame.

Stop members associated with the bed frame set predetermined limits of rotation of each tilt frame, thereby prescribing its pivoted orientation in each of said operative and inoperative dispositions.

An especially favoured configuration of the tilt frame provides a structure in the form of an inverted U, having two strut members defining leg portions connected together at their upper or pivot axis ends by means of a transverse tube or bar to form an integral construction, so that both strut members pivot simultaneously during pivoting displacement of the tilt frame. The strut means or tilt frame structure is preferably mounted so that the strut members are aligned with the longitudinal side edges of the bed frame in the inoperative disposition of the tilt frame.

In a further adaptation of the invention, the abutment region is defined by an end portion of the strut means engaging the base frame, and the tilt frame structure is then pivotably mounted on a back rest portion of the bed frame. In its operative disposition, the tilt frame then extends between its pivot axis attachment to the back rest of the bed frame and an end region of the base frame, so that when the bed frame is lowered, the back rest is automatically lifted in a simple mechanical manner.

The invention provides a simple mechanical structure by virtue of which any suitably equipped lifting bed may be automatically tilted at either its head or its foot. No drive mechanism whatever is involved, and the tilting movement takes place by use of the mechanism provided for varying the height of the bed. A further adaptation of the invention provides for automatically raising the backrest of any lifting bed. - 4 The arrangement of the invention can be fitted to any lifting bed, whether powered by hydraulics, electricity or a mechanical arrangement. In a still further variant, both adaptations of the invention may be present in a single bed structure.

The invention also extends to a lifting bed substantially as described herein with reference to and as shown in any one or more of the accompanying drawings.

The invention will now be described having regard to the accompanying drawings, in which: Figure 1 is a schematic side view of a power-operated high/low lift bed, the power unit having been omitted for reasons of clarity both in the present drawing and from subsequent Figures 2 to 10 which depict a first embodiment of the invention, Figure 2 is a schematic side view of the lifting bed of Figure 1, as provided with a tilt feature according to the invention in a first embodiment, Figure 3 is a partially diagrammatic pictorial representation of the arrangement of Figure 2 from beneath, Figure 4 shows the bed of Figures 2 and 3 when raised to its maximum height, preparatory to the bringing into operation of the tilt feature, Figure 5 shows the bed of Figures 2 and 3 in the disposition of Figure 4, but with the tilt legs raised to their operative disposition, Figure 6 shows the bed of Figures 2 and 3 at the commencement of tilting, Figure 7 shows the bed of Figures 2 and 3 in a maximum foot-up tilt disposition, - 5 Figure 8 is a partially diagrammatic pictorial representation of the bed of the invention in its first embodiment in the disposition of Figure 7 with certain technical features omitted for clarity of understanding of the principles of the invention, Figure 9 shows the bed of the first embodiment of the invention in its maximum head-up tilted disposition, Figure 10 is a schematic pictorial representation from beneath of an alternative embodiment of lifting bed comprising the invention, Figure 11 is a schematic side view of the lifting bed of Figure 10 in the raised position, Figure 12 shows the head end tilt frame of Figures 10 and 11 in a downward disposition, preparatory to a tilting operation, Figure 13 shows the bed of Figures 10 to 12 in a head end raised, tilted disposition, Figure 14 shows the bed of Figures 10 to 12 prepared for foot end tilting, Figure 15 shows the bed of Figures 10 to 12 in a foot end raised, tilted disposition, Figure 15 is a schematic pictorial representation from beneath of a back rest tilting adaptation of the invention, Figure 17 shows the bed of Figure 15 in a raised disposition, Figure 18 shows the back lift tilt frame in a pivoted or operative disposition, preparatory to a tilting operation, and Figure 19 shows the bed in a disposition in which the back rest has been tilted. - 6 Adverting to Figure 1, there is shown in schematic side view, a high/low lift bed 1 suitable for adaptation in accordance with the principles of the present invention. The lifting bed 1 has the following main features: A lift module or base frame 2, suitably wheel or caster 3 mounted for ease of displacement over a support surface 4; a sub-frame 5 underlying a main bed frame 6, the bed frame 5 itself,: and lifting arms 7 defining a parallel linkage lifting mechanism by which the sub-frame 5 and therefore also the bed frame 6 are supported on and spaced from the lift module or base frame 2. The pivoting members or arms 7 of the parallel linkage structure extend between the upper ends of upstanding pillars 8 extending in a substantially vertical upward direction from the top of the lift module or base frame 3 and the lower extremities of corresponding downwardly extending pillars 9, directed substantially vertically downwards from the underside of the sub-frame 5.

One end of each arm 7 is thus pivoted at the upper end of an upstanding pillar 8 and the other end of each arm is likewise pivoted at the lower end of the respective corresponding downward pillar 9. The operation of the parallel linkage mechanism is in accordance with conventional principles and it is driven by a power unit, which is omitted from the present drawing and and also from all other diagrams in the interests of clarity of the remainder of the features of the invention.

Lift module 2 and sub-frame 5 are suitably of an open framework construction having, as shown in Figure 2, side frame members linked by transverse end frame members, and optionally provided also with further cross-bearing as required. The availability however of an open and unobstructed central region is advantageous in putting the present invention into effect.

Figures 2 and 3 show the bed of Figure 1 together with the particular feature provided by the invention, namely two tilt legs 11 together defining a tilt feature. Of the two legs 11 of the tilt feature, one - 7 is located at one side of the bed 1 and the other is located at the other side of the bed 1. Each leg 11 is of cranked configuration, having a short cranked portion 12 extending generally at right angles to the longitudinal direction of the major portion of the leg 11. At the end of the cranked portion 12, the leg 11 is pivoted on the lift module/base frame 2 about a transverse axis which is generally horizontal in the normal disposition of use of the bed 1. At the other or free end of each leg 11, a roller 13 is fitted. The legs 11 on each side of the bed 1 are joined together by a transverse member or tie-bar 14 to form a unitary tilt structure or feature, so that the two legs 11 move in unison. In other words, when the tilt leg or structure 11 on one side of the bed 1 is pivoted upwardly about its pivot axis, the tilt leg 11 on the other side of the bed 1 moves in precisely the same manner through the same angular extent by virtue of the two legs being solidly connected by tube or tie-bar 14. As shown in Figure 2, the legs 11 are in their normal rest disposition and their major or straight sections or portions occupy a substantially horizontal or flat location extending along and in the longitudinal direction of the lift module frame 2, substantially parallel to the longitudinal direction of this structure.

A further feature of the invention is that the bed frame δ is pivoted to the sub-frame 5, suitably at the head end, as shown in Figure 2.

Thus the bed frame 6 is free to pivot in a feet end up manner about the pivot axis 15 between the sub-frame 5 and the bed frame 6, as may be required. Side guides, not shown, are suitably provided to prevent twisting of the bed frame 6 relative to the sub-frame 5. In addition, a stop feature, again not shown but of a suitable conventional construction, is also provided to limit the maximum tilt of the bed frame δ relative to the sub-frame 5.

All of these features of Figure 2 are also shown in the pictorial representation of Figure 3, which also shows more clearly certain of the features of the invention noted above, not fully apparent in Figure 2. In particular, a stop arrangement 16 for the tilt legs is shown, - 8 in the form of abutment portions against which the cranked regions 12 of the tilt legs 11 come into engagement when the tilt legs are pivoted into their operative disposition. The actual functioning of the invention and how tilt of the bed frame is effected will now be described having regard to Figures 4 to 9 inclusive, from which the roles of the various technical features already identified will become apparent.

Referring now to Figure 4, the bed 1 is shown raised to its maximum height. The tilt legs 11 remain however in their generally horizontal position, from which they cannot be raised into the vertical or operative position until this maximum height disposition of the sub-frame 5 and bed frame 6 is achieved. In Figure 5, the bed is again shown at maximum height, as in Figure 4, but the tilt legs 11 have now been swung or lifted into their vertical position. The cranked pivot end structure 12 of the tilt legs Π ensures that when they are swung into this disposition, they are in a stable configuration such as by their abutting against the stop members 15, or by some other like arrangement. In an alternative abutment structure, the cranked portions 12 may come to rest on top of the side frame members of lift module 2, as illustrated in a later Figure. In their vertical disposition, the longitudinal axis of the major portion of the tilt arms 11 extends substantially vertically but is offset from the axis 17 of pivoting for the tilt arms to the extent of the length of the crank arms 12. Thus an overcentre pivoting arrangement is achieved during the motion of the tilt arm 11 from its horizontal or inoperative disposition into its vertical or operative orientation.

In their operating disposition, legs 11 and tie-member 14 essentially define an upwardly opening U.

Tilt is now achieved by lowering the bed. As the sub-frame 5 and bed frame 6 are lowered by reversing the action of the power unit so that the upward movement of the parallel linkage mechanism is reversed and controlled lowering takes place under gravity, the wheels or rollers 13 at the tops or upper ends of the tilt legs 11 engage on two flat tracks (not illustrated) secured to the underside of each side of the bed - 9 frame 6. Since the bed frame is pivoted 15 at the head or front end to the sub-frame 5, it is free to lift at the back or foot end 19.

Thus the bed 1 commences to tilt, as shown in Figure 6, into a feet up disposition, accordingly as the bed frame 5 is lowered. The rollers 13 at the upper ends of the tilt legs 11 ensure a friction-free movement of bed frame 6 relative to the tilt legs 11 according as the lowering action is continued.

Figure 7 shows in schematic side view, maximum tilt in the lowermost position of the lifting bed 1 incorporating the invention. Figure 8 is a matching pictorial representation of the bed in the configuration of Figure 7. In Figure 8, the parallel linkage is omitted in the interests of ease of understanding. In addition, a modified cranked end arrangement 12 is shown for the tilt legs 11, in which the cranked portions 12 rest on the tops of side frame members 21 of lift module 2, this arrangement providing the abutment feature defining the over-centre stable operative disposition of the tilt legs which is defined in Figure 3 by the stops 15.

A maximum head-up tilt disposition is shown in Figure 9. This may readily be achieved by transferring the headboard 22 from the head end 18 to the foot end 19 of the bed 1. In other words, a reversible construction can be provided. However, head-up tilt, in particular to such significant extent as shown in Figure 9, is not a common treatment requirement compared to the feet-up situation. Some 90% of use of the bed of the invention involves feet up end tilt.

The arrangement of the invention enables bed tilt up to about 17°.

Infinite adjustability is also available. Effectively there is power tilt, because the controlled lowering of the bed 1 is used to effect the tilting action in conjunction with the tilt arms 11. In known beds, foot-up tilt usually applies only up to about 12° maximum, and also typically only in predetermined increments, while maximum head-up tilt may be limited to 5°. The arrangement of the invention provides a significantly greater extent of pivoting. The controlled upward power drive and the controlled lowering of the bed of the - 10 invention provides a significant safety advantage.

Adverting now to Figure 10, there is shown in a schematic pictorial view from below, an alternative embodiment of lifting bed 101 incorporating the features of the invention. The lifting bed 101 has a base frame 102 and a bed frame 103 supported on and spaced from the base frame 102 by means of a parallel linkage lifting mechanism 104, having pivoting members extending between transverse bed frame members 105 and portions of the base frame 102.

The particular features provided by the invention in this variant are head and foot tilt frames 111 and 121 respectively. Each tilt frame, 111, 121 has leg or strut members 112 interconnected by means of an upper end cross member 113 of box or tubular construction. The legs 112 and the cross member 113 are welded or otherwise fixedly connected together to define an integral structure of substantially inverted U-shaped configuration. The tilt frame 111 or 121 is pivotally mounted on the underside of the bed frame 103 about a pivot axis 114, substantially coincident with transverse tube or cross-member 113.

Thus, as shown in the drawing, this pivot axis corresponds to the axis of the cross member 113. Each tilt frame 111, 121 is arranged so that it can be pivoted into a disposition in which the legs 112 extend parallel to and in juxtaposition against the longitudinal side members of the bed frame, as illustrated for frame 121, in which disposition the tilt frame is in an inoperative configuration or condition. The operative or downwardly pivoted disposition of the tilt frames is shown for tilt frame 111 in the schematic representation of Figure 10. In this disposition, the legs 112 extend substantially vertically downwards to fulfill a supporting function in a manner to be described. Optional brace members 115 may be provided to extend between the lower end regions of the legs 112 and the cross member 113 to rigidify and strengthen the structure in known triangular manner.

The functioning of the tilt frame 111 or 121 of the invention will now be described having regard to further Figures of the drawings. Figure 11 is a schematic side view showing the lifting bed frame 103 in a - 11 raised disposition, with the head and foot tilt frames 111 and 121 pivoted about their respective axes 114 into their upward or inoperative dispositions. As already described, each tilt frame 111 or 121 has two legs, 112, one at either side of the bed frame, these being joined together by a respective cross member 113 in each tilt frame structure.

Referring now to Figure 12, the head end tilt frame 111 is shown with the legs 112 pivoted down so that their lower ends engage the ground in an abutting manner. The legs 112 of the frame 111 are swung past the centre or vertical position to reach an end stop preventing further rotation. Thus in the operative condition of a tilt frame 111, 121, the frame 111, 121 is pivoted downwardly away from the bed frame 103 through and past 90°, until the legs 112 come into abutment against a stop on the bed frame 103 and the upper ends of the legs 112 are in an over-centre arrangement relative to the locations of the lower or free ends of the legs 12.

Figure 13 then shows the effect of lowering the bed, i.e. reducing the spacing between the bed frame 103 and the base frame 102. As the bed frame 103 is lowered, the bed tilts towards the foot by virtue of the free ends or feet of the legs 112 coming into abutment against or into engagement with the ground or other support surface and taking the weight of the head end of the bed. The lower the bed is dropped, the greater the angle of tilt. Lowering of the bed can be stopped in any position, so that any desired angle of tilt may be achieved. While the tilting frame in question is that located at the head end, the effective use of the head end tilt frame is to effect a foot down tilt of the bed, i.e. in other words, a head end raised configuration.

The bed may be returned to normal operation by lifting it into the raised position, so as to release the head end tilt frame 112 from engagement against the floor, following which it can be pivoted back to the horizontal disposition underlying the bed frame 103 and locked in its raised or inoperative disposition. - 12 Thus the tilt frames 111, 121 provide a simple mechanical structure enabling tilting of a lifting bed by merely swinging the pivotable tilt frame into its over-centre tilt position or operative configuration, in which it is restrained against further rotation by abutment against a stop on the bed frame, and then adjusting the height of the bed until the lower ends of tilt frame strut members engage the floor and take up part of the weight of the bed. Continued lowering of the bed then effects the required tilting action as the opposite end of the bed, i.e. that not supported by a tilt frame, is lowered relative to the end that is supported by the tilt frame.

Figures 14 and 15 show operation of the foot end tilt frame 121 to achieve head down tilt. Precisely the same sequence of operations as already described for Figures 12 and 13 is carried through, save only that tilt frame 121 is used. The result is precisely that previously achieved, differing only in that a head down tilt is achieved, i.e. the foot end of the bed is raised.

Referring now to Figure 16, a further adaptation of the invention to effect the raising of the back rest of a lifting bed is illustrated in partial schematic pictorial view, again from below. In this instance, the bed frame carries a back rest 106, pivoted to the bed frame about an axis 107. The back rest 106 carries a tilt frame 131 which is of essentially identical construction to those already described, but may have different dimensions, especially in respect of leg length, to achieve the required alternative abutment arrangement necessary for back rest tilting. Figure 17 is a side view of a tilting bed incorporating the features of Figure 16 in a raised disposition. The tilt frame 131 is pivoted about axis 134 to the back rest 106, and the lower ends of the legs 132 can in this instance be dropped down to lock onto the lifting module or base frame 102 of the lifting bed.

Figure 18 shows this pivoted down disposition of the back rest tilt frame 131. Again, stops are provided so that the tilt frame 131 may be pivoted through an angle somewhat in excess of 90° into an over - 13 centre position, but further rotation is prevented so that the tilt frame 131 becomes blocked against further pivoting displacement following this 90°+ rotation. In this variant of the invention, the lower ends of the legs of the tilted frame abut against portions of the base frame or lifting module 102, and, as shown in Figure 19, by lowering the bed frame 103, in this case the back rest is tiltingly raised rather than the bed frame itself, as would be achieved by the tilt frame 111 or 121. The lower the bed frame is dropped, the greater the angle of upwards tilt of the back rest 106. Again, the bed may be returned to normal operation by lifting the bed frame 103 into the raised disposition, thereby enabling release from tilting abutment of the back rest tilt frame 131 and allowing it to be pivoted back to the horizontal and locked in its inoperative disposition in substantial alignment with longitudinal side edges of the back rest 106 and/or the bed frame 103.

Although not illustrated in the present drawings, a similar tilting feature may also be provided for a leg lift portion incorporated in a bed frame. In this case, the tilt frame is pivoted to a further pivoting section of the bed frame located towards the foot end of the bed. The structure in question is essentially identical in both concept and detail to that alradv explained in regard to back rest tilting.

In each case, the tilt frame of inverted U shape pivots as a single integral unit, so that if the leg to one side of the bed is swung downwards manually, the integral connection to the other leg by means of the transverse tube ensures that this second leg also pivots simultaneously. The configuration and the structure of most lifting beds is such that this U shaped tilt frame can readily be accommodated or retro-fitted to existing beds without fouling any operative portion of the lifting bed structure. A lifting bed may be provided with head end and foot end tilt frames, and in addition, where the lifting bed incorporates a back rest or foot lift portion, separate tilt frames may be provided for these features, as per Figures 16 to 19, in addition to - 14 the tilt frames 111 and 121. Back rest and foot lift tilting may be provided in combination with the main tilt frames 111 and 121, so that a bed fitted with the features of the invention in their most comprehensive implementation may provide four tilting options. In addition, the features of certain aspects of the invention in its second embodiment, e.g. in respect of backrest or footrest tilting, may also be associated with the first embodiment also.

The invention provides a versatile and flexible structure in which tilting of a lifting bed may be achieved in a simple non-mechanised manner by making use of supporting strut-form members, pivotally mounted on the bed structure, and brought into play in a tiIting-effecting manner by means of use of the normal lifting mechanisms of the bed. The invention thereby provides an economical and advantageous adaptation of existing lifting bed structures resulting in a variety of useful additional features at relatively low cost.

Claims (5)

1. A lifting bed comprising a base frame, a bed frame for supporting a mattress, and means for varying the spacing between the base frame and the bed frame so that the bed frame may be located at any desired spacing above a floor carrying the base frame within a predetermined range of height adjustment, wherein strut means are provided for interposition between a portion of the bed frame and an abutment region, so that a desired fixed spacing may be maintained between said portion of the bed frame and said abutment region when the spacing between the bed frame and the base frame is reduced.

2. A lifting bed according to Claim 1, wherein said abutment region is defined by one or more stop portions of the base frame.

3. A lifting bed according to Claim 2, wherein said bed frame is supported on a sub-frame for pivotal movement of the bed frame relative to the sub-frame, and said means for varying the spacing between the base frame and the bed frame is operative between the bed frame and the sub-frame for height adjustment of the bed frame, said strut means being pivotably mounted on the base frame and comprising two tilt legs having free ends for engagement against undersurfaces of said bed frame, and the other ends of said tilt legs being interconnected for pivotal movement in unison of said tilt legs about a common axis of pivoting.

4. A lifting bed according to Claim 1, wherein said abutment region is defined by an end portion of the strut means engaging a floor carrying the base frame.

5. A lifting bed substantially as described herein with reference to and as shown in any one or more of the accompanying drawings.