A BED

BACKGROUND OF THE INVENTION

THIS INVENTION relates to a bed. It relates, more particularly, to a bed which can be used in inter alia hospitals and care facilities.

In order to prevent bed sores, caused by a lack of blood circulation, from developing on a bed-ridden person, the person's position must be regularly changed to relieve pressure points and to ensure proper blood circulation. This may be a laborious and time-consuming exercise.

Failure to provide adequate movement or massaging to the person results in the development of bed sores which, in extreme cases, could be fatal.

The invention provides a bed aimed at minimizing the risk of bed sores developing on a person lying on the bed.

SUMMARY OF THE INVENTION

According to the invention there is provided a bed including a frame including a base for supporting a mattress; at least one mattress lifter body mounted on the frame via mounting means that provides for displacement of the body along a path which extends along at least a part of the length of the base and along which the lifter body stands proud of the base across at least a part of the width of the base; and displacement means for displacing the mattress lifter body along the path.

In use of the bed, a matching mattress is supported on the base and a person is recumbent on the mattress. The displacement means is operated to displace the mattress lifter body slowly and cyclically along the path, causing it to deform the

mattress. The action of the mattress lifter body on the mattress has an indirect massaging effect on the body of the person, typically to the posterior or lateral surface of the person's body, as it slowly moves up and down the length of the person's body. This means that not only will the person be moved to several positions during the cycles of movement but there will be continuous stimulation of blood flow and lymph fluid flow in the person. The Applicant believes that the dual action of movement and massaging of a person's body will significantly reduce the risk of bedsores developing on the person.

An upper contour of the mattress lifter body may be sloped in the transverse direction of the bed so that it defines an apex on a side of the bed.

The path may be straight.

The mounting means may include at least one longitudinal rail for guiding displacement of the mattress lifter body along the path. The at least one longitudinal rail may include two such rails on opposite sides of the bed.

The displacement means may include a drive unit including at least one longitudinal, rotatable, screw threaded actuation rod; a screw threaded part which is engaged with the shaft to be displaced along the rod through rotation of the rod and which acts on the mattress lifter body; and drive means for rotating the rod.

Alternatively, the displacement means may include at least one pneumatic drive unit. In a particular embodiment of a bed of this kind, the following may apply: the at least one pneumatic drive unit includes two such units on opposite sides of the bed, each including an elongate body extending along the base and defining along its length an inside cylinder and an outside rail; a piston in the cylinder; and a slider slidingly engaged with the rail and connected to the piston; and

the mattress lifter body is engaged with the sliders to be displaced along with them along the rails.

The displacement means may include a microprocessor for controlling its operation.

The mattress lifter body may be a roller assembly including at least one roller that is rotatable about a rotational axis of the assembly, the axis being transverse to the base. The roller assembly may have a rest position at an end of the base, the path extending from the rest position towards the opposite end of the base. In this case, the path may extend along substantially the entire length of the base.

The roller assembly, where provided, may include a shaft and the at least one roller may be a series of spaced apart disc-like rollers on the shaft. The disc-like rollers may be rotatable relative to the shaft. The series of disc-like rollers may define a generally conical or frusto-conical shape, an upper contour of the roller arrangement sloping in the transverse direction of the base and defining an apex on a side of the base.

In a particular embodiment of the bed of the invention including a series of disc-like rollers, as defined above, the following may apply: the base includes a series of spaced apart longitudinal beams, defining slots between them; the shaft of the roller assembly is mounted on the frame via the mounting means, the shaft being disposed transversely and below the longitudinal beams; and the rollers are partially received in the respective slots with a part of each roller standing proud of the base.

The bed may include a mattress on the base. As such, in the case of the lifter body being a roller assembly, as defined above, the mattress may define therein a receiving recess wherein a part of the roller assembly standing proud of the base is accommodated when the roller assembly is in a rest position thereof.

In the case of the lifter body being a roller assembly, as defined above, the bed may include elevation adjustment means for adjusting the elevation of the path of the roller assembly relative to the base.

In a particular embodiment of the bed of the invention, including two pneumatic drive units, a roller assembly having a shaft and rollers, and elevation adjustment means, all as defined above, the following may apply: the shaft of the roller assembly is mounted on the sliders of the pneumatic displacement units; and the elevation adjustment means acts on the pneumatic displacement units to adjust their elevation relative to the base.

The at least one mattress lifter body may be one of a pair of such bodies, one of which is mounted ahead of the other on the frame and each of which displaceable along a path extending along a part of the length of the base. In this case, one or more of the following may apply:

The displacement means may include a microprocessor for controlling its operation, the microprocessor being programmable for displacing the mattress lifter bodies independently, clearly only insofar as their displacement can be independent within the physical constraints of the bed.

The displacement means may include a microprocessor for controlling its operation, the microprocessor being programmable for displacing the mattress lifter bodies into a closely spaced configuration and then to displace them in unison along the base.

The mattress lifter bodies may have respective rest positions on opposite ends of the base.

Upper contours of the mattress lifter bodies may be sloped in opposite transverse directions of the bed so that they define respective apexes on opposite sides of the bed. The pair of mattress lifter bodies may be a pair of roller assemblies, each assembly including a transverse shaft and a series of spaced apart disc-like rollers on the shaft.

The bed may include at least one vibration actuator for operatively inducing vibration in the mattress lifter body.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further described by way of examples with reference to the accompanying diagrammatic drawings in which:

Figure 1 is a perspective view of a first embodiment of a bed, in accordance with the invention;

Figure 2 is a perspective view of the bed of Figure 1 with certain components shown in dotted outline;

Figure 3 is an enlarged, perspective view of a foot end portion of the bed of Figure 1 ; Figure 4 is a perspective view of the underside of a mattress of the bed of

Figure 1 ;

Figures 5 to 8 are plan illustrations of possible operative displacement of rollers of the bed of Figure 1 ;

Figure 9 is a perspective view of a second embodiment of a bed, in accordance with the invention;

Figure 10 and 1 1 are schematic elevations of certain components of the bed of Figure 9, including a pneumatic drive unit, in different operative states; and Figure 12 shows an optional vibration actuator for the bed of Figure 9.

DESCRIPTION OF PREFERRED EMBODIMENTS

In Figures 1 to 3, a hospital bed, in accordance with the invention, is designated generally by the reference numeral 10. The bed 10 includes an elongate metal frame 12 including an elongate metal base 14, the base having a length L; two mattress lifter bodies in the form of a first roller assembly 16 and a second roller assembly 18 ahead of the first; and

displacement means which includes first and second drive units 20 and 22, respectively, that are attached to the frame 12; first actuation rods 24A and 24B which act between the first drive unit 12 and the first roller assembly 16; and second actuation rods 26A and 26B which act between the second drive unit 22 and the second roller assembly 18.

Each of the first and second roller assemblies 16 and 18 is movably engaged with mounting means in the form of opposite straight rails (those on one side of the bed being designated by the reference numeral 23 in Figure 3) defined by the frame 12 and is displaceable along a straight path extending along substantially the entire length L of the base 14, as will be described in more detail below.

The frame 12 has four supporting legs 28A, 28B, 28C, and 28D and extends from a head end 30 to a foot end 32.

The base 14 has a series of transversely spaced longitudinal elongate supports or beams 34 which extend the length L from the head end 30 to the foot end

32. A slot 36 which extends the length L is defined between each two adjacent beams 34. A mattress 38, which is illustrated in Figure 1 and only shown in dotted outline in

Figure 2, is located on the base 14 and is surrounded by elements of the frame 12.

The mattress 38 has two opposite receiving recesses 40 at respective ends thereof. As is shown in Figure 4, each recess 40 is formed on an underside 42 of the mattress 38 and has a tapered profile. When the mattress 38 is positioned on the base 14 and the first and second roller assemblies 16 and 18 are in respective rest positions shown in Figures 1 and 2 then the first and second roller assemblies 16 and 18 are partially received within the respective receiving recesses 40 so that the upper side 44 of the mattress 38 is flat without any bulges being created by the roller assemblies.

The first and second roller assemblies 16 and 18 are of identical construction and only the first roller assembly 16 is described.

With reference particularly to Figure 3, at any given time, an upper portion 46 of the first roller assembly 16 extends above, and thus stands proud of, the base 14 and a lower portion 48 thereof extends below the base 14. The first roller assembly 16 is generally frusto-conically shaped and includes a central shaft 50 and a series of spaced apart disc-like rollers 52 carried on the shaft in a configuration in which the disc-like rollers are free to rotate relative to the shaft 50. Each of the disc-like rollers 52 has a frusto-conical shape and is made from a suitable plastics or rubber material. An upper contour of the roller assembly, defined by the upper regions of the rollers 52, is clearly sloped in a transverse direction of the bed 10 with an apex of the contour being defined on one side of the bed 10 by the largest roller. The roller assembly 18 defines such an apex on the opposite side of the bed 10.

With reference now particularly to Figures 2 and 3, each of the disc-like rollers 52 is partially received in, extends through, and is freely displaceable along a slot 36.

The shaft 50 is linearly displaceably connected to the frame 12 by way of the first and second rods 24 and 26.

At each of its opposing ends 54A and 54B, the shaft 50 has an attachment bracket 56 wherethrough a first rod 24 and a second rod 26 extend.

In respect of the first roller assembly 16, the first rod 24A extends through a threaded aperture defined at 58 through the corresponding bracket 56 and the second rod 26A extends through a guide passage defined at 60 through the bracket 56. The first rod 24A interengages with the bracket 56 around the aperture 58 and the second rod 26A passes freely through the passage 60. The first rod 24B similarly interengages with the opposite bracket 56 of the roller assembly 16 and the second rod 26B passes freely through a passage defined through the bracket.

Similarly, the second rods 26A and 26B are interengaged via threaded apertures with the respective brackets 56 of the shaft 50 of the second roller assembly 18 and the first rods 24A and 24B pass freely through passages defined through the respective brackets.

In this manner the first roller assembly 16 is interengaged with the first rods 24 and the second roller assembly 18 is interengaged with the second rods 26.

Each of the rods 24 and 26 is coarsely threaded and extends from a drive end 62 to a stop end 64. A stopper 66 is attached to the stop end 64 and a first pulley 68, which forms part of the first or second drive unit 20 or 22, is attached to the drive end 62.

The first drive unit 20 is positioned at the foot end 32 and the second drive unit 22 is positioned at the head end 30. The first and second drive units 20 and 22 can operate in synchronisation or independently and are identical. Accordingly only the first drive unit 20 is described.

The first drive unit 20 has an electric motor 70 which drives a transmission arrangement 72. The transmission arrangement 72 has a plurality of pulleys 68 and 74 and belts 76 extending between the pulleys 68 and 74. Through the pulleys 68 and 74 and the belts 76, rotational displacement from the motor 70 is transferred to each of the first rods 24A and 24B which results in rotation of the first rods 24A and 24B.

The operating speed and direction of the motor 70 is controlled by a control unit 78 which is connected to the motor 70. The control unit 78 has a microprocessor 80, which is programmable. The control unit 78 is connected to a power supply 82 which powers the motor 70.

As is shown in Figure 1 , the first and second rods 24 and 26 and the transmissions 72 are protected by moulded plastics covers 84. The covers 84 are shown in dotted outline in Figure 2.

In use, and as is shown in Figures 5 to 8, the control unit 78 is programmed to activate the respective motors 70 in order to cause independent and/or simultaneous displacement of the first and second roller assemblies 16 and 18.

For example the first and second roller assemblies 16 and 18 can each be in a stationary, rest position as is shown in Figure 5. By activating the motor 70 of the second drive unit 22, rotation of the second rods 24A and 24B is caused. The rotation of the second rods 26A and 26B forces the shaft 50 of the second roller assembly 18 is displaced lengthwise across the base 14 towards the foot end 32. As the shaft 50 is displaced across the base 14, the disc-like rollers 52 of the second roller assembly 18 rotate about the shaft 50 as the disc-like rollers 52 are forced into abutment with the underside of the mattress 38. As the second roller assembly 18 is displaced across the base 14, the mattress 38 is locally and progressively deformed along its length until the second roller assembly 18 reaches the foot end 32. In order to return the second roller assembly 18 to the head end 30 the direction of the motor 70 of the second rod 22 is reversed and the second roller assembly 18 is displaced across the base 14 in the manner described until it reaches the head end 30. Thereafter, and as is shown in Figure 7, the first roller assembly 16 is displaced from the foot end 32 to the head end and back in a similar manner through the activation of the motor 70 of the first drive unit 20 by the control unit 78 and the rotation of the first rods 24A and 24B.

Additionally, and as is shown in Figure 8, the first and second roller assemblies 16 and 18 can be displaced into a closely spaced configuration and can then be displaced in unison along the length L of the base 14 by the simultaneous activation of the motors 70 of both the first and second drive units 20 and 22. It will be appreciated that, due to the upper contours of frusto-conical shapes of the respective roller arrangements 16 and 18 being sloped in opposite transverse directions, such displacement in unison along the length of the base will have a twisting effect on the body of a person lying on the mattress 38. The Applicant envisages that this may be beneficial in the case of certain persons.

In use of the bed 10, a person would lie on the mattress 38 and the microprocessor 80 may be programmed to cause, depending on requirement, alternating and/or simultaneous displacement of the first and second roller assemblies 16 and 18. The displacement of each of the roller assemblies 16 and 18 along the length L of the base 14 massages the person, improves blood circulation, and alleviates pressure points on the person's body's contact areas with the mattress 38.

The control unit 78 may, alternatively or additionally, provide for manual (as opposed to programmed) operation thereof to effect displacement of each of the roller assemblies 16 and 18 in accordance with manual inputs by the operator.

Depending on the application single or multiple roller assemblies 16 and 18 can be used and the exact shape of the roller assemblies 16 and 18 can vary. Additionally a single drive unit 20 and 22 and alternative transmission means and actuators such as direct sprocket, cable or chain drives can be used to transfer motion generated by the motor 70 to the shaft 50. A single belt 76 can also be used between the pulleys 68 and 74.

In another example, a servo motor can be connected to each rod 24 and 26 to provide a direct drive in which case the transmission 72 between the motor and the rods 24 and 26 can be in the form of a direct coupling.

To enhance the massaging effect of the roller assemblies 16 and 18, each may be provided with a vibration actuator to cause vibration of the roller assemblies 16 and 18 during use. Such a vibration actuator may be essentially conventional and an example is shown in Figure 12.

The fact that elements of the frame 12 surrounds the mattress 38 is important as this prevents the mattress 38 from being forced from the base 14 as a result of the displacement of the roller assemblies 16 and 18.

The frame 12 can, depending on the application, be positioned on any appropriate structure, which structure can, for example, be wheeled.

In Figure 9, a second embodiment of a bed, in accordance with the invention, is designated generally by the reference numeral 90. The bed 90 includes certain features that are identical or similar to features of the bed 10 of Figures 1 to 8, as described above. Identical or similar features, where designated, are thus designated by the same reference numerals as before and a description of such features is not repeated here.

The bed 90 includes also as a part of each leg 28 of the frame 12, a pneumatic lifter unit 92; two opposite, longitudinal pneumatic drive units 94; a microprocessor controlled control unit 96 for controlling the operation of the units 92 and 94; an arrangement of pressure hoses/pipes 98 (not shown in detail) connecting the respective lifter units 92 and drive units 94 to the control unit 96; and a pressure hose 99 for connecting the control unit 96 to a compressed air supply, e.g. a compressed air supply wall outlet of a type found in certain hospitals.

The pneumatic drive units 94 serve as mounting means for the roller arrangements 16 and 18 and, as will become apparent from what follows, provide for their displacement along respective straight paths that each extends along substantially the entire length of the base 14.

The lifter units 92 and the control unit 96 may, for example, be commercially available units made by Festo AG & Co. KG. The drive units 94 may, for example, be units obtained by modifying commercially available units made by Festo AG & Co. KG, as will be described below.

The control unit may, for example, be a control unit made by Festo AG & Co. KG, suitably configured for use in the bed 90. Its operation may be essentially

conventional and, as such, is not elaborated on herein. Suffice it to say that it controls the operation of the lifter units 92 and the drive units 94 by controlling air flow to and from them.

The pneumatic drive units 94 are identical and the operation of one of them will now be described with reference to Figures 10 and 1 1 . The pneumatic drive unit 94 includes an elongate body in the form of a cylinder barrel 100, defining on its inside a cylinder 102 and on its outside a slider rail 104; two rodless pistons 106.1 and 106.2 inside the cylinder barrel 100; two sliders 108.1 and 108.2, slidably engaged with the slider rail 104 and connected to the pistons 106.1 and 106.2, respectively, to be displaced along with them; and two opposite end caps 1 10, having air ports 1 12.1 and 1 12.2, respectively.

The pneumatic drive unit 94 is obtained by taking a commercially available drive unit having a single piston/slider and modifying it by adding another piston/slider; and providing it with two additional air ports 1 14.1 and 1 14.2 substantially in the positions shown.

The respective air ports 1 12 and 1 14 are connected in communication with the control unit 96 via an arrangement of pressure hoses or pipes 98 (not shown in detail).

With reference to Figure 10, displacement of the piston 106.2 to the left from the position shown is effected by the control unit 96 by feeding air into the port 1 12.2 whilst maintaining the port 1 14.2 closed and the port 1 14.1 in communication with the atmosphere.

With reference to Figure 1 1 , upon displacement of the piston 106.2 into the position shown, in which it effectively closes off the port 1 14.1 , air is trapped between

this piston and the piston 106.1 , arresting the former piston before it makes contact with the latter one. Subsequent displacement of the piston 106.2 to the right is a reverse operation, with air being fed in via the port 1 14.1 whilst maintaining the port 1 14.2 closed and the port 1 12.2 in communication with the atmosphere.

The piston 106.1 is similarly displaceable along the length of the unit 94 and, accordingly, the base 14.

With reference to Figures 10 and 1 1 generally, opposite ends of the shaft 50 of the roller assembly 16 are mounted respectively on the slider 108.1 and an identical slider of the opposite pneumatic drive unit 94 and are thus engaged by the respective sliders. The configuration of the pneumatic drive units 94 and the control unit 96 is such as to ensure that the said sliders are displaced in synchronisation so as to maintain the shaft 50 transverse to the frame 12.

Similarly, opposite ends of the shaft 50 of the roller assembly 18 are mounted respectively on the slider 108.2 and an identical slider of the opposite pneumatic drive unit 94 and these sliders are displaced in synchronisation.

Certain further features of the operation of the bed 90, particularly the possible modes in which its roller assemblies 16 and 18 are displaceable along the length of the base 14, may be similar to those of the bed 10 as described with reference to Figures 8 to 10 and, as such, are not described in detail.

Each lifter unit 92 is similar to each of the drive units 94, but includes a single piston and slider. Opposite ends of each of the drive units 94 are mounted on the respective sliders of the lifter units on the corresponding side. Through synchronised displacement of the sliders of the respective lifter units 92 under control of the control unit 96, synchronised adjustment of the level of the units 94 can be effected. As such, the lifter units 92 serve as height adjustment means for adjusting the level of the roller assemblies 16, 18 relative to the base 14 and, accordingly, the degree to which they stand proud of the base and the degree to which they will operatively deform a mattress

supported on the base 14 as they are displaced along their paths along the length of the base.

In Figure 12, an optional vibration actuator 1 18 for the bed 90 is shown. The actuator 1 18 is an essentially conventional, electrically powered unit and is mounted on the slider 106.1 . The axle 50 is mounted on the actuator 106.1 . Although not shown in the drawing, each of the other sliders also has such an actuator mounted thereon so that each of the roller assemblies 16 and 18 is mounted on the drive units 94 via two opposite vibration actuators. Upon activation of these actuators, they induce vibration in the roller assemblies 16 and 18 to enhance the massaging effect of the roller assemblies.

The exact configuration of the bed of the invention is highly variable and, as such, the invention extends to any bed including the essential features of a bed, as defined herein.