Note: Descriptions are shown in the official language in which they were submitted.
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BED ASSEMBLY
The present invention relates to a bed assembly and to a configurable bed
platform
or frame.
Modern hospital beds are generally designed to be configurable into a variety
of
profiles. Typically, they are provided with a plurality of sections which can
be tilted or
otherwise moved to change a patient's position on the bed. For example, they
are usually
provided with a back rest section which can pivot from a substantially flat
position to a
raised sitting position, witll a thigh rest section which can be pivoted from
a substantially
flat position to a knee raised position, and with leg rest section coupled to
the thigh rest
section and able to be raised with the thigh rest section while keeping the
feet in a lower
position or while keeping the feet in a raised position.
Beds having such a configurable platform are well known in the art and
generally
work satisfactorily. However, they often require the use of a specialised
mattress designed
specifically for that platform. This limits the variety of mattresses to those
available from
the bed manufacturer or other specialist supplier and does not allow for a
user to select
other mattresses not specifically designed for the bed.
Furthermore, bed assemblies of this type are becoming increasingly complex,
leading to the need to maintain and service an increasing nuinber of
components. It is
often difficult to gain access to these components, leading to more time
consuming and
labour intensive servicing.
The present invention seeks to provide an improved bed assembly and
configurable
platform or frame.
According to an aspect of the present invention, there is provided a mattress
support platfonn for a bed assembly including a frame provided with internal
side walls
which provide substantially vertical mattress holding side surfaces, a
plurality of support
elements coupled to the frame for supporting a plurality of mattress support
panels and
depending from the frame, and a plurality of hinges on the frame allowing the
platform to
be configured into a plurality of shapes.
The provision of a frame with substantially vertical mattress holding side
surfaces
can in practice allow any mattress of complementary dimensions to be supported
in the
frame, even a mattress which does not fit precisely into the internal space of
the frame.
Moreover, it is not necessary to use a mattress with particular structural
features, as is the
case with a number of existing hospital beds. Thus, virtually any mattress
could be used,
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dependent upon the needs of the patient and the wishes of the user. This can
be
particularly important when it is deemed a patient would benefit from a
particular mattress
type not supplied by the bed supplier.
The frame preferably provides substantially vertical mattress holding side
surfaces
around the entire of a mattress reception area of the bed.
The hinges are preferably of a type which have a profile which substantially
matches the profile of the remainder of the frame structure, thereby to
present a
substantially smooth frame, not requiring particular coverings or other
measures to protect
the patient and staff from sharp profiles and to cover possible areas which
can collect dirt
and germs.
The frame is preferably formed of struts which have a rounded rectangular
outer
shape in transverse cross-section. Such a shape provides substantially
vertical side walls
while still retaining a smooth profile. Other shapes could be used, such as a
D-shape, in
which the straight portion of the D-shape is located on the inside surfaces of
the frame. It
is also possible to use struts which are circular or oval in cross-section
because these would
still provide vertical mattress support surfaces but such shapes are not
preferred.
The holding elements are preferably a plurality of transverse struts extending
transversally between two opposing side struts of the frame and depending
therefrom.
Holding elements of this type provide, wlien the mattress support panels are
removed, a
substantially unimpeded path to the components of the bed assembly below the
platform,
which can considerably facilitate servicing of these components as described,
for example,
in the applicant's co-pending British patent applications filed the same day
as the present
application.
In the preferred embodiment, the frame is extendable. Advantageously, this is
achieved by providing at one end of the frame, usefully the foot end, a
telescopic
arrangement of extension struts which slide within the frame struts at that
end of the frame.
The hiuiges and depending support elements provide a pivoting arrangement
which
can increase a separation between adjacent mattress support elements and thus
panels when
one of the sections is pivoted upwardly, having the effect of lengthening the
mattress
support area to follow better the stretching of a patient's back during such
action. They
can also provide for a shortening of a separation between adjacent mattress
support
elements and thus panels when one of the sections is pivoted downwardly. These
features
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are described in detail in the following description and covered in the
applicant's
co-pending British patent application number 0523168.3 filed the same day as
the present
application.
According to another aspect of the present invention, there is provided a
mattress
support platforin for a bed assembly including a frame and a plurality of
transverse support
struts coupled to the frame for holding a plurality of mattress support panels
and depending
from the frame, and a plurality of hinges on the frame for allowing the frame
to be
configured into a plurality of shapes.
According to another aspect of the present invention, there is provided a bed
asseinbly including a platform as specified herein.
Embodiments of the present invention are disclosed below, by way of example
only, with reference to the accompanying drawings, in which:
Figure 1 shows a left-side perspective view from above of a preferred
embodiment
of a bed assembly in a flat configuration;
Figure 2 shows a right-side perspective view from above of the bed assembly of
Figure 1 in a chair configuration;
Figure 3 shows the bed assembly of Figures 1 and 2 in the chair configuration
with
the mattress support panels and patient support panels removed;
Figure 4 is a plan view of a part of the bed assembly of Figure 1;
Figures 5A and 5B shows a bed extension mechanism in extended and
non-extended positions;
Figure 6 shows in plan view and in schematic form two mattress support
sections of
the bed of Figure 1;
Figure 7 is a plan view of the bed assembly of Figure 3;
Figure 8 is an enlarged view of a portion of the plan view of Figure 7;
Figure 9 is an enlarged view of a portion of the plan view of Figure 7;
Figure 10 shows a side elevational view of the mattress support panels only of
the
bed assembly of Figure 1, with the bed in a chair configuration;
Figure 11 is an enlarged view of a part of the bed assembly of Figure 1; and
Figure 12 shows a keypad zone of the bed of Figure 1 in use by a patient.
Referring to Figure 1, there is shown a preferred embodiment of bed assembly
10
which includes a wheeled base 12 provided with four castors 14, a headboard 16
and
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footboard 18. Coupled to the base 12 is a bed platform 20 which can be raised
and
lowered relative to the base 12 and tilted by means of one or more electrical
actuators (not
shown), also of conventional type.
The platform 20 is provided with a frame 22 formed, in this einbodiment, of
four
frame sections 24, 26, 28 and 30 which are coupled to one another by means of
hinged
joints 32, 34 and 36. The frame 22 is typically made of metal or a metal
alloy.
Each frame section 24-30 is provided with an upper frame member having
substantially vertical inner side walls 38 (better seen in Figures 2 and 3)
and a plurality of
depending transverse struts 40 (better seen in Figures 3 and 4) which form a
recessed
support surface for supporting, in this embodiment, four mattress support
panels 50, 52, 54
and 56. These panels 50-56, together with the pivoting fraine members 24-30,
form
respectively the backrest section, seat section, thigh rest section and leg
rest section
typically found in conformable beds of this nature.
The hinges 32, 34 and 36 are provided in the upper frame members 24-30 and
enable the fraine members to pivot relative to one another about the hinges 32-
36, as will
be apparent from a consideration of Figures 2, 3 and 7 to 9, and described in
detail below.
It can be seen that the hinges 32-36 are built into the upper frame members 24-
30 and
present substantially smooth outer surfaces in order to prevent any discomfort
or injury to
the patient or care staff.
As can be seen in Figure 1, the mattress support panels 50-56 are curved so as
to
present a concave upper surface when looking down on the bed platform 20. The
panels
50-56 lie below the frame walls 38, preferably by a distance sufficient to
allow a mattress
placed on the panels 50-56 to fit within the frame 22 so as to be held by the
substantially
vertical side surfaces provided by the walls 38 of the frame 22. That distance
is preferably
less than this so that the upper surface of the mattress extends above the
frame 22, to hold
the patient comfortably above the hard surfaces of the frame 22 (as shown in
Figure 11).
At least some of the mattress support panels 50-56 are preferably removable
and
advantageously made of blow mouldings from any suitable plastics material. The
panels
50-56 are rigid.
Cut-outs 60 in the panels 50-56 provide handles for easy removal of the panels
50-56 from the bed 10 and for their handling. There are preferably also
provided snap
fittings 55 (some of which are visible in Figure 10) on the underside surfaces
of the panels
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50-56 which snap onto the transverse struts 40 to retain the panels in place.
In the
preferred einbodiment, each snap fitting is formed from one or more bosses
extending
beyond the lower surfaces of the panels 50-56, the bosses having curved
surfaces which
form a snap fit gripper member which snaps on to the struts 40.
5 Figure 1 also shows two patient retention panels 80, 82. Typically,
corresponding
retention panels are provided on the other side of the bed assembly 10 but are
omitted from
Figure 1 for the purposes of clarity. These panels, which can be of a type
known in the art,
can be moved between the raised position shown and a lowered position in which
they lie
alongside the frame 22 so as to be below the level of the mattress of the bed.
In the raised
position the panels 80, 82 retain a patient on the bed, while in the lowered
position they
enable a patient to get off and get onto the bed and also provide unimpeded
access to the
patient.
Referring now to Figure 2, the bed assembly of Figure 1 is shown in a chair
configuration. In this configuration the back rest 30, 50 is raised by
pivoting of the hinge
32 between the back rest section 30 and the seat section 28. In the
configuration shown the
hinge point 36 between the thigh rest 54 and the leg rest 56 is also raised.
This raised
configuration of the hinge 36 represents a knee break such that in the
configuration shown
in Figure 2 a patient would be sitting up with knees raised.
The various sections 24-30 of the frame 22 can be moved in the manner shown by
means of one or more actuators provided in the bed assembly 10. The actuators
are well
known in the art, as is the type of control system used to control them, so
they will not be
described in fu.rther detail herein.
The bed sections 24-30 and actuators allow the bed to be reconfigured from the
lying position shown in Figure 1 to a sitting position as shown in Figure 2
and also into
many other configurations, including, for example one in which the knee break
at hinge 36
is raised and the leg rest section 24 also raised upwardly to keep a patient's
legs
substantially horizontal. For this latter configuration, there is provided an
actuator which
is coupled to the leg rest section 24 to effect such movement. This actuator
arrangement is
well known in the art so is not described in further detail herein.
Figure 2 also shows a sub-frame 42 which supports the platform 20, typically
by
being attached to the seat section 28 and also to the actuators and to a
control unit. The
sub-frame 42 also supports the struts 44 which raise and lower the sub-frame
42 and hence
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the platform 20 relative to the base 12. This sub-frame is the subject of the
applicant's
co-pending British patent application number 0523174.1 filed the same day as
the present
application and does not need to be described in further detail herein.
Referring now to Figure 3, there is shown a perspective view of the bed
assembly
10 of Figure 2 but wliich oinits for the purposes of clarity the mattress
support panels
50-56, the head board 16, the foot board 18, the patient retention panels 80,
82 and a
number of other components shown in Figure 2.
The transverse struts 40 which depend from the frame 22 are clearly visible in
this
Figure. They are provided in number and in location where support is needed
for the
mattress support panels 50-56 and which allow good access to the bed
components
underlying the platform 20, as will be more apparent from a consideration of
Figure 4. In
this embodiment, there are provided three transverse struts 40 in the back
rest section 30,
in light of the greater weight supported by this section of the bed, and two
struts 40 in each
of the other sections 24-28. Of course, it is possible to provide just two
struts in the section
30 if these are made sufficiently strong.
The back rest section 30, the thigh rest section 26 and the leg rest section
24 are
also provided with longitudinally extending strengthening struts 41 between
two adjacent
transverse struts 40.
It is preferred that the transverse struts 40 are generally rectangular in
cross-section
as this provides a secure coupling with the snap fasteners provided on the
underside of the
mattress support panels 50-56.
Figure 3 also shows two of the actuators 43 used for moving the frame sections
24-30. As can be seen, these are secured to the sub-frame 42.
Referring now to Figure 4, this shows the bed features of Figure 3 in plan
view
with the frame 20 in a flat configuration. It can be seen that the provision
of readily
removable mattress support panels 50-56 and of support struts 40, 41, rather
than a solid
non-removable flat base, provides good access to the components of the bed 10
underlying
the frame 22. In this case, the actuators 43 are readily visible and
accessible from above
the bed 10 through the frame 22, as well as other components such as the
control unit (not
visible) typically provided in such bed assemblies. This enables servicing of
these
components from above the bed, that is without having to turn the bed onto its
side or
upside down.
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Figures 5A and 5B show a detail of the foot section 24 of the frame 22, with
its
mattress support pane156 fitted. The end of the foot section 24 is extendable.
This is
achieved by providing the end strut 110 with first and second parallel rods or
tubes 112,
114 either side thereof. These rods have a transverse shape which corresponds
to the
internal shape of the struts 116, 118 forming the foot rest section 24, so as
to be slidable
therein as shown in Figures 5A and 5B. As will be apparent from Figure 5A,
when the
foot rest section 24 is in its extended condition, the rods 112, 114 continue
the side wall of
the frame 22, thereby retaining the side support surfaces complete around the
whole of the
frame 22 .
First and second latches or locks 120 are provided for locking each rod 112 in
either the retracted or in the extended positions. The latches 120 could
simply be sprung
pins fitting into appropriate apertures or bores in the rods 112, 114 or could
be screw locks
which tighten against the rods 112. The type of latch or lock is not
important.
Referring now to Figure 6, there is shown in plan view in schematic form the
arrangement of the mattress support panels 50, 52 of the bed of Figures 1 and
2. The
support panel 50, which forms the back rest section of the bed 10, includes a
first end wall
62 and an opposing end wal164. The mattress support pane152, which forms the
seat
portion of the bed 10, includes a first end wa1166 and a second end wa1168.
The walls 62
and 66 are adjacent one another, as shown in Figure 6.
When the bed is in a flat position, depicted by the solid lines in Figure 3
and as
shown in Figure 1, the spacing between the two panels 50, 52 is shown as
distance d,
which can be any suitable distance which will not adversely affect the support
of a patient
on a mattress laid over the panels 50-56. The distance d will typically be a
few
centimetres, often around 10 cm or so.
On the other hand, when the support panel 50 is pivoted to a raised patient
sitting
position as shown in Figure 2, the distance between the end walls 62, 66 of
the panels 50,
52 respectively increases to the distance D shown in Figure 6. It can be seen
that distance
D is considerably larger than the distance d when the two panels are lying
flat.
There are two primary factors which cause the increase in the distance between
the
two end walls 62, 66. The first is the curvature of the panels 50, 52 and the
fact that the
pivoting point is at the sides of the panel. The centre of the panels 50, 52
are substantially
below the sides, thereby causing this increase in distance during the pivoting
motion. The
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second factor is that the pivot 32 is raised above even the highest points of
the panels 50,
52 (that is above their raised sides) which causes additional movement away
from the
panel 52 including at the ends 70.
This increase in spacing is advantageous because when a person moves from a
lying position to a sitting position the person stretches at the point of
bending (that is
between the patient's back and lower thighs). Thus, this arrangement follows
the
extension of the person and therefore makes it much more comfortable to a
patient. Prior
art beds, which have the pivot points substantially at the level of the
mattress support
sections and which have mattress support sections which are substantially
flat, do not
benefit from this increase in spacing between the sections and therefore from
any increase
in the effective length of the mattress support base. They can provide a
pinching effect on
the patient.
The reader will appreciate that the two factors mentioned above could be
provided
independently of one another, although with reduced lengthening effect.
Figure 7 shows a plan view of the bed of Figure 1 in the chair configuration,
while
Figure 8 shows an enlarged view of the head end of the bed of Figure 7. A
comparison of
Figure 1 with Figures 7 and 8 shows the increase in spacing between the edges
62, 66 of
the panels 50, 52 from the lying to the seating positions.
There is an other advantageous feature of this structure of the platform 20,
this
being at the thigh section 54. As can be seen in Figure 1, the spacing, D',
between the
thigh rest panel 54 and the leg rest panel 56 is relatively large when the
platfonn 20 is in
the flat configuration. However, when the hinge 36 is raised to form the knee
break, this
spacing is reduced substantially, to d' as shown in Figure 9. This reduction
in spacing
causes the lower surface of the mattress to compress longitudinally as a
result of a
shortening in the overall length of the portions 54, 56 of the mattress
support. This enables
the mattress to maintain contact with the rear of a patient's knee. It has
been found that if
there is no such compression of the mattress longitudinally, as would be the
case if the
spacing between the thigh and leg rest sections 54, 56 were to remain the
same, the
mattress becomes stretched over the knee break and can lose contact with the
rear of a
patient's knees, thereby losing the supporting effect it should provide.
Figure 10 shows the inattress support panels 50-56 in the chair configuration
of the
bed. The spacings between the panels in this configuration can be clearly
seen. There is,
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however, another feature evident in Figure 10, related to the movement of the
thigh rest
section 54. As can be seen in Figure 10, with the thigh rest section pivoted
upwardly as
shown, the rear edge 111 of the thigh rest 54 is higher than the front edge
113 of the seat
section. This is caused by the fact that the rear edge 111 is longitudinally
spaced from the
hinge 34, along the length of the bed. As a result of this, pivoting of the
frame section 28
about the hinge 34 will cause the pane154 not only to pivot but also to rise
relative to its
rest position. This rising of the thigh rest pane154 provides better support
to the underside
of a patient's thigh than do existing configurable bed assemblies.
Referring now to Figure 11, the bed 10 is shown in the lying configuration, in
order
better to see the patient retention panels 80, 82 for retaining the patient on
the bed. The
panels 80, 82 are typically made from a plastics material or from metal
covered with a
plastics cladding.
The patient retention panel 80 is coupled to the frame member 30 forming the
back
rest section of the bed 10 and is able to move therewith, as will be apparent
in particular
from Figure 2. The patient retention pane182 is coupled to the seat section 28
of the fra.ine
22 and in practice does not move as the seat section 28, in this embodiment,
is the one
stationary member of the frame 22 (although it does, of course, move with the
frame 22 as
this is raised, lowered and tilted).
As is best appreciated from Figure 2, when the back rest section 30, 50 is
pivoted
upwardly towards a patient sitting position, the patient retention pane180
will move over
the retention pane182. For this purpose, the pane180 includes a concave facing
surface 92
which faces a convex surface 94 of the retention panel 82. As the pane180
moves
upwardly and around the pane182, the surface 92 slides over the surface 94
retaining
substantially the same gap g between the two surfaces 92 and 94. As a result
of this, the
coinbination of the two panels 80, 82 provides a substantially continuous
support surface
throughout the movement of the retention pane180, without creating between the
two
panels any constriction which could trap part of a patient's body or that of
hospital staff.
As shown in particular in Figures 11 and 12, there can be seen in schematic
form an
example of a preferred embodiment of unit 100 for supporting a keypad (not
shown) which
allows the patient to operate the various functions of the bed 10.
In this embodiment, the keypad unit 100 is provided with a protruding member
102
which extends beyond the general outer perimeter of the patient support
pane180 and in a
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direction towards the foot end of the bed 10. The unit 100 is fitted to the
patient retention
panel 80 so as to move with that panel upon movement of the back rest section
30, 50, in
such a manner that it maintains its position relative to the backrest section
30, 50 and hence
relative to a patient lying on the bed 10. The unit 100 is located so as to be
easily
5 accessible by a patient on the bed by means of the patient's hand at that
side of the bed, as
shown in particular in Figure 6. The position of the unit 100 could be
described as being
approximately at the shoulder area of a patient lying or sitting on the bed
10.
As can also be seen in Figure 12, the shape and structure of the unit 10 is
such that
a patient is able to place his/her fingers on the outer side of the unit 100
and then to operate
10 a keypad (not shown) on the inner/patient side of the unit 100. The patient
is therefore able
to apply an opposing pressure at the rear side of the unit 100 to the pressure
applied when
pressing the buttons of the key pad, which in practice stabilises the unit
100. This feature
contrasts with the existing keypads provided on the patient support panels,
which tend to
be difficult to operate because the panels generally have some flexibility to
them.
The keypad which would be provided in the unit 100 is of a type equivalent to
the
keypads already used in such beds and therefore is not described in any
further detail
herein.
Referring in particular to Figure 11, it is preferred that the unit 100 is
fitted to the
patient support pane180 by first and second flanges 104, 106 which can be
secured to the
pane180 either by suitable snap fit connections and/or by one or more screws.
Within the
unit 100 there is provided a plug or socket which fits to a complimentary
socket/plug to
make the necessary electrical connections between the keypad of the unit 100
and the
control system of the bed 10.
The preferred structure of the keypad unit 100 facilitates the assembly of the
unit
100 to the bed 10 and also enables its easy replacement in case the keypad is
in some way
damaged during use or shipping.
