Note: Descriptions are shown in the official language in which they were submitted.
-1-
Description
Bed System
S Technical Field
The present invention relates to beds generally
and, more particularly, to a novel bed structure
especially suited for low air loss air beds and being
exceptionally economical to manufacture and use.
Background Art
While the present invention and particular
features thereof are described for illustrative
purposes as being applied, in one embodiment, to low
loss air beds, it will be understood that the various
aspects of the invention have applications in other
types of beds, as we7.l as in non-bed applications, and
all such applications are within the intent of the
present invention.
?0 A major problem in health care facilities is
with bed-bound patients who cannot turn or roll over
without assistance. Failure to roll over relatively
frequently causes restriction of blood flow in the
area of bony protuberances on a patient's body which,
in turn, causes ulcerated bed, or pressure, sores.
Such sores are extremely long-healing and, with a
chronically or terminally ill patient, frequently
recur. According to hospital industry standards, it
has been estimated that to cure a single bed sore
costs society an average $40,000 and many patients die
from bed sores. A standard procedure is to have
nursing personnel turn each immobile patient every two
hours. This is not entirely unsatisfactory in a
hospital setting where nursing staff is continually
- 2 - 2t~~~~~
available, but may be an unsatisfactory procedure in
institutions, such as nursing homes, or in private
homes where such assistance may not be available on a
frequent basis. One conventional technique for
avoiding bed sores is to have the patient repose in a
plaster of Paris bed in which the plaster of Paris has
set to the patients contours. Although providing a
hard surface, there is sufficient surface area that
the pressure on the patient's body remains below the
body's capillary pressure.
A recent development to address the problem of
bed sores is the so-called "low loss air bed". This
type of bed comprises a fairly typical hospital bed
which has, instead of a standard mattress, a plurality
of air bags disposed perpendicularly to the axis of
the bed from its head to its foot. The shape of the
air bags permits their deformation to accommodate the
contours of the patient's body without undue local
pressure areas developing. The pressure within the
air bags is adjusted to give just the required support
to each portion of the patient's body and the
adjustment can be changed to periodically vary the
pressure on each or all portions for eating, sleeping,
etc. Such use of air bags greatly reduces the
tendency for bed sores to form and, indeed, can
promote the healing of already formed bed sores.
Typically, small streams of air are ejected from the
upper sections of the air bags which are covered by a
vapor-permeable sheet, such as a microporous
polyurethane-coated nylon fabric. The streams of air
dry any moisture vapor which permeates through the
sheet and, therefore, helps remove another cause of
bed sores and reduces the frequency of bedding
changes. A discussion of the formation and prevention
-3-
of bed sores, as well as some conventional types of
low loss air beds may be found in Bed Sore
Biomechanics, edited by R. M. Kenedi, J. M. Cowden,
and J. T. Scales, Macmillan Press Ltd. publisher,
5 1976, which book and the references cited therein are
made a part hereof by reference.
Conventional air beds typically include features
found on standard hospital beds such as means to raise
or lower head and/or foot portions, means to adjust
10 the height of the bed, etc. Frequently, such air beds
consume a relatively large volume of air, thus
requiring a relatively large blower and creating a
noise problem from the air flow and the controls
therefor unless extraordinary measures are taken to
15 dampen the noise. It would be desirable to have an
air bed having low air flow requirements and having
air flow control components which inherently produce a
low noise level.
Perhaps the greatest disadvantage with
20 conventional air beds is that of high manufacturing
cost. Such beds are fabricated from numerous small
parts manually attached with fasteners and complex
weldments and having a high labor content. Also, some
of the features which are =ncluded in standard
25 hospital beds contribute to the high cost. The result
of the high cost is that the use of such beds is
restricted almost entirely to hospitals that have the
financial means to purchase or rent such beds and,
thus, immobile patients who otherwise could be
30 discharged to a nursing home or private home must be
maintained in the formal hospital setting. It would
be highly desirable to have available an air bed which
could be afforded by those outside of a formal
hospital setting.
-4-
Another class of persons subject to pressure
sores are those who are handicapped and working, but
who are confined to wheelchairs. The day-long
confinement to a wheelchair causes the same problem
S with pressures sores as does confinement in a bed. In
such a situation, when the person develops one or more
such sores, the person must drop out of the person's
position in society for a month or more while the sore
is cured. Of course, when the person returns to the
10 wheelchair, sores will likely recur and the process is
repeated. It has been found that, if such a person is
able to sleep in an air bed, such permits incipient
sores to heal during the night, even though the person
is confined to a wheelchair during the day.
15 Unfortunately, the cost of a conventional air bed puts
it out of the reach of many such persons who must
continue to suffer.
A further factor contributing to the relatively
high cost of conventional air beds is the arrangement
20 of the air bags. Typically, the bags are arranged in
groups of three to five bags each with the bags in a
group supplied with air of the same pressure through a
manifold. It would be simpler to have a single air
bag approximating the dimensions of three or more
25 conventional air bags, but simply making one bag
larger would cause that bag to approach a spherical
shape, thus making it unsuitable for patient support.
However, it would be desirable to have available a
single air bag which would simulate a group of
30 conventional air bags. Such a single bag would
simplify the air supply arrangement and be more
economical to manufacture.
_ 5 _ ~~~.6~'~~
An important cost factor in the use of
conventional air beds is their lack of portability.
This means that shipping and installing such beds
requires a relatively costly procedure and, of course,
5 it is impossible for an ambulatory or wheelchair bound
patient requiring an air bed to conveniently relocate,
or have relocated, such a bed. It would be desirable
to have a device with the therapeutic features of an
air bed, but one that is highly portable and can
easily be shipped by conventional mail or by
commercial parcel delivery services and which can be
easily relocated.
Another feature of standard hospital-type beds
that can contribute to their high cost, and also that
15 contributes to difficulty in their use by the patient
or the patient's aide, is the siderails employed with
such beds. Typically, such siderails are of one of
two types. One type comprises a single-piece tubular
siderail structure ~ohich extends substantially the
20 length of the bed and which must be lifted off to
allow the patient to be moved or, if the patient is
mobile, to allow the patient to exit or enter the
bed. Removal and replacement can be difficult for the
aide and impossible for the impatient. The other
25 typical type comprises a similar siderail structure
which has a complicated and expensive hinged mechanism
to allow the siderail to be lowered to the floor.
This may be more convenient for the aide, but is
impossible for the patient to maneuver if the patient
30 is in the bed.
Accordingly, it is a principal object of the
present invention to provide a bed structure which is
simple and economical to manufacture and which may be
used in a number of applications, including air beds.
- ~Ul~f'7~
A further object of the invention is to provide
a air bed which is simple and economical to
manufacture and which may be used in nursing homes or
private homes.
Another object of the invention is to provide an
air flow control valve which inherently produces a low
level of noise, which is economical to manufacture,
and which may be used for air flow control on air
beds.
An additional object of the invention is to
provide a single air bag which simulates a plurality
of conventional air bags and which may be used for air
beds.
Yet an additional object of the invention is to
provide a bed siderail which is relatively economical
and which is easy to manipulate either by the patient
unattended or the patient's aide.
Yet another object of the invention is to
provide a device offering the features of an air bed,
but one which is highly portable and may be shipped by
conventional mail or by commercial parcel delivery
services.
Other objects of the invention, as swell as
particular features and advantages thereof, will, in
part, be obvious and will, in part, be apparent from
the following description and the accompanying drawing
figures.
Disclosure of Invention
The present invention accomplishes the above
objects, among others, by providing, in one aspect of
the invention, a bed structure having a mattress deck
panel and side panels, with internal reinforcing
bulkheads and single-piece head- and footboards
~~~~f~'~'~
serving as reinforcing bulkheads at the head and foot
of the structure. In another aspect of the invention,
there is provided a low-cost air bed employing the
above structure. In an additional aspect of the
invention, there is provided an air bed which
incorporates the air supply and control components
within the bed structure itself. In a further aspect
of the invention, there is provided a low-noise air
flow control pinch valve. In yet another aspect of
the invention, there is provided a single air bag
which simulates multiple air bags through the use of
welded internal baffles. In yet an additional aspect
of the invention, there is provided a bed siderail
which is patient-operable. In yet a further aspect of
the invention, there is provided a device having the
features of an air bed, which device is highly
portable and which can be shipped by con~~entional mail
or by parcel delivery services.
Brief Description of Drawings
Figure 1 is an exploded perspective view of bed
structure according to the present invention.
Figure 2 is a side elevation view of the
assembled bed structure of Figure 1.
Figure 3 is an end elevation view of the
assembled bed structure of Figure 1.
Figure 4 is a side elevation view of the
assembled bed structure of Figure 1 adapted For use as
an air bed.
Figure 5 is a fragmentary exploded perspective
view of the siderail structure according to the
present invention.
Figure 6 is a detail of Figure 5.
~fl~~~~~
_$_
Figure 7 is a side elevation view of an air bag
constructed according to the present invention.
Figure 8 is a top plan view of the air bag of
Figure 7.
5 Figure 9 shows diagrammatically the air supply
system of the present invention.
Figure 10 is a bottom plan view looking up, with
the bottom panel removed, of the air bed of Figure 4.
Figure 11 is a side elevation view of an air
10 flow control~valve according to the present invention.
Figure 12 is a fragmentary, partially sectional,
exploded perspective view showing the construction and
means of mounting the air filter of Figures 9 and 10.
Figure 13 is a side elevation view of the bed
15 structure of Figure 2 having a portion of the deck
thereof inclinable.
Figure 14 is a side elevation view of another
embodiment of an air flow control valve according to
the present invention.
20 Figure 15 is a cross-sectional top plan view of
the flow control valve of Figure 14.
Figure 16 is a perspective view of an
alternative embodiment of an air bed system according
to the present invention, being transported on a hand
25 truck.
Figure 17 is a perspective view of the air bed
system of Figure 16, with the mattress structure
thereof deflated and rolled, disposed on a hospital
bed.
30 Figure 18 is a fragmentary side elevation view
showing the attachment means for the mattress
structure of Figure 17 and a mattress cover.
Figure 19 is a perspective view of a patient
reposed on the bed system of Figure 16.
~1~~~~
-9-
Figure 20 is a perspective view of a patient
lying on the air bed system of Figure 16, with a fully
inflated mattress structure, but with the mattress
cover removed.
Figure 21 is a perspective view of a patient
lying on the mattress structure of Figure 20, with the
mattress structure partially deflated preparatory to
initiating CPR procedures.
Figure 22 comprises two perspective views
illustrating means for releasably attaching an air
hose to an air bag.
Figure 23 is an end elevation view illustrating
a means of attachment of an air bag to a base pad
according to the present invention.
Figure 24 is a side elevation view of an
alternative mattress structure arrangement according
to the present invention.
Figure 25 is an alternative base pad structure
according to the present invention.
Figure 26 is a top plan view of the air bags of
the mattress structure of Figure 17.
Figure 27 is a perspective view illustrating the
means of manufacture of air bags according to the
present invention.
Figure 28 is a side elevation view of the means
of Figure 27.
Best Mode for Carrying out the Invention
Referring now to the Drawing in which identical
or similar elements are given the same reference
numerals throughout the various figures thereof,
Figure 1 is an exploded perspective view of the bed
structure of the present invention, generally
indicated by the reference numeral 10, and Figures 2,
- l o- ~~~.~if~'~~
3, and 4 are, respectively, side elevation, end
elevation, and side elevation views of the bed
structure assembled, with Figure 4 showing the bed
structure adapted for use as an air bed. Bed
structure 10 includes first and second deck panels 12
and 14 having flanges 16 and 18 running the length of
deck panels 12 and 14, respectively, and extending
orthogonally downward from the inner edges thereof.
Flanges 16 and 18 can be joined along the length
thereof to form a flat horizontal deck.
Extending orthogonally downward from the outer
edges of first and second deck panels 12 and 14,
respectively, are side panels 20 and 22. Reinforcing
bulkheads 24, 26, and 28 are provided for attachment
to deck panels 12 and 14 and side panels 20 and 22.
Completing the basic bed structure are headboard 30
and footboard 32 attached to either end of the
structure formed by attached deck panels 12 and 14 and
side panels 20 and 22.
Although the basic bed structure may be employed
using only the elements described above, its weight
capacity would be somewhat limited. Accordingly, a
bottom panel 34 may be provided for attachment to
bulkheads 24, 26, and 28 and headboard 30 and
footboard 32 for greater reinforcement to permit
higher weight capacity. As will be described below,
bottom panel is also useful when bed structure 10 is
to be used in a low loss air bed embodiment.
Reinforcing members 36, 37, 38, and 39 may be
provided for attachment at the intersections of deck
panels 12 and 14 and side panels 20 and 22 to help
provide support for siderail structures, as generally
indicated by the reference numerals 42, 43, and 44
-1 1 _ ~.~i~~'~
(Figures 2-4), when such siderail structures are used
with bed structure 10.
For convenience in moving bed structure 10,
lockable casters, as at 48, 49, and 50, may be
provided at the lower edges of side panels 20 and 22.
Deck/side panels 12/20 and 14/22, bulkheads 24,
26, and 28 bottom panel 34 and reinforcing members 36-
39 are preferably formed from steel sheet and attached
by spot welding or riveting. The foregoing elements
may be 18-gauge in thickness. Headboard 30 and
footboard 32 are preferably constructed of plastic-
faced composition board and attached by means of
machine screws, as at 46 (Figure 3). Other materials
and attachment methods for the above elements may be
employed, if desired.
The seams formed between flanges 16 and 18 and
between deck panels 12 and 14 and headboard 30 and
footboard 32 are preferably sealed with a suitable
conventional sealant to prevent liquids from seeping
below the deck panels.
Figure 5 is an exploded perspective view of a
portion of a typical siderail structure, generally
indicated by the reference numeral 60, and Figure 6 is
a detail thereof. Siderail structure 60 includes a
mounting boss, generally indicated by the reference
numeral 62, which includes a flange portion 64 and a
shaft portion 66. Flange portion 64 may be mounted to
the side of a bed (not shown) by means of rivets or
screws, as at 67. Siderail structure 60 further
includes a vertical member 68 and a horizontal gate
member 70 formed as an horizontal extension of the
vertical member. Defined in the lower end of vertical
member 68 is a round opening 72 sized to closely
moveably engage shaft portion 66 of mounting boss 62,
-12-
and a threaded hole 74 extending from one edge of the
vertical member to the round opening and sized for
moveable engagement with threaded spring-loaded
locking pin 76. Completing siderail structure 60,
when assembled, is a stop pin 78 fixedly disposed at
the lower end of vertical member 68 for moveable
engagement with a groove 80 defined in flange 64 of
mounting boss 62, a spring washer 82 captured between
flat spacers 84 and 86, the latter spacers bearing
against flange 64 and the back surface of the vertical
member, respectively, a flat spacer captured between
the front surface of the vertical member and a
retaining ring 88 which releasably engages an annular
groove 92 on shaft portion 66 of mounting boss 62, and
a trim cap 94 which is attached to the distal end of
shaft portion 66.
In use, siderail structure 60 may be rotated 90
degrees between a closed position, as indicated by the
positions of siderail structures 42 and 43 on Figure
2~ and an open position, as indicated by the positions
of siderail structures 42 and 43 on Figure 4. When in
its closed position, stop pin 78 engages the upper end
of groove 80, as shown in solid lines on Figure 6,
thus holding the siderail structure against clockwise
motion. To move siderail structure 60 to its open
position, it is rotated 90 degrees counterclockwise so
that stop pin 78 engages the lower end of groove 80,
as shown in dashed lines on Figure 6, thus preventing
further counterclockwise motion of the siderail
structure. Because the center of gravity of siderail
structure 60 is relatively close to its balance point
when the siderail structure is rotated in either
direction, it is relatively easy to operate it through
a full cycle. To move sidewall structure 60 from its
13
open position, one need only exert relatively light
pulling force on it. Thus, sidewall structure 60 is
patient-operable.
Spring washer 82 introduces sufficient friction
into the movement of siderail structure 60 to impede
the motion thereof, thus preventing slamming of the
siderail structure from position to position.
If it is desired to lock siderail structure 60
into either its open or its closed position, one
engages locking pin into hole 96 or hole 98 (Figure
6), respectively, defined in shaft 66 on mounting boss
62. Locking pin 76 may be engaged into either locked
position by rotating the distal end of the spring-
loaded pin 90 degrees from the rest position, thereby
permitting selective indexing in either open or closed
positions.
Siderail structure 60 may be formed of any
suitable material, but is preferably formed from die
cast aluminum and suitably dimensioned for appropriate
strength. Other elements of siderail structure 60 may
be constructed of any suitable conventional materials.
In addition to providing a relatively light,
easily maneuverable siderail structure, the present
invention, employing two siderails on each side of a
bed, has an additional advantage. With a partially
mobile patient, the siderail structure at the foot of
the bed may be opened, while the that at the head of
the bed remains locked in its closed position, so as
to allow the latter to be used as a hand-hold to
assist the patient in exiting and entering the bed.
-14-
While bed structure 10 may be used as a light
and low- cost support of standard composite
mattresses, air mattresses, or water mattresses, it is
especially suited for adaptation to use as an air bed,
as will be described below.
Referring now to Figure 4, there is shown, in
side elevation, bed structure 10 adapted for use as an
air bed, including air bags 112, 113, 114, 115, and
116 disposed on the deck (not shown) of the bed
10 structure. Air bags 112-116 are held in place in
abutting relationship between headboard 30 and
footboard 32 by fastening to the side panels, such as
side panel 20 by means of snaps, as at 118. Over air
bags 112-116 may be disposed a vapor-permeable
15 mattress pad 120 which is held in place by fastening
to side panel 20 by means of snaps, as at 122.
Mattress pad 120 may be a microporous polyurethane-
coated nylon fabric.
The construction of a typical air bag, air bag
20 112, is shown in side elevation on Figure 7 and in top
plan view on Figure 8. Air bag 112 includes
rectilinearly disposed ends 130 and 132, bottom 134,
top 136, and sides 138 and 140. Formed as a downward
extension of side 138 is a snap flap 142 on which are
25 mounted snaps, as at 118. Disposed internally of air
bag 112 are bulkheads 144, 145, and 146 extending
between and attached to bottom 134 and top 136.
Bulkheads 144-146 keep top 136 relatively horizontal
and simulate in one bag the shape of four conventional
30 air bags. The convex segments thus obtained yieldably
support a patient without material wrapping around the
patient. The bag elements may be welded either
thermally or with RF sealing equipment. The material
of the bags is preferrably nylon fabric with an inside
-15 - i~'~~.~F '~~
polyurethane coating, an air bag fabric known in the
art, with the polyurethane material being that which
is fused during welding.
Air is supplied to air bag 112 through a nipple
148, which air inflates the air bag. Nipple 148
extends through a hole 149 (Figure 1) in deck panel 12
for attachment to an air supply hose (element 174 on
Figure 10). The air slowly flows from air bag 112
through orifices, as at 150, defined in top 136 of the
air bag. This flow of air dries any moisture which
may permeate through comforter 120 (Figure 4). The
air is preferrably supplied to air bags 112-116 at a
flow rate of on the order of about 10 CFM and at a
pressure of less than 26mm Hg which is the normal
capillary pressure of a normal person. Actual
pressures are determined by patient physiology and the
need to level the patient's spine for comfort.
The means by which air~.is supplied to air bags
112-116 is shown diagrammatically on Figure 9 and in a
fragmentary bottom plan view looking up, with the
bottom removed, of bed structure 10 on Figure 10.
Supply air is drawn through an opening 158 defined in
bottom 34 near the head end of bed structure 10
(Figure 1), through the internal space of the bed
structure, and through a filter 160 by a blower 162,
the motor of which is connected to an on/off switch
164 and an electrical supply cord 166. Filter 160 is
not shown in proper position on Figure 8, as it. is
actually mounted over opening 161 defined in bottom 34
of bed structure 10 (Figure 1), the reason for which
is described below.
Air from blower 162 passes through an air
silencer 168 and to a manifold 170. From manifold
170, the air flows through air flow control valves,
_ 16_ iG~IEiF'~~
such as flow control valve 172 which supplies air bag
112 (Figure 9), and through hoses 174, 175, 176, 177,
178, and 179. Hoses 174-178 supply air to air bags
112-116, respectively, while hose 179 discharges to
the atmosphere from flow control valve 180 so as to
permit control of the pressure in manifold 170. The
pressure in each of air bags 112-116, and therefore
the firmness or softness of each bag, can be
controlled through adjustment of its associated flow
control valve. With the five air bag arrangement, air
bag 112 is disposed so as to provide support for the
head of the patient's body, air bag 113 for the back,
air bag 114 for the seat, air bag 115 for the thigh,
and air bag 116 for the foot. It will be understood,
for example, that, on Figure 10, air bag supply hose
175 is connected to a nipple (not shown) to supply air
bag 113 with air.
Hoses 174-177 pass through bulkheads 24, 26, and
28, as shown on Figure 10, through openings defined in
the bul~:heads, as at 182, each of which bulkheads is
shown as having defined therein four openings, so as
to provide economy in the use of a standard part.
Filter I60 may be a conventional
filter/silencer, blower 162 may be a conventional
regenerative pressure blower, and silencer 168 may be
a conventional silencer, all as are commercially
available.
Figure 10 also illustrates how joined flanges 16
and 18 form a reinforcement member along the
longitudinal axis of bed structure 10.
Reference to Figures 1 and 10 indicates some of
the low noise features of the present invention as
applied to air beds. First, the air supply components
are disposed in a cavity 190 defined by deck/side
-17-
panels 12/20 and 18/22, bulkhead 28, footboard 32, and
bottom 34, with no openings directly from the cavity
to the surroundings. Blower 162 is mounted to deck
panel 14 rather than to bottom 34, which mounting
position tends to deaden sound and vibrations produced
by the blower. Rather than have air enter cavity 190
directly from the surroundings, which would present an
opening for the exiting of sound, the air is drawn
through opening 158 at the opposite end of bed
10 structure 10 and flows to the cavity at relatively low
velocity around baffles 24, 26, and 28 and through
holes 182 in the baffles. As described below with
reference to Figure 12, filter 160 covers and seals
opening 161 in cavity 190.
15 A further aspect of the present invention which
affords low noise level is the construction of the
flow control valves, such as flow control valve 172
shown in side elevation on Figure 11. Here, control
valve 172 is mounted in a frame and includes a section
20 of flexible tubing 202 a portion of the diameter of
which may be constricted by the advancement of a
convex member 204 disposed at one end of a threaded
shaft 206, at the other end of which shaft is fixedly
attached a knob 208. Shaft 206 passes through an
25 internally threaded boss 210 which is fixed to frame
200. Preferrably, a lubricant is disposed between
tubing 202 and convex member 204. Fitting 212 is
connected to tubing 202 to supply air thereto and
fitting 214 is connected to the tubing to supply air
30 therefrom. As is evident from Figure 11, rotating
shaft 206 so as to advance convex member 204 against
the wall of tubing 202 will cause the flow of air
through valve 172 to be diminished, while withdrawing
convex member 204 will increase the flow of air. It
-18 _ ~.'~f"
has been found that the shape formed by tubing 202 as
it is constricted inherently causes very little noise
to be produced as air flows through the tubing, due to
the shallow entry angle and smooth bore, in contrast
to the gate valves typically used in such air supply
systems, which gate valves are inherently noisy.
Figures 14 and 15 illustrate another embodiment
of a flow control valve according to the present
invention, generally indicated by the reference
numeral 280. Flow control valve includes a generally
rectilinear box-shaped bracket or frame 282 through
one wall 284 of which frame a partially threaded shaft
286 is rotatably disposed. Shaft 286 may be manually
rotated by means of a knob 290 fixedly attached to the
distal end of the shaft. Collars 290 and 292 fixed to
shaft 286 adjacent either side of wall 284 maintain
the shaft in fixed axial relationship with the wall.
The threaded proximal portion of shaft 286
engages the threaded end of a yoke 294 the arms of
which extend through a slot 296 formed in a wall 298
of frame 282. Assuming a normal right hand thread on
shaft 286, it can be seen from Figures 14 and 15 that
rotation of shaft 286 in the clockwise direction will
cause yoke 294 to be drawn to the right, while
rotation of shaft 286 in the counterclockwise
direction will cause yoke 294 to be pushed to the
left.
Fixed to the outer side of wall 298 and
maintaining yoke 294 in slot 296 is an anvil 300
having an outwardly convex cylindrical shape.
Disposed within the arc formed by the joined arms of
yoke 296 is a flexible tube 302 which has a fitting
304 at one end thereof to supply air thereto and a
fitting 306 at the other end thereof to supply air
-19-
therefrom. Tube 302 is disposed so that its axis is
parallel to the axis of cylindrical anvil 300.
It can be seen from inspection of Figures 14 and
15 that rotation of shaft 286 in the clockwise
5 direction will cause yoke 294 to press tube 302
against anvil 300 resulting in the formation of a
constriction of the tube between the yoke and the
anvil, thus decreasing the rate of flow of air
therethrough. Substantially the entire periphery of
tube 302 is contained at the plane of constriction,
with yoke 294 engaging at least one-half the outer
periphery of tube 302 and anvil 300 engaging a large
portion of the balance of the outer periphery of the
tube, so that very precise and repeatable flow control
may be achieved.
It has been found that PVC tubing is an
especially suitable material for tubing 202 and, for
the above application, tubing with a 5/8-inch ID and a
1/8-inch r,~all thickness is preferable.
20 Figure 12 is a exploded perspective detail view
showing the arrangement of filter 160. Filter 160
includes a pleated filter element 240 which fits
concentrically in a housing 242 and an end cap 244
which fits over the end of the filter element and is
25 held in place, and holds the filter element in the
housing and the housing on a plate 246, by means of a
wing nut 248 which engages the threaded end of a
retaining stud 250 attached to one end of the end cap
and which is passed through a hole 252 on the plate.
30 A hose 254 is attached to the other end of end cap 244
to supply filtered air to blower 162 (Figures 9 and
10).
-20-
Filter 160 is mounted to, and closes, opening
161 in bottom panel 34 by engaging a flange 256 formed
on plate 246 with an edge 258 of the opening, as shown
by the dashed arrows, and then rotating the plate into
5 its closed position against the bottom panel, also as
shown by the dashed arrows, and securing it in that
position by inserting the threaded end of a mounting
screw 260 through a hole 262 formed in the plate and
then advancing the mounting screw into a threaded hole
264 formed in the bottom panel.
When thus mounted, air enters filter 160 from
cavity 190 (Figure 10), flows around end cap 244 into
the annulus defined between filter element 240 and
housing 242, through the filter element, and then
15 through hose 254 attached to the end cap. Air is thus
supplied to blower 162 without having any opening
directly from cavity 190 to the surroundings, which
opening could be a conduit for the transmission of
airbourne noise.
20 The placement of filter 160, as shown on Figure
12, permits easy access thereto for cleaning or
replacement of filter element 240 by simply loosening
retaining nut 262 and swinging the filter away from
opening 161.
25 Figure 13 is a side elevation view of the bed
structure of the present invention showing an
embodiment thereof in which a portion of the bed deck
is inclinable, in which figure, elements the same as,
or similar to those shown on~Figures 1-4 are given
30 primed reference numerals. Here, bed structure 10' is
constructed the same as bed structure 10, but first
and second deck panels 12' and 14' are divided athwart
the bed structure so as to form the top of an
inclinable portion 220. Likewise, first and second
-21-
side panels 20'and 22' are divided (only panel 20'
visible) to form the sides of inclinable portion 220,
and headboard 30' is divided as shown. Deck panels
12' and 14' may be provided with a hinge structure at
5 222 and filler panels, as at 224, may be provided for
safety. An upper bottom panel 226 may be provided
along at the bottom of inclinable portion 220
extending between side panels 20' and 22' and
headboard 30'and a lower top panel 228 may be provided
10 extending between the side panels and the headboard.
The means by which inclinable portion 220 is raised
may be any conventional mechanism known in the art,
and may be the telescoping mechanism 230 shown on
Figure 13, and the mechanism used may be adapted by
15 conventional means known in the art to be patient
operable.
Inclinable portion 220 permits adjustment of bed
structure 10' so that a patient may be placed in a
convenient posture for reading or eating. A similar
20 inclinable portion may be provided at the foot of bed
structure 10' instead of, or in addition to,
inclinable portion 220.
Bed structure 10' is preferably constructed
according to the techniques shown and described above
25 with reference to bed structure 10 and may also be
adapted for use as an air bed as taught above.
Figures 16-21 illustrate an air bed system,
generally indicated by the reference numeral 400,
which, among other features, is highly portable and
30 which may be employed in a variety of circumstances.
Referring now to Figure 16, in which bed system
400 is shown ready for shipping or other relocation,
bed system includes only three major elements: a low
loss air mattress structure 12, shown deflated and
_ 2 2 _ iG~U~.~~'~
secured in a roll, an air supply 14, and a coil of
four air hoses 406-409. As can be seen from Figure
16, the entire system is secured to a small hand cart
412 for easy transport. Alternatively, bed system 400
could be boxed and, when so boxed, the overall
dimensions thereof are, for example, well within the
maximum dimensions set by the United Parcel Service of
(girth + length =) 130 inches maximum and the weight
thereof is less than the UPS maximum of 70 pounds, as
well as within the maximum dimensions set by the
United States Postal Service of (girth + width =) 100
inches maximum and the weight thereof is less than the
LISPS maximum of 70 pounds. Thus, a complete low loss
air bed system can be sent across the United States
for a very modest sum and can be air-freighted
anywhere in the world also at relatively low cost.
In Figure 17, mattress structure 402, still in
its deflated and rolled state, has been placed on the
springs 420 of a standard articulated hospital bed,
generally indicated by the reference numeral 422;
although, it will be apparent from inspection of the
drawing figures and from the following description
that the bed system would work quite satisfactorily if
the mattress structure were placed on any type of bed
or even, if necessary, on a large table or on a
floor. Air supply 404 has been conveniently hung from
a bracket 424 which has been placed over the
horizontal frame members of bed 422 and air supply
hoses 406-409 have been connected to the air supply.
It may be assumed that air supply 404 is similar to
that described with reference to Figures 9 and 10,
except that this air supply has been provided with its
own, conventional housing.
-23-
On Figure 18, mattress structure 402 has been
unrolled on bed 422 and inflated. Mattress structure
402 comprises, in this case, four air bags 440-443
(only a portion of 443 visible on Figure 18) of the
5 type described above with reference to Figures 4, 7,
and 8, attached to a base pad 446. Base pad 446 has
attached thereto a plurality of straps, as at 448,
which are buckled around the horizontal members of the
frame of bed 422 and which hold mattress structure 402
10 firmly in position on the bed. Disposed on strap 448
is a snap fitting 450 which may be used for attachment
thereto of a complementary snap fitting 452 on a strap
454 attached to a mattress cover 456 of the type
described above. Thus, mattress cover 456 is firmly
15 held in position over mattress structure 402 without
slipping.
As can be seen on Figure 18, air bag 443 is
inflated by means of hoses 409 attached thereto.
Figure 19 shows bed 422 and bed system 400 with
20 a patient reposed thereon, the bed having the back and
knee portions thereof elevated. This figure
illustrates and important advantage of the air bags of
the present invention. ~'ith conventional air bags,
the ends of the air structure must be supported so
25 that the air bags do not spill over the ends of the
bed. Here, as can be seen on Figure 19, the
structural rigidity of the air bags of the present
invention permit elevating the head~section of bed
422, yet no special provision need be made to support
30 the end of air bag 443 (under mattress cover 456) on
that section.
Figures 20 and 21 illustrate how bed system 400
may be made ready quickly for cardiopulmonary
resuscitation (CPR) procedures, which require that the
patient's back be supported on a firm surface in order
to perform manual chest compressions on the patient.
Figure 20 shows a patient lying on a fully inflated
mattress structure 402. (For greater clarity,
5 mattress cover 456 is not shown on Figures 20 and
21.) When CPR procedures are indicated, an attendant
(not shown) deflates air bags 442 and 443 by grasping
the ends of air hoses 408 and 409 at their connections
to the air bags and disconnecting them. On Figure 21,
10 the attendant has disconnected air hoses 408 and 409
from air bags 442 and 443 which have deflated, thus
lowering the back and seat portions of the patient to
be supported on the surface of base pad 446 (base pad
not visible on Figure 21). CPR can now be started by
15 a person climbing on top of the bed and beginning the
procedure. Keeping the foot and thigh portions of
mattress structure 402 inflated is preferred, as that
causes blood to flow to the head of the patient. The
deflation can be accomplished in 8-15 seconds and the
20 air supply controls do not have to be touched.
Figure 22 illustrates a preferred method of
assuring that the air hoses remain attached to the air
bags and cannot be accidentally disconnected. Since
bed system 400 is designed to be portable, it is
25 necessary that the ends of the hoses ma~~ be secured in
any orientation in which they may happen to be
connected to the air bags. Here, the end of a typical
air hose 466 is attached to an elbow connector 468
sized to fit over a flanged nipple 470 attached to an
30 air bag 472. A plate 474 rotatingly disposed on
nipple 470 has attached thereto the ends of straps 476
and 478. After hose 466 is connected to air bag 472,
straps 476 and 478 are placed over the hose and
connected together by means of a buckle (not shown) or
-25-
they may be Velcro material has shown) and require no
separate mechanical connecting mechanism. Thus,
regardless of the orientation of hose 466 about nipple
470, plate 474 may be rotated so that straps 476 and
5 478 can be positioned to releasably hold hose 466
securely in place.
The embodiment being described includes having
air hose connections to the sides of the air bags.
Alternatively, within the intent of the present
10 invention, air hose connections could be furnished on
the bottoms of the air bags. The former arrangement
is preferred, however, since it offers greater
flexibility in the types of surfaces with which the
bed system may be employed.
15 As illustrated above, base pad 446 is a single
piece of material and it has been found that a
preferred material is 1/8-inch thick neoprene rubber,
especially when mattress structure 402 is to be placed
over springs; although, any suitable material may be
20 employed, provided it has sufficient flexibility to be
rolled or folded into a suitable shape for shipping.
For example, other synthetic rubber materials,
reinforced or not, fabric mats, or even slats
interleaved with webbing, as illustrated on Figure 25
25 may be employed. The bottom panels of the air bags
may also serve as base pads, Figure 24 illustrating
how such air bags could be joined together by means of
snaps, as shown, or by other mechanical means.
Figure 23 illustrates how air bags 440-443 are
30 preferably attached to base pad 446. Here, air bag
440 is shown as being attached to base pad 446 by
means of a plurality of snap fittings, as at 484 and
486.
-26-
Bed structure 10 described above employed five
air bags 112-116, each having four compartments.
While that arrangement is quite satisfactory, it has
been found that the arrangement of air bags 440-443
5 can improve patient comfort in some cases. Figure 26
illustrates such an arrangement wherein it can be seen
that each of air bags 440 and 443 has seven
compartments, while each of air bags 441 and 442 has
four compartments.
10 Figure 27 illustrates the preferred method of
fabricating an air bag. Here, there is first formed
an open sleeve, generally indicated by the reference
numeral 490, comprising bottom 492, top 494, and sides
496 and 498. Then, bulkheads 500-505 are positioned
15 over fixture 508 and the fixture with the bulkheads
thereon is inserted in sleeve 490. Referring now to
Figure 28, sleeve 490 is then placed on a base plate
512 and an RF platen is lowered to top 494 of the
sleeve. RF energy heats fixture 508 and the upper and
20 lower edges of bulkheads 500-505 are thereby welded to
top 494 and bottom 492. Finally, the ends of the air
bag are welded to either end of the sleeve to complete
the fabrication. Such a method of fabrication
provides a rapid and economical method of fabricating
25 air bags or similar articles having internal
bulkheads. Fixture 508 is preferably aluminum or
brass.
It will thus be seen that the objects set forth
above, among those made apparent from the preceding
30 description and the accompanying drawing figures, are
efficiently attained and, since certain changes may be
made in the above construction without departing from
the scope of the invention, it is intended that all
matter contained in the above description or shown on
the accompanying drawing figures shall be interpreted
as illustrative only and not in a limiting sense.
It is also to be understood that the following
claims are intended to cover all of the generic and
specific features of the invention herein described
and all statements of the scope of the invention
which, as a matter of language, might be said to fall
therebetween.
