U.S. patent application number 11/222687 was filed with the patent office on 2007-03-15 for zoned cellular cushion with fail safe inflation zones.
Invention is credited to Robert H. Graebe.
Application Number | 20070056112 11/222687 |
Document ID | / |
Family ID | 37853557 |
Filed Date | 2007-03-15 |
United States Patent
Application |
20070056112 |
Kind Code |
A1 |
Graebe; Robert H. |
March 15, 2007 |
Zoned cellular cushion with fail safe inflation zones
Abstract
A pattern of airflow pathways among inflatable air cells in an
inflatable air cell cushion that result in discrete, isolated
inflation zones that allow the optimal immersion depth and support
of a seated,user when fully inflated and maintain acceptable
immersion depth and support of the seated user in the event of an
air leak from one of the inflation zones. The airflow pathways are
operably connected to a valve wherein opening of the valve places
the normally isolated inflation zones in fluid communication and
closing of the valve isolates the inflation zones.
Inventors: |
Graebe; Robert H.; (Fort
Lauderdale, FL) |
Correspondence
Address: |
POLSTER, LIEDER, WOODRUFF & LUCCHESI
12412 POWERSCOURT DRIVE SUITE 200
ST. LOUIS
MO
63131-3615
US
|
Family ID: |
37853557 |
Appl. No.: |
11/222687 |
Filed: |
September 9, 2005 |
Current U.S.
Class: |
5/655.3 ;
5/654 |
Current CPC
Class: |
A47C 4/54 20130101; A61G
5/1045 20161101; A47C 27/10 20130101; A47C 27/082 20130101; A61G
5/1043 20130101; A61G 7/05769 20130101 |
Class at
Publication: |
005/655.3 ;
005/654 |
International
Class: |
A47C 27/10 20060101
A47C027/10 |
Claims
1. An inflatable cellular cushion for the support of a seated user,
comprising: a base having a front edge, a rear edge, a first side
edge and a second side edge; an array of individual upstanding
inflatable air cells on said base, said array of air cells arranged
in rows and forming a supportive seating area; a plurality of air
conduits, each said air conduit being in fluid communication with a
separate group of said individual cells to form a first
substantially rectangular centrally positioned inflation zone, a
second inflation zone positioned substantially surrounding said
centrally positioned inflation zone on three sides, a third
inflation zone extending along one side of the second inflation
zone, and a fourth inflation zone extending along an opposite side
of the second inflation zone; and a valve in fluid communication
with said plurality of air conduits, said valve capable of being
manipulated from an open position wherein all of the recited
inflation zones are in fluid communication through the valve, to a
closed position wherein the recited inflation zones are out of
fluid communication with each other.
2. In an inflatable cellular cushion having a base and an array of
individual upstanding inflatable air cells arranged in rows across
the base, a pattern of air flow pathways among the inflatable air
cells, said pattern of air flow pathways creating at least two
normally isolated inflation zones that maintain optimal positioning
of a user seated on the cellular cushion when the inflation zones
are inflated and also maintain adequate positioning of the user
seated on the cellular cushion if at least one of the at least two
inflation zones deflates.
3. The pattern of air flow pathways of claim 2 wherein the air flow
pathways create three normally isolated inflation zones.
4. The pattern of air flow pathways of claim 2 wherein the air flow
pathways create four normally isolated inflation zones.
5. An inflatable cellular cushion for the support of a seated user,
comprising: a base; an array of individual inflatable air cells on
said base; at least two air conduits, each of said air conduits
interconnecting a separate series of individual cells forming an
inflation zone of interconnected cells, each of said inflation
zones being positioned on the cushion so as to provide optimal
positioning and immersion of a user seated on the cellular cushion
when the inflation zones are inflated and also maintain adequate
positioning and immersion of the user seated on the cellular
cushion if at least one of the at least two inflation zones
deflates.
6. The inflatable cellular cushion of claim 5 further comprising a
valve in fluid communication with said at least two air conduits,
said valve capable of being manipulated from an open position
wherein all of the recited inflation zones are in fluid
communication through the valve to a closed position wherein the
recited inflation zones are out of fluid communication with each
other.
7. The inflatable cellular cushion of claim 5 wherein the
inflatable air cells are molded neoprene.
8. An inflatable air cell cushion that is resistant to complete
cushion failure in the event of an air leak from at least one air
cell comprising: a base with an array of individual inflatable
cells thereon, said array of cells being divided into at least two
discrete inflation zones comprising interconnected air cells, said
at least two discrete inflations zones positioned so that a
supportive portion of each inflation zone is positioned under a
seated user to provide positioning and support in use and so that a
supportive portion of at least one inflation zone remains inflated
under the seated user in the event another of said zones
deflates.
9. The inflatable air cell cushion of claim 8 comprising at least
three discrete inflation zones.
10. The inflatable air cell cushion of claim 8 comprising at least
four discrete inflation zones.
11. An inflatable cellular cushion for the support of a seated
user, comprising: a base having a front edge, a rear edge, a first
side edge and a second side edge; an array of individual upstanding
inflatable air cells on said base, said array of air cells arranged
in rows and forming a supportive seating area; a plurality of air
conduits, each said air conduit being in fluid communication with a
separate group of said individual cells to form a plurality of
individual inflation zones; wherein said supportive seating area
comprises a pattern of said individual inflation zones that
provides proper positioning and immersion of the user seated on the
supportive seating surface when the inflation zones are inflated
and also maintains adequate positioning and immersion of the user
seated on the supportive seating area if at least one of the
individual inflation zones deflates.
12. The inflatable cellular cushion of claim 11 further comprising
a valve in fluid communication with said plurality of air conduits,
said valve capable of being manipulated from an open position
wherein all of the recited inflation zones are in fluid
communication through the valve, to a closed position wherein the
recited inflation zones are out of fluid communication with each
other.
13. The inflatable cellular cushion of claim 11 further comprising
a first substantially rectangular centrally positioned inflation
zone, a second inflation zone positioned substantially surrounding
said centrally positioned inflation zone on three sides, a third
inflation zone extending along one side of the second inflation
zone, and a fourth inflation zone extending along an opposite side
of the second inflation zone.
14. The inflatable cellular cushion of claim 11 further comprising
a first centrally positioned inflation zone extending from the
front edge of the base to the rear edge of the base; a second
inflation zone positioned on each side of the first inflation zone;
a third inflation zone positioned on each side of the second
inflation zone; and a fourth inflation zone positioned on each side
of the third inflation zone.
15. The cushion of claim 11 wherein the array of individual
inflatable cells are molded from neoprene.
16. An inflatable cellular cushion for the support of a seated
user, comprising: a base; an array of individual upstanding
inflatable air cells on said base, said array of air cells forming
a supportive seating area; a plurality of air conduits, each said
air conduit being in fluid communication with a separate group of
said individual cells to form a plurality of individual inflation
zones; a valve in fluid communication with said plurality of air
conduits, said valve capable of being manipulated from an open
position wherein all of the recited inflation zones are in fluid
communication through the valve, to a closed position wherein the
recited inflation zones are out of fluid communication with each
other; wherein said supportive seating area comprises a pattern of
said individual inflation zones that provides proper positioning
and immersion of the user seated on the supportive seating surface
when the inflation zones are inflated and also maintains adequate
positioning and immersion of the user seated on the supportive
seating area if at least one of the individual inflation zones
deflates while said valve is in a closed position.
17. The inflatable air cell cushion of claim 16 comprising three
air conduits and three individual inflation zones.
18. The inflatable air cell cushion of claim 16 comprising four air
conduits and four individual inflation zones.
19. The inflatable air cell cushion of claim 16 wherein said valve
further comprises a slide valve.
20. The inflatable air cell cushion of claim 16 wherein each
quadrant of the supportive seating area comprises at least two
individual inflation zones.
21. The inflatable air cell cushion of claim 16 wherein each
quadrant of the supportive seating area comprises at least three
individual inflation zones.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
BACKGROUND OF THE INVENTION
[0002] This invention relates in general to inflatable mattresses
and cushions and, more particularly, to improved air flow pathways
among the inflatable cells comprising an inflatable cellular
cushion, resulting in normally isolated inflation fail-safe
inflation zones under vulnerable areas of a seated user's anatomy
in the event there is an air leak in a cell that results in
deflation of at least one other normally isolated zone.
[0003] Individuals who are confined to wheelchairs run the risk of
tissue breakdown and the development of pressure sores, which are
extremely dangerous and difficult to treat and cure. Typically,
much of the individual's weight concentrates in the region of the
ischia, that is, at the bony prominence of the buttocks, and unless
frequent movement occurs, the flow of blood to the skin tissue in
these regions decreases to the point that the tissue breaks down.
Wheelchair cushions exist that reduce the concentration of weight
in the region of the ischia, and these cushions are designed to
distribute the user's weight more uniformly over a larger area of
the buttocks.
[0004] Cellular cushions provide the most uniform distribution of
weight and thus provide the greatest protection from the occurrence
of pressure sores. These cushions have an array of closely spaced
air cells that project upwardly from a common base. Within the base
the air cells communicate with each other, and thus, all exist at
the same internal pressure. Hence, each air cell exerts essentially
the same restoring force against the buttocks, irrespective of the
extent to which it is deflected. The inventor's U.S. Pat. No.
4,541,136 shows a cellular cushion currently manufactured and sold
by ROHO, Inc. of Belleville, Ill., for use on wheelchairs.
[0005] A cellular cushion should provide a highly displaceable
surface that tends to float the user. While this reduces the
incidence of pressure sores, in rare instances it can detract from
the stability one usually associates with a seating surface. Most
persons confined to wheelchairs have little trouble adjusting to
the decrease in stability, but for those who have skeletal
deformities, particularly in the region of the pelvis and thighs,
and for those who lack adequate strength in their muscles, lesser
stability can be a source of anxiety. A variation of the cellular
cushion addresses this problem with totally isolated zones and also
with cells of varying height. By varying the volume of air between
zones, for example, one can accommodate for skeletal deformities
while still maintaining satisfactory protection against pressure
sores. U.S. Pat. No. 4,698,864 shows zoned cellular cushion with
cells of varying height designed by the present inventor. U.S. Pat.
No. 5,163,196 and U.S. Pat. No. 5,502,855 disclose other zoned
cellular cushions having isolated inflation zones.
[0006] The industry has seen an improvement in valves required by
zoned cellular cushions. Early zoned cushions, such as those
disclosed in the afore mentioned patents, employed integral
channels which lead from the several zones and which are connected
through an integral common manifold and associated valve. One such
valve comprises a flap that is folded over to seal off the ends of
the channels or opened to allow communication between the zones
through a manifold contained within the flap. However, in the
flap-type valve, the flap is manually folded closed and secured
with a snap or the like.
[0007] Newer valves designed to be easier to manipulate and
minimize air leakage are the subject matter U.S. Pat. No. 6,687,936
and U.S. Pat. No. 6,687,936, both of which are incorporated herein
by reference. These valves, which can be referred to broadly as
slide valves, when employed for example with a zoned cushion having
a plurality of inflation zones, provide an easily manipulated valve
assembly which can be used to allow fluid communication between two
or more zones or can be used to isolate the zones. The valve also
provides structure for attaching the valve to the cushion to help
prevent dislocation and leakage.
[0008] The valve, in general, includes a casing having an internal
bore and a plurality of openings along the length of the casing
that open into the bore. The openings are connected to the
individual inflation zones via tubing or the like to place the bore
of the casing in communication with the inflation zones. The valve
also includes a movable slide seated snugly within the casing bore.
The slide has a longitudinal internal bore and a number of openings
along its length that communicate with the slide bore. Generally
the number of openings in the slide is the same as the number of
openings in the valve casing. The openings are isolated by seals
positioned on each side of the opening to form discrete air
chambers at each opening. The slide can be manipulated to align the
discrete air chambers with the casing openings so as to
functionally align the slide openings with the casing openings to
allow the inflation zones to communicate and the air to flow to and
from the various inflation zones through the valve slide bore.
Correspondingly, the slide can be manipulated to move the slide
openings and the casing openings out of alignment, thereby sealing
off the inflation zones.
[0009] Heretofore, these novel slide valves have been employed with
zoned cellular cushions comprising four inflation zones, generally
the four quadrants of the cushion. As can be appreciated by one
skilled in the art, a user optimally positioned on such a cushion
has support under the entire buttocks, particularly the vulnerable
ischial area. However, if the quadrants are sealed off or isolated,
and a leak develops in a quadrant, the entire quadrant can deflate
and bottom out. There is a corresponding change in immersion depth
at the entire quadrant of the cushion and the seated user's pelvic
position will change from the initial position. A substantial area
of the user's buttocks also could be vulnerable to pressure sores.
It would be advantageous, therefore, to have air flow patterns in
the cushion that create inflation zones that offer support and
stability to the user, but also create discrete, isolated inflation
zones under the most vulnerable area of the buttocks. In the event
one zone deflates, there still is sufficient support under the
vulnerable areas to maintain user stability and to prevent complete
bottoming-out.
SUMMARY OF THE INVENTION
[0010] In an inflatable cellular cushion having a base and an array
of individual upstanding inflatable air cells, a pattern of air
flow pathways among the inflatable air cells that create a pattern
of normally isolated inflation zones that maintain optimal
positioning and support of a user seated on the cellular cushion
when the inflation zones are inflated and also maintain adequate
positioning and support of the user seated on the cellular cushion
if at least one of inflation zones fails and deflates.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0011] The various aspects of the invention are achieved as set
forth in the illustrative embodiments shown in the drawings, which
form a part of the specification.
[0012] FIG. 1 is a top perspective view of a zoned cellular
cushion;
[0013] FIG. 2 is a bottom plan view of a prior art zoned cellular
cushion;
[0014] FIG. 3 is schematic of one embodiment of air passage
patterns and inflation zones of the present invention;
[0015] FIG. 4 is schematic of another embodiment of air passage
patterns and inflation zones of the present invention; and
[0016] FIG. 5 is schematic of another embodiment of air passage
patterns and inflation zones of the present invention.
[0017] Corresponding reference numerals refer to corresponding
elements of the invention throughout the accompanying drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Referring now to FIG. 1, the letter C designates one
exemplary embodiment of a cellular cushion which is highly flexible
and is designed for use on an underlying supporting surface, such
as the seat of a wheelchair, the seat of a vehicle or the seat of a
conventional chair. Being cellular, when inflated, cushion C
distributes the weight of its occupant generally uniformly over the
entire area of the buttocks and thereby dissipates the pressures
resulting from the supported weight of the ischia, that is, the
bony prominence of the buttocks. It further has the capacity to
position and stabilize the user. Cushion C can incorporate airflow
pathways and inflation zones of the prior art, as shown in FIG. 2,
or the novel airflow pathways and inflation zones of the present
invention, which will be described in greater detail below.
[0019] In general, cushion C includes a base 2 and individual,
inflatable air cells 4 that project upwardly from the base 2.
Generally the air cells 4 are molded as a conformal having a web 5
interconnecting the cells 4. The base is comprised of the web and a
backing 3. Both the backing 3 and the air cells 4 preferably can be
molded or otherwise formed from a highly flexible neoprene. The
cells 4 and web 5 may be formed from neoprene over a mandrel in a
dipping operation as described in U.S. Pat. No. 4,541,136, which is
incorporated herein by reference.
[0020] On the other hand, the air cells 4 can be molded from a
highly flexible neoprene and the base 2 can be vacuum formed of the
web and a backing formed from polyurethane, for example, and
appropriately attached to the conformal. The cushion also can be
fashioned from other materials, such as vacuum or injection or
rotational molded plastic materials. An inflatable air cell cushion
of any material can employ the novel features of the present
invention. The base also can be a semi-flexible or rigid base
without departing from the scope of the invention.
[0021] The base 2 generally is rectangular and the cells 4 are
arranged on it in longitudinal and transverse rows, with each cell
occupying both a longitudinal and a transverse row. It will be
appreciated that although the illustrated embodiment provides for
individual cells each having a configuration consisting of four
fins F, the configuration of the individual cells is incidental to
the invention. The present invention can be used with a cushion
employing any preferred configuration of cells 4, that is, for
example, cells having any number of fins or sides, cells having no
fins, for example, cylindrical, cubical cells or rounded cells.
[0022] The array of cells 4 forms a supportive seating area when
the cells are appropriately inflated.
[0023] In prior art cushions, such as cushion C2 in FIG. 2, the
cells 4 are further arranged in zones, typically in the prior art
four zones r, s, t and u. The zones r and s lie side by side at the
front of the cushion C2 and the zones t and u exist side by side at
the rear of the cushion A. The right zones rand u are separated
from the left zones s and t along a longitudinal axis x, whereas
the front zones r and s are separated from the rear zones t and u
along a transverse axis y.
[0024] Within the base 2 the cells 4 of the zone r communicate with
each other, so that all exist at the same general internal pressure
irrespective of how far any individual cell is depressed. The same
holds true with regard to the cells 4 of the zone s, the cells 4 of
the zone t, and the cells 4 of the zone u. In other words, the
cells 4 of zone rare normally isolated from the cells of the
remaining zones s, t and u. Likewise, the cells 4 of the zone s are
normally isolated as are the cells 4 of zones r, t and u and so
forth. Thus, the cells 4 of each zone r, s, t and u collectively
define a separate inflation zone or compartment.
[0025] A fluid conduit 6 or air passage extends from zone t toward
the front of the cushion. Likewise a fluid conduit 8 extends from
zone u to the front of the cushion. Two shorter conduits 10 and 12
extend from zones s and r respectively toward the front of the
cushion. The conduits 6, 8, 10 and 12 all terminate near an edge of
the cushion and are in fluid communication with the cushion valve
20, as will be explained below. It also will be appreciated that
the various conduits can be formed in any appropriate manner
without departing from the scope of the invention. For example, the
conduits can be formed integrally in the base 2 when the base is
molded or vacuum formed.
[0026] The prior art embodiment of FIG. 2 includes a prior art
configuration of conduits. The conduits can be formed in any
acceptable manner that results in access to the conduits at one
location on the periphery of the cushion so that a valve can be
utilized. By way of example, the conduits can be formed into the
web 5 or can comprise separate tubing without departing from the
scope of the invention. An air filling valve 14 is located at zone
r that is opened and closed simply by turning its end. It will be
appreciated, however, that the air fill valve can be located at any
desirable and convenient location on the cushion.
[0027] The conduits 6, 8, 10 and 12 are operatively connected to a
slide valve 20. When closed, the valve 20 isolates the cells 4 of
the several zones r,s,t and u. But when opened, it interconnects
the zones r, s, t, and u, so that the interiors of all the cells 4
in all zones are in communication and, therefore, all exist at the
same internal pressure. The air filling valve 14 enables air to be
pumped into the cells 4 of the zone in which it is located and,
when the valve 20 is open, the air inflates the cells 4 of all of
the zones r, s, t and u. Use of only one air-filling valve 14
insures all of the cells 4 in the zones r, s, t, and u will be at
the same initial pressure, even though the volume of air in the
cells or zones may vary in use.
[0028] Valve 20 is constructed according to the teachings of U.S.
Pat. No. 6,687,936 or U.S. Pat. No. 6,564,410, both of which are
incorporated herein by reference. In general, when valve 20 is in
the open position, the respective inflation zones of the cushion
are in fluid communication with each other via conduits 6, 8, 10
and 12 through the open slide valve 20. In a closed position, the
ends of conduits 6, 8, 10 and 12 are sealed off and the inflation
zones are isolated.
[0029] The use of a valve that allows intercommunication to
initially perform the immersion calibration and then perform a
posture adjustment and then can be closed for isolation of air
passages allows a means to hold the selected posture and enhance
overall stability of the user while enjoying the benefits of
optimum shape fitting, with floatation support to facilitate blood
flow. A system is considered stable if it returns to its original
position/condition after a disturbing force is removed. The
cushions of the present invention maintain a posture and a high
degree of stability resistive forces must exist. The designs
provide for as many evenly distributed resistive forces as possible
especially when there is reduction in the initial number of active
force elements.
[0030] In order to prepare the cushion C2 for the user, the valve
20 is opened to open the conduits 6, 8, 10 and 12 and thereby
allows the conduits to be in fluid communication with the bore of
the valve slide which places the four zones r, s, t and u in
communication through the valve slide bore. The air-filling valve
14 is opened and air is pumped into it with a pump, which connects
to the valve 14.
[0031] The air initially flows into the cells of zone r, but since
the cells of the remaining zones s, t and u are in communication
with the cells of zone r through the open valve, all of the cells 4
are inflated and the cells 4 reach a state of equilibrium. Enough
air is pumped into the cushion C2 to exceed the requirements for
supporting the user. The valve 14 then is closed and the pump
removed.
[0032] Next, the over-inflated cushion C2 is placed on the
supporting surface upon which it is to rest when supporting a user.
The user then sits upon the cushion C2 in the location he or she
expects to assume and slowly releases air from the air filling
valve 14 to immerse the user. As air is released, the user's
buttocks sink deeper and deeper into the array of cells 4, and they
tend to envelop and assume the contour of the buttocks. Enough air
is released to bring the region of the ischia to within about
1/2inch of the base 2. Of course, as air flows out of the cushion
C2 all of the cells 4 remain at essentially the same internal
pressure because they are interconnected through the open valve.
When the user achieves the desired immersion, the air filling valve
14 is closed.
[0033] While immersed in the cells of the cushion C2, and the valve
20 is open, the user moves, or is moved by others, to the posture
desired to be maintained for an extended period and this causes a
redistribution of air amongst the cells 4 of the several zones r,
s, t and u. In time, the cells 4 of the several zones r, s, t and u
reach equilibrium, that is to say, the flow between the zones r, s,
t and u ceases. At this time the valve slide is manipulated to a
closed configuration, thereby preventing air flow through the slide
bore and thus isolating the zones r, s, t, and u.
[0034] It will be appreciated by those skilled in the art that each
quadrant of the prior art cushion includes only one individual
zone, e.g. r,s,t and u. A user seated substantially centrally on
cushion C2 would have his or her ischial area supported by a
portion of each quadrant. If a leak develops in any of the four
inflation zones, the entire cushion quadrant can completely
deflate, resulting in a bottoming out of that section of the zoned
cellular cushion. If undetected, the seated user's immersion depth
is altered and the user can become destabilized. The seated user
also could develop pressure sores on that area of the anatomy
positioned on the deflated quadrant. The fail safe inflation zone
patterns of the present invention, as will not be described in
detail, can prevent such a failure.
[0035] FIG. 3 illustrates an inflatable cellular cushion, indicated
generally at C3, including air flow pathways through interconnected
cells that can not only create novel inflation zone patterns that
can optimally immerse and position a seated user when fully
inflated, but can also maintain satisfactory immersion depth and
positioning in the event of an air leak from any of the isolated
zones. The terms air passages, air flow passages, air flow passage
patterns, air passage designs, air flow circuits and so forth are
intended to broadly include that air flow between or among
individual inflatable cells that create an inflation zone
comprising those interconnected cells. Hence, different air flow
passage patterns will result in different inflation zone
patterns.
[0036] In general, cushion C3 will include a base and air cells,
such as air cells 4 that project upwardly from the base and may be
formed from dip-molded neoprene as described in U.S. Pat. No.
4,541,136. Other designs of cellular cushions constructed from
alternative materials and molded by other molding techniques, such
as vacuum molded polyvinyl chloride cellular cushions, also fall
within the scope of the invention.
[0037] In any event, cushion C3 includes an air filling valve 14
and slide valve 20, which are positioned on what will be referred
to for purposes of orientation as the front of the cushion. Slide
valve 20 is constructed and functions as described above. Slide
valve 20, as employed with cushion C3, accommodates three conduits
22, 24 and 26.
[0038] As shown, conduit 22 is in fluid communication with a series
of interconnected cells. Because the cells are interconnected,
there is an airflow pathway, indicated schematically at 22A,
through these cells and the interconnected cells form an inflation
zone a. Zone a comprises four alternating rows of interconnected
cells, evenly spaced from the front of the cushion to the back of
the cushion.
[0039] Conduit 24 is in fluid communication with a series of
interconnected cells that comprise a normally isolated inflation
zone b having an internal air flow pathway indicated schematically
at 24A. Zone b comprises three alternating rows of interconnected
cells from front to back of the cushion in the approximate front
two-thirds of the cushion.
[0040] Conduit 26 is in fluid communication with a series of
interconnected cells that comprise a normally isolated inflation
zone c which has an internal airflow pathway 26A. Zone c comprises
two spaced apart rows of interconnected cells, occupying the
approximate back one-third of the cushion. There is one row of
cells from zone a positioned between the two rows of zone c. It
will be appreciated by those skilled in the art that when a user is
appropriately positioned on cushion C3, the predominant portion of
the user's critical ischial region will be supported by the last
four or five rows of cells or the approximate rear one-third to
one-half of the cushion. Hence, the predominant portion of the
user's ischial area will be supported primarily by zone c and at
least one row of cells from inflation zone a.
[0041] Referring to FIG. 3, it is seen that the three inflation
zones a, b and c, form a contiguous support surface across the
expanse of cushion C3. For use, the user is appropriately
positioned on the cushion, as described above in reference to prior
art cushion C. In summary, the valve 20 is opened to open conduits
22, 24 and 26 and thereby allows the conduits to be in fluid
communication with the bore of the valve slide which places the
four zones a, b and c in communication through the valve slide
bore.
[0042] The air-filling valve 14 is opened and air is pumped into it
with a pump. The air initially flows into the cells of zone b, but
since the cells of the remaining zones a and c are in communication
with the cells of zone b through the open valve, all of the cells 4
are inflated and the cells 4 reach a state of equilibrium. Enough
air is pumped into the cushion C3 to exceed the requirements for
supporting the user. The valve 14 then is closed and the pump
removed.
[0043] Next, the over-inflated cushion C3 is placed on the
supporting surface upon which it is to rest when supporting a user.
The user then sits upon the cushion C3 in the location he or she
expects to assume and slowly releases air from the air filling
valve 14 to immerse the user. As air is released, the user's
buttocks sink deeper and deeper into the array of cells 4, and they
tend to envelop and assume the contour of the buttocks. Enough air
is released to bring the region of the ischia to within about 1/2
inch of the base of the cushion. As air flows out of the cushion
all of the cells 4 remain at essentially the same internal pressure
because they are interconnected through the open valve. When the
user achieves the desired immersion, the air filling valve 14 is
closed.
[0044] While immersed in the cells of the cushion C3, the valve 20
is opened, the user moves, or is moved by others, to the posture
desired to be maintained for an extended period and this causes a
redistribution of air amongst the cells 4 of the several zones a, b
and c. The cells 4 of the several zones a, b and c reach
equilibrium. When the user reaches the desired posture, the valve
20 slide is closed to prevent air flow through the slide bore, thus
isolating the zones a, b and C.
[0045] The inventor has determined that the configuration of zones
a, b and c provide appropriate stability and support to the seated
user. However, as can be appreciated, the user's buttocks are
supported by at least a portion of each zone a, b and c. For
example, each of the four quadrants of the cushion defined by the x
and y axes contain at least two inflation zones. The rear two
quadrants include all three inflation zones. Consequently, if a
leak develops in an air cell, and one or more of the normally
isolated zones a, b or c deflates, the seated user will be
adequately supported and positioned by those zones that remain
inflated to prevent destabilization and possible injury due to
bottoming out. Hence, cushion C3 includes fail safe air flow
patterns and fail safe inflation zones.
[0046] FIG. 4 illustrates an inflatable cellular cushion, indicated
generally at C4, that includes another embodiment of novel air flow
passage and inflation zone patterns that result in inflation zones
that allow optimal immersion and positioning of a seated user when
fully inflated, but can also maintain satisfactory immersion depth
and positioning stability in the event of an air leak from any of
the isolated zones. In general, cushion C4 includes a base and air
cells, such as air cells 4 that project upwardly from the base.
There is a slide valve 20 and inflation valve 14 at the front of
the cushion. Valve 20 is in fluid communication with four air
conduits, 28, 30, 32 and 34 and functions as described above.
[0047] Conduit 28 is in fluid communication with air flow pathway
28A among a series of interconnected cells that comprise an
inflation zone d. Conduit 30 is in fluid communication with a
series of interconnected cells forming air flow pathway 30A that
forms an inflation zone e. Likewise, conduit 32 is in fluid
connection with a series of interconnected air cells forming air
flow pathway 32A resulting in inflation zone f. And conduit 34 is
in fluid communication with a series of interconnected air cells
through air flow pathway 34A that comprise inflation zone g. In
this illustrated aspect of the invention, the inflation zones are
arranged in a generally concentric pattern, with generally
centrally positioned zone f being flanked by zone g; zone g is
flanked by zone e; and zone e is flanked by zone d.
[0048] Cushion C4 is set up and inflated in a manner similar to the
cushions described above so that the seated user is optimally
supported and stabilized. However, it can be recognized from the
arrangement of zones d, e, f and g that failure of any one zone
would not result in complete bottoming out of the cushion, since an
adjacent zone would provide sufficient support to prevent a
catastrophic failure. For example each quadrant of cushion C4 as
defined by the x and y axes contains at least three of the
individual inflation zones. Hence, cushion C4 also includes a
failsafe design.
[0049] Cushion C5, shown schematically in FIG. 5, is another
embodiment of a cushion of the present invention employing air flow
pathways that result in normally isolated discrete inflation zones
that provide sufficient support and positioning of a patient even
in the event of a leak, and deflation of at least one of the
individual inflation zones. Cushion C5 is constructed in a manner
described above and includes a base with an array of individual
inflatable cells 4. Cushion C5 includes a slide valve 20 and an
inflation valve 14 at the forward edge. Slide valve 20 is in fluid
communication with four air conduits, these conduits are in fluid
communication with air flow pathways 36, 38, 40, and 42.
[0050] Conduit 36 is in fluid communication air flow pathway 36A
among a series of interconnected cells that comprise an inflation
zone h. Conduit 38 is in fluid communication with a series of
interconnected cells forming air flow pathway 38A that forms an
inflation zone i. Likewise, conduit 40 is in fluid connection with
a series of interconnected air cells forming air flow pathway 40A
resulting in inflation zone j. And conduit 42 is in fluid
communication with a series of interconnected air cells through air
flow pathway 42A that comprise inflation zone k.
[0051] In this illustrated aspect of the invention, the inflation
zone j is rectangular in configuration and located generally in the
center of the cushion. Zone i is positioned on both sides of and
behind zone j, substantially surrounding zone j on three sides.
Zone h extends along the length of one side and approximately half
of the rear edge of the cushion. Zone k extends along the length of
the opposite side and the other half of the rear edge of the
cushion. As can be appreciated from FIG. 5, even if zone j would
fail, zones h, i and k would appropriately and safely support a
seated user, particularly the critical ischial area. Likewise, if
either zone h, i or k failed, the seated user would be safely and
appropriately supported by the remaining inflated zones.
[0052] Cushion C5 is set up and inflated in a manner similar to the
cushions described above so as to optimally support and stabilize
the seated user. Each quadrant of cushion C5 as defined by the x
and y axes contains at least three of the individual inflation
zones. Hence, Cushion C5 also includes a failsafe design. In the
event of failure, the remaining inflated zones provide adequate
support and stabilization for the user. Cushion C5 has particular
advantages in that if zone h or k fail, the other of the zones
still would provide some support across the rear edge of the
cushion so that the user remain would remain positionally stable
front to back, while zone i helps maintain lateral support and
stability.
[0053] It will be appreciated that the cushions heretofore
described provide inflation zone patterns that provide optimal
immersion and positioning when fully inflated, while also providing
acceptable immersion and positioning if there is deflation of a
zone. These inflation zone patterns are intended to be illustrative
of the broader invention, and other inflation zone patterns may
also provide such immersion and support, without departing from the
scope of the invention. Therefore, the embodiments shown should be
considered as illustrative of the broader aspects of the invention
and should not be considered as limiting the scope of the appended
claims.
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