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Description  |
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1. Field of the Invention
This invention relates to a body support system and more particularly to a
support which is useful in articles such as seats, beds and the like.
2. Description of the Prior Art
Conventional body support devices like seats and mattresses are stuffed
with either natural materials such as chaff, straw, millet, kapok or
synthetic material such as foams of polystyrene, polyurethane or rubber.
The natural "fills" over a period of time from repeated compression and/or
adsorption of fluids lose their resiliency and are difficult to clean and
sanitize. While synthetic materials are more sanitary and are not moisture
retaining the solid monlithic fills made from these synthetic materials
are soft, resilient and deformable. These synthetic fill materials have
not produced satisfactory comfort to the user. Another drawback for
conventional synthetic monolithic fills is that they do not permit
ventilation, thereby, causing discomfort to the user by insulating body
heat. Other forms of synthetic material have been used as fill e.g.,
flakes, granules, pellets and powders to provide cushioning devices. A
typical example of one such cushioning device is commonly referred to as a
"bean bag." A "bean bag" assembly is generally filled with soft and
compressible polystyrene foam pellets which lose their spongy resilience
after a period of use. As a result, the bean bag gradually collapses, the
pellets lose their ability to flow and redistribute under the weight of a
body thereby, decreasing the comfort of the user. The present invention
substantially overcomes the above mentioned shortcomings of the prior art
body cushioning devices by providing a unique body support system with a
fill of non-absorbent and non-compressible flowable particles.
Other natural "fills" not mentioned above are air and water. Water beds of
one type or another have long been used by hospitals for the treatment of
patients having varying problems such as bedsores and skin burns. Like the
present invention, the primary advantage of the water bed is that it
uniformly distributes the body weight so that the entire body surface in
contact with the mattress is evenly supported thus avoiding uncomfortable
pressure points unavoidable with conventional innerspring mattresses. A
major disadvantage is the substantial weight of water beds. A filled
double-sized mattress, for example, weighs between 1500-2000 pounds.
Because of this substantial weight of water, great stresses are placed
upon the mattress sidewalls creating potential for rupture of the
water-tight envelope. These deficiencies of weight and possibility of
leakage limit the location of use for water beds. Another disadvantage is
the oscillating wave action caused by a person's movement on the bed.
While this wave action only lasts for a matter of seconds, it echos or
reverberates completely through the bed.
Still another problem occurs with water beds when there is a substantial
weight difference between two persons. The heavier person will sink in the
mattress while the lighter person will hardly make an indentation on the
support surface. The body support system of the present invention
alleviates all of the above noted problems associated with water beds. For
example, the solid, non-absorbent and non-compressible beads fill cannot
leak in the liquid sense of the word and make the bed useless. While the
beads of this invention have flowable properties of a liquid when
subjected to external force the beads would not generate the oscillating
wave action of water. Furthermore, the problem of weight differential is
overcome, since each body weight makes its own impression by bead
displacement in each individual bag. At the same time the lateral force
component is absorbed by adjacent flexible bags. The net effect is
individual comfort in a double-size bed.
Gas-inflatable mattresses and cushions have long been articles of commerce.
Air mattresses have found wide utility as sleeping bags. However, with the
conventional air mattress, which is placed upon an irregular surface such
as the earth, the inflation pressure must be great enough to support the
load above the highest irregularity in the surface. This requirement
generally necessitates having some sort of air pump or equivalent device
for inflating the mattress, and results in a support which has very little
give and which easily transmits shock to the body which is being
supported. All current designs of air mattresses incorporate at least one,
and generally both, of the above-mentioned limitations of excessive
firmness and the requirement of providing for high pressure. The solid
particles of this invention obviate these deficiencies associated with air
and other gas filled mattresses. First, there is no inflation pressure
required. Second, the particles operate by body displacement in a manner
similar to a liquid rather than by gas expansion principles which result
in an uncomfortable "pushing back" against the body weight.
SUMMARY OF THE INVENTION
The present invention relates to a polymorphic body support system
comprising a base structure being dimensioned to receive a person thereon,
a plurality of support elements contiguously arranged on the base
structure defining a generally planar supporting surface. Each of the
support elements is comprised of a closed flexible bag containing a
plurality of beads. These beads are characterized as non-absorbent,
non-compressible and capable of free flow with respect to each other
within the bag when subjected to the weight of a body member. Thus when
the system is subjected to a person's weight, the particles on the upper
surface of the bag conform to the body member supported thereon. Each of
the contiguous flexible bags is independently responsive to the
compressive force component resulting from the presence of the body member
and jointly responsive to the force components to provide a comfortable
contour support for the person. The bags are filled in varying degrees to
provide varying support characteristics.
Thus, it is the principal object of the present invention to provide a
maximal body comfort by evenly distributing body contact pressures.
Another principal object of this invention is to provide a body support
system having internal relatively hard elements which provide the needed
rigidity for orthopedic purposes, a soft surface to avoid bruises,
abrasions or other similar damage to the skin of the user and yet is
comfortable for sleeping or lounging purposes.
A still further object of this invention is to provide a body support
system which can be used in a great variety of shapes and forms without
compromising the desired comfort.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view elevation partly cutaway in cross-section of one
embodiment of this invention showing a plurality of support elements which
are depressed under the weight of a body in order to form a supporting
surface conforming to the body contour;
FIGS. 2, 3 and 4 are side elevations to an enlarged scale showing bags of
this invention with varying degrees of fill providing head support.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A typical polymorphic body support system of this invention is shown in
FIG. 1. The body support system is comprised of a plurality of support
elements comprising closed flexible bags 11 manufactured from any natural
or synthetic soft textile material 12 which are filled with a plurality of
hard, non-absorbent and non-compressible flowable beads 13. The plurality
of bags 11 are placed in contiguity to each other on a conventional
bedstead having a horizontal supporting surface 20 as a suitable
supporting structure.
In FIG. 1 there is shown a body support system according to the present
invention with a plurality of support elements as represented by flexible
bags 11 which are depressed under the weight of body 15. As illustrated
when the weight of the body 15 is brought to bear on the flexible bags 11,
the beads 13 being capable of free flow with respect to each other within
the bag flow out of the volume displaced by the body 15. The constraint on
the lateral force component provided by the flexible bag and adjacent bags
or retainer walls (not shown) causes the beads to to be displaced in
generally upward direction surrounding the body 15 so as to permit the
upper surface of the supporting elements to conform to the body member
thereon. In effect this increases the amount of vertical or compensatory
support over a larger load area eliminating pressure points and provides a
comfortable contour support. When a person sits or reclines on the body
support system of this invention, the beads 13 are displaced from the
volume of space occupied by the user's body 15 and they flow into
unoccupied portions within the interior of the bag 11. The flow and
redistribution of the beads 13 enable the body support elements 11 both to
conform to the contours of the user's body. Each support element is
independently responsive to the compressive force component of the
respective body number thereon and jointly responsive to the lateral force
components with adjacent flexible bags in the same plane. The result is a
highly comfortable means for reclining or sitting. For most sleepers, this
would provide an extra measure of comfort. For invalids, the body support
system of this invention provides a more uniform distribution of weight
which avoids deleterious concentrations of supporting force that
contributes to the development of bedsores or decubitus ulcers.
Surprisingly, the hard non-absorbent and non-compressible flowable beads
which provide the needed internal structural rigidity and orthopedic
support also provide a comfortable sleeping environment. Any solid
material which has the property of free flow with respect to each other
within the closed flexible bag when subjected to an external pressure is
suitable as a bead composition. Physical properties which enhance the free
flow characteristic of the bead are desirable. For example, the beads
should be smooth and be non-compressible to the extent that they do not
deform when subjected to body weights within the human range. In most
cases beads having compressive strength of at least 300 pounds per square
inch are satisfactory. Technically there is no upper limit to the
compressive strength parameter as the flowable bead filter. Suitable
materials include metals, metal alloys, glass, ceramics, and plastics
including thermoplastic and thermoset resins. The metals and metal alloys
include both ferrous and non-ferrous compositions e.g., steel, brass,
bronze or copper ball bearings.
Suitable thermoplastic resins are the acrylonitrilebutadiene-styrenes
(ABS), acetals, acrylics, cellulosics, chlorinated polyethers,
fluoro-olefins, polyamides, phenylene oxide resins, polycarbonates,
polyolefins, polyamides, polyphenylene sulfides, vinyl aromatics,
polysulfones, polyvinyl halides and polyvinylidene halides. Specific
examples of the above thermoplastic polymers are polymethyl methacrylate,
cellulose acetate butyrate, chlorinated polyether, polytetrafluoroethylene
polychlorotrifluoroethylene, ethylene-propylene, copolymers nylon-6, 6,
high density polyethylene, polypropylene, solid polystyrene, polysulfone,
polyvinyl chloride and vinyl chloride-vinylidene copolymer.
Suitable thermoset resins are the allylics, amino, epoxies, furfural
alcohol polymers, phenolics, silicones, polyesters, urethanes and vinyl
esters.
Specific examples of the above thermoset resins include diallyl phthalate,
diallyl isophthalate, formaldehyde-urea, formaldehyde-melamine, furfural
alcohol cured with isopropyl sulfuric acid or p-toluene sulfonyl chloride
or p-toluene sulfonic acid and phosphoric acid, phenol-formaldehyde and
polydimethylsiloxane.
Other useful non-absorbent and non-compressible bead fillers include metal
nucleus coated with a thermoplastic or thermoset resins. For example,
steel ball bearings coated with polyethylene or polyvinyl chloride or
polytetrafluoroethylene are useful.
The fill beads can have any round configuration e.g., a sphere, cylinder,
frustum, disc or toroid. In practice, it has been found that the size of
the beads can be conveniently between 1 and 50 millimeters and preferably
between 5 and 15 millimeters and most preferably between 1 and 5
millimeters in diameter. These size ranges insure that the beads readily
adapt to the contours of the body. In another embodiment where the
particles have a disc configuration, the thickness of the center is about
1/3 to 1/5 of the diameter, this thickness then tapers to a thin edge
around the circumference of the disc. The preferred diameter of the disc
is from 5 to 60 millimeters and most preferably between 5 and 25
millimeters. In a further embodiment, the disc can have the central
section removed to yield a toroidal or doughnut shape. According to a
further aspect of the present invention, it is preferable that particles
of the same size and shape be used together. Although for specific
purposes different sizes and shapes may be used together.
Each flexible bag component of this invention defines a unitary interior
volume, each portion of the volume freely communicating with every other
portion to allow uninhibited flow of the beads from space to space. The
bag is usually constructed of soft breathable textile material, for
example, a porous natural fabric such as cotton, wool, silk, juta, flax,
lines, hemp, ramie or a synthetic fabric manufactured from a polyester
polyacrylamide, nylon and rayon or blends of these materials i.e.,
cotton-polyester, silk-wool and the like or elastic textiles such as
spandex and amidex. For more durable service but generally not for surface
body contact layers, the bag can be manufactured from olefin fibers or
films such as polyethylene or polyvinyl chloride.
The size and shape of the bag can be varied depending on the intended use.
For bedding purposes the bag is generally of oblong tubular outline
similar to a conventional pillow. In one embodiment, it is preferred that
the overall body support system be made of a plurality of relatively small
units as shown in FIG. 1. This arrangement of relatively small units not
only provides ease of mobility but also allows for a wide spectrum of bed
sizes and shapes which can be obtained by merely adding or subtracting
units as required. In the production of the flexible bag component, the
bag is filled to between 70 and 90 volume percent and fully sealed by
conventional means such as heat sealing, stitching or with adhesives. When
elastic textiles are used such as spandex or amidex the bag in its relaxed
state is filled to about 90 to 100 volume percent and preferably about 95
volume percent.
According to this invention a plurality of flexible bags can be used with
or without a retainer. The retainer can be made from metal, plastic or
wood and can be of varied sizes and designs. For example, it can be a
conventional bedstead, a sandbox or it can be a natural cavity i.e., a
hole in the ground. The support elements or flexible bag assembly can also
be used without a retainer or a support structure for such uses as a body
support for station wagons and camper trucks. For sleeping bags and
camping use the flexible bag assembly can be placed on any irregular or
inclined surface yet it provides a well stabilized relatively
shock-insenstive and comfortable load-bearing area. The beads will fill
the volume of the irregular bottom in a fluid-like manner to provide a
generally planar surface. Along that surface the pressure is equalized and
the irregularities of the bottom are not transmitted to the surface level.
Another advantage over the conventional mattress system is that the
flexible bag assemblies of this invention are easily removed, are washable
and dry readily. The bag assemblies can be cleaned with readily available
laundry equipment. This is particularly useful for hospitals and nursing
homes who care for patients who are incontinent and have draining lesions.
In an alternative embodiment of this invention elastic bags e.g. those made
using a fabric such as spandex are filled in the range of 20 to 50% with
fill beads. Bags filled only to this lesser degree exhibit special
characteristics not found in or possible with bags filled in the 70 to
100% fill range as described above.
Empty elastic bags have a shape without stretching; an elastic bag which is
90% filled contains a volume of pellets which just extend the bag to its
minimal "full" volume with only slight stretching of the fabric beyond its
minimal set. A bag filled to that level tends to assume its own shape,
that is a rectangular empty bag when 90% filled takes on the shape of a
rectangular pillow having depth, but in plane view still appearing as a
rectangle. When distorted the 90% filled (and more filled) bag tends to
retain and return to its undistorted shape. For example, the 90% filled
rectangular bag after distortion tends to return to the rectangular pillow
shape.
Less filled bags have less tendency to return to their original undistorted
shape. A 20% filled bag (or less filled), laid flat, can be put into
almost any shape and will not return to the basic shape of the cloth
material. Thus a rectangular bag only 20% filled can be pushed into almost
any shape which will be retained until a new shape is imposed. The bag is
wilted rather than plump.
Basically in the more filled bags there is a slight tension tending to pull
the pellets into a more or less cohesive single mass. In the less filled
bags, the pellets are free to move apart in various directions. When an
object is impressed upon the more filled bag, there is a slight tendency
from the outset to extrude and to elastically resist penetration. The less
filled bags on the other hand will accept an impressed object without
counterpressure until the volumes of the pellets and the intruding object
combine to create some tension in the fabric and a resistance to further
penetration.
But the less filled bag has dual characteristics not possible with the more
filled bag. With a less filled bag one can isolate the pellet mass, for
example, in one half, fold over the excess cloth and roll the whole into a
unit now with the characteristics of the more filled bag. Thus the less
filled bag may be arranged to have either characteristic reversibly, e.g.
a 20% or 90% filled characteristic. The less filled bags, e.g. 20-50% can
be arranged to resist intrusion to a greater or lessor degree from zero to
a maximum by rolling or folding the bag into progressively tighter
patterns. The more filled bag, e.g. 70-90% can be varied to a lesser
degree but its resistance to intrusion can never be reduced to zero in any
arrangement.
The ability to reshape the 20 to 50% filled bag is especially advantageous
in the polymorphic support system of this invention in providing body
support in zones of tight contour changes, for example, between the
shoulders and base of the head. FIGS. 2, 3 and 4 illustrate respectively
the use of approximately 90%, 70% and 20% filled bags for such an
application. In FIG. 2 the man 15 is shown with the base of his head
supported on a 90% filled bag 11 which is one of many comprising a support
system of this invention (as in FIG. 1). The bag 11 is unfolded. In FIG. 3
the head of the man 15 is supported on a bag 16 filled approximately 70%.
One fold in the bag 16 compacts the beads and retains them in an elastic
wedge of localized support. In FIG. 4 the head of the man 15 is supported
on a bag 18 filled 20% with beads and folded many times until the desired
contour and degree of elastic support is achieved.
In an embodiment, bags filled 70-90% may be used for the major support
areas, as illustrated in FIG. 1, supplemented with folded 20-50% filled
bags in the close zones, e.g., at the base of the head as previously
described and illustrated. In an alternative embodiment 20-50% filled bags
may be folded in varying degrees to comprise the entire support system of
this invention. In actual use, folded 20-50% bags in tight contour zones,
e.g., at the base of the head, have provided excellent vertical support
while at the same time providing a slight tractive effect due to the
elastic resistance of the bag to intrusion.
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