U.S. patent number RE31,898 [Application Number 06/611,460] was granted by the patent office on 1985-05-28 for inflatable-deflatable flexible structural component.
This patent grant is currently assigned to Goodyear Aerospace Corporation. Invention is credited to Charles A. Suter.
United States Patent |
RE31,898 |
Suter |
May 28, 1985 |
**Please see images for:
( Certificate of Correction ) ** |
Inflatable-deflatable flexible structural component
Abstract
An inflatable-deflatable flexible structural component
comprising a flexible foam core portion having a fabric covering,
the fabric being sealed against loss of air by a flexible
elastomeric coating.
Inventors: |
Suter; Charles A. (Stow,
OH) |
Assignee: |
Goodyear Aerospace Corporation
(Akron, OH)
|
Family
ID: |
26749658 |
Appl.
No.: |
06/611,460 |
Filed: |
May 17, 1984 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
069076 |
Sep 2, 1970 |
03675377 |
Jul 11, 1972 |
|
|
Current U.S.
Class: |
52/2.18; 206/522;
264/321; 264/54; 428/12; 428/178; 428/311.51; 428/317.1; 428/318.4;
428/71; 441/41; 5/709; 52/22; 52/309.11; 52/309.6 |
Current CPC
Class: |
B63B
7/08 (20130101); B65D 90/02 (20130101); E04H
15/20 (20130101); E04H 2015/202 (20130101); Y10T
428/233 (20150115); Y10T 428/249964 (20150401); Y10T
428/249987 (20150401); Y10T 428/249982 (20150401); Y10T
428/24661 (20150115); E04H 2015/206 (20130101) |
Current International
Class: |
B63B
7/00 (20060101); B63B 7/08 (20060101); B65D
90/02 (20060101); E04H 15/20 (20060101); E04B
001/343 (); E04G 009/08 (); B32B 003/08 () |
Field of
Search: |
;5/449,481
;52/2,309.6,309.11 ;114/345 ;206/522 ;264/54,321
;428/12,71,76,178,304.4,311.1,311.5,317.1,317.3,317.5,317.7,318.4,319.7
;441/38,40,41,114-116 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
428124 |
|
Jul 1967 |
|
CH |
|
984604 |
|
Feb 1965 |
|
GB |
|
Primary Examiner: Van Balen; William J.
Attorney, Agent or Firm: Milliken; P. E. Wolfe; J. D.
Germain; L. A.
Claims
What is claimed is:
1. An inflatable-deflatable flexible structural component
comprising a flexible open celled foam core portion having a fabric
covering adhered to and enclosing said foam and having a valve
means in communication therewith, the fabric being sealed against
loss of air by a flexible elastomeric coating.
2. The structural component of claim 1 wherein the foam is
reticulated.
3. The structural component of claim 1 wherein the foam core is a
polyurethane foam and the fabric covering the foam is nylon having
a coat of polyurethane thereon.
Description
This invention relates to an inflatable-deflatable flexible
structural component having relative dimensional stability and
which can be collapsed into a package of relatively small size and
to the method of manufacturing such a component.
The described structural component would be used to make
inflatable-deflatable shelters, boats, shipping containers, and
other articles.
Flexible inflatable-deflatable shelters, boats and shipping
containers have been manufactured from rubberized fabric for many
years. A major limitation in the design of such objects is that an
inflatable flexible component will tend to assume a round shape
when inflated. Thus, inflated articles are made as a series of
tubes, spheres, or other bodies with surface of revolution. This is
undesirable, since it limits configuration and design flexibility
and leads to a large number of separate inflated components to make
an object of the desired configuration and also increases the
material and construction costs.
It is an object of this invention to provide a method of making an
inflatable-deflatable structural component, the walls of which will
assume a shape upon inflation other than that of a surface of
revolution.
The objects and advantages of this invention may be more readily
understood and appreciated by reference to the accompanying drawing
where
FIG. 1 is a perspective view of a block of foam of the shape
desired and
FIG. 2 is a perspective view of the finished inflatable-deflatable
structural component having portion in section to illustrate the
construction features.
The above objects of this invention can be accomplished by covering
an open cell foam preferably of the reticulated type with a
rubberized fabric to give a container which encloses the foam and
which can be inflated by the introduction of air usually at about
5-20 pounds per square inch pressure and can be deflated by placing
a vacuum on the container. Preferably the open cell foam is shaped
in the desired configuration at the time the foam is being molded
or at the time it is being cut from the slab stock. For instance,
the foam may be formed in a mold having the desired rectangular
configuration, for instance 3.times.3 feet.times.3 inches. Then
this foam is given a brush or roll coat of a suitable adhesive and
the rubberized fabric is spread thereon and adhered to the foam by
the adhesive with the seams in the fabric being cemented together
with a suitable fabric adhesive.
Polyurethane foams can be prepared by reacting an organic
polyisocyanate with a hydrocarbon polyol of about 500 to 10,000
molecular weight and preferably 700 to 4,000 molecular weight in
the presence of a blowing agent such as water, a low boiling or gas
generating agent or combinations of these, either with or without
various polyurethane catalysts. Other useful foams are latex foam
and vinyl resin foams.
These foams can be reticulated by subjecting the foam to a flame
front or fire polishing to remove the thin diaphragm covering of
the windows of the individual cells and cause thickening of the
cell walls as the foam passes through a state approximating its
thermoplastic or flow temperature.
The nature of the reticulated foams may more readily be understood
by reference to the following examples wherein all parts are by
weight unless otherwise indicated.
EXAMPLE I
One hundred thousand parts by weight of a hydroxyl terminated
copolymer of butadiene and acrylonitrile of about 2,000 molecular
weight where the butadiene content is approximately 85 percent and
the acrylonitrile content is approximately 15 percent containing
3,000 parts of water, 270 parts of dibutyl tin dilaurate, 90 parts
of 2-dimethylamino-2-methyl-1-propanol and 25 parts of silicone
.gamma. and 200 parts of Silicone L-520 were mixed in a suitable
one-shot foam apparatus (an Admiral Foam machine) with 35,000 parts
of a commercial toluene diisocyanate (80/20 isomeric mixture) and
allowed to foam in a cubic shaped mold of about 1 cubic foot to
form a foam having a density of about 2 pounds per cubic foot. A
specimen of this cured foam was placed within a suitable retaining
mold and the pores or cells thereof filled with a mixture of
approximately 20 percent propane and 80 percent oxygen. Then the
mold was closed and the propane-oxygen mixture was ignited by
passing a current from a 10,000-volt spark generator through an
automobile spark plug projecting within the mold. The resulting
explosion reticulated or fire polished the foam to give a foam bun
having approximately 5 pores per inch. In other cases foams were
successfully reticulated containing up to 100 pores per inch. This
reticulated foam had an orange color and a density of approximately
2 pounds per cubic foot, a tensile strength of approximately 12 to
14 pounds per square inch and an ultimate elongation of
approximately 150 to 160 percent and a tear resistance of 5 pounds
per inch.
Silicon L-520 is a blocked silicone oxyalkylene copolymer where the
hydrocarbon radicals of the blocks are oxyethylene and oxypropylene
containing 15 to 19 oxyethylene and 11 to 15 oxypropylene units.
Silicone .gamma. is a poly oxyalkylene silicone where the alkylene
radical is propylene.
EXAMPLE II
Other foams were made with the recipe shown for Runs A to D, in
Table 1:
TABLE 1 ______________________________________ Run Numbers A B C D
______________________________________ Polybutadiene diol 100 100
100 100 Water 3 3 3 3 Dibutyltin dilaurate 0.26 0.33 0.33 0.33
2-Dimethylamino-2-methyl-1- 0.44 0.44 0.42 0.44 propanol Silicone y
0.025 0.05 0.05 0.05 Silicone L-520 0.20 0.23 0.28 0.25 Toluene
diisocyanate 38 38 38 38 (80/20 isomers)
______________________________________
The foam from Run A had relatively large cells, while the foam from
Run B had cells of approximately the same average size except some
smaller cells were intermixed with the larger cells. The foams of
Runs C and D have very noticeable windows covering the cells.
Instead of polybutadiene diol, the polyisoprene diols can be used
to make foams, too.
Other foams can be made by the one-shot method although the
prepolymer or other well-known methods could be used with
appropriate adjustment of the catalyst and blowing agent ratios.
Also, any of the polyether or polyesters useful for making foams
can be used, too. For instance, in Example II a polybutadiene diol
having a hydroxyl content of 0.75 milliequivalents per gram was
used as the resin and the ingredients were mixed and foamed
according to the one-shot technique. The resulting foams had
varying cell size with noticeable windows or thin films covering
the cells.
A crude methane diphenyl diisocyanate, about 60 parts per 100 parts
of the polybutadiene diol, was used instead of toluene diisocyanate
to make a satisfactory foam with the above polyols. Other organic
polyisocyanates can be used.
Any organic polyisocyanate or mixtures of polyisocyanates may be
employed in preparing the cellular polyurethane products. The
amount of polyisocyanate employed should be at least sufficient to
crosslink the active-hydrogen-containing polymeric material and to
react with the water present to generate carbon dioxide gas so
generated causes the liquid reaction mixture to foam and form
cellular products. In general, it is preferred to use from 2 to 8
equivalents of isocyanate per mol of polymeric material with best
results being obtained by the use of approximately 3 mols of a
diisocyanate per mol of polymeric material. Representative examples
of polyisocyanates which may be employed are the diisocyanates such
as hexamethylene diisocyanate; paraphenylene diisocyanate;
meta-phenylene diisocyanate; 4,4'-diphenylene diisocyanate;
1,5-naphthalene diisocyanate; 4,4'-diphenylene methane
diisocyanate; the tolylene diisocyanates; 4,4'-diphenyl ether
diisocyanate; 3,3'-dimethyl 4,4'-diphenyl diisocyanate; and
3,3'-dimethoxy 4,4'-diphenyl diisocyanate; the triisocyanates such
as 4,4',4"-triphenyl methane diisocyanate; and toluene
2,4,6-triisocyanate; the tetraisocyanates such as
4,4'-dimethyldiphenyl methane 2,2',5,5'-tetraisocyanate and
mixtures of polyisocyanates. Of these the liquid tolylene
diisocyanates, such as 2,4-tolylene diisocyanate and 2,6-tolylene
diisocyanate or mixtures thereof and toluene 2,4,6-triisocyanate
are particularly preferred.
A copolymer containing approximately 75 percent butadiene and
approximately 25 percent styrene and having a hydroxyl content of
0.75 milli-equivalents per gram (designated hereinafter as Resin
CS-15) can be used to prepare a foam by the one-shot technique.
The hydrocarbon diols or polyols of 2 to 5 hydroxyls useful in this
invention in general are prepared by polymerizing an olefin such as
a conjugated diolefin alone or in conjunction with an alpha olefin
to give a polymer which is then hydroxyl terminated. Representative
examples of these olefins are ethylene, propylene, butylene,
amylene, hexylene, styrene, acrylonitrile and related aliphatic and
aromatic olefins of about two to 20 carbon atoms, with those of two
to 12 being the more desirable ones. The conjugated diolefins are
represented by butadiene, isoprene, piperylene, ethyl butadiene and
the other well-known conjugated diolefins having from four to 12
carbon atoms.
The polymerization of the olefins may be achieved with an alkali
metal such as lithium or organo-alkali compounds and then the
hydroxyl group is introduced by removal of the alkali metal with
water, formaldehyde, ethylene oxide and other agents well known to
the art. It should be indicated that the degree of saturation or
unsaturation can be controlled by hydrogenation.
The foams prepared in Example I, as well as the polyisoprene diol
prepared foam, were reticulated according to the technique
described in Example I and the resulting foams were found to be
equivalent in physical characteristics to the commercial
reticulated polyesterurethane foams and superior thereto in their
resistance to hydrolysis and microbiological attack.
The amount of blowing agent used is controlled normally by the
density desired in the finished foam. For instance, the water can
vary from 0.5 to about 5 or 6 parts per hundred. The blowing agents
such as the fluorinated hydrocarbons and methylene chloride can be
used in equivalent amounts to vary the foam density.
Reticulated foam is used within this specification to indicate a
foam which has been fire polished to destroy the membranes or thin
films joining the strands which divide contiguous cells without
destroying the strands of the skeletal structure, or has been
treated chemically to destroy the strands or windows.
EXAMPLE III
A block of reticulated polyester polyurethane foam obtained from
the Foam Division, Scott Paper Company, as Scott Industrial Foam,
20-10 pores per inch, having the dimensions 30.times.30.times.31/2
inches, was covered with a square woven nylon cloth which
previously had been coated with 50/50 toluene methyl ethyl ketone
solution of a polyurethane liquid reaction mixture of 2,000
molecular weight polyethylene adipate, polypropylene adipate, 2,000
molecular weight polybutylene adipate reacted with toluene
diisocyanate (80/20 isomer mixture), to form a prepolymer and then
further reacted with methylene orthodichloroaniline and
mercaptobenzothiazole. The liquid reaction mixture used to precoat
the cloth was also used as the adhesive between the coated fabric
and the foam and in seaming the coated fabric. A valve was adhered
to the coated fabric. The structural component was heated in an
oven at 230.degree. F. for 3 hours, prior to making the final
seams, to evaporate all solvent from the foam and adhesive.
The structural component was then attached to a vacuum pump. The
panel was reduced in thickness from 31/2 inches to 3/8 inch. The
structural component was then inflated with compressed air. The
panel was essentially dimensionally stable as the pressure was
increased from 0 to 10 p.s.i. Between 10 and 20 p.s.i. there was
some increase in thickness. Thus, this degree of inflation is
sufficient to give the bag the desired rigidity without destroying
the foam, where p.s.i. is gauge.
EXAMPLE IV
An open celled polypropylene ether urethane foam unreticulated,
having dimensions such as 12.times.2 feet.times.4 inches may be
covered with an open weave nylon fabric with the seams 5 being
cemented together with a polyurethane reaction mixture. Then the
foam 6 covered with cloth 7 may be given a coating of a very dilute
(about 5-10 percent solids) polyurethane reaction mixture to tie
the cloth to the foam and also at least partly fill the interstices
of the fabric. With the cloth bonded to the foam, it is preferred
that the next coat of polyurethane reaction mixture be applied in a
more concentrated form, i.e. less solvent to build up an airtight
covering of about 5 to 25 mils depending on pressure to which the
finished container is to be subjected. A valve member 8 may be
placed on the cloth prior to application of the first coat of
polyurethane and thus be built into the finished container.
It should be appreciated that where the foam is so shaped (for
instance, the part shown in dotted outline 10 in FIG. 1 is removed)
this container could be a ladder or related structural member.
While certain representative embodiments and details have been
shown for the purpose of illustrating the invention, it will be
apparent to those skilled in this art that various changes and
modifications may be made therein without departing from the spirit
or scope of the invention.
* * * * *