CA1087644A

CA1087644A - Elastomeric cushioning devices for products and objects

Info

Publication number: CA1087644A
Application number: CA313,875A
Authority: CA
Inventors: Marion F. Rudy
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-10-20
Filing date: 1978-10-20
Publication date: 1980-10-14
Also published as: JPS54116063A; GB2010085B; JPS5910902B2; DE2845798A1; FR2406520B2; FR2406520A2; DE2845798C2; GB2010085A

Abstract

ABSTRACT OF THE DISCLOSURE

Devices for packaging and/or cushioning products and objects, the devices including elastomeric sheets sealed together at predetermined locations to form separate and discrete chambers, or intercommunicating chambers, inflated initially partially or entirely with gas or gases which have very low diffusion rates from each chamber through the elastomeric sheets, ambient air diffusing more readily through the sheets into each inflated chamber to provide a total pressure therein which is the sum of the partial pressure of the air in the chamber and the partial pressure of the gas or gases in the chamber. Not only does the air diffusing into a chamber increase the total pressure therein above the initial inflation pressure of the gas or gases, but the air in the chamber inhibits outward diffusion of the gas or gases from the chamber or compensates for any loss of pressure caused by such outward diffusion of the gas or gases.

Description

~Q876~

1 The present invention relates to devices for protecting products or objects, and more particularly to cushioning devices having yieldable chambers filled with a gaseous medium and functioning to protect objects and products to prevent damage thereto.
Heretofore, packaging materials have been provided which - are made by heat-sealing air-containing chambers between plastic sheets to provide cushioning protection for the products during handling and shipping. The chambers are separate and discrete and usually either cylindrical or spherical in shape, containing air at atmospheric pressure. The sheets are usually non-elastomeric and comprised of laminations of several layers of films, with one or more of the layers being barrier material (like PVDC Saran), and one or more of the other layers being heat-sealable.
Thin-film, single layer (unlaminated) elastomeric films have not proved practical for use as a cushioning material because such films have relatively high gaseous diffusion rates for most gases. The gas-filled chambers go "flat" in an unacceptable ~` short time period when any pressure differential whatsoever exists between the gas inside the enclosure and the surrounding atmosphere.
As an example, if the chambers are formed by inflating and elas-tically stretching the film, they lose about fifty percent of ` their original volume in approximately one to four weeks from the date of manufacture, and in about six months the chambers are essentially flat. Laminated films are only marginally heat- -sealable and have relatively poor physical properties, except for prohibitively expensive films. Barrier films having low diffusion rates for most gases are used to prevent the air from being squeezed out of the chambers when external loads are applied over protracted periods of time, or when the material is ~ ..
-- 1 -- .

87~

1 subject to elevated temperatures.
In present products, the chambers are pre-formed and then partially inflated only, thus forming somewhat wrinkled non-pressurized enclosures to allow for expansion and contrac-tion of the contained gas, so that the cushioning product can be carried in airplanes without over inflating and rupturing.
One type of known cushioning device is disclosed in United States Patent No. 3,589,037.

Because thin laminated barrier-type material is used in present cushioning devices, the cushioning material fails by rupturing when the internal pressure in each chamber exceeds more than about 3 to 4 psig. Since laminated barrier material is difficult to heat seal, the welds integrating sheets to one another are weak and deteriorate with age or temperature.
Accordingly, prior cushioning devices are limited in the steady state loads they will support. As an example, one hundred fifty pounds per square foot loading is often specified as a maximum. Moreover, they are seriously limited in the dynamic (shock) loads they can withstand without rupture and loss of air. As a result, use of cushioning devices is normally limited to protecting light weight products only, such as instruments, electronic components, and the like.
. ..
Attempts have been made to use prior cushioning devices outside of the packaging field, e.g. for resilient, shock absoring insoles in shoes, cushioning material to replace foam in boots, protective padding for athletic gear, and the like. These attempts have not been successful because of the fragile nature of the material and the marginal strength of the welds, as well as the basic problem of large volume changes caused by changes in altitude.
':

- 2 -::~
- .
, 1(~876~4 1 It is an object of the present invention to provide an improved, permanently inflated cushioning device made from high-strength, fatigue resistant elastomeric material having high structural strength and the ability to withstand high steady-state loads and large shock loads, as well as having very good resistance to the repeated application of extreme cyclical loading combined with severe flexing.
Another object of the invention is to provide an elastomeric cushioning device having a plurality of separate and discrete chambers inflated with gas, and in which changes in atmospheric pressure and temperature variations do not result in rupture of the individual pneumatic chambers or cells, despite increase in the gas pressure within the chambers and small changes in their volume,,the cushioning device being durable, reliable, and having a long service life.
In its general aspects, cushioning devices embodying the invention include a pair of elastomeric, permeable sheets sealed together at desired intervals to form communicating or discrete chambers which are filled or inflated, partially or entirely, with a gas, or a mixture of gases, to a prescribed pressure, which may be atmospheric or above atmospheric. The gas or gases selected have very low diffusion rates through the permeable sheets to the exterior of the chambers, the surround-ing air having a relatively high diffusion rate through the ~ ;
sheets into the chambers, producing an increase in the total pressure in the chambers, resulting from the addition of the -partial pressure of the air therein to the partial pressure of the gas or gases therein. Although the pressure of the gas or gases initially placed in the chambers may decrease at a very slow rate, because of diffusion of such gas or gases --' 1{18~649~
1 through the elastomeric sheets, the ambient air diffuses more readily through the sheets into the chambers, to effect an increase in total pressure in the chambers above the initial inflation pressure of the gas or gases in the chambers, This total pressure in the chambers may decrease over an extended period, but it will still remain above the initial inflation pressure of the gases for a long time, and will lose pressure very slowly over an additional extended time period, during which the cushioning device is still effective to perform its cushioning or shock absorbing function.
The cushioning devices have application other than in the cushioning field. The devices can be formed as athletic floor mats, shaped to function as life preservers, handle grips for vibrating tools, and as shipping pallets, where they are disposed between two rigid members. ~ -Other devices embodying the invention are those which are intermittently subject to loading, such as permanently inflated pillows and permanently inflated cushioning to re-place foam pads in upholstered furniture. When a person sits or lies on such devices, some of the air in the chambers will be diffused outwardly from the chambers, but when the load is removed, the air will be replaced by air diffusing back into the pillow chambers, automatically effecting their reinflation and placing them in condition to appropriately rece~ve the next cycle of loading. Other applications of cushioning devices will be referred to later on in the specification.
This invention possesses many other advantages and has other purposes which may be made more clearly apparent from a consideration of several forms embodying its principles.

: . .
;, .. , : - ..

lQ8~

1 These forms are shown and described in the present specifica-tion and in the drawings accompanying and constituting a part thereof. They will now be described in detail, for the purpose of illustrating the general principles of the invention;
but it is to be understood that such detailed description is not to be taken in a limiting sense.
Referring to the drawings:
Figure 1 is a top plan view of a portion of a cushioning or shock absorbing device embodying the invention;
Figure 2 is a section taken along the line 2-2 on Figure 1, the cushioning device being made of thin elastomeric film material, and disclosing spherical chambers of the cushion device inflated to relatively high pressure; ~:
Figure 3 is a view corresponding to Figure 2 of a cushioning device which may be made of thicker, higher modulus elastomerie material, and disclosing spheroidal chambers of :
the device;
Figure 4 is a top plan view of another embodiment of eushioning or shoek absorbing deviee;
Figure 5 is a seetion taken along the line 5-5 on Figure 4;
Figure 6 is a top plan view of yet another embodiment of eushioning or shoek absorbing deviee;
Figure 7 is a seetion taken along the line 7-7 on Figure 6;
Figure 8 is a top plan view of a further embodiment of eushioning or shoek absorbing deviee embodying the invention, whieh ean also function as a seal or gasket;
Figure 9 is a seetion taken along the line 9-9 on Figure 8;

.
- , , : : .
- . . . : . . .
... . : .

lO~

1 Figure 10 is a section taken along the line 10-10 on Figure 8;
Figure 11 is a graph showing the self-pressurization of the elastomeric chambers due to reverse diffusion of air into the chambers;
Figure 12 is a graph similar to Figure 11, showing - the pressure rise due to self-pressurization of the elasto-meric chambers with different mixtures of air and other gas initially in the chambers.
In the form of invention disclosed in Figures 1 and 2, a segment of a cushioning device 10 is illustrated, formed from two sheets 11, 12 of elastomeric material provided with circular welds 13 (as by use of radio frequency heat sealing techniques) to form discrete, spherical chambers 14, which are partially or completely inflated by a gas having a low diffusion rate through the material of which the elasto-meric sheets are made. The spherical chambers shown in Figure 2 result from providing thin elastic films or sheets 11, 12 of material, and inflating them to relatively high pressures. As disclosed in Figure 3, thicker, higher modulus films are used, which, when inflated to substantially the same pressure as the chambers disclosed in Figure 2, will form spheroidal chambers 14a. The spheroidal chambers would also -be formed with the thinner films shown in Figure 2, provided - -the chambers were inflated to lower pressures than the pressures used in the chambers of Figure 2.
As disclosed in Figures 4 and 5, the two sheets of elastomeric material lla, 12a are welded to one another at circular locations 13a spacing the chambers from one .
.

~ ` 108~
1 another and surrounding each chamber. In one manner of making the product of Figure 4 and 5, the upper sheet lla is first vacuum formed before welding to provide dome-ended cylindrical chambers 14b. While vacuum is still applied, the upper sheet and lower sheet are welded to one another in the circular pattern 13a disclosed. The desired gas is then introduced into the chambers forming the cylindrical chamber shapes 14b illustrated in Figure 5.
In the cushioning device illustrated in Figures 6 and 7, the upper and lower sheets llb, 12b are adhered to one another with a square weld pattern 13b to produce spheroidal chambers 14c. This square pattern at the weld region has a lesser overall weld area than the circular spherical design of Figures 1 and 2, providing a more complete and uniform pneumatic supporting surface.
In the cushioning device disclosed in Figures 8, 9 and 10, the welds 13c are provided in a rectangular pattern, as disclosed in Figure 8.~ When pressurized, each chamber 14d is elongate, as disclosed in Figure 9, and has a circular section, as disclosed in Figure 10.
The elastomeric materials that can be used in forming the cushioning device preferably should have certain character-istics. One characteristic is excellent heat-sealability by various means especially through use of dielectric heat sealing techniques. Thus, high-strength, high integrity welds securing the sheets to one another can be obtained which can withstand high, steady-state stress levels, as well as long duration cyclical variation in stress and stress reversals, which occur under severe dynamic loading conditions. A
second characteristic relates to appropriate physical properties ' . ' ' : . . ~, , . , . ~ ' , : -. , . . .: .:

1087~
1 of tensile strength, modulus of elasticity and tensile relaxation (creep). A third characteristic is very low permeability to the selected inflation gases/vapors (herein-after sometime referred to as "supergas") but fairly high permeability to air (N2 and 2) Another important factor in the cushioning devices is the group of special gases/vapors which are used for inflating the sheets or films. These gases/vapors are in a class by themselves as exhibiting extremely low diffusion rates through the special elastomeric materials, since they have very large molecules and very low solubility coefficients.
The gases are inert, non-polar, of uniform/symmetric, spherical, spheroidal (oblate or prolate) or symmetrically branched molecular shape. They are non-toxic, non-flammable, non-corrosive to metals. They are excellent dielectric gases and liquids, have high levels of electronic attachment and capture capability, and exhibit remarkably reduced rates of diffusion through all polymers, elastomers and plastics (solid film).
When the special gases are used to inflate enclosures made from these special elastomeric materials, it is possible for the cushioning device to maintain the initial inflation pressure for very long periods of time without a significant loss in pressure. This is termed "permanent" inflatation.
"Permanent" inflation is a result of the combination of two important factors : (1) the extremely low permeabilities of the supergases combined with, (2) the phenomenon of "self pressurization".
Many tests were conducted during a five-year period which confirmed the very low diffusion rates of the supergases ~0876~
1 through typical elastomeric films. The supergases tested were most of the gases/vapors from the group consisting of: hexa-fluoroethane, sulfur hexafluoride, perfluoropropane, perfluoro-butane, perfluoropentane, perfluorohexane, perfluoroheptane, octafluorocyclobutane, perfluorocyclobutane, hexafluoropropylene, tetrafluoromethane, monochloropentafluoroethane, 1,2-dichloro-- tetrafluoroethane; 1,1,2-trichloro-1,2,2 trifluoroethane, chloro- ;
trifluoroethylene, bromotrifluoromethane, monochlorotrifluoro-methane, and monochlorodifluoromethane. The preferred gases/
vapors are hexafluoroethane and sulfur hexafluoride. ~i~
Typical sheets or films tested were most of those from the group of materials consisting of: polyurethane, poly-ester elastomer, fluoroelastomer, chlorinated polyethylene, polyvinyl chloride, chlorosulfonated polyethylene, polyethylene/
ethylene vinyl acetate copolymer, neoprene, butadiene acrylonitrile rubber, butadiene styrene rubber, ethylene ;~
propylene polymer, natural rubber, high strength silicone rubber, low density polyethylene, adduct rubber, sulfide rubber, methyl rubber, butyl rubber, and thermoplastic rubber. Poly-urethane is the preferred material.
Most of the tests were conducted at relatively high pres-; sures (20 psig) to accelerate the diffusion rate of the super-gases, thereby making the tests conservative. In many of the tests, after two years of testing, the pressure in the chambers still exceeded the initial inflation pressure. In all of the tests, the~pressure decline was extremely slow. At relatively low inflation pressures of a few ounces to a few pounds per square inch, this time would be extended by at least five times (from two years to ten years). In addition, for all of the tests the pressure actually rose significantly above the , :

-- 108~6~
1 initial inflation pressure during the first two to four months of the tests. It is this pressure rise phenomenon which is termed "self-pressurization".
Self-pressurization is the result of the low per-meability of the special films or sheet with respect to their resistance to the pressure of the supergases, coupled with the much higher permeability of the special films or sheets to the passage of air therethrough. The air in the natural atmospheric environment surrounding the inflated chambers diffuses into the chambers until the partial pressure of air inside the chambers is equal to the partial pressure outside the chambers (i.e. 14.7 psia). The total pressure within each chamber is the sum of the partial pressure of air plus the partial pressure of the supergas. Because essentially none of the supergas diffuses out while the air is coming in, a pressure rise of about 14.7 psi is possible within a constant volume enclosure made from one of the elastomeric materials.
Figure 11 is a graph indicating the pressure rise in an actual elastomeric enclosure typical of the new packaging or cushioning device, the enclosure being initially pres-surized to 1.0 psig with one of the supergases, such as Freon 116. As is seen, the pressure after six weeks increased from 1.0 psig to 6.5 psig (Curve 1). This is a 650% rise in pressure, even though the enclosure stretched and its volume increased by approximately 40~ during the test. Had the volume remained constant, the total pressure would have increased to 15.2 psig, with this particular supergas, as shown in Curve 2. -When the cushioning device is used for packaging materials, each pressurized chamber is inflated so as to - 10;. -.. - , - -~76'~ ~
1 operate at low pressures, normally less than 2.0 psig. There-fore, it is necessary to mitigate the increase in pressure due to self-pressurization. This can be done by inflating the chambers with mixtures of air and supergas. As Curve 1 of Figure 12 indicates, a mixture of 25% supergas and 75% air in the elastomeric chamber enclosure results in a pressure rise of from 1.0 to 2.2 only. The pressure rise in a constant volume enclosure having mixtures of supergas and air of 25-75%, 50-50% and 100-0% are also shown in Figure 12.
Further reduction in pressure rise can be achieved if the pressure chambers are not distended to the full, un-stressed volume at initial inflation, but are in a wrinkled condition immediately after inflation. As the self-pressuriza-tion pressure rise occurs, the chamber volume expands and the pressure of the supergas falls. The key to this approach is to have the supergas partial pressure fall and arrive at the design pressure at the exact point when the chamber becomes full distended. The ambient air passes through the elastomeric films into the chamber to increase the pressure therein.
That is, the partial pressure of the air will add to the partial pressure of the supergas and produce the total pressure, which will be above zero psig. However, the volume of the chamber ~ -will expand, because of its initial wrinkled condition, expansion continuing as the self-pressurization continues until the final volume of the chamber is reached. This will take several weeks to occur to reach the stable condition and the desired final internal pressure, which, for example, may be 1/2 psig. The inward diffusion of the ambient air to reach the stable condition is referred to as "aging".
At the end of the aging, the pressure in the chamber ' ~

-- 11~ -- ' ~ ~' . ~

~ 10876~ :
1 is made of air at atmospheric pressure (14.7 psia) plus the partial pressure of the supergas. It is the partial pressure of tne supergas which elevates and maintains the gauge pres-sure in the chamber above zero. If there were no supergas in ~ -the chamber, it would contain 100% air and the device would not function properly. During use with loads applied, the air would squeeze out of the chamber and the cushioning device -would go flat, inasmuch as barrier materials are not used, as in other packaging materials. Accordingly it is the supergas which gives the device its permanent inflation characteristics, and the device must contain a sufficiently large percentage of supergas in the gas mixture to function properly throughout the duration of its useful life. Hence, the pressure in the device must be at least slightly higher than atmospheric pressure, the particular pressure depending on design loading conditions. From a manufacturing standpoint, it is desirable to fill the chambers with gases at atmospheric pressure.
Because of the self-pressurization phenomenon, this can be done. After manufacturing is completed, the self-pressuriza- -'.
tion automatically eleyates the pressure the desired amount above atmospheric pressure during the aging process.
As mentioned above, it is a relatively small percentage of supergas within the device which gives it its permanent inflation characteristics, and permits the device to be used under heavy load for extremely long periods of time without significant loss in pressure. The use of minimum quantities of supergas and maximum quantities of air reduces the cost of the cushioning device. The optimum amount of supergas depends upon the cycle. Heavy loads require higher concentrations of supergas.

., ' . -: , ~ . , - 108~6~ :
1 The foregoing can be explained by the fact that when a load is applied, the cushioning device is compressed somewhat and the pressure of both the supergas and air rises sufficiently to support the load. Because the pressure of the air is now above atmospheric pressure, it can gradually diffuse out of the chambers under load. The supergas will not diffuse out. As long as the load is applied, the air will continue to slowly diffuse out of the chambers and the chambers will slowly be compressed to smaller volumes, thereby raising the pressure of the supergas. The sum of the partial pressures of air plus supergas is always sufficient to support the load with the air pressure dropping and the supergas pressure rising. If the load is applied continuously and long enough (e.g. three to four months for normal load), the ultimate condition is reached where the partial pressure of the air has been reduced as far as it can go, that is, 14.7 psia (atmospheric pressure).
The supergas pressure is then at its maximum value. The diffusion process will have stabilized and no more gas will diffuse out.
If the load is removed, the "self-pressurization"
phenomenon will take over and the air will diffuse inwardly, the pressure within the chambers returning to the original no-load condition. The cusioning device, therefore, has a self-compensating and self-restoring characteristic.
In normal use, loads will usually not be applied long enough to even approach the ultimate condition described above. However, it is desirable that the device continue to function properly even under the worst conditions for "bottoming-out". To ensure that the chambers will never "bottom-out", the chambers should contain a large enough --- 10~76~
1 percentage of supergas in the no-load condition so that in the worse condition (when the air volume has been reduced as far as it can go) the chambers still contain an acceptable volume of gas.
The "self-restoring" or "self-reinflation" ability of the cushioning device is applicable to devices which are intermittently loaded, such as permanently inflated pillows and permanently inflated cushioning to replace foam pads in upholstered furniture. Only relatively minute quantities of supergas are required in the air-supergas mixture in the air chambers to provide support under load. Some air will diffuse out while a person sits on the pillow or inflated furniture, but when the load is removed (especially overnight) the air diffuses back into the pillow or pad, which automatically reinflates itself to be ready for the next cycle of loading.
Changes in altitude affect the elastomeric cushioning - devices. At high altitudes, the ambient pressure is low and the difference in pressure between the pressure within the chambers and the pressure external thereof is much higher than at sea level. With barrier material type products of the prior art, flown in airplanes in which the cabins are usually pressurized to about 5,000 to 8,000 foot elevation, the air chambers expand greatly and may burst. With the elastomeric products embodying the present invention, pressure increases do not have any impairment in performance because of their -superior physical characteristics and the higher integrity of the welds. If left at high altitudes, such as may occur - in Denver, Colorado, the air in the chambers would soon diffuse outward and the product would return toward its initial inflated condition. Correspondingly, the lowering . . .- . . . ~ ~.
,' ' ., . . ~" ~- ' . ' ', . ' :

~087~
l Of the cushioning devices to lower altitudes, or to sea level will result in the diffusion of the ambient air back into the chambers.
Other applications for the cushioning devices outside the industrial packaging field are as a lighweight, highly durable cushioning member for shoes and boots, such as ski boots and shoe-type skates, such as hockey skates and roller skates. The permanently inflated product is made with appropriate configurations to surround the foot and lower leg as an improved cushioning member to replace foam padding in boots. Another application of the cushioning device is as a permanently inflated tongue to fit over the instep portion of the foot.
The permanently inflated cushioning device may be used as an insole or boot liner, overcoming the deficiencies of prior products and providing much better resiliency, shock absorption and greater insulation against cold. An insole construction is disclosed and claimed in applicant's Canadian Patent Application, Serial No. 293,986, filed December 28, 1977, now Canadian Patent 1,068,108.
Another use of the cushioning device of the present invention is to function as door and window seals, which can be used in lieu of prior art extruded rubber or foam plastic stripping. After a period of use, the foam packs down, losing its shape and resiliency. Seals embodying the present invention can be made from the long, narrow, rectangular chambers dis-closed in Figures 8 to 10, which can be cut and spliced into widths and lengths consistent with the particular sealing applications involved.
The elastomeric cushioning devices of the present invention also find application as a permanently inflated . t,~
. .
.. - . .. . . : . ~ . . .-`- 10~37t~g~4 1 liner disposed between the shell of a helmet and the head of the wearer. The shock absorption characteristic is highly advantageous in helmets used for football, motorcycling, and similar activities. If these helmets are designed to have a rigid (but lightweight) external shell used in conjunction with the permanently inflated liner, extreme severe shock - loads of over 1500 G's can be attenuated to under 125 G's.
Tests have been conducted with a motorcycle helmet in accordance with the U.S. Department of Transportation procedures.
In these tests, a helmet with a simulated head therein is dropped onto a steel hemispherical anvil from a height of approximately 8 feet. The Department of Transportation specifications call for a peak shock not to exceed 800 G's for two milliseconds. The cushioned liner embodying the present invention meets and exceeds this specification by a substantial margin. As far as is known, no other helmet has successfully met the Department of Transportation require-ments.
In the same manner, the cushioning device can be made and used as padding for athletic gear, such as football shoulder pads, kidney pads, leg pads, and for similar pads in other sports, such as hockey, baseball, and the like.

:

_ 16 _ - , . ~
. . : , . . . . . .

Claims

embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A cushioning device exposed to air at atmospheric pressure, comprising a sealed member of elastomeric material providing a multiplicity of adjacent chambers, said chambers being inflated at least partially with gas to a desired initial value, said elastomeric material having characteristics of relatively low permeability with respect to said gas to resist diffusion of said gas from said chambers through said elasto-meric material and of relatively high permeability with respect to the ambient air surrounding said member to permit diffusion of said ambient air through said elastomeric material into said inflated chambers to provide a total pressure in each chamber which is the sum of the partial pressure of the gas in each chamber and the partial pressure of the air in each chamber.

2. A cushioning device as defined in Claim 1, said adjacent chambers being discrete and separate from one another.

3. A cushioning device as defined in Claim 1, wherein said gas is selected from a group consisting of: hexafluoroethane, sulfur hexafluoride, perfluoropropane, perfluorobutane, perflu-oropentane, perfluorohexane, perfluoroheptane, octafluoro-cyclobutane, perfluorocyclobutane, hexafluoropropylene, tetra-fluoromethane, monochloropentafluoroethane, 1,2-dichlorotetra-fluoroethane, 1,1,2-trichloro-1,2,2 trifluoroethane, chloro-trifluoroethylene, bromotrifluoromethane, and monochlorotri-fluoromethane.

4. A cushioning device as defined in Claim 1, wherein said elastomeric material is selected from a group of materials consisting of: polyurethane, polyester elastomer, butyl rubber, fluoroelastomer, chlorinated polyethylene, poly-vinyl chloride, chlorosulfonated polyethylene, polyethylene/
ethylene vinyl acetate copolymer, neoprene, butadiene acryloni-trile rubber, butadiene styrene rubber, ethylene propylene polymer, natural rubber, high strength silicone rubber, low density polyethylene, adduct rubber, sulfide rubber, methyl rubber, and thermoplastic rubber.

5. A cushioning device as defined in Claim 2, wherein said elastomeric material is selected from a group of materials consisting of: polyurethane, polyester elastomer, butyl rubber, fluoroelastomer, chlorinated polyethylene, polyvinyl chloride, chlorosulfonated polyethylene, polyethylene/ethylene vinyl acetate copolymer, neoprene, butadiene acrylonitrile rubber, butadiene styrene rubber, ethylene propylene polymer, natural rubber, high strength silicone rubber, low density polyethylene, adduct rubber, sulfide rubber, methyl rubber, and thermoplastic rubber.

6. A cushioning device as defined in Claim 1, wherein said gas under pressure is hexafluoroethane.

7. A cushioning device as defined in Claim 1, wherein said gas under pressure is sulfur hexafluoride.

8. A cushioning device as defined in Claim 2, said chambers being of spherical shape.

9. A cushioning device as defined in Claim 2, said chambers being of spheroidal shape.

10. A cushioning device as defined in Claim 2, said chambers being of generally cylindrical shape.

11. A cushioning device as defined in Claim 2, said chambers each having a portion of substantially square shape.

12. A cushioning device as defined in Claim 2, said chambers each having a portion of rectangular shape.

13. A cushioning device as defined in Claim 2, said chambers each having a portion of rectangular shape, some of said chambers being in staggered relation with respect to other of said chambers.

14. A cushioning device as defined in Claim 1, wherein said elastomeric material is an ether based polyurethane.

15. A cushioning device as defined in Claim 6, wherein said elastomeric material is an ether based polyurethane.

16. A cushioning device as defined in Claim 7, wherein said elastomeric material is an ether based polyurethane.

17. A cushioning device as defined in Claim 2, said chambers being partially collapsed when inflated with said gas to said initial value.

18. A cushioning device as defined in Claim 10, said chambers being partially collapsed when inflated with said gas to said initial value.

19. A cushioning device as defined in Claim 1, said member comprising two layers of elastomeric material sealed to one another at spaced intervals to define said chambers.

20. A cushioning device as defined in Claim 19, wherein said layers are sealed to one another at spaced circular weld areas to form spherical chambers upon inflation of said chambers.

21. A cushioning device as defined in Claim 19, wherein said layers are sealed to one another at spaced circular weld areas to form spheroidal chambers upon inflation of said chambers.

22. A cushioning device as defined in Claim 19, wherein said layers are sealed to one another at spaced circular weld areas to form generally cylindrical chambers upon inflation of said chambers.

23. A cushioning device as defined in Claim 19, wherein said layers are sealed to one another at spaced weld areas to form generally dome shaped chambers, each chamber having a portion at the weld area of substantially square shape.

24. A cushioning device as defined in Claim 19, wherein said layers are sealed to one another at spaced weld areas to form generally arch shaped chambers, each chamber having a portion at the weld area of substantially rectangular shape.

25. A cushioning device as defined in Claim 20, said chambers being partially collapsed when inflated with said gas to said initial value.

26. A cushioning device as defined in Claim 21, said chambers being partially collapsed when inflated with said gas to said initial value.

27. A cushioning device as defined in Claim 22, said chambers being partially collapsed when inflated with said gas to said initial value.

28. A cushioning device as defined in Claim 19, wherein said gas is selected from a group consisting of: hexafluoroethane, sulfur hexafluoride, perfluoropropane, perfluorobutane, perfluoro-pentane, perfluorohexane, perfluoroheptane, octafluorocyclobutane, perfluorocyclobutane, hexafluoropropylene, tetrafluoromethane, monochloropentafluoroethane, 1,2-dichlorotetrafluoroethane, 1,1,2-trichloro-1,2,2 trifluoroethane, chlorotrifluoroethylene, bromotrifluoromethane, and monochlorotrifluoromethane.

29. A cushioning device as defined in Claim 19, wherein said elastomeric material is selected from a group of materials consisting of: polyurethane, polyester elastomer, butyl rubber, fluoroelastomer, chlorinated polyethylene, polyvinyl chloride, chlorosulfonated polyethylene, polyethylene/ethylene vinyl acetate copolymer, neoprene, butadiene acrylonitrile rubber, butadiene styrene rubber, ethylene propylene polymer, natural rubber, high strength silicone rubber, low density polyethylene, adduct rubber, sulfide rubber, methyl rubber, and thermoplastic rubber.

30. A cushioning device as defined in Claim 28, wherein said elastomeric material is selected from a group of materials consisting of: polyurethane, polyester elastomer, butyl rubber, fluoroelastomer, chlorinated polyethylene, polyvinyl chloride, chlorosulfonated polyethylene, polyethylene/ethylene vinyl acetate copolymer, neoprene, butadiene acrylonitrile rubber, butadiene styrene rubber, ethylene propylene polymer, natural rubber, high strength silicone rubber, low density polyethylene, adduct rubber, sulfide rubber, methyl rubber, and thermoplastic rubber.

31. A cushioning device as defined in Claim 1, said initial inflating gas being diluted with air to form an initial chamber inflating mixture therewith having a pressure above atmospheric.

32. A cushioning device as defined in Claim 1, said ambient air diffusing through said sealed member into said chambers and increasing the pressure in said chambers above said initial valve.