Note: Descriptions are shown in the official language in which they were submitted.
1097045
BACKGROUN~ OF THE INVENTION
The present invention pertains to inflat~ble structuresand more particularl-~ ~o load supportLng structures where the
f~mction is to provide a measure of resiliency or a spring
effect. Accordingly, the present invention can be used to
advantage in the construction of air or water beds to control
the shape and resiliency thereof.
Air beds and water ~eds have ~een marketed with various
types of connections between the top and ~ottom sheets that
function as the springs or ties used in conventi~nal bedsprings
or mattresses. Exemplary connections or ties ~etween
imperforate upper and lower plastic ~alls of prior fluid-filled
beds include inflatable cylinders or beams as shown in Nail's
U.S. Patent No. 3,705,429 and zig-zag sheets as shown in
Melzer's U.S. Patent No. 2,703,770. The cylind~rs and beams
disclosed by Nail serve as ties between the top and bottom
; sheets of the structure, but are molded to a generally
cylindrical or rectangular shape and, as such, cannot readily
assume a smoothly flattened configuration when the structure
is deflated, thus hindering the collapse thereof to a neatly
folded configuration ~laving minimum volume. This problem is
overaome to some extent by use of one or more ties in the form
of zig-zag sheets between the upper and lower sheets as is
shown by Melzer, but this increases the cost of materials,
construction is more complex, and there is limited choice Oc the
pattern of "tufting" that can be provided. In addition, the
walls of the air cav~ties in Melzer's structure are
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11 ~097045
1 interconnected with each other, as are the air cavities them-
2 selves, and shape and load control functions are not equivalent
3 to those provided by use of individual, free-standing pockets
4 located within an outer inflatable chamber. Smoothly flattened
bladder configurations are known to have been used in connection
6 with inflatable toys and the like, but they included undesirable
7 perforated top and/or bottom walls, permitting air to free~ly
8 enter the bladder from the outside of the device.
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~097045
1 SUMMARY OF THE INVENTION
2 A primary object of the present invention is, therefore, to over-
3 come the aforementioned problems and disadvantages associated
4 with prior inflatable structures.
,
6 One particular object is to provide an inflatable structure with
7 imperforate top and bottom walls having improved provisions for
8 shape and load control upon inflation, but which can be totally
9 collapsed and thus fully flattened upon deflation.
11 Another object is to provide an easily constructed inflatable
12 structure such as an air bed or water bed, having an inflatable
13 chamber with imperforate outer walls that are tled together by
14 means of a plurality of independent bladders that are in a flat-
tened state when the structure is deflated, and which assume a
16 generally cylindrical shape when the structure is inflated.
17
18 Still another object is to provide such an inflatable structure
19 having "pancake" bladders therein which become ex.ended for
shape and load control of the s.ructure when it is inflated, and
21 which flatten out like pancakes when the structure is derlated.
22 l
23 Other objects and advantages of the present invention will be-
24 come apparent from the following description, the drawings and
the appended claims.
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~097045
According to the invention, an inflatable structure
is provided which comprises an inflatable chamber with opposed
imperforate walls formed of substantially non-expansible air
impervious material and which are progressively separable by
continued inflation of the chamber. A bladder formed of a
flexible substantially non-expansible material is located
within the chamber and is joined to both of the opposed walls
thereof on a bladder axis. The bladder is axially extensible
from a flattened state and is convolutedly inwardly collapsible
toward the axis upon progressive separation of the opposed
walls of the chamber. A plurality of such bladders, spaced
apart from each other, can be employed in inflatable structures
intended for use as air or water beds.
In accordance with one aspect of the invention there
is provided the process of constructing a baffled inflatable
mattress by the aid of perimetric flexible plastic material
forming a top and bottom of the mattress and a plurality of
individual bags or bladders, each comprising two juxtaposed
flat flexible plastic layers joined together adjacent their
outer edges, at least one of the layers having an access
opening for insertion and removal of a relatively rigid
separator, said process comprising: (a) positioning each of
the bags or bladders between the top and bottom of the mattress
with a relatively rigid separator between the layers of the bag
or bladder; (b) thereafter closing a heat sealing machine over
the top and bottom layers, and over said bag or bladder, with
the separator therebetween to seal the layers of said bag or
b}adder to the top and bottom layers respectively at a place
or places located within the region of attachment of the layers,
- 30 without disturbing the continuity of the top and bottom of the
mattress; (c~ removing the separator through said access opening;
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109~045
(d) repeating the foregoing steps as necessary until the bags
or bladders are all arrayed and attached; and (e) thereafter
closing the perimetric flexible plastic material for
containment of a fluid.
The presently disclosed inflatable structure thus
comprises an improvement for tying the opposed imperforate
walls of the inflatable structure together and, when desired,
for controlling resiliency of the structure. Fabrication of
the structure includes the step of confrontingly aligning
two sheet members of a flexible substantially non-expansible
material, joining the perimeters of the sheet members together,
and thereby forming a flat "pancake" bladder. The bladder
thus formed is thereater placed between the opposed walls
of the inflatable chamber of the structure and is aligned so
that each sheet member thereof confronts one of the opposed
walls. Each of the opposed walls of the inflatable chamber is
then joined to the sheet member of the bladder that confronts
it, and wi~h the joint therebetween being located inwardly of
the perimeter of the sheet member.
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1Q9'7045
1 BRIEF DESCRIPTION OF THE DRAWINGS
2 A detailed description of the invention will be made with re-
3 ference to the accompanying drawings wherein like numerals
4 designate corresponding parts in the several figures. These
drawings, unless described as diagrammatic or unless otherwise
6 indicated, are to scale.
8 FIGURE 1 is a perspective view, partly in section, of an air
9 bed constructed in accordance with the present invention.
1~
11 FIG. 2 is a somewhat enlarged elevational view, in section, of
12 the air bed of FIGURE 1, and illustrates the air bed while
13 deflated and during an assembly step wherein one of the deflated
14 "pancake" bladders is being joined to the opposed walls of the
inflatable chamber of the air bed by sealing with a heated ring.
1~
17 FIG. 3 is a somewhat enlarged elevational view, in section, of
18 the air bed of FIGURE 1, and illustrates the "pancake" bladder in
19 an extended, cylindrically convoluted state, following inflation
of the air bed.
21 ~
22 FIG. 4 is a downward view of the structure shown in Fl~. 3.
1 23
24 FIG. 5 is a perspective view illustrating sealing of the peri-
meters of the two confrontingly aligned sheet members of the
~;1 26 "pancake" bladder shown in the drawings.
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1 FIG. 6 is a somewhat enlarged downward view, partly in section,
2 of the flattened "pancake" bladder located between the upper and
3 lower opposed walls of the air bed shown in FIGS. 1-4.
FIGS. 7 and 8 are perspective views of the "pancake" bladder
6 following perimetric sealing and perforation of the sheet members
7 thereof, and further illustrating insertion of a heat insulating
8 paddle into the bladder prior to ring sealing of the sheet
9 members to the opposed walls of the air bed.
13
11 FIG. 9 is a somewhat enlarged perspective view showing sections
12 of the upper and lower opposed walls of the air bed of FIGS.
13 1-4 and a deflated "pancake" bladder therebetween, just after
14 sealing of the sheet members of the bladder to the walls and
subsequent to removal of the heat insulating paddle from the
16 cavity of the bladder.
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l 1t;>q97~5
1 ¦ DETAILED DESCRIPTION OF PREFERR~:D EMBODI,~ lT
2 ¦ ~he following detailed description is of the best presently co~-
3 ¦ templated mode of carrying out the invention. This description
4 ¦ is not to be taken in a limiting sense, but is made merely for
5 ¦ purposes of illustrating the general principles of the invention
~¦ since the scope of the invention is best defined by the appended
7 claims. -
9 The term "inflatable structure" as used herein is intended to
mean any structure that is inflated by means of a suitable fluid
11 such as air or water, and is intended to include air beds, air
12 mattresses, water beds, inflatable cushions, pillows or furniture ,
13 and also such structures as inflatable watercraft, aircraft,
14 chutes, slides, toys and the like.
1~
1~ The opposed walls of the inflatable cham~er of the present struc-
17 ture are formed from a flexible, substantially non-expansible
18 air impervious material auch as a thermoplastic resin. The term
19 "substantially non-expansible material" as used herein is intend
ed to mean a material that has a relatively limited degree of
21 stretch with respect to that exhibited by a non-reinforced
22 rubber. Examples of such materials include thermoplastic poly-
23 meric substances that are strong, yet flexible at room tempera-
24 tures, and a preferred thermoplastic material for construction o
the present structures can be selected from commercially avail-
26 able polyvinyl chloride compounds.
',~ .
28 In FIG. 1, an inflatable structure is represented at 1, and
29 comprises an inperforate upper wall 2, and an opp~sed perforate
lower wal~ 3, which along with sidewalls 4, enclose an air
31 chamber 5. The upper and lower walls are thermally bonded to
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1 ihe side-wall seams 6 and 7, and a conventional air valve or
2 valves 8, are installed in a.wall or walls as means for injecting
3 air or water into the chamber 5, and for the subsequent emptying
4 thereof. Bladders constructed in accordance with the present
invention are represented at 9.
6 .
7 As previously indicated, the upper and lower walls 2 and 3 are
8 made of a flexible, substantially non-expansible air impervious
: g material, such as polyvinyl chloride, and the same type of mater-
ial can be used for constructing the sidewall 4 and the bladders
11 9. It will be understood, however, that different materials can
12 be used for the upper and lower walls 2 and 3, the sidewall,
13 and the b~adders when such is preferred.
14
Referring to FIG. 5, in this example, each of the bladders 9 is
formed from two circular sheet members 10 and 11, which have been
17¦ punched or otherwise cut from an elongated sheet of thermoplastic
. 18¦ resin. Thereafter, the two circular members are confrontingly
¦ aligned, one over the other, and placed between two heated rings
20¦ ~ 12 and 13:for sealing of the edges of the members by displacing .
21¦ the rings toward each other so that the edges of the sheet mem-
~2Z¦ bers 10 and 11 are pressed together between the heated ring sur-
faces 14 and 15. Softening of the plastic all the way around the
~:24~ perimeter lS of each circular sheet member is thereby effected,
Z5 ~ and there is a welding or fusion of the softened plastic which
2:6~` :~results in the joining of the two members at their perimeters to
Z7~ form a seam 17 ~FIGS. 2, 3, 7 and 9), but there is no fusion and
~;.Z8~ joinlng of the plastic sheet members 10 and 11 inwardly of this
sea~m. A flat "pancake" bladder comprising the peripherally join-
i 31 l 1 ed cular sheet mem~ers is thereafter recovered, and is
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~97045
1 ¦ subsequently installed between the upper and lower opposed walls
2 ¦ 2 and 3 of the air bed 1. Other methods of forming the bladder
3 ¦ 9 may utilize a pair of overlyins sheets which are fused together
41 in multiple, spaçed ring patterns and the patterns are cut out
sl just outside the fused ring.
61 ,,
71 The bladders are provided with venting means so that they can
81 become filled with the fluid injected into the chamber 5 during
9 inflation of the structure. Accordingly, one or both of the
sheet members 10 and 11 can be perforated to provide one or more
11 openings 18, therein before or after forming the perimetric seam
12 17 of the bladder. After forming the openings 18, the bladder
13 can be attached to the upper and lower walls of the air bed by
14 thermal sealing in a manner similar to that employed for peri-
lS metric sealing of sheet members 10 and 11. Refering to FIG. 2,
1~ the flat, "pancake" bladder 9 is inserted between the upper and
17 lower walls 2 and 3 of the structure for joining of these walls
18 with the bladder bv heat sealing through use of heated rings 19
19 and 20. An insulating member is emplaced within the bladder,
and thus between the sheet members thereof, to prevent heat seal
21~ ing of the sheet members to each other during the sealing there-
22 of to the outer walls of the structure. As shown in FIGS. 7 and
23 8, the insulating member can be in the form o~ a metal plate 21,
24 and can be equipped with a handle 22, or other appropriate hand-
ling means, to facilitate insertion of the plate into the bladde
26 cavity 23 and subsequent removal therefrom. Accordingly, the
27 bladder 9 can be provided with a slit 24 in its wall to permit
28 lnsertion and removal of the plate 21, and it will be appreciate
that the handle 22 also serves as an aid in prope~ly locating th
plate 21 with respect to the bladder and the heat rings 19 and 2
when the bladder is placed between the walls 2 and 3 for sealing
32 thereto.
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105~7045
l Once a bladder 9 and an emplaced plate 21 have been positioned
2 in a desired location between the opposed walls 2 and 3, and the
3 bladder and the walls have been placed between the heated rings
4 19 and 20 with the bladder centered with respect thereto, the
heated rings are then brought toward each other to compress the
6 bladder sheet members 10 and ll against the walls 2 and 3 to
7 effect the joining thereof. Accordingly, sufficient heat and
8 pressure are applied by means of the heat rings to effect welding
9 or fusion of the thermoplastic walls of the bladder and the
walls 2 and 3, and this results in formation of ring seals 23 and
ll 26 at the sites where the fusion occurs. Once the formation of
12 the ring seals is completed, the heat rings l9 and 20 are separa-
13 ted from each other as shown in F~G. 2, and plate 21 is withdrawn
14 from the bladder through slit 24, as shown in FIG. 9. Thereafter
other like bladders are sealed to walls 2 and 3 in the same
lZ fashion as previously described. The foregoing provides a manu-
17 facturing method which is relatively simple, reliable and in-
18 expensive.
' 19
As previously indicated, the bladders 9 are aligned on a bladder21 axis which is generally perpendicular to the opposed walls 2 and
22 3 of the inflatable structure. Such an axis is illustrated by
23 ~ line A-A in the drawings. A plurality of bladders can be aligned
on an equivalent numher of axes arranged in any c~nvenient patt-
ern to provide various air spring effects or "turfing" patterns
26 as may be desired.
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1~97045
1 FIGS. 2, 6 and 9 illustrate the "pancake" bladder 9 in a flatten-
2 ed state, i.e. the configuration of the bladder when the struc-
3 ture 1 is deflated. FIGS. 1, 3 and 4 illustrate the bladder in
4 an extended, convolutedly inwardly collapsed state following in-
flation of the air bed by injection of a fluid into the inflat-
6 able chamber 5. As can been seen from the drawings, the bladders
7 are axially extensible from the flattened state and convolutedly
8 inwardly collapsable toward the aixs A-A upon progressive separa-
9 tion of the opposed walls 2 and 3 of chamber 5 during the infla-
tion thereof. More specifically, as the walls 2 and 3 move apart
11 from each other during inflation of the air bed, the bladder
12 sheet members 10 and 11 are caused to move apart from each other
13 in opposite directions along the axis A-A, thereby forming a
14 bladder cavity 23 between the sheet members which fills with the
fluid being sl~cked into chamber 5 through the openings 18 and
1~ slit 24. As further separation of the walls 2 and 3 occurs by
17 continued inflation of chamber 5, the sheet members 10 and 11
18 assume a biconical configuration in alignment with axis A-A, and
19 eventually the sheets partially collapse inwardly toward the axis
to form convolute folds 27. When this convolutedly inward colla-
21 pse of the bladder members has progressed to the maximum degree,
22 the bladder is essentially no longer axially extensible, and it
23 thereby restrains further separation of the opposed walls 2 and
24 ~ 3. :
~25
26 Each of the bladders 9, therefore, has an axial extension limit
27 equivalent to a maximum desired separation distance between the
28 opposed walls 2 and 3 when the air bed has been fully inflated.
29 This axial extension limit is established by constructing the
bladder so that the difference between the diameter of each of
31 the sheet members 10 and 11 and that of its respective ring seal
32 25 or 26 is approximately one-half of the desired separation
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11)9704~ ~
1 distance between the opposed walls 2 and 3 when chamber 5 has
2 been fully inflated. The seal rings 25 and 26 can, nonetheless,
3 have any diameter selected to provide both satisfactory strength
4 of attachment to the walls 2 and 3 and a desired appearance for
esthetic purposes. Where preferred, the attacnment'of the bla-
6 dders to walls 2 and 3 can have other than a ring or circular
7 confi~uration, and regardless of the shape, size and nature of
8 the joint between the bladders and the opposed walls, the max-
9 imum separation dis~ance between the walls can be increased by
use of bladder sheet members 10 and 11 of a larger diameter,
11 and can be decreased by use of sheet members having a smaller
12 diameter. More specifically, the extension limit of the bladders
13 can be increased or decreased by selectively increasing or de-
14 creasing the sheet members 10 and 11.
lZ As shown in the drawings, each of the bladders 9 is provided with
17 venting means, e.g. openings 18 and the slit 24 functions as
18 venting means whereby the bladder cavity 23 becomes filled with
19 the fluid injected into chamber 5 of the structure 1 during the
inflation thereof, but it will be understood when a bladder is
21 thus filled, it nonetheless provides an "air spring" effect even
22 though fluid is partially ejected from its cavity back into the
23 chamber 5 when a load is placed on ~he air bed and causes it to
24 become compressed. Such occurs as a result of the fluid in
chamber 5 being under pressure, hence causing a retarded dis-
26 charge of fluid from the bladder cavity. In a similar fashion,
27 the cavity does not immediately refill after a compressive load
28 is removed from the air bed, and the bladders thus "breathe"
29 UpDn applicati~n and release of pressure on the s~tructure 1.
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9704.~ ~
1 It will be appreciated that the rate at which the bladders
2 breathe is dependent upon the number and size of openings such
~ as 18 and 24, and that both the number and size of the openings
4 is subject to variation depending on the degree of resiliency and
load control desired. '
7 As shown in FIGS. 1, 3 and 4, the structure 1 is shown to be in-
8 flated with the bladders 9 extended along axis A-A to their max-
9 imum limit, and whereby the bladders have assumed a convoluted
cylindrical configuration. Accordingly, the opposed walls 2 and
11 3 are restrained by the extended bladders from further separating
12 from each other, which also being ~estrained to a considerable
13 degree from lateral displacement. Shape control is thus provided
14 by the bladders, and an "air spring" effect for load control is
also provided when the bladders are suitably adapted to provide
lZ such an effect.
17
18 It should be re-emphasized out that the present bladder constru-
19 ction is paxticularly advantageous from the standpoint of ease
of~manufacture as well as convenient storage, i.e. upon dis-
21 charging the fluid from chamber 5, the bladders return to a flat
22 "pancake" configuration as shown in FIG. 2 50 that the entire
23 deflated structure becomes quite flat for folding and rolling in-
24 ; to a volume approaching the smallest possible size.
25~
26~ ~ A~ inflatable structure that fulfills the previously stated
27 ~objects has now been described in detail, and since the descrip-
28 tion hàs not included details on all conceivable embodiments
29 thereof, it will be understood that o~her embodiments will be-
come apparent which are within the spirit and scope of the in-
31 vention defined in the following claims.
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