CA1097045A - Fluid filled beds and the like - Google Patents

Abstract

FLUID FILLED BEDS AND THE LIKE

ABSTRACT OF THE INVENTION

Apparatus and method are disclosed which pertain to inflatable structures useful as air beds and the like. Shape and load con-trol are facilitated by a plurality of bladders that are located within an inflatable chamber of the structure and are joined to opposed imperforate walls thereof. The bladders are provided with vents which lend to the interior of the chamber, and upon inflation of the structure and resultant separation of the opposed walls of the chamber, the bladders are caused to extend from a flattened state, become filled with the fluid used for inflating the structure, and assume a roughly cylindrical con-voluted configuration. Being made of a flexible, substantially non-extensible material, such as vinyl plastics, there is a limit to which the bladders can extend, and further vertical separation or lateral shifting of the attached opposed walls is thereby restrained. When the bladders are provided with vents, they "breathe" when a physical load is applied to the inflated struc-ture or removed from it, hence, regulating resiliency by means of an "air spring" effect.

Description

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 ,'' ~

"
. .

-2-, '7 .
.

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.

9 __ ~ __ lZ

~ 18 ~; 19 .-~ , 2~9 ` 32 ~; ~ , :
~ .

~' - .-.-. , .

I~
~097045 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.

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.
~'.' .'~ '; 26 1 ~ __ , . ' 27 1 _ `~ 2 a ¦

' 32 ~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;

~; -5-.

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.

i .
' ' :

-5a-1Q9'7045 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.

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.
7 _ 2~ __ ~` 2 3o .

r~ 32 .
- . .

ll 1~)9704S

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.

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.
17 __ 8 __ 23 ;
24~ ~ :
25~ ~ ;

2~7~ .

~- ~'' _7_ .

1:' ' ~

II c 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 -`-` 109704S

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.

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 ~32 .~ . _g_ . '' 1..~.. .
~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.

~,

-10- -Il. .
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.
27 __ .
28 __ 29~ .
.

32 -ll-Il,, 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 ~:

t~ -12-~, . . .

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.
30 __ 31 __ 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.

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.

32 __ ..

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

Claims (2)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. 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 bladder to the top and bottom layers respectively at a place or places located within the region of attachment of the layers, without disturbing the continuity of the top and bottom of the mattress;
(c) removing the separator through said access opening;
(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.

2. The process as set forth in claim 1 including the steps of making the bags or bladders of companion substantially circular disks and sealing the disks of each bag or bladder respectively to the top and bottom of the mattress along a substantially circular ring located centrally of the disks, the ring being of substantially smaller diameter than the disks for subsequent axial extension of the bags or bladders to substantially biconical form when said mattress is inflated with fluid.