Abstract:
A flexible pressure vessel is constructed from at least one pair of upper and mating lower dome shaped cell portions. Upper and lower passageway portions extend outwardly from each cell portion to surrounding sheet material. The portions are joined to form a passageway for connection to a valve or another cell. Upper and lower reinforcing rings surround the cell portions. Blankets of fiber reinforced material are attached over the cell portions and stitched in place through the surrounding resilient material. Cell shaped sponges impregnated with absorbent materials are encased in impermeable plastic tubing and inserted into the cells. High-strength filaments are wound around the tubing to provide additional pressure handling capability. Heat-reflecting plastic film or metal foil is inserted between blankets and the cell portions. Reinforcing rings are attached over and fastened through the blankets around the cells. An apparatus and method are described for constructing the flexible pressure vessel.

Description:
EARLIER FIELD APPLICATION  
       [0001]    The instant application is a continuation-in-part of applicant&#39;s prior application filed May 23, 2001 and having U.S. Ser. No. 09/864,521, the disclosure of which is specifically incorporated by reference herein. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The invention pertains to devices for storing gases and fluids under pressure. More particularly, the invention relates to pressure vessels that are formed out of flexible materials and that can be made to conform to a variety of shapes.  
         BACKGROUND OF THE INVENTION  
         [0003]    Typically, pressure vessels capable of containing liquids or gases at significant pressures have involved fixed shape cylinders or spheres formed of high-strength metals such as steel or aluminum. Such pressure vessels, while successful for their designed applications, involve a number of problems. First, such metallic cylinders are relatively heavy compared to the gases or fluids that they contain. Second, pressure cylinders contain all of the gas or liquid in a single space. Should the vessel rupture, the entire vessel is destroyed, often with a violent explosion sending shards of metal in all directions. Third, metallic cylinders have a definite shape and cannot be adapted to fit readily in many space-constrained applications. The present invention involves a number of small cells linked to each other by small conduits. The cells are collected in a flexible matting material that adds to the structural integrity of the cells. A pressure vessel of this type can be lightweight, adaptable to a variety of spaces and unusual applications, and is inherently safer in rupture situations.  
           [0004]    Various designs have been developed using linked cell technologies, most in the area of packaging materials. U.S. Pat. No. 4,551,379 issued to Kerr discloses heat-sealable packaging material comprised of interconnected cells formed by laminating two facing sheets of air impermeable material to define designated partitions and passageways. Discontinuities are provided at selected locations in each of the partitions to provide limited communication between the adjacent passages. The packaging material may be cut to the desired length and sealed at one end and then inflated by the insertion of a suitable manifold at the other end and supplying pressurized air. While inflation is maintained, the passages are sealed by a heat-sealing bar trapping the air within the passages.  
           [0005]    U.S. Pat. No. 4,096,306 issued to Larson, describes air inflated cushioning material comprising a series of interconnected cells formed by heat-sealing two facing sheets of film together. Here the cells are connected to each other and a central passageway that is used to inflate the cells. After inflation, the entrance to the passageway is then sealed.  
           [0006]    U.S. Pat. No. 4,465,188, issued to Soroka et al, is directed to an inflatable packaging structure that includes an envelope with an inner liner. The inner liner located within envelope includes an inflatable first layer and a second or upper inflatable layer formed of flexible sheets of heat sealable plastic material. The sheets are sealed to form zones that are connected to a single valve used for inflation.  
           [0007]    U.S. Pat. No. 5,267,646 issued to Inoue et al. describes containers formed of laminated, interconnected cells. The cells are arranged in pairs that can communicate with each other. One chamber is designed to hold powdered, liquid or solid preparations while the second chamber is designed to hold an oxygen absorbent and a desiccant.  
           [0008]    U.S. Pat. No. 5,824,392 issued to Gotoh et al., is directed to a method and apparatus for producing an air cushion having a plurality of independent bubbles. The bubbles have communicating portions extending in a continuous direction so that a plurality of them may be filled simultaneously and then individually sealed. A sheet of bubbles is formed by heat-sealing films together having the bubble forming depressions shapes with a hollow tubing communicating portion extending at the center line of the films in a continuous direction. A portion corresponding to the bubble forming depressions communicates with the right and left sides of the communicating portion. Air blown from a nozzle and fed through the communicating portion inflates the bubbles so that the films can be sealed at the communicating conjunction area making each bubble independent.  
           [0009]    While other variations exist, the above-described designs involving linked cell technologies are typical of those encountered in the prior art. It is an objective of the present invention to provide a flexible pressure vessel that is capable of maintaining gasses or liquids at relatively high pressures. It is a further objective to provide this capability in a vessel that is light in weight and that presents a significantly reduced risk of injury in rupture situations. It is a still further objective of the invention to provide a pressure vessel that may be easily adapted to a variety of space constraints.  
           [0010]    It is yet a further objective to provide a pressure vessel that is durable, easily serviced, and that may be produced inexpensively. It is still a further objective to provide a flexible pressure vessel that is protected against contamination by liquids and gases that it may contain. It is another objective to provide means to increase the pressure handling capabilities of the flexible pressure vessel. It is yet another objective of the invention to provide such increased pressure handling capability with a minimal increase in weight.  
           [0011]    While some of the objectives of the present invention are disclosed in the prior art, none of the inventions found include all of the requirements identified.  
         SUMMARY OF THE INVENTION  
         [0012]    The present invention addresses many of the deficiencies of prior art flexible container and pressure vessel inventions and satisfies all of the objectives described above.  
           [0013]    A flexible pressure vessel providing the desired features may be constructed from the following components. At least one upper dome-shaped cell portion is provided. The upper cell portion is formed from a first sheet of resilient material and has an inner surface, an outer surface, an inner perimeter, an outer perimeter, a border of sheet material surrounding the outer perimeter, and at least one upper passageway portion. The upper passageway portion extends outwardly from the inner perimeter to the surrounding sheet material.  
           [0014]    At least one mating lower dome-shaped cell portion is provided. The lower cell portion is formed from a second sheet of resilient material and has an inner surface, an outer surface, an inner perimeter, an outer perimeter, a border of sheet material surrounding the outer perimeter, and at least one lower passageway portion. The lower passageway portion extends outwardly from the inner perimeter to the surrounding sheet material. The upper cell portion is joined to the mating lower cell portion such that a cell is formed. The cell has at least one passageway extending outwardly from the cell for connection to either a passageway of another cell or a valve.  
           [0015]    A first ring is provided. The first ring has a first inner circumference, an outer circumference and a first predetermined thickness. The first ring is sized and shaped to fit frictionally over the upper cell portion and surround its outer perimeter. A second ring is provided. The second ring has a second inner circumference, an outer circumference and a second predetermined thickness. The ring second ring is sized and shaped to fit frictionally over the lower cell portion and surround its outer perimeter.  
           [0016]    A first flexible blanket is provided. The first blanket has an upper surface, a lower surface and is sized and shaped to cover the upper cell portion and surrounding sheet material. The first blanket is fixedly attached at its lower surface to the outer surface of the upper cell portion and surrounding sheet material. A second flexible blanket is provided. The second blanket has an upper surface, a lower surface and is sized and shaped to cover the lower cell portion and surrounding sheet material. The second blanket is fixedly attached at its lower surface to the outer surface of the lower cell portion and surrounding sheet material. A valve is provided. The valve is connected to the passageway and provides means for controlling a flow of either of gasses and liquids into and out of the cell.  
           [0017]    In a variant of the invention, heavy duty stitching is used to attach the first blanket to the second blanket. The stitching penetrates the first and second blankets and the first and second resilient sheets between the upper and lower cell portions and serves to prevent movement of the first and second rings with respect to the upper and lower cell portions.  
           [0018]    In another variant, the heavy duty stitching is high-pressure hoop and lock braiding. In still another variant, a cell-shaped sponge is inserted between the upper cell portion and the lower cell portion prior to joining the upper and lower cell portions. The sponge serves to prevent the cell from collapsing after either of gas and liquid is removed from the cell. In yet another variant, the sponge is impregnated with a with a zeolite compound.  
           [0019]    In yet a further variant of the invention, either a heat-reflecting plastic film or a metal foil is inserted between at least one of the first blanket and the upper cell portion or the second blanket and the lower cell portion.  
           [0020]    In still a further variant, the upper cell portion is joined to the lower cell portion by either radio frequency welding or high strength adhesive. In another variant, either of the first and second blankets is formed of high-strength fiber impregnated material. In still another variant the passageway has a cross-section of between 0.050 and 0.100 inches.  
           [0021]    In yet a further variant, the flexible pressure vessel includes an upper retaining plate. The upper retaining plate has a third inner circumference, an outer circumference and a third pre-determined thickness. The upper retaining plate is sized and shaped to fit over the upper cell portion and surround its outer perimeter when the upper cell portion is covered by the first blanket. The third inner circumference is larger than the outer circumference of the first ring.  
           [0022]    A lower retaining plate is provided. The lower retaining plate has a fourth inner circumference, an outer circumference and a fourth pre-determined thickness. The lower retaining plate is sized and shaped to fit over the lower cell portion and surround its outer perimeter when the lower cell portion is covered by the second blanket. The fourth inner circumference is larger than the outer circumference of the second ring. Means are provided for attaching the upper retaining plate to the lower retaining plate. When the upper retaining plate is attached to the lower retaining plate, surrounding the upper and lower cell portions and the first and second blankets covering the first and second rings, the pressure capacity of the cell will be increased.  
           [0023]    In still a further variant of the invention, the means for attaching the upper retaining plate to the lower retaining plate includes a series of holes. The holes penetrate the upper retaining plate between its outer circumference and the third inner circumference, the lower retaining plate between its outer circumference and the fourth inner circumference and the first blanket, the border of sheet material surrounding the outer perimeter of the upper cell portion, the border of sheet material surrounding the outer perimeter of the lower cell portion and the second blanket. The holes are outside of the outer circumference of the first and second rings.  
           [0024]    A series of fastening means are provided. The fastening means are sized and shaped to pass through the series of holes and capable of securing the upper retaining plate to the lower retaining plate. In another variant, the fastening means is a series of bolts and locking nuts. In still another variant, the fastening means is a series of rivets.  
           [0025]    In a further variant of the invention, the means for attaching the upper retaining plate to the lower retaining plate includes a series of holes. The holes penetrate the upper retaining plate between its outer circumference and the third inner circumference, the first blanket, the border of sheet material surrounding the outer perimeter of the upper cell portion, the border of sheet material surrounding the outer perimeter of the lower cell portion and the second blanket. The holes are outside of the outer circumference of the first and second rings.  
           [0026]    A series of pins is provided. The pins are affixed orthogonally along an upper surface of the lower retaining plate and are sized, shaped and located to fit slidably through the series of holes and extending slightly above an upper surface of the upper retaining plate. A series of welds are used to fixedly attach the pins to the upper retaining plate, thereby securing the upper and lower retaining plates to each other.  
           [0027]    In still another variant, a series of cell shaped sponges is provided. A tube is provided. The tube is formed of flexible, gas and liquid impervious material and is sized and shaped to surround the sponges. The sponges are inserted in the tubing at spaced intervals. The encased sponges are inserted between the upper cell portions and the lower cell portions prior to joining the upper and lower cell portions. The tubing extends through the passageways. The sponges serve to prevent the cells from collapsing after either of gas and liquid is removed from the cells. The tube serves to prevent contamination of gas or liquid by the inner surfaces of the upper and lower cell portions.  
           [0028]    In yet another, the sponges are impregnated with a zeolite compound.  
           [0029]    In a final variant of the invention, the tube is formed from material selected from the group comprising: thermoplastic polyurethane elastomer, polyurethane polyvinyl chloride, polyvinyl chloride, and thermoplastic elastomer.  
           [0030]    An apparatus for fabricating a flexible pressure vessel includes first and second rolls of planar resilient material. First and second thermal die stamping stations are provided. The stamping stations are capable of forming the upper and lower cell portions. Means are provided for moving resilient material from the first and second rolls of planar resilient material into the first and second thermal die stamping stations.  
           [0031]    A radio frequency welder is provided, the welder is capable of joining the upper cell portion to the lower cell portion. Means are provided for moving the first and second cell portions into the radio frequency welder. A series of first and second rings is provided. The first ring is sized and shaped to fit frictionally over the upper cell portion and to surround its outer perimeter. The second ring is sized and shaped to fit frictionally over the lower cell portion and to surround its outer perimeter.  
           [0032]    First and second rolls of high-strength fiber impregnated blanket material are provided. Means are provided for attaching the first and second blankets over the upper and lower cell portions. Means are provided for attaching a valve to a passageway of a cell.  
           [0033]    In variant of the apparatus for fabricating a flexible pressure vessel, a series of cell-shaped sponges are provided. Means are provided for inserting the cell-shaped sponges between the upper and lower cell portions. In still another variant, first and second rolls of either heat-reflecting plastic film or metal foil are provided. Means are provided for attaching either heat-reflecting plastic film or metal foil to the outer surface of at least one of the upper cell portion and the lower cell portion.  
           [0034]    In another variant, means are provided for moving the blanketed cells to a high pressure hoop and lock braiding machine for stitching. In yet another variant, a series of cell shaped sponges is provided. A tube is provided. The tube is formed of flexible, gas and liquid impervious material and is sized and shaped to surround the sponges. Means are provided for inserting the sponges in the tube at spaced intervals. Means are provided for inserting the encased sponges between the upper cell portions and the lower cell portions prior to joining the upper and lower cell portions. The tube extends through the passageways.  
           [0035]    In a final variant of the apparatus for fabricating a flexible pressure vessel means are provided for positioning an upper retaining plate to fit over the upper cell portion and surround its outer perimeter when the upper cell portion is covered by the first blanket. Means are provided for positioning a lower retaining plate to fit over the lower cell portion and surround its outer perimeter when the lower cell portion is covered by the second blanket.  
           [0036]    Means are provided for producing a series of holes that penetrate the upper retaining plate between its outer circumference and the third inner circumference, the lower retaining plate between its outer circumference and the fourth inner circumference and the first blanket, the border of sheet material surrounding the outer perimeter of the upper cell portion, the border of sheet material surrounding the outer perimeter of the lower cell portion and the second blanket. The holes are outside of the outer circumference of the first and second rings. Means are provided for inserting and securing fastening means through the holes, thereby securing the upper and lower retaining plates to each other.  
           [0037]    A method for fabricating a flexible pressure vessel includes the following steps: Providing first and second rolls of planar resilient material. Providing first and second thermal die stamping stations. Moving the first and second rolls of planar resilient material into the first and second thermal die stamping stations. Forming upper and lower cell portions in the first and second thermal die stamping stations.  
           [0038]    Providing a radio frequency welder. Moving the first and second cell portions into the radio frequency welder. Joining the upper cell portion to the lower cell portion in the radio frequency welder. Fitting a first ring frictionally around the outer perimeter of the upper cell portion and fitting a second ring frictionally around the outer perimeter of the lower cell portion. Providing first and second rolls of either of heat-reflecting plastic film and metal foil. Attaching either heat-reflecting plastic film or metal foil to the outer surface of at least one of the upper cell portion and the lower cell portion.  
           [0039]    Providing first and second rolls of high-strength fiber impregnated blanket material. Attaching the first and second blankets over the upper and lower cell portions and either the heat-reflecting plastic film or metal foil. Stitching through the first and second blankets and the resilient material surrounding the upper and lower cell portions. Providing a valve and attaching the valve to a passageway of a cell.  
           [0040]    A variant of the method for fabricating a flexible pressure vessel includes the following additional steps: Providing a series of cell-shaped sponges impregnated with a zeolite compound. Inserting the cell-shaped sponges between the upper and lower cell portions prior to joining the upper and lower cell portions.  
           [0041]    Another variant includes these steps: Providing first and second rolls of either heat-reflecting plastic film or metal foil. Attaching either heat-reflecting plastic film or metal foil to the outer surface of at least one of the upper cell portion and the lower cell portion.  
           [0042]    Still another variant includes moving the blanketed cells to a high pressure hoop and lock braiding machine prior to stitching. Yet a further variant of the method includes the following steps: Providing a series of cell shaped sponges. Providing a tube. The tube is formed of flexible, gas and liquid impervious material and is sized and shaped to surround the sponges. Providing means for inserting the sponges in the tube at spaced intervals. Providing means for inserting the encased sponges between the upper cell portions and the lower cell portions prior to joining the upper and lower cell portions. Extending the tube through the passageways.  
           [0043]    In yet another variant of the invention, the method for fabricating a flexible pressure vessel includes the following additional steps: Providing upper and lower retaining plates. Providing a series of holes. The holes penetrating the upper retaining plate between its outer circumference and the third inner circumference, the lower retaining plate between its outer circumference and the fourth inner circumference and the first blanket, the border of sheet material surrounding the outer perimeter of the upper cell portion, the border of sheet material surrounding the outer perimeter of the lower cell portion and the second blanket. The holes are outside of the outer circumference of the first and second rings. Inserting and securing a series of fastening means through the holes, thereby securing the upper and lower retaining plates to each other.  
           [0044]    In still a further variant, a series of cell shaped sponges is provided, as is a tube. The tube is formed of flexible, gas and liquid impervious material and is sized and shaped to surround the sponges. The sponges are inserted in the tube at spaced intervals, the encased sponges are wound with high-strength filament material. The filament wound tubing containing the sponges is inserted between the upper cell portions and the lower cell portions prior to joining the upper and lower cell portions with the tube extending through the passageways. The sponges serve to prevent the cells from collapsing after either gas or liquid is removed from the cells. The tube serves to prevent contamination of either gas or liquid by the inner surfaces of the upper and lower cell portions and the filament material serves to increase strength of the tubing.  
           [0045]    In yet a further variant, the sponge is impregnated with a zeolite compound.  
           [0046]    In still a further variant of the invention, the tube is formed from material selected from the group comprising thermoplastic polyurethane elastomer, polyurethane polyvinyl chloride, polyvinyl chloride and thermoplastic elastomer.  
           [0047]    In another variant, the high-strength filament material is selected from the group comprising KEVLAR®, carbon fiber, steel, stainless steel and nylon.  
           [0048]    In still another variant, an apparatus for fabricating a flexible pressure vessel further comprises a series of cell shaped sponges and a tube. The tube is formed of flexible, gas and liquid impervious material and is sized and shaped to surround the sponges. Means are provided for inserting the sponges in the tube at spaced intervals. Means are provided for winding the encased sponges with a high-strength filament material. Means are provided for inserting the filament wound tubing containing the sponges between the upper cell portions and the lower cell portions prior to joining the upper and lower cell portions with the tube extending through the passageways.  
           [0049]    In yet another variant, an apparatus for fabricating a flexible pressure vessel further comprises means for positioning an upper retaining plate to fit over the upper cell portion and surround its outer perimeter when the upper cell portion is covered by the first blanket. Means are provided for positioning a lower retaining plate to fit over the lower cell portion and surround its outer perimeter when the lower cell portion is covered by the second blanket. Means are provided for producing a series of holes. The holes penetrate the upper retaining plate between its outer circumference and the third inner circumference, the lower retaining plate between its outer circumference and the fourth inner circumference and the first blanket, the border of sheet material surrounding the outer perimeter of the upper cell portion, the border of sheet material surrounding the outer perimeter of the lower cell portion and the second blanket. The holes are outside of the outer circumference of the first and second rings. Means are provided for inserting and securing fastening means through the holes, thereby securing the upper and lower retaining plates to each other.  
           [0050]    In still another variant of the invention, a method for fabricating a flexible pressure vessel further comprises the following steps: Providing a series of cell shaped sponges. Providing a tube formed of flexible, gas and liquid impervious material that is sized and shaped to surround the sponges. Inserting the sponges in the tubing at spaced intervals. Winding the encased sponges with a high-strength filament material. Inserting the filament wound tubing containing the sponges between the upper cell portions and the lower cell portions prior to joining the upper and lower cell portions with the tubing extending through the passageways.  
           [0051]    In a final variant of the invention a method for fabricating a flexible pressure vessel further comprises the following steps: Providing upper and lower retaining plates. Providing a series of holes. The holes penetrate the upper retaining plate between its outer circumference and the third inner circumference, the lower retaining plate between its outer circumference and the fourth inner circumference and the first blanket, the border of sheet material surrounding the outer perimeter of the upper cell portion, the border of sheet material surrounding the outer perimeter of the lower cell portion and the second blanket. The holes are outside of the outer circumference of the first and second rings. Inserting and securing a series of fastening means through the holes, thereby securing the upper and lower retaining plates to each other.  
           [0052]    An appreciation of the other aims and objectives of the present invention and an understanding of it may be achieved by referring to the accompanying drawings and the detailed description of a preferred embodiment. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0053]    [0053]FIG. 1 is a plan view of a first embodiment of the invention illustrating diamond-shaped cells, connecting passageways and a valve;  
         [0054]    [0054]FIG. 2 is a plan view of a second embodiment of the invention illustrating circular-shaped cells, connecting passageways and a valve;  
         [0055]    [0055]FIG. 3 is a partial cross-sectional view of the FIG. 2 embodiment illustrating the upper and lower cell portions, upper and lower rings, upper and lower blankets and reinforcing stitching;  
         [0056]    [0056]FIG. 4 is a partial cross-sectional view of the FIG. 2 embodiment illustrating the an included cell-shaped sponge;  
         [0057]    [0057]FIG. 5 is a partial cross-sectional view of the FIG. 2 embodiment illustrating a metal or foil layer surrounding the cell portions;  
         [0058]    [0058]FIG. 6 is a partial cross-sectional view of the FIG. 2 embodiment illustrating the radio frequency welding or high-strength adhesive used to join the cell portions;  
         [0059]    [0059]FIG. 7 is a partial cross-sectional view of the FIG. 2 embodiment illustrating first and second blankets formed of high-strength fiber impregnated material;  
         [0060]    [0060]FIG. 8 is a partial cross-sectional view of the FIG. 2 embodiment illustrating upper and lower retaining plates held in place by welded pins;  
         [0061]    [0061]FIG. 9 is a plan view of the FIG. 2 embodiment with the addition of the upper and lower retaining plates;  
         [0062]    [0062]FIG. 10 is a partial plan view of the cells and connecting passageways;  
         [0063]    [0063]FIG. 11 is a perspective view of a first ring;  
         [0064]    [0064]FIG. 12 is a partial cross-sectional view of the FIG. 2 embodiment illustrating upper and lower retaining plates held in place by nuts and bolts;  
         [0065]    [0065]FIG. 13 is an exploded perspective view of the upper and lower retaining plates and fastening bolts;  
         [0066]    [0066]FIG. 14 is a schematic illustrating an apparatus for making the flexible pressure vessel;  
         [0067]    [0067]FIG. 15 is a plan view of the cell shaped sponges encased in an impermeable plastic tube;  
         [0068]    [0068]FIG. 16 is a side elevational view of the cell-shaped sponges encased in an impermeable plastic tube;  
         [0069]    [0069]FIG. 17 is a partial cross-sectional view of the FIG. 2 embodiment illustrating the cell-shaped sponge encased in the impermeable plastic tube;  
         [0070]    [0070]FIG. 18 is a plan view of the cell shaped sponges encased in an impermeable plastic tube and wound with a high-strength fimament;  
         [0071]    [0071]FIG. 19 is a side elevational view of the cell-shaped sponges encased in an impermeable plastic tube and wound with a high-strength fimament;  
         [0072]    [0072]FIG. 20 is a partial cross-sectional view of the FIG. 2 embodiment illustrating the cell-shaped sponge encased in the impermeable plastic tube and wound with a high-strength filament; and  
         [0073]    [0073]FIG. 21 is a schematic illustrating an apparatus for making the flexible pressure vessel including cell-shaped sponges encased in the impermeable plastic tube and wound with a high-strength filament. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0074]    FIGS.  1 - 3  illustrate a flexible pressure vessel  10  providing the desired features that may be constructed from the following components. At least one upper dome-shaped cell portion  14  is provided. The upper cell portion  14  is formed from a first sheet  18  of resilient material and has an inner surface  22 , an outer surface  26 , an inner perimeter  30 , an outer perimeter  34 , a border of sheet material  38  surrounding the outer perimeter  34 , and at least one upper passageway portion  42 . The upper passageway portion  42  extends outwardly from the inner perimeter  30  to the surrounding sheet material  38 .  
         [0075]    At least one mating lower dome-shaped cell portion  46  is provided. The lower cell portion  46  is formed from a second sheet  50  of resilient material and has an inner surface  54 , an outer surface  58 , an inner perimeter  62 , an outer perimeter  66 , a border of sheet material  70  surrounding the outer perimeter  66 , and at least one lower passageway portion  74 . The lower passageway portion  74  extends outwardly from the inner perimeter  62  to the surrounding sheet material  70 . The upper cell portion  14  is joined to the mating lower cell portion  46  such that a cell  78  is formed. The cell  78  has at least one passageway  82  extending outwardly from the cell  78  for connection to either a passageway  82  of another cell  78  or a valve  86 .  
         [0076]    A first ring  90  is provided. The first ring  90  has an inner circumference  94 , an outer circumference  98  and a first predetermined thickness  102 . The first ring  90  is sized and shaped to fit frictionally over the upper cell portion  14  and surround its outer perimeter  34 . A second ring  106  is provided. The second ring  106  has an inner circumference  110 , an outer circumference  114  and a second predetermined thickness  118 . The second ring  106  is sized and shaped to fit frictionally over the lower cell portion  46  and surround its outer perimeter  66 .  
         [0077]    A first flexible blanket  122  is provided. The first blanket  122  has an upper surface  126 , a lower surface  130  and is sized and shaped to cover the upper cell portion  14  and surrounding sheet material  38 . The first blanket  122  is fixedly attached at its lower surface  130  to the outer surface  26  of the upper cell portion  14  and surrounding sheet material  38 . A second flexible blanket  134  is provided. The second blanket  134  has an upper surface  138 , a lower surface  142  and is sized and shaped to cover the lower cell portion  46  and surrounding sheet material  70 . The second blanket  134  is fixedly attached at its upper surface  138  to the outer surface  58  of the lower cell portion  46  and surrounding sheet material  70 . A valve  86  is provided. The valve  86  is connected to the passageway  82  and provides means for controlling a flow of either of gasses and liquids into and out of the cell  78 .  
         [0078]    In a variant of the invention, as illustrated in FIGS. 3 and 4, heavy duty stitching  146  is used to attach the first blanket  122  to the second blanket  134 . The stitching  146  penetrates the first  122  and second  134  blankets and the first  18  and second  50  resilient sheets between the upper  14  and lower  46  cell portions and serves to prevent movement of the first  90  and second  106  rings with respect to the upper  14  and lower  46  cell portions.  
         [0079]    In another variant, as illustrated in FIG. 4, the heavy duty stitching  146  is high-pressure hoop and lock braiding  150 . In still another variant, also illustrated in FIG. 4, a cell-shaped sponge  154  is inserted between the upper cell portion  14  and the lower cell portion  46  prior to joining the upper  14  and lower  46  cell portions. The sponge  154  serves to prevent the cell  78  from collapsing after either of gas and liquid is removed from the cell  78 . In yet another variant, the sponge  154  is impregnated with a zeolite compound.  
         [0080]    In yet a further variant of the invention, as illustrated in FIG. 5, either a heat-reflecting plastic film  158  or a metal foil  162  is inserted between at least one of the first blanket  122  and the upper cell portion  14  or the second blanket  134  and the lower cell portion  46 .  
         [0081]    In still a further variant, as illustrated in FIG. 6, the upper cell portion  14  is joined to the lower cell portion  46  by either radio frequency welding  166  or high strength adhesive  170 . In another variant, as illustrated in FIG. 7, either of the first  122  and second  134  blankets is formed of high-strength fiber impregnated material  174 . In still another variant the passageway  82  has a cross-section of between 0.050 and 0.100 inches.  
         [0082]    In yet a further variant, as illustrated in FIGS. 8, 9,  12  and  13 , the flexible pressure vessel  10  includes an upper retaining plate  250 . The upper retaining plate  250  has a third inner circumference  254 , an outer circumference  258  and a third pre-determined thickness  262 . The upper retaining plate  250  is sized and shaped to fit over the upper cell portion  14  and surround its outer perimeter  34  when the upper cell portion  14  is covered by the first blanket  122 . The third inner circumference  254  is larger than the outer circumference  98  of the first ring  90 .  
         [0083]    A lower retaining plate  266  is provided. The lower retaining plate  266  has a fourth inner circumference  270 , an outer circumference  274  and a fourth pre-determined thickness  278 . The lower retaining plate  266  is sized and shaped to fit over the lower cell portion  46  and surround its outer perimeter  66  when the lower cell portion  46  is covered by the second blanket  134 . The fourth inner circumference  270  is larger than the outer circumference  114  of the second ring  106 . Means  282  are provided for attaching the upper retaining plate  250  to the lower retaining plate  266 . When the upper retaining plate  250  is attached to the lower retaining plate  266 , surrounding the upper  14  and lower  46  cell portions and the first  122  and second  134  blankets covering the first  90  and second  106  rings, the pressure capacity of the cell  78  will be increased.  
         [0084]    In still a further variant of the invention, the means  282  for attaching the upper retaining plate  250  to the lower retaining plate  266  includes a series of holes  286 . The holes  286  penetrate the upper retaining plate  250  between its outer circumference  258  and the third inner circumference  254 , the lower retaining plate  266  between its outer circumference  278  and the fourth inner circumference  274  and the first blanket  122 , the border of sheet material  38  surrounding the outer perimeter  34  of the upper cell portion  14 , the border of sheet material  70  surrounding the outer perimeter  66  of the lower cell portion  46  and the second blanket  134 . The holes  286  are outside of the outer circumference  98 ,  114  of the first  90  and second  106  rings.  
         [0085]    A series of fastening means  290  are provided. The fastening means  290  are sized and shaped to pass through the series of holes  286  and capable of securing the upper retaining plate  250  to the lower retaining plate  266 . In another variant, as illustrated in FIGS. 12 and 13, the fastening means  290  is a series of bolts  294  and locking nuts  298 . In still another variant, the fastening means  290  is a series of rivets  302 . (Figure needed)  
         [0086]    In a further variant of the invention, as illustrated in FIG. 8, the means  282  for attaching the upper retaining plate  250  to the lower retaining plate  266  includes a series of holes  286 . The holes  286  penetrate the upper retaining plate  250  between its outer circumference  258  and the third inner circumference  254 , the first blanket  122 , the border of sheet material  38  surrounding the outer perimeter  34  of the upper cell portion  14 , the border of sheet material  70  surrounding the outer perimeter  66  of the lower cell portion  46  and the second blanket  134 . The holes  286  are outside of the outer circumference  98 ,  114  of the first  90  and second rings  106 .  
         [0087]    A series of pins  306  is provided. The pins  306  are affixed orthogonally along an upper surface  310  of the lower retaining plate  266  and are sized, shaped and located to fit slidably through the series of holes  286  and extending slightly above an upper surface  314  of the upper retaining plate  250 . A series of welds  318  are used to fixedly attach the pins  306  to the upper retaining plate  250 , thereby securing the upper  250  and lower  266  retaining plates to each other.  
         [0088]    In still another variant, as illustrated in FIGS.  15 - 17 , a series of cell shaped sponges  154  is provided. A tube  338  is provided. The tube  338  is formed of flexible, gas and liquid impervious material and is sized and shaped to surround the sponges  154 . The sponges  154  are inserted in the tube  154  at spaced intervals. The encased sponges  154  are inserted between the upper cell portions  14  and the lower cell portions  46  prior to joining the upper  14  and lower  46  cell portions. The tube  338  extends through the passageways  82 . The sponges  154  serve to prevent the cells  78  from collapsing after either of gas and liquid is removed from the cells  78 . The tube  338  serves to prevent contamination of gas or liquid by the inner surfaces  22 ,  54  of the upper  14  and lower  46  cell portions.  
         [0089]    In yet another variant, the sponges  154  are impregnated with a zeolite compound.  
         [0090]    In still another variant of the invention, the tube  338  is formed from material selected from the group comprising: thermoplastic polyurethane elastomer, polyurethane polyvinyl chloride, polyvinyl chloride, and thermoplastic elastomer.  
         [0091]    An apparatus  178  for fabricating a flexible pressure vessel  10  as illustrated in FIG. 14, includes first  182  and second  186  rolls of planar resilient material  18 ,  50 . First  190  and second  194  thermal die stamping stations are provided. The stamping stations  190 ,  194  are capable of forming the upper  14 , and lower  46  cell portions. Means  198  are provided for moving resilient material  18 ,  50  from the first  182  and second  186  rolls of planar resilient material  18 ,  50  into the first  190  and second  194  thermal die stamping stations.  
         [0092]    A radio frequency welder  206  is provided, the welder  206  is capable of joining the upper cell portion  14  to the lower cell portion  46 . Means  210  are provided for moving the first  14  and second  46  cell portions into the radio frequency welder  206 . A series of first  90  and second  106  rings is provided. The first ring  90  is sized and shaped to fit frictionally over the upper cell portion  14  and to surround its outer perimeter  34 . The second ring  106  is sized and shaped to fit frictionally over the lower cell portion  46  and to surround its outer perimeter  66 .  
         [0093]    First  226  and second  230  rolls of high-strength fiber impregnated blanket material  174  are provided. Means  234  are provided for attaching the first  122  and second  134  blankets over the upper  14  and lower  46  cell portions. Means  246  are provided for attaching a valve  86  to a passageway  82  of a cell  78 .  
         [0094]    In a variant of the apparatus  178  for fabricating a flexible pressure vessel  10 , a series of cell-shaped sponges  154  are provided. Means  202  are provided for inserting the cell-shaped sponges  154  between the upper  14  and lower  46  cell portions prior to joining the upper  14  and lower  46  cell portions.  
         [0095]    In another variant, first  214  and second  218  rolls of either heat-reflecting plastic film  158  or metal foil  162  are provided. Means  222  are provided for attaching either heat-reflecting plastic film  158  or metal foil  162  to the outer surface  26 ,  58  of at least one of the upper cell portion  14  and the lower cell portion  46 . In still another variant, means  238  are provided for moving the blanketed cells  78  to a high pressure hoop and lock braiding machine  242  for stitching.  
         [0096]    In yet another variant, as illustrated in FIGS.  14 - 17 , a series of cell shaped sponges  154  is provided. A tube  338  is provided. The tube  338  is formed of flexible, gas and liquid impervious material and is sized and shaped to surround the sponges  154 . Means  342  are provided for inserting the sponges  154  in the tube  338  at spaced intervals. Means  346  are provided for inserting the encased sponges  154  between the upper cell portions  14  and the lower cell portions  46  prior to joining the upper  14  and lower  46  cell portions. The tube  338  extends through the passageways  82 .  
         [0097]    In still another variant of the apparatus  178  for fabricating a flexible pressure vessel  10  means  322  are provided for positioning an upper retaining plate  250  to fit over the upper cell portion  14  and surround its outer perimeter  34  when the upper cell portion  14  is covered by the first blanket  122 . Means  326  are provided for positioning a lower retaining plate  266  to fit over the lower cell portion  46  and surround its outer perimeter  66  when the lower cell portion  46  is covered by the second blanket  134 .  
         [0098]    Means  330  are provided for producing a series of holes  286  that penetrate the upper retaining plate  250  between its outer circumference  258  and the third inner circumference  254 , the lower retaining plate  266  between its outer circumference  278  and the fourth inner circumference  274  and the first blanket  122 , the border of sheet material  38  surrounding the outer perimeter  34  of the upper cell portion  14 , the border of sheet material  70  surrounding the outer perimeter  66  of the lower cell portion  46  and the second blanket  134 . The holes  286  are outside of the outer circumference  98 ,  114  of the first  90  and second  106  rings. Means  334  are provided for inserting and securing fastening means  290  through the holes  286 , thereby securing the upper  250  and lower  266  retaining plates to each other.  
         [0099]    In still a further variant, as illustrated in FIGS.  18 - 20 , a series of cell shaped sponges  154  is provided, as is a tube  338 . The tube  338  is formed of flexible, gas and liquid impervious material and is sized and shaped to surround the sponges  154 . The sponges  154  are inserted in the tube  338  at spaced intervals, the encased sponges  154  are wound with high-strength filament material  350 . The filament wound tubing  338  containing the sponges  154  is inserted between the upper cell portions  14  and the lower cell portions  46  prior to joining the upper  14  and lower  46  cell portions with the tube  338  extending through the passageways  82 . The sponges  154  serve to prevent the cells  78  from collapsing after either gas or liquid is removed from the cells  78 . The tube  338  serves to prevent contamination of either gas or liquid by the inner surfaces  22 ,  54  of the upper  14  and lower  46  cell portions and the filament material  350  serves to increase strength of the tubing  338 .  
         [0100]    In yet a further variant, the sponge  154  is impregnated with a zeolite compound.  
         [0101]    In still a further variant of the invention, the tube  338  is formed from material selected from the group comprising thermoplastic polyurethane elastomer, polyurethane polyvinyl chloride, polyvinyl chloride and thermoplastic elastomer.  
         [0102]    In another variant, the high-strength filament material  350  is selected from the group comprising KEVLAR®, carbon fiber, steel, stainless steel and nylon.  
         [0103]    In still another variant, as illustrated in FIG. 21, an apparatus  178  for fabricating a flexible pressure vessel  10  further comprises a series of cell shaped sponges  154  and a tube  338 . The tube  338  is formed of flexible, gas and liquid impervious material and is sized and shaped to surround the sponges  154 . Means  202  are provided for inserting the sponges  154  in the tube  338  at spaced intervals. Means  354  are provided for winding the encased sponges  154  with a high-strength filament material  350 . Means  358  are provided for inserting the filament wound tubing  338  containing the sponges  154  between the upper cell portions  14  and the lower cell portions  46  prior to joining the upper  14  and lower  46  cell portions with the tube  338  extending through the passageways  82 .  
         [0104]    In yet another variant, as illustrated in FIGS. 8, 9 and  12 - 14  and  21 , an apparatus  178  for fabricating a flexible pressure vessel  10  further comprises means  322  for positioning an upper retaining plate  250  to fit over the upper cell portion  14  and surround its outer perimeter  34  when the upper cell portion  14  is covered by the first blanket  122 . Means  326  are provided for positioning a lower retaining plate  266  to fit over the lower cell portion  46  and surround its outer perimeter  66  when the lower cell portion  46  is covered by the second blanket  134 .  
         [0105]    Means  330  are provided for producing a series of holes  286 . The holes  286  penetrate the upper retaining plate  250  between its outer circumference  258  and the third inner circumference  254 , the lower retaining plate  266  between its outer circumference  278  and the fourth inner circumference  274  and the first blanket  122 , the border of sheet material  38  surrounding the outer perimeter  34  of the upper cell portion  14 , the border of sheet material  70  surrounding the outer perimeter  66  of the lower cell portion  46  and the second blanket  134 . The holes  286  are outside of the outer circumference  98 ,  114  of the first  90  and second  106  rings. Means  334  are provided for inserting and securing fastening means  290  through the holes  286 , thereby securing the upper  250  and lower  266  retaining plates to each other.  
         [0106]    In still another variant of the invention, as illustrated in FIGS.  18 - 21 , a method  362  for fabricating a flexible pressure vessel  10  further comprises the following steps: Providing a series of cell shaped sponges  154 . Providing a tube  338  formed of flexible, gas and liquid impervious material that is sized and shaped to surround the sponges  154 . Inserting the sponges  154  in the tubing  338  at spaced intervals. Winding the encased sponges  154  with a high-strength filament material  350 . Inserting the filament wound tubing  338  containing the sponges  154  between the upper cell portions  14  and the lower cell portions  46  prior to joining the upper  14  and lower  46  cell portions with the tubing  338  extending through the passageways  82 .  
         [0107]    In a final variant of the invention, as illustrated in FIGS. 12, 13 and  21 , a method  362  for fabricating a flexible pressure vessel  10  further comprises the following steps: Providing upper  250  and lower  266  retaining plates. Providing a series of holes  286 . The holes  286  penetrate the upper retaining plate  250  between its outer circumference  258  and the third inner circumference  254 , the lower retaining plate  266  between its outer circumference  278  and the fourth inner circumference  274  and the first blanket  122 , the border of sheet material  38  surrounding the outer perimeter  34  of the upper cell portion  14 , the border of sheet material  70  surrounding the outer perimeter  66  of the lower cell portion  46  and the second blanket  134 . The holes  286  are outside of the outer circumference  98 ,  114  of the first  90  and second rings  106 . Inserting and securing a series of fastening means  290  through the holes  286 , thereby securing the upper  250  and lower  266  retaining plates to each other.  
         [0108]    The flexible pressure vessel  10  and apparatus  178  and method for making same have been described with reference to particular embodiments. Other modifications and enhancements can be made without departing from the spirit and scope of the claims that follow.