MXPA97005899A - Pressure container, adjustable, compue - Google Patents

Abstract

The present invention relates to a pressure vessel, characterized in that it comprises: at least two end cells, each end cell having a cross section comprising: an arcuate outer wall defining a substantially constant outer wall radius; arched upper wall having a unitary end with the outer wall in an upper-outer connection, the upper wall defining a substantially constant upper wall radius which is smaller than the outer wall radius, and a secured mesh around the cells of end, the mesh comprising a substantially flat upper sheet that is in generating tangent to the upper-outer union of each of the extrusion cells

Description

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PRESSURE CONTAINER, ADJUSTABLE, COMPOUND FIELD OF THE INVENTION The present invention relates to a pressure vessel for retaining compressed fluids, and more preferably to a composite pressure vessel having a plurality of storage cells that are tangentially joined within a composite mesh that closely and efficiently approaches a rectangular volume.

TECHNICAL BACKGROUND OF THE INVENTION Pressure vessels have been widely used to store liquids and gases under pressure. The capacity of a pressure vessel depends on the internal volume of the pressure vessel and the pressure that the container is capable of containing safely. In addition to their storage capacity, the size, internal shape, external shape and weight of the pressure vessel are frequently important in a particular application. REF: 25372 A growing application of pressure vessels is the storage of natural and compressed gas ("CNG"). The CNG is increasingly seen as preferable to gasoline to fuel vehicles. CNG burns in general cleaner than gasoline, leading to a visible reduction in air pollution, and corresponding reductions in health care costs. Natural gas is also a relatively abundant fuel. Therefore, approaches have been devised to convert vehicles supplied with gasoline to convert them using CNG instead of gasoline. Known approaches to converting a vehicle for use with CNG include replacing the gasoline tank with conventional, natural gas storage cylinders. Unfortunately, the use of conventional CNG cylinders restricts the driving range of the converted vehicle to approximately 193 to 225 km (120 to 140 miles), which severely limits consumer acceptance of these conversions. The driving range of this converted vehicle could be increased by simply adding more CNG storage cylinders. This could be done, for example, by mounting the additional CNG cylinders inside the vehicle's luggage rack. However, it is desirable to generate accommodate the CNG storage cylinders within the limited space previously occupied by the gasoline tank. A suggested approach to increase the vehicle handling interval is to carry more CNG within the same storage cylinders. This is achieved by pumping more CNG into the storage cylinders thereby increasing the pressure inside the storage cylinders. However, the increase in storage pressure often requires thickening of the walls in the storage cylinders to provide them with sufficient structural strength to withstand the higher pressure. The increase in wall thickness requires either an increase in the external size of the storage cylinders, thus preventing the storage of the cylinders in the space previously occupied by the gasoline tank, or a reduction in the storage volume of the cylinders, thereby reducing the volume of the stored CNG and therefore reducing the vehicle handling interval. The thickening of the walls also increases the weight of the storage cylinders, thereby decreasing the fuel efficiency of the vehicle. Other approaches to increase the handling interval of CNG fueled vehicles propose to vary the shape of the CNG storage containers. Currently, spheres, cylinders and certain combinations of spherical and cylindrical sections are preferred. As illustrated in Figures 1 and 2, a conventional pressure vessel 100 includes several compartments 102 secured together. Each compartment 102 is defined geometrically as a portion of a "tube and dome" shape. Geometrically, a tube and dome includes 104 straight which is circular with a radius R in the cross section (see Figure 2). Two compartments 102 are combined by dividing each compartment 102 along a plane 106 which is parallel to the longitudinal axis 108 of the tube 104. The truncated faces of the two compartments 102 are then secured together with each other. Each one or more central compartments 110 is then divided along two planes 106 parallel to the longitudinal axis 112 of the central compartment tube. In the resulting container or container 100, the compartments 102 are not tangent to each other at the joints 114 where they are joined. Each tube 104 is terminated at each end by a portion of a hemispherical dome 116 having the same radius R as the tube 104. These tube and dome packages have several disadvantages when used in applications requiring substantially rectangular pressure vessels. These applications include, but are not limited to, the storage of CNG, for use in fueling a vehicle. The vehicle can be a vehicle reconverted with CNG tanks after it was previously fueled with gasoline, or it can be a vehicle designed from the start to operate with CNG. The disadvantages of the tube and dome geometry appear from the differences between that geometry and a substantially rectangular geometry. In the case of reconverted vehicles, the desire for substantially rectangular containers appears because many gasoline tanks are singularly to substantially rectangular casings, as generally indicated by a rectangular casing 118, in dashed lines and FIGS. 2. In the case of vehicles initially designed for use in CNG, the preference for a substantially rectangular pressure vessel may appear from other design considerations. In any case, a tube and dome compartment 102 is a very poor approximation to these rectangular volumes. Arranging the truncated portions of several tube and dome compartments 102 together to form the pressure vessel 100 improves the approach, but, nevertheless, the volumes 120 remain unused, in the form of shims that are not used for the storage of CNG The unused volumes 120, which are defined by the circular walls of the adjacent tube and dome compartments 102, can occupy a significant percentage of the internal volume of the rectangular envelope 118. The elimination of the required unused volumes 120 that are substantially as a rectangular wrap shape. But the construction of a CNG container with a rectangular shell shape, strong enough to withstand typical CNG storage pressures, will require excessively thick walls, because the rectangular envelope is so far removed in the form of a sphere. In addition to the unreacted volumes 120, the container 100 has the disadvantage that the compartments 102 tend to detach at the joints 114 due to the stresses occurring at the joints 114. The thickening of the walls of the compartments 102 to overcome the tendency of detachment reduces the storage capacity of the container 100 or increases its size, and also increases the weight of the container. In this way, it would be an advantage in the art to provide a pressure vessel that approximates a rectangular volume. Also, it would be an advantage to provide a pressure vessel that facilitates the reconversion of gasoline vehicles by having an external shape compatible with the rectangular shell shape of the exterior of the gas tank. It would be an additional advantage to provide this pressure vessel having generally circular cross sections. It would also be an advantage to provide this pressure vessel that resists the tendency to detach when subjected to internal storage pressures. This pressure vessel is described and claimed herein.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a pressure vessel having a new geometry. In one embodiment, the pressure vessel is configured to resist pressurized compressed natural gas ("CNG") stored within the container and the container approaches the rectangular shape of a conventional gasoline tank. The pressure vessel withstands a normal operating pressure of up to approximately 253.11 kg / cm2 (3,600 psi) and has sufficient explosion resistance to withstand approximately three times the normal operating pressure, specifically, an explosion resistance of approximately 773.41 kg. / cm2 (11,000 psi). The new geometry of the present pressure vessel is described herein by reference to geometric operations such as the division of a shape with a plane. These geometrical operations do not necessarily correspond to the manufacturing methods, but are illustrations of the geometry of the pressure vessel to be manufactured.

One embodiment of the pressure vessel includes two end cells. Each end cell includes a semi-cylindrical outer wall. The geometry of the outer wall is defined by dividing a first cylindrical container with a plane through its longitudinal axis to create a half cylinder. Each end cell also includes a top wall of a quarter of a cylinder and a bottom wall of a quarter of a cylinder. The upper wall and the lower wall are unitary with the outer wall. The geometry of the upper wall is defined by dividing a second cylindrical container having the same length as the first cylindrical container but also having a smaller radius. The second cylindrical container is divided with two perpendicular planes through its longitudinal axis. The lower wall is defined similar to dividing a third cylindrical container with two perpendicular planes. A rectangular section connects the lower end of the upper wall with the upper end of the lower wall. The end of each cell thus defines a curve which in the present is denoted as a "polradial" curve, in reference to the different radii of the outer and upper or lower walls. Each end of the walls of the half and quarter of the cylinder, joined together, is finished off by one stage.

Each cap corresponds in its shape (not necessarily the materials currently used) to an elastic sheet secured to a closed poliradial curve as a limit condition and then subjected to a uniform strain pressure. The new geometry of the present invention is further illustrated by a cross section taken transverse to the longitudinal axis of one of the end cells. The cross section defines a polradradial curve that includes an arcuate outer wall, an arched upper wall, and an arcuate lower wall. The outer wall corresponds to the semi-cylinder with the largest radius, which is therefore called the radius of the outer wall. The upper wall, which has a unitary end with the outer wall in the upper-outer connection, corresponds to the fourth upper cylinder, and thus has an upper wall radius which is smaller than the outer wall radius. The lower wall, which has a unitary end with the outer wall in a lower-outer connection, corresponds to the lower cylinder room. In this mode, the radius of the lower wall is equal to the radius of the upper wall, but these radii may differ in other modalities. Thus, in general, a polradial cross section may include circular arcs having either two or three different radii. Alternative embodiments of the pressure vessel include one or more interior cells secured between the end cells. In the cross section, each inner cell has a semicylindrical upper portion secured to the semi-cylindrical inner portion by two straight inner walls. The inner cells are secured tangent to and adjacent to each other, with the end cells secured tangent and adjacent to the inner, outermost cells. The radii of the upper and lower portions of the semi-cylindrical lower wall are the same as the radii of the upper wall and the lower wall, quarter-cylinder, respectively, in the end cells. In this way, the end cells and the inner cells of the present pressure vessel are generally tangent to each other where they meet, different from the compartments of the previously known pressure vessels. This aspect of the new geometry of the present pressurized container reactivates the tendency of adjacent cells to detach.

A mesh is secured around the end cells and around any of the interior cells that are present. The mesh includes a substantially flat upper sheet which is generally tangent to the upper-outer joint of each of the end cells and to the upper half-cylindrical portion of each inner cell. The mesh also includes a substantially flat bottom sheet that is generally tangent to the outer rubber junction of each of the end cells and to the semi-cylindrical bottom portion of each inner cell. The mesh strengthens the pressure vessel by helping to stop the cells tangent to one another and by reinforcing the walls of the cells. The pressure vessel of the present invention defines unused volumes in the form of shims between the mesh and the cells that are not used for the storage of pressurized fluid. In one embodiment, the pressure vessel is strengthened by the substantial filling of the unused volumes with foam or rubber shims placed between the mesh sheets and the cells. The pressure vessel of the present invention includes a valve capable of providing fluid communication between an inner chamber of the pressure vessel and an outer, pressurized fluid line such as a CNG line connected to the valve. The interiors of the various cells forming the present pressure vessel are configured to be in fluid communication with each other, so that only one valve is needed to control the flow of fluid in and out of the pressure vessel. The valve includes a pressure relief mechanism for pouring pressurized fluid if the internal pressure of the pressure vessel exceeds a predetermined value. The valve also includes a fusible plug to provide emergency venting in the presence of high temperatures. Advantageously, the pressure vessel of the present invention facilitates the reconversion of gasoline powered vehicles because the filled weight of the pressure vessel does not exceed the filled weight of a conventional gasoline tank which substantially occupies the same volume cover. In addition, the pressure vessel can be configured with accessories that define external pressures capable of coupling the conventional belts of gasoline tanks. In this manner, the same tank belts previously used to secure the gas tank to the vehicle can be used, without substantial alteration or substantial testing to secure the pressure vessel to the vehicle. Those skilled in the art will appreciate that the pressure vessel of the present invention is not limited to the use to reconversion of vehicles. The present invention also has applications in the design of new vehicles, as well as in other applications that benefit from the use of pressure vessels having a substantially rectangular shape. The pressure vessels according to the present invention are made with metal or composite parts. In one embodiment, the cells are formed of a liner such as a metal sheet or a synthetic polymer film to provide gas impermeability. The liner is overwrapped by a composite layer using the filament winding or other method familiar to those skilled in the art. Inner holes may be provided in the walls of the cells for communication for fluids between the cells, or an external distributor may be subsequently joined to provide this communication. The cells are placed adjacent to each other, and all the cells are then overwrapped by a composite mesh. The compound used in the cells, the mesh, or both may include carbon, glass, graphite, aramid, or other known fibers bonded in a thermoplastic or thermosetting resin. In another embodiment, the cells are formed of metal by stamping, extrusion, or other similar process for those skilled in the art. The metal parts are welded together, and then overwrap with a composite mesh. Examples of suitable metals are titanium, aluminum and steel. In summary, the present invention provides a pressure vessel in which the cells are tangentially joined and overwrapped with a reinforcing mesh. The new geometry of the pressure vessel provides generally circular cross sections that resist the tendency to detach in response to internal pressure. The exterior of the pressure vessel conforms generally to the external shape of a conventional gasoline tank and includes accessories that define depressions for coupling the conventional belts of the gasoline tanks. The features and advantages of the present invention will become more fully apparent through the following description of the appended claims taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a pressure vessel of the prior art.

Figure 2 is a cross section taken along line 2-2 of Figure 1.

Figure 3 is a perspective, sectional, partial view of an embodiment of the pressure vessel of the present invention.

Figure 4 is a cross section of a portion of the pressure vessel, taken along line 4-4 of Figure 3.

Figure 5 is a perspective, sectional view of a first alternative embodiment of a pressure vessel of the present invention.

Figure 6 is a perspective, sectional view of a second alternative embodiment of a pressure vessel of the present invention.

Figure 7 is a perspective view with part separation illustrating selected components of the embodiment shown in Figure 3.

Figure 8 is a perspective, partially cut away view of an alternative embodiment of a pressure vessel of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES Reference is now made in the Figures, where similar parts are referred to by similar numbers. The present invention relates to a pressure vessel in general, and more specifically to a tank for holding compressed natural gas ("CNG") for the supply of fuel to a vehicle (not shown). of the present pressure vessel is generally indicated at 10 in Figure 3. This embodiment of the pressure vessel 10 includes three cells 12 secured within a mesh 14. The three cells 12 include a left end cell 16, a cell 18 of right end and an inner cell 20. The cells 12 have a new geometry and other important features that will be described in detail after they point to the other main components of the pressure vessel 10. The right end cell 18 is preferably configured with a valve 22 to control the flow of fluid in and out of the pressure vessel 10. The valve 22 preferably includes a pressure relief means, for the controlled release of the pressurized fluid from the pressure vessel 10, if the internal pressure of the pressure vessel 10 exceeds a predetermined value. In one embodiment the pressurized fluid is CNG and the predetermined value for controlled fluid release is approximately 253.11 kg / cm2 (3,600 p.s.i.). The suitable pressure release means includes a mechanical pressure release mechanism of the familiar type and the technique that is configured to vent CNG at a predetermined, established pressure. The suitable pressure release means also preferably includes a meltable plug to provide emergency vent in the presence of high temperatures, such as temperatures that can cause the temperature inside the pressure vessel 10 to be above the predetermined value. It is currently preferred that the fusible plug be configured to provide emergency relief when the temperatures in the tank increase approx. above 200 ° F. those skilled in the art will appreciate that the pressure vessel 10 could also be usefully configured with the valve 22 in another location or with more than one valve. Brackets 24 are placed in the form of shims to extend along between the cells 12 and the mesh 14. For clarity of illustration, the portions of these supports 24 have been cut in Figure 3. The supports 24 generally fill the volume without use in the form of shims between the cells 12 and the mesh 14 to provide structural support for the mesh 14. Suitable materials for the supports 24 include rubber, resilient foam, and other rigid or semi-rigid materials familiar to those skilled in the art. The exterior of the pressure vessel 10 is configured with fittings defining depressions 25 for accepting and retaining the conventional belts of the fuel tanks (not shown). It is currently preferred in retrofit applications that the outside of the pressure vessel 10 also generally conform to the shape of a conventional gas tank., both in its general rectangular shape and in its dimensions. The depressions 25 and other adjustment features of the pressure vessel 10 facilitate the replacement of a conventional gasoline tank in the pressure vessel 10, during the conversion of the vehicle, from a gasoline-powered configuration to a configuration powered by CNG. With reference to Figure 4, the end cell 18 includes an outer wall 26 positioned around a liner 28. The outer wall 26 is preferably made of a composite material, such as carbon, glass, graphite, aramid or other known known fibers. in a thermoplastic or thermosetting resin such as epoxy. The liner 28 can be made of a gas impervious material, such as sheet metal or other synthetic polymer film. Although the new geometry and other features of the present invention were described with reference to the end cell 18, other cells 12 of the pressure vessel 10 may also include new features. The outer wall 26 is generally semi-cylindrical. The geometry of the outer wall 26 is defined by dividing the first cylinder with a plane through a longitudinal axis 30. The longitudinal axis 30 extends through a point 32 perpendicular to the plane of Figure 4. The radius 34 of the wall outer 26 is thus substantially constant through an arc of approximately 180 degrees. An upper wall 36 in general of a quarter of a cylinder, and a lower wall 38 in general of a quarter of a cylinder are joined to the outer wall 26. The upper wall 36 is unitary with the outer wall 26 in the upper-outer connection 40 , and the lower wall 38 is unitary to the outer wall 26 in a lower, outer junction 42. The quarter-cylinder geometry of the walls 36 and 38 is defined by dividing a second and third cylinder each having the same length as the cylinder of the outer wall 26 but also having smaller tube radii 44 and 46, respectively. Each of the second and third cylinders are divided with two perpendicular planes through its longitudinal axis to define the quarter cylinder. The upper half of the outer wall 26 and the upper wall 36 thus define a polradial curve. The lower half of the outer wall 26 and the lower wall 38 define a second poliradial curve. In this currently preferred embodiment, the radius 44 of the upper wall 36 is equal to the radius 46 of the lower wall 38, but in alternative embodiments these radii differ. However, the radius 34 of the outer wall 26 is always greater than any of the spokes 44 and 46. An internal wall 48 substantially straight connects the upper wall 36 and the lower wall 38. The inner wall 48 is unitary with the top wall 36 and the lower pair 38 in the upper-inner joint 50 and a lower-inner joint 52, respectively. The inner wall 48 is generally tangent to the upper wall 36 in the upper-inner connection 50 and is generally tangent to the lower wall 38 in the inner-lower connection 52. The mesh 14 (Figure 3) includes an upper sheet 54 which is generally tangent to the upper wall 36 at the upper-outer joint 40. The mesh 14 also includes a lower sheet 56 which is generally tangent to the lower wall 38 in the lower-outer joint 42. The topsheet 54 and the top wall 36 substantially define an unused volume 58 that is not used for the storage of pressurized fluid. The lower sheet 56 and the lower wall 38 substantially define an unused, similar volume 60. Unused volumes 58, 60 are preferably substantially filled by brackets 24 in the form of shims (Figure 3). As illustrated in Figure 3, it is currently preferred to configure each end of each cell 12 with a cover 62. In one embodiment, the covers 62 in the end cells 16, 18 have a geometry which is smoothly interpolated between a portion of a sphere that has a radius equal to the radius 34 of the outer wall, on the one hand, and the portions of sphere having the upper wall radius 44 and the lower wall radius 46, on the other hand. The geometry of the caps 62 in the inner cell 20 smoothly interpolates between a portion of a sphere having a radius equal to the outer wall radius 34, on the one hand, and portions of the spheres having the upper wall radius 44 and the lower wall radius 46, on the other hand. In alternative embodiments, caps 62 have different geometries that smoothly blend spheres having three spokes 34, 44 and 46. In one embodiment, each cap 62 corresponds in shape to a hypothetical elastic sheet that is secured to the closed polyrradial curve defined by end of cell 12 and then a uniform strain pressure is subjected. In analytical terms, the end of cell 12 defines a boundary condition and the shape of cover 62 is determined by manipulating differential equations that correspond to the deformation of the uniform sheet by spatially uniform forces such as gas pressure. Those skilled in the art will appreciate that different elasticities of the sheet can lead to differently sized covers, and will easily choose between these possible shapes according to the approaching rectangular volume and other design imitations. Figures 5 and 6 illustrate two alternative embodiments of the pressure vessel. Each embodiment is shown sectioned along a line that generally corresponds at the position to line 4-4 in Figure 3. Although the embodiment shown in Figure 5 includes a left end cell 16 and an end cell 18 right, does not include cell 20 inside. In contrast, the embodiment shown in Figure 6 includes a left end cell 16, a right end cell 18, and two interior cells 20. More generally, the pressure vessel embodiments of the present invention may include zero or more interior cells. As shown in Figure 6, each inner cell 20 has a substantially semicircular upper cross-section 21 which is generally tangent to either the upper wall 36 of an end cell 16, 18 or the upper semicircular cross-section 21 of the another cell 20 inside. Each inner cell 20 also has a substantially semicircular lower cross-section 23 which is generally tangent to either the lower apparatus 38 of an end cell 16, 18 or to the semicircular lower cross-section 23 of another inner cell 20. In this embodiment, the radius of each upper, semi-circular cross-section 21 is substantially equal to the radius of the upper wall of the upper walls 36. As illustrated in Figures 5-7, the interior chambers of the cells 12 of the pressure vessels must be placed in communication for fluids together by one or more orifices 64. In this way, the pressure within the interiors of the cells 12 is equalized, and only one valve 22 is needed to control the flow of the pressurized fluid in and out several cells are in general tangents where they unite with each other. Those skilled in the art may also identify other modalities in accordance with the teachings herein. With reference to Figure 7, the present pressure vessel is manufactured by methods familiar to those skilled in the art. One approach forms the cells 12 by placing the liner 28 (Figure 4) around a mandrel (not shown) having the desired geometry and dimensions. The desired geometry of the mandrel, which provides the tangential encounters between the cells 12 (see Figures 5 and 6) and the other new geometrical features of the present invention, is readily determined by those skilled in the art in accordance with the teachings herein. . The desired dimensions of the mandrel are easily determined by those skilled in the art from the information that includes the strength of the materials used to form the cells 12., the pressures of the cells 12 that must resist, and the dimensions of the space in which the pressure vessel must be adjusted, finished. In one embodiment, the materials used to form the cells 12 include prepreg graphite tow that is from the pressure vessel. An alternative embodiment, illustrated in Figure 8, provides communication for fluids between the cells 12 through an external distributor 66. The distributor is constructed of metal or other familiar materials. In this embodiment, the pressure relief valve 22 and the meltable plug are integrated into the distributor 66. Although the pressure vessels illustrated in Figures 3 through 6 are generally in the form of a row of cylinders, alternative embodiments employ the new geometry of the present invention in pressure vessels having other general shapes. For example, some embodiments include toroidal cells having in the cross section the new geometry of the present invention. Other modalities include four end cells before two end cells. In these embodiments, a cross section of each of the four end cells includes at least one poliradial curve, and may include two polradradial curves in the form of an outer wall of a quarter circle that is unitary with two smaller walls of a quarter of a circle. The mesh is generally tangent to the end cell at the junctions between the outer wall and the smaller unit walls, and winds them with a combination of ring and helical windings to provide sufficient strength to withstand a normal operating pressure within the pressure vessel of approximately 253.11 kg / cm2 (3,600 psi) and a burst or explosion resistance of approximately two or three times that expression. The complete inventions of this type of pressure vessel are those in general of the conventional gas tank (not shown) that the pressure vessel replaces. The present pressure vessel can also be used in applications other than the conversion of gasoline-powered vehicles for use with CNG, in which case criteria other than the size of a conventional gasoline tank will define the desired dimensions of the pressure vessel. After the liner 28 is placed around the mandrel, the liner 28 is overwrapped by composite material using a filament winding, tube coating, tape wrapping, automatic fiber replacement, another method familiar to those skilled in the art. The aligned holes 64 can be configured in the walls of the cells 12 either by machining after the composite material of the cell wall has cured or by placing the composite fibers around a suitable fitting. The valve 22 secures one of the end cells 18 by a polar metal protrusion. The cells 12 are then placed adjacent to one another as shown in Figure 3. The rubber supports 24 are placed or glued against the cells 12. Then, the cells 12 are wrapped around the composite mesh 14. The mesh 14 includes known composite materials and is applied by the filament winding or other technique of family application to those skilled in the art. The complete assembly is then placed in a shell mold (not shown). The mold is generally square shaped with silicone rubber inserts that couple the inside of the box on one side and the shape of the outer, desired, pressure vessel on the other. A combination of expansion and pressurization of silicone inserts of the cell liners 28 is then employed to compact the composite material to the desired shape. Those skilled in the art will appreciate that other manufacturing techniques may also be employed to form pressure vessels in accordance with the teachings herein.

In another embodiment, the cells 12 are formed of metal by stamping, extrusion or other process familiar to those skilled in the art. The metal parts are welded together and then overlaid with the composite 14 mesh. Suitable materials include titanium, aluminum and steel. In summary, the present invention provides a pressure vessel that approximates the internal volume of a conventional gasoline tank. The geometry of the cells uses upper walls and lower walls whose radii are smaller than the radius of the outer wall. Because the cells are joined tangentially, and because the fence is tangential to the cells and supports the cells, the pressure vessel of the present invention generally has circular cross sections that resist the tendency to detach. In addition, the present pressure vessel conforms to the external shape of a conventional gas tank. The exterior of the present pressure vessel is generally rectangular and is provided with fittings defining depressions for attaching the belts that previously retained the gas tank to the vehicle.

The invention can be incorporated into other specific forms without departing from its essential characteristics. The described modalities will be considered in all aspects only as illustrative and not restrictive. Any of the explanations provided in the present of the scientific principles employed in the present invention are only illustrative. The scope of the invention is therefore indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning of the equivalence interval of the claims will be encompassed within its scope.

It is noted that in relation to this date, the best method known by the applicant to carry out the present invention, is the conventional one for the manufacture of the objects to which it refers. Having described the invention as above, the content of the following is claimed as property:

Claims (27)

1. A pressure vessel, characterized in that it comprises: at least two end cells, each end cell having a cross section comprising: an arcuate outer wall defining an outer wall radius, substantially constant; an arcuate upper wall having a unitary end with the outer wall in an upper-outer connection, the upper wall defining a substantially constant upper wall radius that is smaller than the outer wall radius; and a mesh secured around the end cells, the mesh comprising a substantially flat top sheet that is tangentially generated to the upper-outer joint of each of the end cells.

2. The pressure vessel according to claim 1, characterized in that the end cells comprise a composite material.

3. The pressure vessel according to claim 1, characterized in that the mesh comprises a composite material.

4. The pressure vessel according to claim 1, characterized in that each of the end cells comprises a substantially semi-cylindrical portion.

5. The pressure vessel according to claim 1, characterized in that the external wall radius is substantially the same for each of the outer walls and the upper wall radius is substantially the same for each of the upper walls.

6. The pressure vessel according to claim 1, characterized in that an inner cell adjacent to at least one of the upper walls of the end cells is secured, and the mesh is secured around this inner cell.

7. The pressure vessel according to claim 6, characterized in that a portion of the inner cell adjacent to the mesh has a substantially semicircular upper cross section.

8. The pressure vessel according to claim 7, characterized in that the upper, substantially semicircular cross section of the inner cell is generally tangent to at least one of the upper walls of the end cells.

9. The pressure vessel according to claim 7, characterized in that a radius of the substantially semicircular upper cross section of the inner cell is substantially equal to the radius of the upper wall of at least one of the upper walls.

10. The pressure vessel according to claim 1, characterized in that at least two interior cells are secured between the end cells, each of the upper walls of the end cells is adjacent to at least one of the inner cells, and the Mesh is secured around the inner cells.

11. The pressure vessel according to claim 1, further comprising a shim placed between the upper sheet of the mesh and at least one of the upper walls to resist the forces driving the upper sheet towards the upper wall.

12. A pressure vessel, characterized in that it comprises: at least two composite end cells, each end cell having a cross section comprising: an arcuate outer wall defining an outer wall radius, substantially constant; an arcuate upper wall having a unitary end with the outer wall in an upper-outer connection, the upper wall defining a substantially constant upper wall radius that is smaller than the outer wall radius; a lower, arcuate wall having a unitary end with the outer wall in a lower-outer connection, the lower wall defining a substantially constant lower wall radius that is smaller than the outer wall radius; and an inner wall having a unitary upper end with the upper wall having a unitary lower end with the lower wall; and a composite mesh secured around the end cells, the mesh comprising a substantially flat top sheet that is generally tangent to the upper-outer joint of each of the end cells, and a substantially flat bottom sheet that is general tangent to the lower-outer union of each of the end cells.

13. The pressure vessel according to claim 12, characterized in that the upper wall radius and the lower wall radius are substantially equal.

14. The pressure vessel according to claim 12, characterized in that an inner cell adjacent to at least one of the lower walls and adjacent to at least one of the lower walls is secured, and the mesh is secured around this inner cell.

15. The pressure vessel according to claim 14, characterized in that a portion of the inner cell adjacent to the mesh has a substantially semicircular upper cross section which is generally tangent to the upper wall of at least one of the end cells and a lower substantially semicircular cross section which is generally tangent to the lower wall thereof of the end cells.

16. The pressure vessel according to claim 12, characterized in that it further comprises a valve capable of selectively providing fluid communication between an inner chamber of the pressure vessel and an outer, pressurized fluid line connected to the valve.

17. A pressure vessel, characterized in that it comprises: at least two composite end cells, each of the end cells comprising a substantially semi-cylindrical portion, each of the end cells having a cross section comprising: an outer wall substantially semicircular having an outer wall radius; an upper wall substantially of a quarter of a circle having an upper wall radius less than the outer wall radius, the upper wall having a unitary end with the outer wall in an upper-outer connection; a bottom wall substantially of a quarter of a circle having a lower wall radius substantially equal to the upper wall radius, the lower wall having a unitary end with the outer wall in a lower-outer joint; and a substantially straight inner wall having a unitary upper end with the upper wall and having a unitary lower end with the lower wall; and a composite mesh secured around the end cells, the mesh comprising a substantially flat top sheet that is generally tangent to the upper-outer joint of each of the end cells, and a substantially flat, bottom sheet that is generally tangent to the upper-outer joint of each of the end cells, and a substantially flat lower sheet which is generally tangent to the lower-outer joint of each of the end cells.

18. The pressure vessel according to claim 17, characterized in that it also comprises a top shoe placed between the upper sheet of the mesh and at least one of the upper walls to resist the forces driving the upper sheet towards the upper wall, and a lower shim placed between the lower sheet of the mesh and at least one of the lower walls to resist the forces pushing the lower sheet towards the lower wall.

19. The pressure vessel according to claim 17, characterized in that at least two interior cells secure between the end cells, each of the upper walls of the end cells is adjacent to at least one of the inner cells, and the Mesh is secured around these interior cells.

20. The pressure vessel according to claim 19, characterized in that a portion of each of the inner cells has a substantially semicircular upper cross section adjacent to the upper sheet of the mesh, at least one of the upper, substantially semicircular cross sections, is generally tangent to at least one of the upper walls of the end cells, each of the inner cells has a substantially semicircular lower cross section, adjacent to the bottom sheet of the mesh, and at least one of the lower cross sections substantially semicircular is generally tangent to at least one of the lower walls of the end cells.

21. The pressure vessel according to claim 17, characterized in that the filled weight of the pressure vessel does not exceed the filled weight or gasoline tank which occupies substantially the same volume cover as the pressure vessel.

22. The pressure vessel according to claim 17, characterized in that the pressure vessel is configured with accessories that define external pressures capable of coupling the belts of the gas tank that are capable of securing the container under pressure to the vehicle.

23. The pressure vessel according to claim 17, characterized in that the cells of the pressure vessel are configured with at least one orifice that provides communication for fluids between the interiors of the cells.

24. The pressure vessel according to claim 17, characterized in that the pressure vessel cells are configured with an external distributor that provides communication for fluids between the interiors of the cells.

25. The pressure vessel according to claim 17, further comprising a valve capable of selectively providing fluid communication with an interior chamber of the pressure vessel.

26. The pressure vessel according to claim 25, characterized in that the valve comprises a collapsible plug.

27. The pressure vessel according to claim 25, characterized in that the valve comprises a mechanical pressure relief mechanism that is configured to vent the pressurized fluid to a predetermined, established pressure.