End bosses for type IV pressure vessels

Abstract

A Type IV compliant pressure vessel has an improved mechanical bond between the outer composite shell and the boss. The pressure vessel includes an inner polymer liner with a flared edge fixedly bonded to the boss. The boss has a bore in fluid communication with the interior of the pressure vessel. Additionally, the boss has a shank extending between the liner and the outer composite shell. The shank includes a plurality of spikes that protrude radially away from the boss. A resin and fiber outer composite shell surrounds the outer periphery of the liner and the outer periphery of the shank. The spikes are embedded in the outer composite shell to mechanically fasten the outer composite shell to the boss.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 62 / 867,910, filed June 28, 2019.

[0002]

[0002] The present invention relates to bosses for Type IV pressure vessels, including Type IV compliant pressure vessels. More particularly, the present invention relates to a boss design having spikes embedded in an outer composite shell with a liner located inside the boss. [Background technology]

[0003]

[0003] Pressure vessels generally store fluids and / or gases under pressure, such as natural gas, oxygen, nitrogen, hydrogen, propane, and the like. Type IV pressure vessels or tanks have a metal-free body that typically comprises a carbon fiber reinforced polymer composite wound and / or braided on a thermoplastic polymer liner. A valve is connected to the vessel to fill the vessel with compressed fluid. However, the valve cannot be directly connected to the polymer liner. Therefore, a boss needs to be provided to connect the valve to the vessel.

[0004]

[0004] The first known method of forming a Type IV pressure vessel by attaching a boss to a polymer liner and an outer composite shell is illustrated in U.S. Pat. No. 10,180,210. The first known method utilizes an injection molding process to mold the liner around a locking feature in the boss to mechanically lock the boss to the liner. This first known method provides excellent surface contact between the polymer liner and the outer surface of the boss. The seal between the liner and the boss is formed by the interface between the liner and the boss. Additionally, the boss typically includes a lip feature that seals itself when the boss is pressurized. The gas-tight boss / liner assembly is supported by the outer cover of the composite shell. There is no coupling between the sealing mechanism and the mechanical constraint. The joint between the boss and the liner is not prestressed.

[0005]

[0005] However, this first known method requires that the liner be molded around the boss before wrapping the liner with the composite fibers. Furthermore, the first known method has no mechanical engagement between the boss and the outer composite shell. Thus, the boss can separate from the outer composite shell under stress, allowing the boss to rotate within and / or slide axially relative to the outer composite shell. Movement of the boss relative to the liner and / or outer composite shell can result in leakage and potential failure of the connection between the boss and the pressure vessel.

[0006] A second known method of forming a boss for a Type IV pressure vessel is illustrated in US Publication No. 2018 / 283612, in which a hose-type crimp, e.g., a ferrule is crimped around a laminated assembly of an outer composite shell, a polymer liner, and a boss. The second known method includes a boss that slides within an opening in the liner so that the liner sits against the outer surface of the boss. The ferrule is crimped around the boss and the composite shell after the liner is covered with the outer composite shell to fixedly bond the boss to the outer composite shell. The boss may include ridges along the outer surface of the boss to grip the inner surface of the liner. The hose-type crimp fitting relies on the crimp pressure to provide a composite seating and seal. Gas attempting to escape along the liner tends to open a gap between the boss and the liner. The ferrule and the composite are prestressed to a state that resists the opening of the gap. The ferrule is also axially stressed by providing a grip on the composite and resisting axial displacement of the stem.

[0007]

[0007] However, this second known method relies on crimping pressure to fixedly couple the boss to the liner. The boss can rotate within the liner under increased load on the boss if the crimping force on the joint between the boss and the liner is insufficient. Furthermore, the second known method relies on a ferrule to fixedly couple the boss to the outer composite shell without a direct mechanical engagement between the boss and the outer composite shell. Axial and rotational loads on the boss can weaken the connection between the boss and the outer composite shell. The boss can separate from the outer composite shell under stress, allowing the boss to rotate within the outer composite shell and / or slide axially relative to the outer composite shell. Movement of the boss relative to the liner and / or outer composite shell can result in leakage and potential failure of the connection between the boss and the pressure vessel.

[0008]

[0008] Therefore, it would be desirable to mechanically couple a boss directly to the outer composite shell of a Type IV pressure vessel. It would further be desirable to mechanically couple a boss directly to a liner of the pressure vessel. It would be desirable to form a seal between the liner and the boss. It would also be desirable to constrain rotational movement of the boss relative to the liner and relative to the outer composite shell when a torque is applied to the boss. It would further be desirable to constrain axial movement of the boss relative to the liner and relative to the outer composite shell when an axial force is applied to the boss. In addition, it would be desirable to fixedly couple the liner to the boss without using a molding process and without requiring the use of ferrules to crimp the liner to the boss. Finally, it would be desirable to fixedly couple the outer composite shell to the boss without relying on ferrules to crimp the outer composite shell to the boss. Summary of the Invention

[0009] A Type IV compliant pressure vessel is provided with an improved mechanical bond between an outer composite shell and a boss. The pressure vessel includes an inner polymeric liner having a flared edge fixedly bonded to the boss. The boss has a bore in fluid communication with the interior of the pressure vessel. In addition, the boss has a shank extending between the liner and the outer composite shell. The shank includes a plurality of spikes that project radially away from the boss. An outer composite shell of resin and fiber surrounds the outer periphery of the liner and the outer periphery of the shank. The spikes are embedded into the outer composite shell to mechanically fasten the outer composite shell to the boss.

[0010] Advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view of a portion of a Type IV pressure vessel having a boss assembled between a polymeric liner and an outer composite shell according to one embodiment of the present invention. [Diagram 2]

[0012] 2 is an enlarged cross-sectional view of portion 2 of the pressure vessel of FIG. 1 illustrating a spike embedded in the outer composite shell protruding from the boss and illustrating a seal insert compressing the liner flare section against the boss. [Diagram 3]

[0013] FIG. 3A is a perspective view of the boss of FIG. 1 removed from the pressure vessel.

[0014] Figure 3B is a cut-away view of the boss of Figure 3A illustrating the micro-ridges on the boss cone face, Figure 3C is a cut-away view of the boss of Figure 3A illustrating the rough surface texture on the boss cone face, and Figure 3D is a cut-away view of the boss of Figure 3A illustrating the smooth surface texture on the boss cone face. [Figure 4]

[0015] FIG. 4A is a cross-sectional view of the seal insert of FIG. 1 removed from the pressure vessel.

[0016] Figure 4B is a perspective view of a portion of the seal insert of Figure 4A illustrating the micro-ridges on the cone face of the seal insert, Figure 4C is a perspective view of a portion of the seal insert of Figure 4A illustrating the rough surface texture on the cone face of the seal insert, and Figure 4D is a perspective view of a portion of the seal insert of Figure 4A illustrating the smooth surface texture on the cone face of the seal insert. [Diagram 5]

[0017] FIG. 1 illustrates a known method of wrapping strands of resin impregnated fiber around a liner in a helical pattern. [Figure 6]

[0018] FIG. 2 illustrates a braiding process in which fiber strands are overbraided around the pressure vessel of FIG. 1. [Figure 7]

[0019] FIG. 2 is a cross-sectional view of a second embodiment of the pressure vessel of FIG. 1 in which the shank of the boss extends along a tapered region of the liner. [Figure 8]

[0020] FIG. 2 is a cross-sectional view of a third embodiment of the pressure vessel of FIG. 1 in which the shank of the boss extends partially along the tapered region of the liner. [Figure 9]

[0021] FIG. 3B is a perspective view of another embodiment of the boss of FIG. 3A. [Figure 10]

[0022] FIG. 3B is a perspective view of an embodiment of a spike prior to assembly with the boss of FIG. 3A. [Figure 11]

[0023] FIG. 11 is a perspective view of the spike embodiment of FIG. 10 having a cylindrical pin protruding longitudinally away from the base of each spike. [Figure 12]

[0024] FIG. 12A illustrates an assembly method in which the cylindrical spike of FIG. 10 is press-fit into the hole of the boss of FIG. 3A.

[0025] FIG. 12B illustrates an assembly method in which the cylindrical spike of FIG. 11 is press-fit into the hole of the boss of FIG. 3A.

[0026] FIG. 12C illustrates an assembly method in which the cylindrical spike of FIG. 10 is welded to the boss of FIG. 3A.

[0027] FIG. 12D is a diagram illustrating the pyramidal spike of FIG. 10 integrally formed with the boss of FIG. 3A. [Figure 13]

[0028] 2 is a cross-sectional view of the pressure vessel of FIG. 1 taken along section line AA illustrating a row of spikes disposed around the periphery of the boss. [Figure 14]

[0029] FIG. 14 illustrates a first embodiment of portion C of the cross-sectional view of the pressure vessel of FIG. 13 showing spikes partially embedded in the outer composite shell. [Figure 15]

[0030] FIG. 14 illustrates a second embodiment of portion C of the cross-sectional view of the pressure vessel of FIG. 13 showing spikes embedded in all of the layers of fiber strands that form the outer composite shell. [Figure 16]

[0031] FIG. 7 illustrates a first embodiment of portion B of the pressure vessel of FIG. 6 illustrating tetrahedron-shaped spikes extending through the braided fiber strands of the outer composite shell. [Figure 17]

[0032] FIG. 7 illustrates a second embodiment of portion B of the pressure vessel of FIG. 6 illustrating a cylindrically shaped spike extending through the braided fiber strands of the outer composite shell. [Figure 18]

[0033] FIG. 2 is an exploded view of a liner / boss subassembly according to one embodiment of the present invention. [Figure 19]

[0034] FIG. 19 is an exploded view of an elongated subassembly including a pair of liner / boss subassemblies and a sacrificial tube section of FIG. 18 in accordance with one embodiment of the present invention. [Figure 20]

[0035] FIG. 20 is a perspective view of the elongated subassembly of FIG. 19. [Figure 21]

[0036] 20 is a perspective view of the elongated subassembly of FIG. 19 passing through the braiding machine of FIG. 6. FIG. [Figure 22]

[0037] FIG. 20 is a perspective view of the elongated subassembly of FIG. 19 being overbraided with a plurality of fiber strands. [Figure 23]

[0038] FIG. 23 is a perspective view of the elongated subassembly of FIG. 22 after trimming of the braided fiber strands and removal of the sacrificial tube section. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012]

[0039] Referring to the drawings, in which like numerals refer to like or corresponding parts throughout the several views, a Type IV pressure vessel 10 (comprising a polymeric liner 14 and an outer composite shell 18) for containing liquids and / or gases under pressure is shown in FIGS. 1 and 2 according to one embodiment of the present invention. The pressure vessel 10 is suitable for storage of compressed liquids and / or gases such as nitrogen, hydrogen, natural gas, helium, dimethyl ether, liquefied petroleum gas, xenon, and the like. Pressure vessels 10 for hydrogen storage for automotive applications are typically designed for nominal operating pressures of up to 70 MPa. In comparison, pressure vessels 10 for compressed natural gas storage are typically designed for nominal operating pressures of up to 25 MPa.

[0013]

[0040] 1 and 2, pressure vessel 10 includes a polymeric liner 14 fixedly bonded to boss 16 with an outer composite shell 18 surrounding an outer periphery 14' of polymeric liner 14. Liner 14 includes an interior hollow body 20 defined by an elongated cylindrical wall 22 extending between a first end 26 and a second end 30. A longitudinal axis of pressure vessel 10 is indicated by element 32. In the embodiment shown in FIG. 1, liner 14 includes a neck region 40, a tapered region 42, and a chamber region 44. Polymeric liner 14 includes opposing inner and outer surfaces 50, 54 and an inlet opening 58 at first end 26. Inlet opening 58 of liner 14 includes a flared edge 62 that is fixedly bonded to boss 16 with a sealing insert 134.

[0014]

[0041] 1 is generally formed from one or more polymeric materials, such as nylon (PA), ethylene vinyl acetate (EVA), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), ethylene vinyl alcohol (EVOH), polytetrafluoroethylene (PTFE), polyurethane (PU), and / or polyvinyl chloride (PVC). The polymeric liner 14 can be formed of a single layer of polymeric material or can include a multi-layer structure of two or more polymer layers, and can further include one or more metal layers or additives, as desired for a particular application.

[0015]

[0042] The boss 16 of FIG. 1 is shown removed from the pressure vessel 10 in FIG. 3A. With reference to FIGS. 2 and 3A, the boss 16 has a bore 86 passing axially through the boss 16 between opposing ends 88, 88' of the boss 16. The longitudinal axis of the boss 16 is indicated by element 32 in FIG. 3A. The bore 86 is comprised of a neck portion 98, a cone face 102, and a male-female mating face 94. The boss cone face 102 may include one or more fine ridges 102A, a rough surface texture 102B, and / or a smooth surface texture 102C, as illustrated in FIGS. 3B-3D, respectively. In the embodiment shown in FIGS. 1 and 2, the flared edge 62 of the liner 14 is fixedly bonded and sealed to the cone face 102.

[0016]

[0043] Flared edge 62 of liner 14 fits over cone face 102. Flared edge 62 may be formed during the extrusion process of liner 14 or may be formed or thermoformed directly into cone face 102 of boss 16. Neck section 118 of liner 14 fits over neck portion 98. Neck section 118 is formed during the extrusion process of liner 14 and may additionally be thermoformed to neck portion 98 to enhance the seal.

[0017]

[0044] The seal insert 134 shown in Figures 1 and 2 is shaped to fit and engage with the male and female mating surfaces 94 of the boss 16. The seal insert 134 of Figure 1 is shown in Figure 4A prior to assembly with the boss 16. With reference to Figure 4A, the seal insert 134 has a generally cylindrical main body portion 138 with the male and female mating surfaces 142 extending around the outer periphery of the cylindrical main body portion 138 and configured to matingly engage with the male and female mating surfaces 94 by threads, press fit, swage, or the like. The longitudinal axis of the seal insert 134 is indicated in Figure 4A by element 32.

[0018]

[0045] Additionally, the seal insert 134 includes a bore 158 passing axially through the seal insert 134. Extending from the main body portion 138 of the seal insert 134 is a cone face 162 that is configured to seal against the flared edge 62 of the liner 14. The cone face 162 may include one or more fine ridges 162A, rough surface textures 162B, and / or smooth surface textures 162C, as illustrated in Figures 4B-4D, respectively.

[0019]

[0046] Also, as shown in FIG. 2, when the seal insert 134 engages the male and female mating surface 94 of the boss 16, the flared edge 62 of the liner 14 is compressed between the outer surface 166 of the seal insert 134 and the boss cone surface 102 of the bore 86 to provide a seal.

[0020]

[0047] Compression applied by the seal insert 134 against the flared edge 62 of the liner 14 forms a seal between the liner 14 and the boss cone surface 102 of the boss 16, as shown in FIGURE 2. Sandwiching the liner 14 between the bore 86 and the seal insert 134 forms an initial seal between the boss 16 and the liner 14. The neck portion 98 forms a seal with the outer surface 54 of the inner surface 14 after the liner 14 is pressurized.

[0021]

[0048] Alternatively, one or more auxiliary seals, such as O-rings or the like, may be included adjacent the liner 14, bore 86, and / or seal insert 134, if desired for a particular application. The seal between the liner 14 flared edge 62, the boss cone face 102, and the seal insert 134 may be improved by including rough surface textures 102B, 162B and / or fine ridges 102A, 162A on the boss cone face 102 and / or on the cone face 162 of the seal insert 134, if desired for certain embodiments. In other embodiments, a satisfactory seal may be obtained with smooth surface textures 102C, 162C on both the boss cone face 102 and the cone face 162 of the seal insert 134.

[0022]

[0049] Returning to Figure 3, the boss 16 has a generally cylindrical portion 178 coupled to a shank 182. In the embodiment shown in Figures 1-3A, the shank 182 has a generally cylindrical shape with an outer bearing surface 198. The bearing surface 198 of the shank 182 lies against the outer composite shell 18. The shank 182 shown in Figure 1 extends along the neck region 40 and also along a portion of the tapered region 42 of the liner 14.

[0023]

[0050] The mechanical fastening between the outer composite shell 18 and the boss 16 is achieved by a spike 186 that protrudes radially away from the bearing surface 198 of the shank 182, as shown in Figures 1 and 2. The spike 186 is at least partially embedded in the outer composite shell 18 to mechanically fasten the boss 16 to the outer composite shell 18. The engagement of the spike 186 with the outer composite shell 18 allows the boss 16 to resist internal pressures and also increases the amount of allowable boss torque without the boss 16 separating from the liner 14 and / or the outer composite shell 18.

[0024]

[0051] The boss 16 optionally includes a flange shoulder 200 located on an outer surface 202 of the boss 16 generally between the cylindrical portion 178 and the shank 182, as shown in Figures 1-3A. The flange shoulder 200 contacts the outer composite shell 18. Alternatively, the outer composite shell 18 can extend along a portion of the shank 182 without the flange shoulder 200 abutting the boss 16.

[0025]

[0052] The liner 14 is optionally fabricated with mounting features 206 (shown in FIG. 18 ) that aid in the positioning and assembly of the boss 16 to the liner 14. The liner 14 is cut and / or trimmed, if necessary, to allow assembly with the boss 16. After the boss 16 and other fixtures are assembled with the liner 14, the liner 14 and / or boss 16 are optionally heated to cause the liner 14 to fit and / or adhere to the boss 16.

[0026]

[0053] After the boss 16 and liner 14 are assembled, the liner 14 and / or shank 182 can be covered with a resin barrier layer, such as a polymeric film, if desired for a particular application. Additionally, an optional breather layer or secondary gas barrier layer can be wrapped around portions and / or the entire length of the liner 14 and shank 182, as desired for a particular application. Suitable materials for the breather layer include woven fiberglass cloth, non-woven fiberglass cloth, and the like. Suitable gas barrier layers include metallized films, EYOH membranes, and the like.

[0027]

[0054] The outer composite shell 18 of the pressure vessel 10 is typically formed by placing a resin impregnated fabric 214 onto the liner 14 after the liner 14 and boss 16 are assembled, as shown in FIGS.

[0028]

[0055] A first known method of applying the resin impregnated fibers 214 to the liner 14 is filament winding, illustrated in FIG. 5. A plurality of fiber filaments 214 are grouped together to form a fiber strand 216. A plurality of fiber filaments 214 can be grouped together to form a fiber strand 216 before or during the manufacturing process for applying the fibers 214 to the liner 14. Similarly, a single fiber strand 216 or a grouping of multiple fiber strands 216 can be applied at a given time as desired for the manufacturing process. The fiber strands 216 can be applied to the liner 14 by continuously wrapping one or more fiber strands 216 around the liner 14 in an overlapping helical pattern to form one or more wrapped fiber layers 218, as illustrated in FIG. 5. The fiber strands 216 can be coated with a liquid resin 220 before being wrapped to the liner 14, as shown in FIG. 5. Alternatively, the fiber strands 216 can be coated with liquid resin 220 after being wrapped in the liner 14 and / or the fiber filaments 214 can be pre-impregnated with resin 220. The resin 220 is cured such that the resin 220 and the wrapped fiber layers 218 form a rigid outer composite shell 18 that surrounds the liner 14.

[0029]

[0056] A second method of applying the resin impregnated fibers 214 to the liner 14 is to braid the fibers 214, as illustrated in Figure 6. Similar to the first method, multiple fiber filaments 214 are assembled to form fiber strands 216. Multiple fiber strands 216 are over-braided around the liner 14 to form a braided fiber layer 224 using a braiding machine 226, as illustrated in Figure 6. Additionally, the fiber strands 216 can be impregnated with resin 220 before, during, and / or after braiding the fiber strands 216 around the liner 14.

[0030]

[0057] Overbraiding a plurality of fiber strands 216 around an elongated liner 14 using braiding, a process illustrated in FIG. 6, will form a braided fiber layer 224 that conforms to the large diameter cylinder section 228, the small diameter cylinder section 232, and the tapered transition section 236 of the elongated liner 14 for the pressure vessel 10. Similarly, the overbraiding process 226 shown in FIG. 6 can form the braided fiber strands 216 onto the shank 182 of the boss 16. The overbraiding process 226 is a preferred method of applying the resin impregnated fiber 214 to a conforming pressure vessel 10, which can include a plurality of spaced apart large diameter cylinder sections 228, with adjacent large diameter sections 228 connected by the small diameter cylinder sections 232. When the resin 220 is cured, the resin 220 and the braided fiber strands 216 form a rigid outer composite shell 18 that surrounds the liner 14.

[0031]

[0058] The outer composite shell 18 shown in Figure 1 includes one or more layers of resin impregnated fibers 214. Suitable fibers 214 for the outer composite shell 18 include one or more of carbon fibers, glass fibers, basalt fibers, boron fibers, aramid fibers, high density polyethylene fibers (HDPE), Zylon™ poly(p-phenylene-2,6-benzobisoxazole fibers (PBO), aramid fibers, Kevlar® polyparaphenylene terephthalamide fibers, nylon fibers (PA), polyethylene naphthalate (PEN), polyester fibers (PL), and the like. Suitable resins 220 include one or more of epoxy resins, vinyl ester resins, polyester resins, thermoplastic resins, urethanes, and the like.

[0032]

[0059] The selection of materials and dimensions for the liner 14, as well as the type and amount of resin 220 and fibers 214 forming the outer composite shell 18, are selected based in part on the desired operating conditions of the pressure vessel 10. Additionally, the inclusion of one or more of a breather layer, a barrier layer, and / or a metal layer between the liner 14 and the outer composite shell 18, as well as the material composition of the additional layers, are based in part on the desired operating conditions of the pressure vessel 10.

[0033]

[0060] The outer composite shell 18 is formed around the outer periphery 198 of the shank 182, where the outer composite shell 18 abuts a flange shoulder 200, as illustrated in FIG. 2. The fiber strands 216 are trimmed adjacent the flange shoulder 200 to form a composite free edge 240, which supports and protects the composite free edge 240. If the boss 16 does not have a flange shoulder 200, the fiber strands 216 are trimmed in place to form the composite free edge 240. The composite free edge 240 can be protected and / or reinforced by applying tape 242 covering the flange shoulder 200 and the composite free edge 240, as shown in FIG. 7. Alternatively, the composite free edge 240 near the flange shoulder 200 can be covered by additional fiber strands 216, a crimp ring such as a ferrule, or the like. Suitable fibers 214 for covering the composite free edge 240 include carbon fiber, fiberglass, nylon fiber, and the like. Applying tape, fiber strands 216, and / or crimp rings onto the composite free edge 240 can prevent delamination of the edge, enhance the aesthetics of the pressure vessel 10, and / or provide a support area for mounting the pressure vessel 10.

[0034]

[0061] Optionally, the inner surface 194 of the shank 182 can be configured to matingly engage the tapered section 236 of the liner 14, such as illustrated in FIGS. 7 and 8. FIG. 7 shows a second embodiment of the pressure vessel 10 having a boss 16A with a shank 182A that supports the tapered section 236 along the entire tapered region 42 of the liner 14. Optionally, the boss 16A extends along the tapered section 236 all the way past the tapered region 42 and also overlaps a portion of the large diameter cylinder section 228 of the liner 14. The shank 182A shown in FIG. 7 provides a full taper seating along the tapered section 236. The boss 16A absorbs most of the hoop stress of the liner 14 and reduces the load on the tapered section 236 of the liner 14. The increased contact area between the boss 16A and the liner 14 in FIG. 7 improves the quality of the seal. The amount of boss torque that can be tolerated without the boss 16 separating from the liner 14 and / or outer composite shell 18 is increased by the addition of spikes 186 that protrude radially from the shank 182A.

[0035]

[0062] In contrast to the embodiments shown in Figures 1 and 7, the boss 16B of the third embodiment shown in Figure 8 has a shank 182B that supports the tapered section 236 along a portion of the tapered region 42 of the liner 14. The boss 16B provides partial taper settling because the shank 182B only supports a portion of the tapered region 42. The short shank 182B shown in Figure 8 provides less support for the tapered section 236 than the long shank 182A shown in Figure 7. However, the short shank 182B has a lower material cost than the long shank 182A. Additionally, the boss 16B of Figure 8 is lighter than the full taper settling boss 16A shown in Figure 7. The shape, length and dimensions of the shanks 182, 182A, 182B are selected based in part on the desired operating conditions of the pressure vessel 10, as well as secondary factors such as material cost, component weight, and the like.

[0036]

[0063] Turning to FIG. 1, the spikes 186 project radially away from the shanks 182, 182A, 182B and are embedded in the outer composite shell 18 to mechanically fasten the bosses 16, 16A, 16B to the outer composite shell 18. The spikes 186 can be distributed across the outer bearing surfaces 198 of the shanks 182, 182A, 182B. A fourth embodiment is shown in FIG. 9 of the boss 16C, illustrating an alternative arrangement of the spikes 186 on the shank 182C. As illustrated by FIG. 9, the spikes 186 can be located in one or more specific zones 238, 238′ of the shank 182C. The number, shape, size and location of the spikes 186 attached to the shanks 182-182C are selected based on the expected nominal operating pressure or boss torque of the pressure vessel 10 in use, the dimensions of the shanks 182-182C, the dimensions of the outer composite shell 18, and the like. The spikes 186 can be distributed over the entire outer bearing surface 198 of the shank 182B, or the spikes 186 can be located in specific zones 238, 238' of the shank 182B.

[0037]

[0064] The boss 16C is shown in Figure 9 prior to assembly with the pressure vessel 10. The boss 16C has a shank 182C configured to matingly engage the tapered section 236 of the liner 14. As such, the shank 182C has a tapered conical and / or cylindrical shape that abuts the flange shoulder 200. When the boss 16C is assembled with the liner 14 and covered with the outer composite shell 18, the spikes 186 project radially away from the outer bearing surface 198 of the shank 182C and are embedded into the outer composite shell 18 to mechanically fasten the boss 16C to the outer composite shell 18.

[0038]

[0065] 9 are optional vent grooves 248 that extend longitudinally along the outer bearing surface 198 of the shank 182C and radially along the flange shoulder 200. The boss 16C can include any number and configuration of vent grooves 248 as desired for a particular application to allow hydrogen gas to vent from the interface between the liner 14 and the outer composite shell 18 to the atmosphere. The gas permeates the liner 14 and collects in the gap between the liner 14 and the outer composite shell 18. The permeated gas vents through the vent grooves 248 to the atmosphere, preventing subsequent collapse of the liner 14.

[0039]

[0066] In addition, as shown in FIG. 1, because both the liner 14 and the outer composite shell 18 are fixedly coupled to the boss 16, the force applied to the boss 16 is distributed to the outer composite shell 18. In contrast, when the boss 16 is inserted into the opening of the liner 14 covered by the outer composite shell 18 and the ferrule is subsequently crimped around the outer composite shell 18, the boss 16 only directly contacts the liner 14. The ferrule is fixedly coupled to the outer composite shell 18 and fixedly coupled to the boss 16. However, the boss 16 is not fixedly coupled directly to the outer composite shell 18. Instead, the connection between the ferrule and the outer composite shell 18 and the connection between the ferrule and the boss 16 form a mechanical connection between the boss 16 and the outer composite shell 18. Gaps can form between the liner 14 and the outer composite shell 18 over time. Additionally, the ferrule can become separated from the outer composite shell 18 and / or from the boss 16. Rotational and axial loading of the boss 16 can potentially weaken the attachment of the liner 14 to the outer composite shell 18, weaken the ferrule crimp, and / or increase the gap formed between the liner 14 and the outer composite shell 18. If the ferrule crimp is loosened sufficiently, the boss 16 can rotate within the ferrule. Movement of the boss 16 relative to the outer composite shell 18 due to a weakened ferrule crimp can cause the boss 16 to separate from the liner 14. The replacement of the ferrule with the spike 186 of the boss 16 directly bonds the boss 16 to the outer composite shell 18 when the spike 186 is embedded into the outer composite shell 18. In some embodiments, the spike 186 can be combined with the ferrule to increase the mechanical bond between the boss 16 and the outer composite shell 18. The inclusion of spikes 186 embedded in the outer composite shell 18 can be combined with several different fastening methods for attaching the boss 16 to the liner 14 and outer composite shell 18 as desired and / or required, depending on the expected loads on the boss 16.

[0040]

[0067] The spikes 186 can have a variety of shapes, such as those illustrated in FIG. Suitable spike 186 variations include, by way of non-limiting example, a cylindrical spike 264, a tetrahedral spike 268, a pyramidal spike 270, and a cone-shaped spike 274. The tetrahedral spike 268 has three sides 280. The pyramidal spike 270 has four or more sides 280, including, but not limited to, five, six, seven, or more sides 280. Each spike 186, 264, 268, 270, 274 has a spike main body 278 that extends between a spike tip 282 and a spike base 286. The spike tip 282 can be pointed, as illustrated by the pyramidal spike 270. Alternatively, the spike tip 282 can have a rounded shape, as exemplified by the spike tip 282 of the conical spike 274. Spikes 186 of any shape suitable for the intended application can be used, including a mixture of spike 186 shapes and sizes.

[0041]

[0068] The spike base 286 can include a cylindrical pin 288 that protrudes longitudinally away from the spike base 286, as illustrated in FIG. 11. Non-limiting embodiments illustrated in FIG. 11 are a cylindrical spike 264, a tetrahedral spike 268, a pyramidal spike 270, and a cone-shaped spike 274, which have a cylindrical pin 288 that protrudes away from the spike base 286. The pin 288 allows different shaped spikes 186, 264, 268, 270, 274 to be mounted in a circular hole 290 in the shank 182, as illustrated in FIG. 12B. The circular hole 290 can be a concave cavity, a through hole, and / or a combination of a cavity and a through hole. Additionally, the pin 288 and hole 290 can be non-circular in some embodiments.

[0042]

[0069] 12A-12D illustrate a method of attaching the spikes 186, 264, 268, 270, 274 to the shank 182. Shown in FIG. 12A is the pressing of the cylindrical spike 264 into a circular hole 290 in the shank 182, as illustrated by arrow D. The cylindrical spike 264 can be press fit (illustrated by arrow D) into the circular hole 290, which is sized to receive the cylindrical spike 264 in a male-female manner. The circular hole 290 can be a partial depth hole 290 or a through hole 290, as desired for a particular application.

[0043]

[0070] The second attachment method shown in Fig. 12B is similar to the attachment method shown in Fig. 12A. The cylindrical spike 264, the tetrahedral spike 268, the pyramidal spike 270, and the conical spike 274 may include a cylindrical pin 288 that protrudes away from the spike base 286, as shown in Fig. 11. The pin 288 is press-fit (illustrated by arrow E) into a circular hole 290 in the shank 182 having an inner diameter sized to female-male engage with the pin 288, as shown in Fig. 12B. The addition of the pin 288 to the spike base 286 allows the non-cylindrical spikes 268, 270, 274 to be press-fit into the shank 182 using the circular hole 290.

[0044]

[0071] Welding the spike 186 to the shank 182 is a third attachment method illustrated in FIG. 12C. The spike base 286 of the spikes 186, 264, 268, 270, 274 can be welded 286A and / or glued to the shank 182. FIG. 12C illustrates welding the spike base 286 of the cylindrical spike 264 to the outer bearing surface 198 of the shank 182. A weld line 286A is formed around the base 286 of the spike 186. The weld line 286A increases the diameter of the spike 186, but is unlikely to cause a problem during the overbraiding process 226 because the weld line 286A is adjacent to the shank 182. In some embodiments, the spike 186 can be glued to the shank 182 using an adhesive. The welding and adhesive attachment methods can accommodate a variety of spike 186 shapes, including the cylindrical spike 264, tetrahedral spike 268, pyramidal spike 270, and cone-shaped spike 274 shown in FIG. 11, as well as spikes 186 of other shapes.

[0045]

[0072] A fourth method, illustrated in Figure 12D, is to machine and / or form the spike 186 when the shank 182 is formed. The fourth method can be used to form, by way of non-limiting example, the cylindrical shaped spike 264, the tetrahedral shaped spike 268, the pyramidal shaped spike 270, and the cone shaped spike 274. During the machining process, material is removed around the spike 186 to form the spike 186. Alternatively, the spike 186 can be integrated into the forming tool when the boss 16 is formed during the forming process.

[0046]

[0073] 3A, a plurality of spikes 186 are fixedly coupled to the shank 182 of the boss 16. In the embodiment shown in FIG. 3A, the spikes 186 are distributed around the circumference 198 of the shank 182. The spikes 186 may be arranged in a plurality of rows 294, 294' of spikes 186, with four rows 294, 294' of spikes 186 shown in the exemplary embodiment of FIG. 3A.

[0047]

[0074] 3A, a row 294, 294' of spikes 186 is defined as a plurality of spikes 186 spaced about the circumference 198 of the shank 182, where the axial distance measured between the end 88' of the boss 16 and the center of each spike tip 282 in the row 294, 294' of spikes 186 is within a range defined by a predetermined amount. In one embodiment, the predetermined amount can be a multiple of the maximum width 186' of the spikes 186 including the row 294, 294' of spikes 186, where the multiple is, by way of non-limiting example, 1, 2, 3 or more.

[0048]

[0075] Adjacent rows 294, 294' of spikes 186 are spaced axially of boss 16, as shown in FIGURE 3A. The axial distance 294A between adjacent rows 294, 294' of spikes 186 can be uniform between the rows 294, 294', or the spacing can be non-uniform, i.e., some rows 294, 294' are spaced closer to each other than the spacing between other rows 294, 294' of spikes 186.

[0049]

[0076] Additionally, the spikes 186 in the first row 294 are aligned in the axial direction of the boss 18 with the spikes 186 in the second row 294' of the spikes 186 of the embodiment shown in FIG. 3A. However, it will be understood that the number of any spikes 186, the number of rows 294, 294' of any spikes 186, as well as the relative alignment of the spikes 186 in the first row 294 to the positional alignment of the spikes 186 in the adjacent row 294' can be varied without changing the scope of the invention. Spikes 300A-300D illustrate alternative exemplary spike 186 locations on the shank 182 of FIG. 3A. If spikes 300A, 300B are included, the second row 294' of spikes 186 would have more spikes 186 than are present in the first row 294 of spikes 186. Further, spikes 300A and 300B are offset from spikes 186 forming a first row 294 of spikes 186. Spikes 300C and 300D are located proximate spike 300E to create a localized zone 238 with additional spikes 300C-300E. Additionally, spikes 186 in the first row 294 of spikes 186 can be circumferentially offset from spikes 186 in an adjacent row 294' of spikes 186, as illustrated in FIG. 16 described below, if desired for a particular application.

[0050]

[0077] An exemplary arrangement of the spikes 186 around the circumference 198 of the shank 182 is illustrated in FIG. 13. FIG. 13 is a cross-sectional view of the pressure vessel 10 of FIG. 1 taken along section line AA. FIG. 13 shows twelve spikes 186 forming a row 294 of spikes 186 attached to the shank 182. The spikes 186 are shown in FIG. 13 to be equidistantly spaced around the circumference 198 of the shank 182. However, the spikes 186 can be positioned such that the spikes 186 are not equidistantly spaced around the circumference 198 of the shank 182. The spikes 186 shown in FIG. 13 are fully embedded within the outer composite shell 18. However, in some embodiments, the spikes 186 can be configured to partially penetrate into the outer composite shell 18.

[0051]

[0078] Further, the number of spikes 186 can be selected based on the requirements of a particular application. The shank 182 preferably includes at least four spikes 186. Although a generally cylindrical spike 264 is shown in FIG. 13, a tetrahedral shaped spike 268, a pyramidal shaped spike 270, a conical shaped spike 274, and the like can be used in place of the cylindrical spike 264 if desired for a particular application. Additionally, the spikes 186 can include spikes 186 of one or more shapes, i.e., as a non-limiting example, a first portion of the spikes 186 can be selected to be cylindrical spikes 264 and the remaining spikes 186 can be pyramidal shaped spikes 270.

[0052]

[0079] Further, instead of distributing the spikes 186 about the circumference 198 of the shank 182 as illustrated in Fig. 13, the spikes 186 can be distributed in one or more localized zones 238, 238' of the shank 182 as shown in Fig. 9. Alternatively, the spikes 186 can be distributed in two or more localized zones 238, 238' of the shank 182, where the two or more localized zones 238, 238' are spaced apart on the outer bearing surface 198 of the shank 182. Optionally, the two or more zones 238, 238' may be at selected locations about the circumference 198 of the shank 182. Additionally, the two or more zones 238, 238' can be located equidistantly apart on the circumference 198 of the shank 182 if desired for a particular application.

[0053]

[0080] 14 and 15, the overall length of the spike 186 can be selected based on the thickness of the outer composite shell 18, the nominal operating pressure or amount of torque expected on the boss 16, the dimensions of the boss 16, and the number of spikes 186 attached to the shank 182. FIGS. 14 and 15 show an enlarged view of portion C of the pressure vessel 10 shown in FIG. 13, illustrating the variation in the length of the spike 186 compared to the thickness of the outer composite shell 18. With reference to FIG. 14, the outer composite shell 18 is shown as including three exemplary fiber layers 224A-C. The spike 186 in FIG. 16 extends through the first fiber layer 224A. In contrast, FIG. 18 shows the spike 186 having a length sufficient to penetrate all three fiber layers 224A-C. Various embodiments of the pressure vessel 10 may include more or fewer fiber layers 224A-C than are shown in FIGS. 14 and 15. Thus, the spikes 186 can be sized to protrude into and / or through any desired number of fiber layers 224A-C, including both the braided fiber layer 224 and the wrapped fiber layer 218. Additionally, the spikes 186 can be embedded in and / or protrude through additional layers of material between the liner 14 and the outer composite shell 18, including barrier layers, breather layers, metal film layers, and the like.

[0054]

[0081] 10-15, the overall shape of the spikes 186, the maximum outer diameter 186' of the spikes 186, the profile of the spike tips 282, the overall height of the spikes 186, the circumferential distance between adjacent spikes 186, the number of spikes 186, and the arrangement of the spikes 186 on the shank 182, and the like, are selected based in part on the expected rotational and axial forces on the boss 16, the manner in which the fibers 214 are applied to the liner 14, and in part on the dimensions of the shank 182, the outer composite shell 18, and the inclusion of filler layers between the liner 14 and the outer composite shell 18. For example, multiple spikes 186 having an increased overall length can be fixedly coupled to the shank 182 when elevated rotational and / or axial loads are expected on the boss 16 during use. Fewer and / or shorter spikes 186 can be selected for a particular application in which lower rotational and axial loads on the boss 16 are expected.

[0055]

[0082] The placement, shape, and overall dimensions of the spikes 186 are selected based in part on the overbraiding process 226 illustrated in FIG. 6. A conforming pressure vessel 10 is shown in FIG. 6 and has a liner 14 with a large diameter cylinder section 228 connected to a small diameter cylinder section 232 by a tapered cylinder section 236. The flared edge 62 of the liner 14 is previously fixedly bonded to the bore 86 of the boss 16 before the fibers 214 are overbraided around the liner 14. A plurality of fiber filaments 214 are grouped into fiber strands 216. The plurality of fiber strands 216 are overbraided around the liner 14 using a braiding machine 226 as illustrated in FIG. 6. The braided fiber strands 216 conform to the outer surface 54 of the liner 14, and the density of the braided fiber strands 216 on the surface 54 of the liner 14 varies as the outer diameter of the liner 14 changes. The braided fiber strands 216 transition smoothly from the liner 14 to cover the shank 182 without affecting the overbraiding process 226 .

[0056]

[0083] The over-braiding process 226 can form a braided layer 224 of fiber strands 216 around the spikes 186 protruding from the shank 182, as illustrated in Figures 16 and 17. Each of Figures 16 and 17 shows an enlarged view of portion B shown in Figure 6. Figure 16 illustrates a tetrahedral shaped spike 268, and Figure 17 illustrates a cylindrical shaped spike 264. With reference to Figure 16, each fiber strand 216 includes a plurality of fiber filaments 214. The exemplary embodiment shown in Figure 6 has an outer bearing surface 198 of the shank 182 with a diameter of about 25 mm, the fiber strands 216 have a nominal strand width 216' of about 4 mm, the outer composite shell 18 includes a plurality of braided layers 224 of fiber strands 216, and the outer composite shell 18 is about 5 mm thick. However, the radial thickness of the outer composite shell 18 can be greater or less than about 5 mm, as desired, based on the boss diameter and the requirements of a particular application.

[0057]

[0084] 16, the maximum outer diameter 186' of each spike 186 is preferably less than the nominal strand width 216' of the fiber strands 216 used to form the braided fiber layer 224. More preferably, the maximum outer diameter 186' of the spike main body 278 and the maximum outer diameter 186' of the spike tip 282 of each spike 186 is less than or equal to about half the nominal strand width 216' of the fiber strands 216. More preferably, the maximum outer diameter 186' of the spike tip 282 and the maximum outer diameter 186' of the spike main body 278 of each spike 186 is between about 0.2 mm and about 2.0 mm. The spike base 286 of each spike 186 can be larger than the above range, depending on needs and on the method of attachment of the spike 186 to the shank 182. For example, the spikes 186 attached to the shank 182 can have a flared base 286A that is larger than the spike main body 278 caused by the welding process. For spikes 186 having a non-cylindrical shape, such as tetrahedral shaped spikes 268, pyramidal shaped spikes 270, and the like, the maximum outer dimension 186' of the spike base 286 of each spike 186, 268, 270 is preferably equal to or less than the nominal strand width 216' of the fiber strand 216, more preferably equal to or less than half the nominal strand width 216' of the fiber strand 216, and most preferably between about 0.2 mm and about 2.0 mm. However, spikes 186 having larger and / or smaller diameters 186' can be selected for a particular application as needed.

[0058]

[0085] 10-15, the length of each spike 186 is preferably between about 0.5 mm and about 5 mm as measured between the spike tip 282 and the spike base 286. More preferably, the length of each spike 186 is sized to be embedded in at least the first fiber layer 224A forming the outer composite shell 18, as shown in FIG. 14. However, each spike 186 may optionally have an overall length sufficient to penetrate any desired number of fiber layers 224, 224A-C, 218, including both the braided fiber layer 224 and the wrapped fiber layer 218. Additionally, the length of the spike 186 may be selected to penetrate optional supplemental layers, such as one or more of a barrier layer, a breather layer, and the like, if desired for a particular application.

[0059]

[0086] Adjacent spikes 186A, 186B shown in FIG. 16 are preferably spaced apart by at least one nominal strand width 216' of the fiber strand 216. The nominal strand width 216' of the fiber strand 216 is defined as the approximate width 216' of the fiber strand 216 as illustrated in FIG. 16. For the exemplary embodiment shown in FIG. 6 having a nominal width 216' of the fiber strand 216 of about 4 mm, the preferred minimum spacing between adjacent spikes 186 is at least 4 mm, i.e., the preferred minimum spacing is equal to or greater than the nominal strand width 216' of the fiber strand 216. Individual spikes 186 can be spaced closer together than the nominal strand width 216' of the fiber strand 216, so long as the minimum distance between adjacent spike tips 282 is preferably equal to or greater than the nominal strand width 216' of the fiber strand 216. The number of spikes 186 can be as few as about four, with the maximum number of spikes 186 being determined by the outer diameter and length of the shank 182, while spacing the spikes 186 at least one nominal strand width 216' apart of the fiber strands 216. Furthermore, when the boss 16 includes multiple rows 294, 294' of spikes 186, adjacent rows 294, 294' are preferably spaced apart by at least one nominal strand width 216' of the fiber strands 216.

[0060]

[0087] The textile strands 216 are braided around the spikes 186, such as illustrated by the relative positions of the textile strands 216A-216D and the spikes 186A, as shown in Figures 16 and 17. When the textile strands 216, 216E are aligned with the spikes 186, such as illustrated by the textile strands 216E and the spikes 186E shown in Figures 16 and 17, some of the textile filaments 214 of the textile strands 216E will be laid down around the spikes 186E, while the textile strands 216E are divided into groups of filaments 214, such as illustrated by 214E and 214F. The engagement between the textile strands 216A-216E and the spikes 186, 186A, 186E causes the braided textile layer 224A to interlock with the spikes 186, 186A, 186E. Additional braided fiber layers 224B, 224C interface with spikes 186, 186A, 186E in a similar manner. Each braided fiber layer 224A-224C braided around a spike 186, 186A, 186E will increase the strength of the mechanical connection between boss 16 and outer composite shell 18. The mechanical connection between boss 16 and outer composite shell 18 is further enhanced by the curing of resin 220 impregnated within fiber strands 216, 216A-216E. Fiber strands 216, 216A-216E will similarly interface with spikes 186, 186A, 186E as they are helically wrapped around shank 182 forming wrapped fiber layer 218.

[0061]

[0088] 18-23 illustrate a method of continuously manufacturing a pressure vessel 10, and in particular a conformable pressure vessel 10 with an overbraided outer composite shell 18. An exploded view of a liner / boss subassembly 318, 318' is shown in FIG. 18. The liner / boss subassembly 318, 318' includes a liner 14, 14A, a boss 16, 16D, and a seal insert 134, 134'. The longitudinal axis of the liner / boss subassembly 318, 318' is indicated by element 32 in FIG. 18. The liner 14, 14A optionally includes a positioning feature 206 integrated into the cylinder neck region 118 of the liner 14, 14A for positioning the boss 16, 16D during assembly. The positioning feature 206 can include, as non-limiting examples, recessed channels, ridges, protrusions, and the like. The shank 182 of the boss 16, 16D slides over the liner 14, 14A such that the flared edge 62 of the liner 14, 14A is inserted into the bore 86 of the boss 16, 16D all the way until the end 88' of the boss 16, 16D engages the locating feature 206 of the liner 14, 14A. The seal insert 134, 134' is assembled with the bore 86 of the boss 16, 16D such that the cone surface 162 of the seal insert 134, 134' pinches the liner 14, 14A against the boss cone surface 102 of the bore 86. Assembling the boss 16, 16D, liner 14, 14A, and seal insert 134, 134' forms a liner / boss subassembly 318, 318' illustrated in FIG.

[0062]

[0089] 19, a liner / boss subassembly 318, 318' is fastened to each end 322, 322' of a sacrificial tube section 324 to form an elongated subassembly 332. The sacrificial tube section 324 is defined by a cylindrical wall 336 extending between the opposing ends 322, 322'. Additionally, the end 88 of each boss 16, 16D and the end 322, 322' of the sacrificial tube section 324 are configured to matingly engage and fixedly and / or releasably couple the liner / boss subassembly 318, 318' to the sacrificial tube section 324. FIG. 20 illustrates the elongated subassembly 332 of a pair of liner / boss subassemblies 318, 318' coupled to the opposing ends 322, 322' of the sacrificial tube section 324. Any number of the liner / boss sub-assemblies 318 , 318 ′ may be coupled together with the sacrificial tube section 324 to form an elongated assembly 332 before passing the liner / boss sub-assemblies 318 , 318 ′ through one or more braiding machines 226 .

[0063]

[0090] 21 illustrates the process of feeding the elongated assembly 332 through the braiding machine 226, as illustrated by arrow G. Each liner 14, 14A includes one or more large diameter cylinder sections 228, a small diameter cylinder section 232, and a tapered liner section 236 extending between adjacent large and small diameter sections 228, 232. The braiding machine 226 overbraids the multiple fiber strands 216 around the outer periphery 54' of the liner 14, 14A. The braiding process 226 automatically braids the fiber strands 216 onto the outer periphery 54' of the elongated assembly 332, with the braided fiber layer 224 conforming to the outer contour 54, 54' of the liner 14. As the elongated assembly 332 passes through the braiding machine 226, the fiber strands 216 are braided around the outer periphery 54, 54' of the liners 14, 14A, bosses 16, 16D, and sacrificial tube section 324 as these components 14, 14A, 16, 16D, 324 pass through the braiding machine 226. The elongated assembly 332 can be passed sequentially through multiple braiding machines 226, with each braiding machine 226 configured to overbraid a single layer 224 of the braided fiber strands 216.

[0064]

[0091] The elongated assembly 332 can be wrapped with one or more barrier layers, breather layers, metal film layers, and the like prior to overbraiding the fiber strands 216 around the elongated assembly 332. Additionally, one or more barrier layers, breather layers, metal film layers, and the like can be applied to the elongated assembly 332 after and / or before overbraiding the individual fiber layers 224, 224A-C. As a non-limiting example, a breather layer can be wrapped around the entire elongated assembly 332 prior to overbraiding the first fiber layer 224, 224A around the periphery 54' of the elongated assembly 332. As another example, a metal film layer can be wrapped around the liner 14, 14A around the periphery 54' of the first braided fiber layer 224A, after which additional fiber layers 224B, 224C can be overbraided around the elongated assembly 332.

[0065]

[0092] FIG. 22 illustrates the elongated assembly 332 after passing through the braiding machine 226 and before the braided fiber layer 224 is trimmed adjacent the flange shoulder 200 of each boss 16, 16D. As shown in FIG. 22, the entire elongated assembly 332 is overbraided with fiber strands 216. The braided fiber layer 224 is trimmed adjacent the flange shoulder 200 of each boss 16, 16D (as illustrated by arrow K shown in FIG. 22) to form a composite free edge 240. The sacrificial tube section 324 is removed from each boss 16, 16D after the braided fiber layer 224 is trimmed. FIG. 23 shows the elongated assembly 332 after trimming to form separate pressure vessels 10, 10'. The composite free edge 240 on each boss 16, 16D can be covered with tape 242 and / or a crimped ferrule, if desired.

[0066]

[0093] One advantage of the pressure vessel 10 having a liner 14 fixedly coupled to a boss 16 having a spike 186 projecting outwardly from the boss 16 embedded in the outer composite shell 18 is that the boss 16 is mechanically coupled directly to the outer composite shell 18 as well as mechanically coupled to the liner 14. A second advantage is that a seal is achieved between the liner 14 and the boss 16 by fixedly coupling the liner 14 to the boss cone face 102 of the bore 86 that passes axially through the boss 16. A third advantage is that the embedded spike 186 of the outer composite shell 18 limits rotation of the boss 16 relative to the outer composite shell 18. A fourth advantage is that the embedded spike 186 of the outer composite shell 18 limits axial movement of the boss 16 relative to the outer composite shell 18 because the boss 16 and the outer composite shell 18 are mechanically coupled by the spike 186. A fifth advantage is that the liner 14 is fixedly coupled to the boss 16 without the use of a molding process and without the use of ferrules to crimp the liner 14 to the boss 16. A sixth advantage is that the outer composite shell 18 is fixedly coupled to the boss 16 without relying on ferrules to crimp the outer composite shell 18 to the boss 16.

[0067]

[0094] The present invention has been described in an illustrative manner, but it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Claims

1. 1. A pressure vessel for containing liquids and / or gases under pressure, comprising: a polymeric liner including a hollow body defined by an elongated cylindrical wall having opposing inner and outer surfaces extending between a first end and a second end of the polymeric liner, the polymeric liner including an inlet opening near the first end of the polymeric liner, the inlet opening being defined by a flared edge of the polymeric liner; an outer composite shell including a resin and a fiber, the outer composite shell surrounding an outer periphery of the polymer liner; a boss having a bore axially passing therethrough, the bore being defined by a cylinder wall having an inner surface, the bore being in fluid communication with an interior of the pressure vessel; Including, the boss has a shank with opposing inner and outer bearing surfaces, the inner bearing surface oriented toward the outer surface of the polymer liner and the outer bearing surface oriented toward the outer composite shell; the shank includes a plurality of spikes fixedly coupled to the shank and projecting radially away from the outer bearing surface, each of the plurality of spikes being at least partially embedded within the outer composite shell; the flared edge of the polymer liner is fixedly coupled to the boss; the outer composite shell is formed by braiding a plurality of textile strands about the polymer liner and the shank of the boss to form a layer of braided textile strands; each of the plurality of textile strands includes a plurality of textile filaments, and each of the plurality of textile strands has a nominal strand width; each pair of adjacent spikes having a respective spike tip and spaced apart by at least said nominal strand width; A pressure vessel for containing liquids and / or gases under pressure.

2. The pressure vessel of claim 1 , wherein the plurality of spikes comprises four or more spikes.

3. The pressure vessel of claim 2 , wherein at least a first portion of the plurality of spikes form a first row of spikes spaced about a circumference of the shank.

4. The pressure vessel of claim 2 , wherein the plurality of spikes are distributed across at least one zone on the circumference of the shank.

5. The plurality of spikes are distributed across two or more zones on the circumference of the shank. The pressure vessel of claim 4 , wherein the two or more zones are spaced apart on the circumference of the shank.

6. a second portion of the plurality of spikes forming a second row of spikes spaced about the circumference of the shank; 4. The pressure vessel of claim 3, wherein the second row of spikes are spaced axially of the boss from the first row of spikes.

7. 7. The pressure vessel of claim 6, wherein each spike of the second row of spikes is circumferentially offset from a spike of the first row of spikes.

8. A second portion of the plurality of spikes forms a second row of spikes spaced about the circumference of the shank; the second row of spikes are spaced axially from the first row of spikes; 4. The pressure vessel of claim 3, wherein the first row of spikes and the second row of spikes are separated by an axial distance of the boss of at least the nominal strand width.

9. Each spike of the plurality of spikes has a spike main body defined between a spike base and a spike tip of the spike, the spike base being fixedly coupled to the shank; the spike tip of each spike of the plurality of spikes has a maximum width that is less than the nominal strand width; The pressure vessel of claim 3 , wherein the spike main body of each spike of the plurality of spikes has a maximum width that is less than the nominal strand width.

10. A pressure vessel as described in claim 9, wherein each spike of the plurality of spikes has a maximum cross-sectional width of between about 0.2 mm and about 2.0 mm.

11. A pressure vessel as described in claim 10, wherein each spike of the plurality of spikes has a spike length defined between the spike base and the spike tip, the spike length being between about 0.5 mm and about 5 mm.

12. A pressure vessel as described in claim 11, wherein the spike base of each spike of the plurality of spikes is welded and / or glued to the shank of the boss.

13. The pressure vessel of claim 11, wherein each spike of the plurality of spikes is press-fit into a hole in the shank of the boss.

14. A pressure vessel as described in claim 13, wherein at least one of the plurality of spikes includes a pin that protrudes axially away from the spike base, the pin being configured to be press-fitted into a hole in the shank of the boss.

15. A pressure vessel as described in claim 11, wherein at least one of the plurality of spikes is a cylindrically shaped spike.

16. A pressure vessel as described in claim 11, wherein at least one of the plurality of spikes is a tetrahedral shaped spike.

17. The pressure vessel of claim 11, wherein at least one of the plurality of spikes is a pyramidal spike having four or more sides.

18. A pressure vessel as described in claim 11, wherein at least one of the plurality of spikes is a conical spike.

19. The pressure vessel of claim 11, wherein at least one of the plurality of spikes has a rounded spike tip.

20. The boss includes a flange shoulder formed on an outer portion of the boss; The pressure vessel of claim 3 , wherein the flange shoulder abuts the outer composite shell.

21. The method of claim 20, wherein the flared edge of the polymer liner extends axially into the bore of the boss to form a contoured neck; The pressure vessel of claim 3 , wherein the polymer liner is fixedly bonded to the inner surface of the bore of the boss.

22. The bore of the boss includes an inner cylinder neck portion formed on the inner surface of the boss, and a boss cone surface formed on the inner surface of the boss adjacent to the inner cylinder neck portion, 22. The pressure vessel of claim 21, wherein the flared edge of the polymer liner extends axially into the bore of the boss to form the contoured neck, the contoured neck of the polymer liner including a cylindrical neck region that bends outwardly to form a cone-shaped flared edge that substantially matches the inner cylindrical neck portion of the boss and the boss cone face.

23. The pressure vessel includes a seal insert shaped to fit and engage within the bore of the boss, the seal insert having a cone surface configured to matingly engage with the boss cone surface; 23. The pressure vessel of claim 22, wherein when the seal insert engages the bore of the boss, the flared edge of the polymer liner is radially compressed between the cone surface of the seal insert and the boss cone surface of the boss.

24. A pressure vessel for containing liquid and / or gas under pressure, comprising: a polymeric liner including a hollow body defined by an elongated cylindrical wall having opposing inner and outer surfaces extending between a first end and a second end of the polymeric liner, the polymeric liner including an inlet opening near the first end of the polymeric liner, the inlet opening being defined by a flared edge of the polymeric liner; an outer composite shell including a resin and a fiber, the outer composite shell surrounding an outer periphery of the polymer liner; a boss having a bore axially passing therethrough, the bore being defined by a cylinder wall having an inner surface, the bore being in fluid communication with an interior of the pressure vessel; Including, the boss has a shank with opposing inner and outer bearing surfaces, the inner bearing surface oriented toward the outer surface of the polymer liner and the outer bearing surface oriented toward the outer composite shell; the shank includes a plurality of spikes fixedly coupled to the shank and projecting radially away from the outer bearing surface, each of the plurality of spikes being at least partially embedded within the outer composite shell; the flared edge of the polymer liner is fixedly coupled to the boss; the flared edge of the polymer liner extends axially into the bore of the boss to form a contoured neck; the polymer liner is fixedly coupled to the inner surface of the bore of the boss; the bore of the boss includes an inner cylinder neck portion formed on the inner surface of the boss and a boss cone surface formed on the inner surface of the boss adjacent the inner cylinder neck portion; the flared edge of the polymer liner extends axially into the bore of the boss to form the contoured neck, the contoured neck of the polymer liner including a cylindrical neck region that curves outwardly to form a cone-shaped flared edge that substantially matches the inner cylindrical neck portion of the boss and the boss cone surface; The boss cone surface has one or more ridges extending across the boss cone surface. A pressure vessel for containing liquids and / or gases under pressure.

25. A pressure vessel for containing liquid and / or gas under pressure, comprising: a polymeric liner including a hollow body defined by an elongated cylindrical wall having opposing inner and outer surfaces extending between a first end and a second end of the polymeric liner, the polymeric liner including an inlet opening near the first end of the polymeric liner, the inlet opening being defined by a flared edge of the polymeric liner; an outer composite shell including a resin and a fiber, the outer composite shell surrounding an outer periphery of the polymer liner; a boss having a bore axially passing therethrough, the bore being defined by a cylinder wall having an inner surface, the bore being in fluid communication with an interior of the pressure vessel; Including, the boss has a shank with opposing inner and outer bearing surfaces, the inner bearing surface oriented toward the outer surface of the polymer liner and the outer bearing surface oriented toward the outer composite shell; the shank includes a plurality of spikes fixedly coupled to the shank and projecting radially away from the outer bearing surface, each of the plurality of spikes being at least partially embedded within the outer composite shell; the flared edge of the polymer liner is fixedly coupled to the boss; the flared edge of the polymer liner extends axially into the bore of the boss to form a contoured neck; the polymer liner is fixedly coupled to the inner surface of the bore of the boss; the bore of the boss includes an inner cylinder neck portion formed on the inner surface of the boss and a boss cone surface formed on the inner surface of the boss adjacent the inner cylinder neck portion; the flared edge of the polymer liner extends axially into the bore of the boss to form the contoured neck, the contoured neck of the polymer liner including a cylindrical neck region that curves outwardly to form a cone-shaped flared edge that substantially matches the inner cylindrical neck portion of the boss and the boss cone surface; At least a portion of the boss cone surface has a rough surface texture. A pressure vessel for containing liquids and / or gases under pressure.

26. A pressure vessel as described in claim 23, wherein at least a portion of the boss cone surface has a smooth surface.

27. ​​A pressure vessel as described in claim 23, wherein the seal insert is fixedly connected to the boss by a crimp fitting and / or a press-in fitting.

28. A pressure vessel as described in claim 23, wherein the seal insert is connected to the bore of the boss by a threaded joint.

29. A method of forming a first polymer liner having a first elongated cylindrical wall extending between opposing first and second ends, a first flared edge near the first end, and a first inlet opening at the first flared edge; forming a first boss having a first cylindrical portion connected to a first shank, a first bore passing axially through the first boss, and a first plurality of spikes projecting radially away from the first shank; fixedly coupling the first flared edge of the first liner to the first bore of the first boss to form a first liner / boss subassembly; braiding a first plurality of textile strands about at least a portion of an outer periphery of the first liner / boss subassembly to form a first braided textile layer; a second elongated cylindrical wall extending between opposed first and second ends; forming a second polymer liner having a second flared edge near the first flared edge and a second inlet opening at the second flared edge; forming a second boss having a second cylindrical portion connected to a second shank, a second bore passing axially through the second boss, and a second plurality of spikes projecting radially away from the second shank; fixedly coupling the second flared edge of the second liner to the second bore of the second boss to form a second liner / boss subassembly; forming a sacrificial tube section having a third cylindrical wall extending between the first tube end and the second tube end; fixedly coupling the first liner / boss subassembly and the second liner / boss subassembly to the first end and the second end, respectively, of the sacrificial tube section to form an elongated assembly; braiding a second plurality of textile strands about a circumference of the elongate assembly to form a braided textile layer; trimming the braided fiber layer; removing the sacrificial tube section from the elongated assembly to form a separate pressure vessel; A method of forming a Type IV pressure vessel comprising:

Images