Patent Publication Number: US-11649933-B2

Title: Integrated composite mounting structure for use in pressure vessels and pressure vessel systems

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/066,982 filed Jun. 28, 2018, which is the United States National Phase of Patent Application No. PCT/US2017/012039 filed 3 Jan. 2017, which claims priority to U.S. Patent Application No. 62/273,591 filed 31 Dec. 2015, each of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     This invention relates to systems and methods used to mount pressure vessels to a vehicle or within a system used to transport fuels or gases. 
     More than 90% of high pressure storage vessels use metal designs which are monolithic in nature so they can be mounted, without risk of damage to the vessels, within a system or to a vehicle using metal straps or neck mounts. The mounts typically include (1) at least two sets of two-part metal straps clamped onto a cylindrical section of the vessel and bolted together, the straps then bolted to rails running horizontal to the axis of the vessel and (2) two sets of two-part machined blocks (boss mount) which are clamped down onto the neck of the vessel and bolted together, the blocks then bolted to rails running perpendicular to the axis of the vessel. These metal strap and neck mounts can be rapidly stamped out or CNC machined for high volume and low cost. 
     However, within the last 20 years all composite pressure vessels have come into use. The prior art mounts cause damage, degradation and potential failure to the composite vessel from factors such as torsion on the boss (boss mount) and pressure cycling that causes vibration, rubbing of the straps against the vessel, and abrasion to the vessel. Neck mounting systems are problematic because they exert forces directly on the neck of all composite vessels which can cause a break in the boss shell interface and render a vessel obsolete. These neck mounted systems are also costly and do not provide any additional function or value to the vessel. 
     These systems and methods are also difficult to handle and install due to their multicomponent design and the added weight of the mounting brackets. Additionally, the systems and methods only serve the singular purpose of fixing the vessels to rails whereas the disclosed invention provides protection from drops and impact from all directions. 
     SUMMARY 
     Preferred embodiments of a mounting structure made according to this invention are useful in applications where bulk quantities of gases or liquids need to be stored or transported and in over-the-road or marine transport applications as well as aviation and aerospace applications. 
     The mounting structure includes a plurality of alternating bands wrapped about the pressure vessel in a spaced-apart helical grid pattern. The structure, which is cured to form an integral part of the vessel&#39;s exterior, extends past the domed ends of the vessel and tapers past these ends toward the vessel&#39;s central longitudinal axis (or axis of rotation) to forma skirt. A plurality of mounting points are provided which can accommodate various shapes of mounting hardware. 
     Objectives of the invention include providing a mounting structure that (1) forms an integral part of the exterior surface of a composite pressure vessel; (2) increases safety; (3) serves as a protective structure in case of impact, fire, drop, or chemical attack; (4) simplifies the installation of vessels into a system and decreases installation time; (5) does not add a significant amount of weight or width to the vessel compared to prior art strap-mounted or neck-mounted systems; and (6) eliminates or reduces the need for metal straps that can damage the external layers of the composite pressure vessel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a front elevation view of a preferred embodiment of the mounting structure formed and cured about an exterior of a composite pressure vessel. 
         FIG.  2    is a detail view taken along section  2  of  FIG.  1   . 
         FIG.  3    is a detail view taken along section  3  of  FIG.  1   . 
         FIG.  4    is an isometric view of the mounting structure of  FIG.  1   . 
         FIG.  5    is a detail view taken along section  5  of  FIG.  4   . 
     
    
    
     ELEMENTS AND NUMBERING USED IN THE DRAWINGS AND DETAILED DESCRIPTION 
     
         
         
           
               10  Mounting structure 
               11  Bands or ribs 
               13  Central longitudinal axis 
               15  Mounting points 
               17  Skirt 
               21  End 
               25  Helical grid pattern 
               30  Composite, cylindrical pressure vessel or pressure vessel 
               31  End or dome 
               33  Central longitudinal axis or axis of rotation 
               35  Exterior surface or body 
           
         
       
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Preferred embodiments of a mounting device or structure is integral to a high-pressure vessel and can be used to mount the vessel within a system for transporting fuels or gases or to a vehicle. Some embodiments provide systems and methods for producing a tubular helical ribbed architecture which is integrated into the exterior body of a composite pressure vessel and includes a continuous plurality of fibers impregnated with resin matrix which are wound under tension onto the pressure vessel forming helical composite ribs which extend the length of the vessel, protrude past the cylindrical portion of the vessel and taper past the dome ends toward the central longitudinal axis of the vessel. 
     Referring now to  FIGS.  1  to  5   , a preferred embodiment of the mounting structure  10  is made of a plurality of bands or ribs  11  of continuous tow polymer resin-impregnated fibers wrapped about a pressure vessel  30  in a spaced-apart intersecting or crisscrossing helical (grid) pattern. On each end of the vessel  30  the ribs  11  extend past the ends or dome  31  of the vessel  30 , with the mounting structure  10  tapered towards the central longitudinal axis or axis of rotation  33  of the vessel (and therefore the central longitudinal axis  13  of the mounting structure  10 ). In this way, each end  23  of the mounting structure  10  is smaller in diameter than that of the vessel  30  and forms an open end that effectively traps the vessel  10 . 
     The amounting structure  10  is manufactured by filament-winding continuous tows of polymer resin-impregnated fibers around the vessel  30  in an alternating, banded helical wrapping pattern. The vessel  30  is then placed into an oven to cure so the mounting structure  10  becomes integrated into the exterior surface or body  35  of the vessel  30  rather than being a separate structure apart from the vessel  30 . Alternatively, the vessel  30  may be cured first with the mounting structure  10  then added and cured to become an integral part of the vessel  30 . 
     Unlike strap-mounted systems, structure  10  forms an integral part of the exterior surface  35  of the vessel  30  and cannot move relative to the vessel  30  or loosen during transport or use. The mounting structure  10  eliminates the need for the prior art two-part metal strap mounting arrangement. The structure  10  also is not neck-mounted, nor does it require the kind of mounting brackets associated with the prior art neck mount. 
     Once the structure  10  is cured, mounting hardware (not shown) can be installed on mounting points  15  formed by the bands  11  or intersection of the bands  11 . The ends  21  may serve as a skirt  17  to enable vertical standing mounts (because the length of the structure  10  is grater than that of the vessel  30 ). The structure  10  itself protects the vessel  30  from drops and impacts. 
     The mounting hardware can be any shape preferable—including but not limited to circle, square, hexagonal—depending on the system the vessel  30  is being mounted within. A preferred pressure vessel  30  is composite pressure vessels manufactured by Infinite Composites Technologies (Houston and Tulsa) or their equivalent.