Abstract:
Structure, for sealing, from the outside, a liquid-leaking puncture wound in the wall of a liquid container. This structure includes a patch body having a perimetered cavity selectively securable via a self-torque-limiting bolt to the outside of such a container in a manner whereby the cavity overlies and faces the wound, with the cavity&#39;s perimeter surrounding the wound, and a patch pellet contained and confined in the cavity, and formed, at least in part, of a liquid-reaction substance which, with the patch body secured to the container, reacts to contact with liquid leaking from the container at least by imbibing such liquid and swelling to apply wound-sealing pressure, and more preferably by additionally reacting with leakage liquid to form a sticky coagulant mass for aiding in applying sealing pressure to the wound. The patch body may either be placed directly against the outside of a container or may be employed with an intermediate, resilient gasket which centralizes the symmetrical introduction of leakage liquid into the pellet-containing cavity in the patch body.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation from Regular U.S. patent application Ser. No. 11/067,565, filed Feb. 25, 2005, now U.S. Pat. No. 7,044,166 B1, granted May 16, 2006, for “Liquid Tank Puncture Repair Kit and Method” which claims priority to U.S. Provisional Patent Application Ser. No. 60/627,628, filed Nov. 11, 2004, for “Fluid Tank Puncture Repair Kit and Method”. The entire disclosure contents of that predecessor, Regular U.S. Patent Application, and of the mentioned, prior filed U.S. Provisional Patent Application, are hereby incorporated herein by reference. 
    
    
     BACKGROUND AND SUMMARY OF THE INVENTION 
     This invention pertains to structure (a repair kit) for patching a leak of liquid from a puncture wound in the wall of a liquid container. Two, different preferred embodiments of, and manners of practicing, the invention are described and illustrated herein in the setting of making an emergency, from-the-outside, repair of a ballistic (such as from a bullet) puncture wound in the container wall of a military vehicle fuel tank—a setting wherein the invention has been proven to offer significant defensive advantage in a combat zone. As will be seen, the two, herein-disclosed embodiments of the invention differ in component count, and in specific leak-sealing methodology. 
     While, as will become apparent, the invention has significant utility in other settings, it is illustrated and described herein in a military vehicle setting which serves to highlight the key features of the invention. 
     A special characteristic of the invention in its preferred form is that it includes a wound-patching component which possesses a “substance”, referred to herein as a liquid-reaction substance, that reacts to leaking liquid, such as hydrocarbon fuel, to create a collaboration with such liquid thereby to produce a fluid-and-“substance” triggered coagulant that swells to seal a container puncture wound. 
     Somewhat more broadly viewed, this just-above-mentioned component substance, whether or not effective to create a coagulant mass, nevertheless preferably imbibes leakage liquid, swells in size, and, with the structure of the invention positioned adjacent a container puncture wound for use, is confined and stabilized in such a manner that, in its swelling and ultimately swollen conditions, it applies progressively increasing, and ultimately robust, sealing pressure to close the wound. 
     In one embodiment of the invention, what is referred to herein as a patch body has a perimeter portion which directly engages the effective outside surface of a container to seal thereagainst in the implementation of puncture-wound sealing. In another disclosed and illustrated embodiment of the invention, a unique, washer-like, resilient sealing gasket is employed intermediate the just-mentioned perimeter portion of the patch body and a container&#39;s outside surface. This gasket functions to implement a somewhat different wound-sealing methodology. In both embodiments of the invention as illustrated herein, a unique hollow-stem, self-torque-limiting bolt is preferably utilized to make an attachment to the outside of a container of the type possessing a self-healing puncture-defeating coating which is there applied to the container. 
     Another feature of the invention comes into play in a circumstance, described herein, where the container whose puncture wound is to be sealed is itself externally coated with an intended self-sealing coating which is formed with a liquid-reaction material (“substance”) which is compatible with that employed in the patch-kit structure and practice of the present invention. In this kind of setting, the sealing response behavior of the invention uniquely collaborates with the self-sealing capabilities of such a coating. 
     All of the features and advantages of the invention will become more fully apparent as the description which now follows is read in conjunction with the accompanying drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a simplified, small-scale side view of a military vehicle which possesses an exposed, side-mounted fuel tank (liquid container). This illustrated tank is one which is coated with an intended self-sealing coating of the type mentioned above. 
         FIG. 2  is an enlarged, fragmentary view of a portion of the fuel tank shown in  FIG. 1 , wherein a penetrating bullet wound (puncture) has just occurred. Around this puncture, a small portion of a special, nominally self-sealing, tank coating has been broken away to provide a clearer view of the mentioned wound, and of the direct outside surface of the fuel tank. 
         FIG. 3  is a further enlarged, fragmentary cross-sectional view of the mentioned fuel tank and its outer coating taken generally along the line  3 - 3  in  FIG. 2 . 
         FIG. 4  presents a view similar to that provided in  FIG. 2  showing the mentioned puncture wound, and picturing (in dashed lines) the intended footprint of a wound patch sealing structure which will be employed in accordance with the present invention to seal the illustrated wound. 
         FIG. 5  is a somewhat enlarged and exploded view which isolates and shows each of the several components of one embodiment of the patch sealing kit structure of the invention. 
         FIG. 6  is a still further enlarged, isolated, isometric and fragmentary view showing the same embodiment of the patch sealing structure proposed by the present invention which is illustrated in  FIG. 5 . In this figure, all components in this kit embodiment are also shown, including a patch body with a perimetered cavity, an embedded washer in this body, what is referred to herein as a patch pellet which includes a special substance described in this document, as mentioned above, as being a liquid-reaction substance, and a specially designed, hollow-shank, threaded patch-body anchoring bolt. 
         FIG. 7 , which is presented on about the same scale employed in  FIG. 6 , shows a cross-sectional, isometric view of the patch kit of this invention, as illustrated in  FIG. 6 , in an operative condition sealing a puncture (bullet) wound in a fuel tank. 
         FIG. 8  is a transverse, cross-sectional view illustrating essentially the same information contained isometrically in  FIG. 7 , and additionally illustrating what is referred to herein as a coagulant mass which develops during preferred practice of the invention to aid in the important wound-sealing behavior of the invention. 
         FIG. 9  presents an enlarged detail, drawn from near the center of  FIG. 8 , illustrating how a specially designed, unique, hollow-shank bolt in the kit of this invention accommodates self-torque-limiting securement of other components in the invention to a punctured liquid container whose outside surface is coated, per se, with a certain kind of penetration-sealing material which is physically compatible (i.e., somewhat like) material employed in the structure of the invention. 
         FIG. 10  is like  FIG. 5 , except that it illustrates the above-mentioned, gasket-employing embodiment of the invention. 
         FIG. 11  is a bottom isometric view of the embodiment of  FIG. 10 , shown with all components assembled and ready for use. 
         FIG. 12  is a larger-scale, top isometric view which is directly related to what is shown in  FIG. 11 . 
         FIG. 13  is a larger scale view, similar to that presented in  FIG. 11 , but with the structure of  FIG. 11  sliced open to reveal details of internal construction. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Turning now to the drawings, and referring first to  FIGS. 1-4 , inclusive, shown at  10  in  FIG. 1  is a military vehicle which possesses an exposed, side-mounted hydrocarbon fuel tank  12 , also referred to herein as a liquid container. Fuel in this tank is typically under a residual, above-atmospheric pressure attributable principally to the vapor pressure of the contained fuel per se. This residual pressure might typically be as high as about 4- to about 5-psi above atmosphere pressure. Such a condition, of course, exacerbates fuel leakage if the tank is punctured, as by a bullet. 
     It should be understood that the word “container” as employed herein is not confined to meaning only a vehicle&#39;s fuel tank. It may also apply, as examples, to a conduit, to a fuel-supply tanker, to holding tanks, to rail tanker cars, and to other kinds of liquid containers. 
     While it is not necessary that tank  12  be coated with a self-sealing protective jacket, or skin,  14 , tank  12  herein is so coated, and the illustrated and described preferred embodiment of the invention will be seen to have special “collaborative” utility in the presence of such a coating.  FIG. 3  illustrates coating  14  in cross section. 
     Coating  14  herein includes, effectively, a stack of three layers  14   a ,  14   b ,  14   c.  Layer  14   a  lies directly against the outside surface  12   a  of tank  12 , has a thickness herein of about ⅛-inches, and is formed of an elastomer, such as the product sold under the trademark TUFF STUFF® (FR (fire resistant) made by Rhino Linings USA, Inc. in San Diego, Calif. Layer  14   b  (shown abutting layer  14   a  at the location of a dashed line in  FIG. 3 ) has a thickness herein of about ⅛- to about 3/16-inches, and is formed of a composite of the same elastomer material just mentioned for layer  14   a , and entrained (about 20% by weight) fuel imbiber beads (not specifically shown in  FIGS. 1-4 , inclusive) such as those bearing the product identifier IMB230300 made by Imbibitive Technologies America, Inc. in Midland, Mich. Layer  14   c  (shown abutting layer  14   b  at the location of a dash-dot line in  FIG. 3 ) has a thickness herein of about ¼- to about ⅜-inches, and is formed of the same elastomer material which is employed in layer  14   a . The outer side of layer  14   c  defines the outside surface of coating  14 . 
     Both of the fundamental materials which are employed in coating  14  herein are referred to as being liquid-reaction substances. The term “reaction substances” refers to the fact that when hydrocarbon leakage fuel from tank  12  contacts these materials, a chemical/mechanical reaction takes place which causes material-imbibing of such fuel, and volume-swelling of the imbibing material. Additionally, and preferably though not necessarily, a congealing/coagulating reaction occurs with respect to the interaction which occurs between leakage fuel and the imbiber beads, which reaction produces a sticky coagulant mass that, as will be seen, significantly contributes to the puncture-sealing capability of the present invention. 
     In  FIGS. 2 and 4 , shown at  16  is a bullet wound puncture, also referred to herein as a liquid-leaking puncture wound, in the wall of container  12 . And, while coating  14  nominally is deemed to be capable of sealing this wound on its own, the structure of the present invention and its behavior come into play when this does not happen. 
     Adding attention now to  FIGS. 5-9 , inclusive, in the drawings, one embodiment of the patch kit structure of the present invention is shown generally at  18 . Structure  18  includes a patch body  20  possessing the shape, generally, of a cylindrical hockey puck, formed of a suitable rubber material, and including, on one of its circular sides, a domed patch cavity  20   a  which is perimetered by downwardly facing, annularly ribbed perimeter structure  20   b  which is seen to include ribs  20   c . An annular steel washer  22  is embedded in body  20  as shown (except in the exploded illustration of  FIG. 5 ). Body  20  has an outside diameter preferably of about 3-inches, with the diameter of the edge rim of cavity  20   a  being about 2½-inches. 
     Washer  22  and body  20  are centrally apertured, as can be seen, to provide operative clearance for the elongate, threaded shank  24   a  of a hex bolt  24  which has a hex head  24   b  and a central long axis  24   c  (see  FIGS. 4 and 5 ). As can be seen in  FIGS. 6-8 , inclusive, the upper portion of the central aperture in body  20  is exposed for ultimate bearing contact (as will be explained) between embedded washer  22  and the underside of bolt head  24   b . The end of shank  24   a  which is opposite the end joined to bolt head  24   b  has an elongate, hollow, cylindrical interior region  24   c , the inner (upper) end of which is closed at  24   d . Bolt  24  functions herein as an attaching device, or mechanism, especially suited for use with a container like tank  12  which is coated with a modest thickness (about ⅝-inches) self-sealing coating, like coating  14 . As will be further explained shortly, bolt  24  is also referred to herein as a self-tapping, self-torque-limiting bolt. 
     Shown at  26  recessed within cavity  20   a  in  FIGS. 6-8 , inclusive, is what is referred to herein as a patch pellet which is flat-annular in configuration, and formed with a suitable wicking-fabric material  26   a  (see  FIG. 5 ) shaped as an annular bag, or outer envelope, which holds a fill of the same reaction-substance beads mentioned earlier herein. A few of such beads are shown generally and schematically at  26   b  in  FIGS. 6-8 , inclusive. 
     In  FIG. 6 , structure  18  is shown assembled for use before attachment to a punctured container. In  FIGS. 7 and 8 , structure  18  has been attached effectively to tank  12  (via screw securement to coating  14 ) to seal against fuel leakage from previously mentioned bullet puncture wound  16  which has not been healed by coating  14 . 
     To seal against fuel (liquid) leakage from wound  16 , with structure  18  pre-assembled as shown in  FIG. 6 , body  20  is placed to seat perimeter structure  20   b  against the exposed outside surface of coating  14 , with the “footprint” of the body generally relating to puncture wound  16  as illustrated by a dashed-line circle  28  in  FIG. 4 . With this disposition established, wound  16  is effectively located within the perimeter rim of cavity  20   a , and bolt  24  is sufficiently laterally offset, preferably about ½-inches, from the puncture wound so that it is “aimed”, so-to-speak, at an unpunctured portion of coating  14 . 
     Bolt  24  is then pressed against coating  14 , and thereafter screwed in a self-tapping manner to tightness, as follows. The unique hollow end of the shank in the bolt screws self-tappingly into coating  14 —cutting an annular and deepening, threaded path into the coating until the inner “end”  24   d  of the hollow interior region  24   c  of bolt shank  24   a  engages and begins to bear against the upper surface of the portion of coating  14  which now extends into this hollow interior. By the time that this bearing contact has been established, bolt head  24   b  is already bearing sufficiently downwardly on washer  22  to begin to drive and compress body perimeter structure  20   b  against coating  14  in an annular region surrounding wound  16 . Bolt tightening continues until sufficient compression exists in the coating material portion which bears against the inner end  24   d  of the bolt-shank hollow automatically to establish an appropriate “tightness torque”. 
     In  FIGS. 7 and 8 , shank interior  24   c  is shown with an exaggerated length, with end  24   d shown spaced somewhat upwardly from the portion,  14   a  of coating  14  which extends upwardly into this interior. This has been done in these two figures simply to provide a clearer illustration here of the inside of shank  24   a . In reality, interior end  24   d , with the components of the invention positioned substantially as shown in  FIGS. 7 and 8 , would be bearing firmly and tightly downwardly on coating portion  14   a . This condition is clearly pictured if in  FIG. 9 . This special bolt design thus, through appropriate “interior” length selection which is well within the skill in the relevant art, automatically establishes a proper final torque tightness (self-torque-limiting). 
     This bolt tightening action attaches and binds (anchors) structure  18  firmly to tank  12  through the connection thus established with coating  14  so as to drive body  20  into secured sealing tightness around the perimeter of cavity  20   a.    
     Later on, if it is desired to add an extra measure of sealing “security” regarding this embodiment of the invention, a ribbon of a suitable urethane caulking material (not illustrated) may be applied around the outside perimeter of body  20  where that perimeter meets with coating  14 . 
     Leaking fuel floods cavity  20   a  wherein it becomes trapped, and is quickly wicked into pellet  26  to contact beads  26   b  therein. Pellet  26  is trapped and positionally stabilized in the chamber defined between cavity  20   a  and the confronting outside surface of coating layer  14   c . The beads and fuel promptly react with one another to form, collaboratively, a swelling coagulant which, as it swells, becomes compressed within the small volume of stabilized space which is defined between cavity  20   a  and the confronting surface of coating  14 . The result of this activity is an immediate, full, and secure compressive seal against fuel leakage from tank  12  through wound  16 .  FIG. 8  illustrates, in dark cross-hatching at  29 , a resulting coagulant mass. 
     An additional matter to note is that, aiding in the leakage-sealing process which is implemented by the behavior of the present invention, is enhanced compression in the zone of the puncture wound, introduced by reactive pressure which develops between coating  14  and external structure body  20  due to tightening of bolt  24 , and associated tensing in shank  24   a . This tensing condition is referred to herein as a “tension reaction force”. 
     Turning attention now to  FIGS. 10-13 , inclusive, here there is illustrated an important alternative embodiment of the invention. Those specific components of this embodiment which are essentially the same as like components included in the first-described embodiment, are given, in these four drawings figures, the same respective reference numbers. 
     This alternative embodiment of the invention includes one additional component in the form of a uniquely configured, annular, resilient gasket  30 . Gasket  30  herein has an outside diameter which is slightly greater than that of patch body  20 , a thickness of about ⅛-inches, and is formed of a PVC/Nitrile/Neoprene polymer sold under the trademark Duraform™. Specifically, this material is referred to by its manufacturer, Monmouth Rubber &amp; Plastics Corp. of Long Branch, N.J., with an inventory number IVN41. 
     As can be seen especially well in  FIGS. 11 and 13 , gasket  30  possesses a central throughbore  30   a  which accommodates the shank of bolt  24 . Gasket  30  is unique in its design, in that plural (four herein), generally T-shaped through-slits  30   b  are formed at orthogonally related locations distributed circumferentially about throughbore  30   a , as can been seen best in  FIGS. 10 ,  11  and  13 . Throughbore  30   a  and through-slits  30   b  are referred to collectively herein as central passage structure. 
     Significantly, with the structure of  FIGS. 10-13 , inclusive, installed for use, slits  30   b  provide central passageways for the controlled, central symmetrical introduction of leakage liquid into the region containing pellet  26 . As the material located centrally in pellet  26  swells in response to contact with this liquid, a very effective, “axially symmetric” (relative to axis  24   c ) seal develops against the outside of a container, like fuel tank  12 . A certain amount of liquid-reaction imbibing and swelling also occurs in the material (mentioned above) which forms gasket  30 , and this behavior contributes additionally to the sealing capability of this embodiment of the invention. 
     It will be understood that this invention may be implemented in various ways which do not necessarily involve dealing with leakage from a container which is jacketed with a coating like coating  14 . Where such a coating is, however, involved as described herein, the “reaction substance” portion of the coating clearly collaborates with the patching/sealing structure of the invention. Also the invention may readily be adapted and employed to deal with leaking liquids which are other than hydrocarbon fuel liquid by selecting and employing “reaction substances” which are appropriate to the particular liquid involved. The invention may also be implemented in a manner wherein “liquid reaction” does indeed involve material-swelling, but not necessarily the formation of a coagulant mass. Thus, effective sealing may readily be achieved simply with the use, in pellet  26 , of a reaction substance which merely imbibes leakage liquid, and swells appreciably in size as a result. 
     The structure of this invention is quite clearly very simple in construction, is easily carried for emergency use when required, and is very easily installed quickly for rapid, effective leak stoppage. 
     From a methodologic perspective, the invention can be expressed in a number of different ways. A few of these ways are set forth immediately below in several, letter-identified paragraph statements, as follows: 
     Accordingly, while a preferred embodiment of the invention, and certain variations thereof, have been described and illustrated herein, it is appreciated that other variations and modifications may be made without departing from the spirit of the invention.