Patent Publication Number: US-2011072634-A1

Title: Wedging retainer gasket construction

Description:
CROSS REFERENCE TO RELATED CASES 
     This application is a divisional of U.S. patent application Ser. No. 11/102,262, filed Apr. 8, 2005, which claims priority to U.S. Provisional Application Ser. No. 60/603/726; filed Aug. 23, 2004, the disclosures of which are expressly incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates broadly to a sealing construction for providing a fluid seal intermediate a pair of opposed, mating parts or structures, and more particularly to such a construction including a wedge-shaped seal member which is adapted to fill a void volume created by a radiused edge of one of the mating parts so as to prevent fluid accumulation in such volume. 
     In basic construction, gaskets of the type herein involved are formed of one or more resilient sealing elements which are supported by sheet metal plate or other retainer which may be machined, stamped, molded or otherwise formed to conform to the geometry of the mating surfaces to be sealed. Particularly, the seal members may be molded-in-place or otherwise mounted in grooves formed into one or both sides of the retainer. Representative such gaskets are shown, for example, in U.S. Pat. Nos. 3,195,906; 3,215,442; 3,259,404; 3,578,346; 3,635,480; 3,720,420; 3,746,348; 4,026,565, 4,625,978, 5,890,719; 6,460,859; 6,553,664; 6,598,883; 6,69537; and 6,669,205, in U.S. Pat. Appln. Pub. Nos. 200210135137A1 and US2002/0030326A1, and in co-pending U.S. Provisional Pat. Appln. Nos. 60/497,777, filed Aug. 26, 2003, and U.S. patent application Ser. No. 10/827,672, filed Apr. 19, 2004, and are marketed commercially by the Composite Sealing Systems Division of Parker-Hannifin Corporation, San Diego, Calif., under the tradenames “Gask-O-Seal” and “Integral Seal.” 
     Retainer gaskets of the type herein involved are employed in a variety of sealing applications, such as in commercial, industrial, or military equipment, vehicles, or aircraft for compression between the opposing or faying surfaces of a pair of mating parts or structures to provide a fluid-tight interface sealing thereof. In service, the gasket is clamped between the mating surfaces to effect the compression and deformation of the seal member and to develop a fluid-tight interface with each of those surfaces. The compressive force may be developed using a circumferentially spaced-apart arrangement of bolts or other fastening members, or by a threaded engagement of the mating parts. 
     Particularly in certain applications such as for ports, windows, access panels, or other openings in hulls, airframes, or other superstructures, there may be instances wherein liquids such as water may accumulate in spaces or other void volumes between the parts. Such accumulation may lead to corrosion and loss of service life. It therefore is believed that improvements in retainer gaskets such as for the above-mentioned applications would be well-received by the industries concerned. 
     BROAD STATEMENT OF THE INVENTION 
     The present invention is directed to a retainer gasket construction particularly adapted for vertical mount and other applications such as for ports, windows, access panels, or other openings in hulls, airframes, or other superstructures. The gasket includes a generally-annular retainer and a wedge or similarly-shaped sealing element extending radially along at least a portion of one or both of the inner and/or the outer perimeter of the retainer. 
     When the gasket is placed between the interfacing surfaces to be sealed, with at least one of those surfaces having an edge confronting one of the sides of the gasket, the wedge-shaped sealing element thereof is positioned to extend into a void space defined along that edge. Such space may be formed, for example, by a radius or chamfer extending between the edge and the face of the corresponding one of the interfacing surfaces. In this regard, when the gasket thereupon is compressed between the interfacing surfaces, the wedge shape of the sealing element assists in filling with seal material the void space that otherwise would be formed at the radiused edged of the one of the surfaces. In so filling such space, the gasket of the present invention advantageously eliminates an area in which fluid otherwise could collect. Such collection can result in increased potential for corrosion and a loss of service life. 
     The present invention, accordingly, comprises the article possessing the construction, combination of elements, and arrangement of parts which are exemplified in the detailed disclosure to follow. Advantages of the present invention include a gasket construction which reduces the potential for corrosion of the interfacing surface being sealed. Additional advantages include a gasket construction which is economical to manufacture, and which may be adapted for use with various sealing configurations. These and other advantages will be readily apparent to those skilled in the art based upon the disclosure contained herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein: 
         FIG. 1  is a plan view of a representative embodiment of a gasket construction according to the present invention; 
         FIG. 2  is an enlarged, fragmentary cross-sectional view of the gasket of  FIG. 1  taken through line  2 - 2  of  FIG. 1 ; 
         FIG. 3  is a perspective view of one of the mating surfaces in a representative application for the gasket of  FIG. 1 ; 
         FIG. 4  is an enlarged perspective view showing the edge detail of the mating surface of  FIG. 3 ; 
         FIG. 5A  is a fragmentary, cross-sectional, somewhat schematized and exploded assembly view showing the gasket of  FIG. 1  as interposed between the mating surface of  FIG. 3  and an associated mating surface; and 
         FIG. 5B  is a view as in  FIG. 5A  in showing the gasket of  FIG. 1  as compressed within the assembly of  FIG. 5A . 
     
    
    
     The drawings will be described further in connection with the following Detailed Description of the Invention. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Certain terminology may be employed in the following description for convenience rather than for any limiting purpose. For example, the terms “forward” and “rearward,” “front” and “rear,” “right” and “left,” “upper” and “lower,” “top” and “bottom,” and “right” and “left” designate directions in the drawings to which reference is made, with the terms “inward,” “inner,” “interior,” “inside,” or “inboard” and “outward,” “outer,” “exterior,” “outside,” or “outboard” referring, respectively, to directions toward and away from the center of the referenced element, the terms “radial” or “vertical” and “axial” or “horizontal” referring, respectively, to directions, axes, or planes perpendicular and parallel to the longitudinal central axis of the referenced element. Terminology of similar import other than the words specifically mentioned above likewise is to be considered as being used for purposes of convenience rather than in any limiting sense. 
     In the figures, elements having an alphanumeric designation may be referenced herein collectively or in the alternative, as will be apparent from context, by the numeric portion of the designation only. Further, the constituent parts of various elements in the figures may be designated with separate reference numerals which shall be understood to refer to that constituent part of the element and not the element as a whole. General references, along with references to spaces, surfaces, dimensions, and extents, may be designated with arrows or underscores. 
     For the illustrative purposes of the discourse to follow, the precepts of the retainer gasket construction of the present invention are described in connection with the configuration thereof for use within a port, window, access panel, or other opening assembly such as within a hulls, airframe, or other superstructures. In view of the discourse to follow, however, it will be appreciated that aspects of the present invention may find utility in other fluid sealing applications requiring a gasket of the type herein involved. Use within those such other applications therefore should be considered to be expressly within the scope of the present invention. 
     Referring then to the figures wherein corresponding reference characters are used to designate corresponding elements throughout the several views with equivalent elements being referenced with prime or sequential alphanumeric designations, shown generally at  10  in the plan view of  FIG. 1 , with the reverse side in the illustrated embodiment being understood to be substantially the same as the side shown, is a representative embodiment according to the present invention of a wedging-effect retainer gasket construction configured for interposition between a mating pair of mutually-opposed interfacing surfaces. In basic construction, gasket  10  includes a generally annular and, typically, planar retainer,  12 , and one or more pairs of generally annular seal elements,  14   a - b  (with element  14   b  being on the reverse of the side of the gasket  10  depicted in  FIG. 1) and 16   a - b , which may be supported, such as with elements  14   a - b , on a corresponding side of the retainer, or as extending, such as with elements  16   a - b , from and along at least a portion of a corresponding perimeter of the retainer  12 , to be compressible intermediate the interfacing surfaces (not shown in  FIG. 1 ) for effecting a fluid-tight or other environmental and/or electromagnetic interference (EMI) seal therebetween. 
     Retainer  12  may be configured and sized as shown for interposition between the interfacing surfaces, such as about a port, window, or other opening in a hull, airframe, or other superstructure, and an associated cover for such opening. In this regard, retainer  12  may extend in the radial directions defined by the orthogonal horizontal or radial axes referenced at  20   a - b  in  FIG. 1  as having an inner perimeter or margin, referenced at  22 , and an outer perimeter or margin, referenced at  24 . The perimeters  22  and  24  generally define, respectively, the inner and outer diametric extents of the retainer  12  which generally may be sized such that the gasket  10  is receivable intermediate the interfacing surfaces to be sealed. Together, the inner and outer perimeters  22  and  24  define a closed geometric shape which, in turn, encloses an opening,  26 , which may be configured for registration with the opening in the assembly to be sealed. Although the shape of retainer  12  is shown for purposes of illustration to be generally rectangular, such shape alternatively may be square or otherwise regular or irregular polygonal, or otherwise curvilinear, or circular, elliptical, otherwise arcuate or curvilinear, as particularly may depend upon the specifics of the intended application. Retainer  12  also may be provided to have one or more dividers, such as referenced in phantom at  28 , or other partitions formed therein, and may even have an open, i.e., linear or rectilinear, geometry rather then closed geometry shown. 
     With additional and, for the moment, particular reference to cross-sectional view of  FIG. 2 , retainer  12  further may be seen to be formed relative to a central or vertical axis, referenced at  30 , which axis extends in an axial direction generally normal to the radial direction referenced by axes  20  of  FIG. 1 , as having mutually-opposing upper and lower radial sides or faces,  32   a - b , respectively, extending between the inner and outer perimeters  22  and  24 , and mutually-opposing inner and outer axial sides or faces,  34   a - b , respectively, each of which delineates a corresponding one of the perimeters  22  and  24  in extending between the radial faces  32   a - b . Radial faces  32  each may be generally planar within the plane of the axes  20 , but alternatively may exhibit one or more degrees of curvature or other deviations out of that plane to match the curvature of the corresponding interfacing surfaces to be sealed. Axial surfaces  34  similarly may be generally planar within the plane of axis  30  and one of the axes  20   a - b  as the case may be, but alternatively may be angled relative to axis  30 . 
     Optionally, retainer  12  may be alternatively configured for the attachment of a corresponding one of the seal elements  16   a - b  thereto as having a continuous or discontinuous undercut or rabbet, referenced in  FIG. 2  at  40   a - b  and in phantom at  42   a - b , formed about one or both of the axial faces  34  in or on one or both of the radial faces  32 . Although not required, such rabbets  40  and  42  may be provided to function as flash control channels and additionally to provide an increased bondline surface for the attachment and support of the seal elements  16  on the retainer  12 . 
     Returning to the plan view of  FIG. 1 , the inner and outer perimeters  22  and  24  of retainer  12  define a widthwise extent, referenced at “w”, of the retainer therebetween which is sized such that gasket is receivable intermediate the interfacing surfaces to be sealed. Depending upon the specifics of the application, retainer  12  additionally may be provided as including a plurality of throughbores or apertures, one of which is referenced at  50  for the location and alignment of the gasket  10  between the interfacing surfaces. Each of the apertures  50  may be formed into the retainer  12  to extend axially through the upper and lower radial faces  32   a - b  thereof intermediate the inner and outer perimeters  22  and  24 . The apertures  50  particularly may be spaced-apart along the retainer as disposed along a predefined bolt path, such as is shown at  52  and  54 , and may be employed for receiving the bolts or other fasteners which are conventionally used for joining the interfacing surfaces under a predetermined torque load. Advantageously, apertures  50  in conjunction with retainer  12  additionally provide a positive stop delimiting the compression of the gasket  10  in avoiding the over-compression thereof during installation or maintenance. 
     Retainer  12  itself may be fabricated from a rigid or flexible metal, plastic, ceramic, or other material or composite which may be machined, cast, molded, stamped, or otherwise fabricated. Suitable metal materials for the construction of retainer  12  include aluminum, steel, stainless steel, copper, brass, titanium, nickel, and alloys thereof, with aluminum being preferred for many applications. The metal may be anodized, plated, or otherwise for increased corrosion resistance. Depending upon its material of construction and the intended application, retainer  12  may have an axial thickness, referenced at “t” in  FIG. 2 , defined between radial faces  32   a - b  of between about 0.025-1 inch (0.0635-2.5 cm), thereby making the retainer generally rigid or flexible, as the case may be, within the joint to be assembled. 
     As is shown in the views of  FIGS. 1 and 2 , retainer  12  further may be formed, against as depending upon the specific requirements of the intended application, as having a pair of grooves,  60   a - b  (with groove  60   b  being on the reverse of the side of the gasket  10  depicted in  FIG. 1 ), for the mounting of the elements  14   a - b . Each of the grooves  60  may be machined or otherwise recessed into a corresponding one of the radial faces  32  of retainer  12  intermediate the inner and outer perimeters  22  and  24  thereof, and as extending substantially continuous along the closed geometry of the retainer  12  about the opening  26 . As may be seen best in  FIG. 2 , each of the grooves  60   a - b  may be configured as a generally U-shaped channel including an axial inner sidewall,  62   a - b , adjacent the inner perimeter  22 , and an opposing axial outer sidewall,  64   a - b , adjacent the outer perimeter  24  which is disposed a spaced-apart radial distance from the corresponding inner sidewall  62 . A radial bottom wall,  66   a - b , extends intermediate a corresponding pair of the inner and outer sidewalls  62  and  64 . 
     With retainer  12  being provided as has been described, in the further construction of the gasket  10 , each of the seal elements  14   a - b  may be adhesively bonded, interference fit, molded, or otherwise received within a corresponding one of the retainer grooves  60 . In the case of the seal elements  16   a - b , each of these elements, in turn, may be adhesively bonded, molded on, or otherwise attached to or otherwise supported about a face  34  of a corresponding retainer perimeter  22  or  24 . Each of the elements  14  and  16  may be provided, independently and as shown, as continuous or, alternatively, discontinuous, i.e., segmented or otherwise interrupted, single, double, or multiple beads, lobes, or other rings of one or more elastomeric materials. 
     As may be seen best in  FIG. 2 , each of the seal elements  14   a - b  may be formed with a corresponding groove  60   a - b  as a solid or, as shown, hollow bead,  70   a - b , and as additionally having a base portion,  72   a - b , each of which supports a corresponding one of the beads  70   a - b  on an bottom wall  66   a - b  of the corresponding groove  60   a - b . Although a single element  14  is shown to be provided on each face  32  on opposite lateral sides of the holes  50 , such as for the purpose of providing EMI sealing, it should be appreciated that each of the grooves  60   a - b  may have a corresponding groove, such as shown in phantom at  60   a ′- b ′, for receiving additional seal elements  14  (not shown). As provided, each of the beads  70  is contactable by one of the mating interface surfaces for the axial sealing compression of the seal elements  14  within the intended application. In this regard, each of the beads  70  may be spaced apart from the groove sidewalls  62  and  64  or, alternatively, oriented to one or the other side so as to define one or more annular gaps,  74   a - b  and  76   a - b , with the sidewalls to accommodate the deformation of the beads  70  when compressed such that the surfaces thereof each may lie coplanarly with a corresponding one of the retainer surfaces  32  when the seal elements  14  are energized between the interface surfaces. 
     Each of the seal elements  16 , in turn, may extend radially from the retainer  12  and generally coplanarly therewith, and may be formed as having, respectively, an inboard side,  80   a - b , and an opposing outboard side,  82   a - b , which defines the corresponding inner or outer sealing periphery of the gasket  10 . Particularly, the inboard side  80   a  of the seal element  16   a  is attached to the inner perimeter  22  of the retainer  12  such that the outboard side  82   a  of the element  16   a  thereby defines the inner periphery of the gasket  10  in extending, preferably, generally continuously about the retainer inner perimeter  22 . Similarly, the inboard side  80   b  of the seal element  16   b  is attached to the outer perimeter  24  of the retainer  12  such that the outboard side  82   b  of the element  16   b  defines the outer periphery of the gasket  10  in extending, preferably, generally continuously about the retainer outer perimeter  24 . 
     For the axial, sealing compression of the seal elements  16  between the mating interface surfaces within the intended application, each of the elements  16   a - b  may be configured, as may be seen best in  FIG. 2 , as having at least one bead or bead portion, referenced at  84   a - b , respectively, for effecting the sealing of the interfacing surfaces. Depending upon the geometry of those surfaces, the beads or bead portions  84 , as well as beads  70   a - b  of elements  14   a - b , may be provided to extend axially beyond the corresponding radial faces  32  of the retainer  12  for abutting, compressive contact with a corresponding one of the interfacing surface. That is, bead portions  70  and  84  may be provided, as is shown in  FIG. 2 , to protrude between about 1-100 mils (0.025-2.5 mm) beyond the corresponding radial face  32 . Beads  84  may be shaped, as is shown, to have a generally circular or elliptical cross-sectional geometry, but alternatively may be configured as being lobe or otherwise arcuate-shaped. Double or other multiple bead arrangements also may be provided. 
     In the described configuration, each of the beads  70  and  84  presents, in the case of beads  70 , a generally hemispherical bearing surface,  90   a - b , respectively, and, in the case of the beads  84 , oppositely disposed, generally hemispherical upper,  92   a - b , and lower,  94   a - b , bearing surfaces which together with the surfaces  90  define the upper and lower sealing surfaces of the gasket  10 . Each of the seal elements  14  and  16  is shown in the illustrative embodiment  10  of  FIG. 1  to extend about the peripheries of retainer  12  for generally coaxial registration with the margins of the interface faces of the application, although it will be appreciated that different and/or independent geometries of gasket  10  and the seal element  14  and  16  thereon may be envisioned depending upon the configuration of the corresponding interface surfaces of the intended application, and indeed, the elements  14  and  16  may be interchanged. 
     In accordance with the precepts of the present invention, seal element  16   a  further may be configured additionally as having an wedging portion, referenced at  100 , disposed outboard of the bead portion  84   a  to extend radially along at least a segment or other continuous or discontinuous portion of the length thereof. As may be seen best in the cross-sectional view of  FIG. 2 , wedging portion  100  may be formed integrally with the bead portion  84   a  in the seal element  16   a . Wedging portion  100  may be generally wedge-shape in having a axially thicker outboard side,  102 , which tapers radially inwardly to an axially thinner inboard side,  104 , which may be disposed adjacent the bead portion  84   a . The thicker outboard side  102  functions as a wedge in the manner which is to be described, and thereby itself presents in the illustrated embodiment of gasket  10  oppositely disposed, radially inwardly angled upper and lower tapered surfaces,  106   a - b , respectively, each of which may extend radially outwardly to upper and lower bearing surfaces,  108   a - b , which may extend axially beyond the extent of a corresponding one of the bearing surfaces  92   a  and  94   a  of bead portion  84   a . The tapered surfaces  106   a - b  also may extend radially inwardly to connect with the seal element  16   b  via a transitional portion,  109 . 
     Although wedging portion  100  is shown to be double-sided and generally symmetrical, it should be appreciated that single-sided and/or asymmetrical designs may be envisioned, e.g., with one of the bearing surfaces  108   a - b  being smaller than the other or with one extending conterminously with the bead portion  84   a  or as being generally flat, and therefore should be considered to be within the scope of the invention herein involved. Moreover, although wedging portion  100  is shown in  FIG. 1  to extend generally continuously along the segment of the seal element  16   a  delineated by the line  110 , it may be appreciated that portion  100  may be discontinuous, i.e., broken, interrupted or stepwise, along the segment  110 . Addition or other continuous or discontinuous segments of the portion  100  also may be provided. Alternatively, portion  100  may be provided to extend continuously or discontinuously along the entirety or substantially the entirety of the element  16   a . Likewise, a portion  100  also may be provided, as represented by the line designated  110 ′, as formed integrally with the bead portion  84   b  of element  16   b  in addition to or as an alternative to the portion  100  formed in the element  16   a.    
     In the manufacture of gasket  10 , with the retainer  12  being formed, for example, as a metal stamping, molding, or machine part, with grooves  60  being stamped, molded, or machined therein the corresponding radial faces  32 , such grooves, along with the axial faces  34  of the retainer  12  may be primed with a bonding agent, such as a siloxane or silane, to assist in the chemical bonding of the seal elements  14  and  16  thereto. The primed retainer  12  then may be placed into a heated molded cavity for the injection, compression, or transfer molding of an uncured rubber or other elastomeric compound forming the seal elements  14  and  16 . Each of the elastomeric seal elements  14  and  16  thereby may be formed and cured-in-place as vulcanized directly onto retainer  12 . The outboard mold flash, referenced at  120   a - b , as may be seen in the cross-sectional view of  FIG. 2 , need not be removed as having no effect on the sealing performance of the gasket  10 . Alternatively, one or more of the elastomeric seal elements  14  and  16  may be molded in a separate operation and bonded to retainer  12  using an adhesive, an interference fit, a mechanical attachment, or the like. 
     Each of the seal elements  14  and  16  may be formed, independently, of a rubber or other elastomeric material which may be selected specifically for high temperature performance or otherwise for compatibility with the fluid being handled. Suitable materials include natural rubbers such as Hevea, as well as thermoplastic, i.e., melt-processible, or thermosetting, i.e., vulcanizable, synthetic rubbers such as fluoropolymers, chlorosulfonate, polybutadiene, polybutadiene, buna-N, butyl, neoprene, nitrile, polyisoprene, silicone, fluorosilicone, copolymer rubbers such as ethylene-propylene (EPR), ethylene-propylene-diene monomer (EPDM), nitrile-butadiene (NBR) and styrene-butadiene (SBR), or blends such as ethylene or propylene-EPDM, EPR, or NBR. The term “synthetic rubbers” also should be understood to encompass materials which alternatively may be classified broadly as thermoplastic or thermosetting elastomers such as polyurethanes, silicones, fluorosilicones, styrene-isoprene-styrene (SIS), and styrene-butadiene-styrene (SBS), as well as other polymers which exhibit rubber-like properties such as plasticized nylons, polyesters, ethylene vinyl acetates, and polyvinyl chlorides. As used herein, the term “elastomeric” is ascribed its conventional meaning of exhibiting rubber-like properties of compliancy, resiliency or compression deflection, low compression set, flexibility, and an ability to recover after deformation, i.e., stress relaxation. 
     Fillers and additives may be included in the formulation of the seal elements depending upon the requirements of the particular application envisioned. Such fillers and additives may include conventional wetting agents or surfactants, pigments, dyes, and other colorants, dispersants, opacifying agents, anti-foaming agents, antioxidants, anti-static agents, coupling agents such as titanates, chain extending oils, tackifiers, pigments, lubricants such as molybdenum disulfide (MoS 2 ), stabilizers, emulsifiers, antioxidants, inerts, thickeners, and/or flame retardants such as aluminum trihydrate, antimony trioxide, metal oxides and salts, intercalated graphite particles, phosphate esters, decabromodiphenyl oxide, borates, phosphates, halogenated compounds, glass, silica, which may be fumed or crystalline, silicates, mica, and glass or polymeric microspheres, as well as fillers which are thermally- and/or electrically-conductive such as oxides, nitrides, carbides, diborides, graphite, and metal particles, and mixtures thereof. Other electrically-conductive fillers include metal flakes and fibers, as well as conductive or non-conductive particles, plates, fibers, hollow or solid microspheres, elastomeric balloons, or other particulates plated or otherwise coated with a metal. The particle size of such fillers typically is not considered critical, and may be or a narrow or broad distribution or range, but in general may be between about 0.250-250 μm. Such fillers and additives may be blended or otherwise admixed with the formulation, and may comprise between about 0.05-80% or more by total volume thereof. The formulation may be compounded in a conventional mixing apparatus. 
     For EMI shielding purposes, the electrically-conductive filler may loaded in the composition in a proportion sufficient to provide the level of electrical conductivity and EMI shielding effectiveness within the gap which is desired for the intended application. In this regard, an EMI shielding effectiveness of at least 10 dB, and usually at least 20 dB, and preferably at least about 60 dB or higher, over a frequency range of from about 10 MHz to 10 GHz is considered acceptable. Such effectiveness translates to a filler proportion which generally is between about 10-80% by volume or 50-90% by weight, based on the total volume or weight, as the case may be, of the compound, and a bulk or volume resistivity of not greater than about 1 Ω-cm, although it is known that comparable EMI shielding effectiveness may be achieved at lower conductivity levels through the use of an EMI absorptive or “lossy” filler such as a ferrite or nickel-coated graphite. As is also known, the ultimate shielding effectiveness of the seal elements  14 , if provided for EMI shielding, may vary based on the amount of the electrically-conductive or other filler material, and on the thickness thereof. 
     Advantageously, seal elements  14  and  16  exhibit a reduced yield stress as compared to retainer  12  and, accordingly, are deformable for conforming to irregularities existing between the interfacing surfaces. As will be more fully appreciated hereinafter, as given compressive load is applied to the seal elements  14  and  16 , an increased bearing stress is provided thereon by virtue of the reduced surface area contact of the bearing surfaces of the bead portions  90 ,  92 ,  94 , and  106  on the interfacing surfaces. This increased stress will be sufficient to exceed the reduced yield stress of the seal elements  14  and  16  for the deformation thereof effecting the fluid-tight, EMI, and/or other sealing of the interfacing surfaces. 
     In service, it has been observed that the provision of seal elements  14  and  16  advantageously facilitates the installation and replacement of gasket  10  in accommodating for tolerances or other minor differences in the torque load of the bolts or other fastening members conventionally employed to join the interfacing surfaces. That is, by virtue of the resiliency of the elastomeric seal elements  14  and  16 , the fluid integrity and other sealing of the gasket  10  may be maintained to some degree even if the joint spacing between the interfacing surface is less than exactly uniform. Moreover, the combination of a relatively incompressible retainer  12  and relatively compressible seal elements  14  further provides a gasket construction which minimizes torque loss and thereby obviates much of the need for the periodic re-torquing of the fastening members used to secure the interfacing surfaces. That is, it is well-known that gaskets of the type herein involved may develop a compression set which is manifested by fluid leaks as the tension in the bolts is relaxed and the fluid-tight sealing of the interfacing surfaces is compromised. In this regard, the provision of seal elements  14  and  16  ensures positive sealing, with retainer  12 , in turn, synergistically providing generally non-yielding contact in establishing an alternative load torque path minimizing the compression set and leak potential of the gasket  10 . Thus, the use of a retainer allows the mating parts to bear stress loads which otherwise would cause the deformation or extrusion of a gasket which lacked a retainer. In the case of a metal retainer  12 , such contact additionally affords improved heat transfer between the interface surfaces, and also develops relatively high seal stresses for assured fluid-tight sealing of the interfacing structures. 
     Referring now to the perspective view of  FIG. 3  and the detail view of  FIG. 4 , a representative application for gasket  10  of the present invention is shown generally at  150  as an opening,  152 , in a generally vertically-orientated portion,  154 , of a hull or other superstructure, which opening  152  is surrounded at an edge,  156 , by one the interfacing surfaces,  158 , of the assembly for the gasket  10 . A series of bolt, rivet, or other fastener holes, one of which is referenced at  160 , each of which has an associated boss,  162 , is formed in the surface  158  as surround the opening  152 . Although the edge  156  is shown in the views of  FIGS. 3 and 4  to surround an opening, it should be appreciated that such edge alternatively may surround a groove or the like. Such edge  156  also may be the inner or outer periphery of surface  158  itself. 
     As indicated by the arrow referenced at  160  in  FIG. 3 , water and other fluids to which the hull portion  154  may be exposed may settle down by gravity into the area designated at  161 . As may be seen best in the enlarged view of such area of  FIG. 4 , the fluid particularly may collect in a void volume or other space, referenced at  164 , along the edge  156 . In the illustrative application  150  of  FIGS. 3 and 4 , the void space  150  may be defined along the edge  156  by a radius or chamfer,  166 , extending between the radial terminus, referenced at  168 , of the surface  158  and the edge  156 . 
     Turning now to the exploded assembly view of  FIG. 5A , a representative joint assembly incorporating gasket  10  of the present invention and hull portion  154  of  FIG. 3  is shown generally at  200 . Within joint assembly  200 , gasket  10  of the present invention is interposed between a pair of mutually-facing, axially spaced-apart interfaces surfaces. One of such surfaces is the surface  158  of the hull portion  154 , and the other of such surfaces, referenced at  170 , may be on an associated cover or other panel,  172 , for the opening  152 . The surface  170  may have holes or other openings, one of which is referenced at  202 , for registration with the holes  160  of surface  170 . 
     As interposed therebetween surfaces  158  and  170 , the opening  26  of the gasket  10  may be aligned in registration with the hull opening  152 , with the gasket  10  otherwise being disposed coaxially about the opening  152  with each of the retainer apertures  50  being aligned in registration intermediate a corresponding pair of holes  160  and  202 . In this regard, each of the apertures  50  may be sized to receive therein a corresponding one of the bosses  162  of the holes  160 . As further may be seen in  FIG. 5A , the bead portion  84   a  of seal element  16   a  is disposed radially inwardly of the terminus  168  of edge  156  of surface  158  for compression therebetween and surface  170 , but with at least the outboard side  102  of wedging portion  100  being disposed to extend radially past, i.e., outwardly, of the terminus  168  of the confronting surface  158  and at least partially into the area of the void space  164  along the edge  156 . 
     Turning now to  FIG. 5B , as the interfacing surfaces  158  and  170  are displaced in the assembly  200 , now referenced as  200 ′, such as by the tightening of bolts or other fasteners (not shown) received through the aligned holes  50 ,  160 , and  202 , into abutting contact with the corresponding radial faces  32  of gasket  10 , it may be seen that seal elements  14   a - b  and  16   b  each are contacted by a corresponding interfacing surface  158  and/or  170 , and are compressed therebetween and, in the case of elements  14   a - b , a corresponding groove bottom wall  66   a - b , from the free state shown in  FIG. 5A  into the energized state shown in  FIG. 5B . Such energized state effects, for example, an EMI seal in the case of elements  14  and a generally fluid-tight seal in the case of element  16   b  between each of the interfacing  158  and  170  and the retainer  12  of the gasket  10 . 
     In the energized state of  FIG. 4B , it further may be seen that the wedging portion  100  of seal element  16   a  is wedged by or against the surface  170 . Such wedging action causes at least the outboard side  102  of the wedging portion  100  extending beyond the radial terminus  168  of surface  158  to be deflected into or otherwise made to fill and occupy at least a portion of the space  164  which otherwise would be defined, such as is represented at  210 , by the radius or chamfer  166  and a confronting surface such as the end portion of the seal element  16   b  or alternatively, the other interfacing surface  170 . However, by the occupation of the space  164  by the wedging portion  100 , the accumulation of fluid in the space  164  may be excluded or at least reduced, with a corresponding reduction in the potential for corrosion to develop in such space. 
     Thus, a unique gasket construction for commercial, industrial, military, or other applications is described which exhibits reliable sealing properties while providing for the exclusion of fluid accumulation between the interfacing surfaces. 
     As it is anticipated that certain changes may be made in the present invention without departing from the precepts herein involved, it is intended that all matter contained in the foregoing description shall be interpreted in as illustrative rather than in a limiting sense. All references including any priority documents cited herein are expressly incorporated by reference.