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.
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.
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:
The drawings will be described further in connection with the following 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
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 20a-b in
With additional and, for the moment, particular reference to cross-sectional view of
Optionally, retainer 12 may be alternatively configured for the attachment of a corresponding one of the seal elements 16a-b thereto as having a continuous or discontinuous undercut or rabbet, referenced in
Returning to the plan view of
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
As is shown in the views of
With retainer 12 being provided as has been described, in the further construction of the gasket 10, each of the seal elements 14a-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 16a-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
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, 80a-b, and an opposing outboard side, 82a-b, which defines the corresponding inner or outer sealing periphery of the gasket 10. Particularly, the inboard side 80a of the seal element 16a is attached to the inner perimeter 22 of the retainer 12 such that the outboard side 82a of the element 16a thereby defines the inner periphery of the gasket 10 in extending, preferably, generally continuously about the retainer inner perimeter 22. Similarly, the inboard side 80b of the seal element 16b is attached to the outer perimeter 24 of the retainer 12 such that the outboard side 82b of the element 16b 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 16a-b may be configured, as may be seen best in
In the described configuration, each of the beads 70 and 84 presents, in the case of beads 70, a generally hemispherical bearing surface, 90a-b, respectively, and, in the case of the beads 84, oppositely disposed, generally hemispherical upper, 92a-b, and lower, 94a-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
In accordance with the precepts of the present invention, seal element 16a further may be configured additionally as having an wedging portion, referenced at 100, disposed outboard of the bead portion 84a 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
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 108a-b being smaller than the other or with one extending conterminously with the bead portion 84a 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
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 120a-b, as may be seen in the cross-sectional view of
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 (MoS2), 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
As indicated by the arrow referenced at 160 in
Turning now to the exploded assembly view of
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
Turning now to
In the energized state of
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.
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.
Number | Date | Country | |
---|---|---|---|
Parent | 11102262 | Apr 2005 | US |
Child | 12960685 | US |