Patent Description:
This application claims the benefit under <NUM> U. §<NUM>(e) of <CIT>, entitled, "Sealing Rings and Sealing Ring Assemblies for High Temperature End Applications,".

This invention relates to the field of sealing assemblies having sealing rings within the assembly, and the sealing rings for use in such assemblies, particularly to those which are useful in semiconductor manufacturing applications, and more particularly to those that are useful in "subfab" areas including for use as vacuum and pressure sealing assemblies including vacuum sealing rings.

Sealing assemblies are known for various end applications, for example, for use in sealing joined parts, such as doors, gates, pipes, portals, vents, and similar joining or reversibly mating parts. Sealing assemblies typically incorporate one or more sealing rings and are employed in various industries, such as the fluid handling, aerospace and semiconductor areas. In the semiconductor areas, there are sealing assemblies for doors and gates between various reaction chambers in semiconductor processing equipment in the microchip manufacturing area. There are also seals for use in various assemblies employed in the manufacturing support systems, for example in a "subfab" environment, such as incoming delivery conduit for reactants, air handling conduit and exhaust vacuum system piping.

In many of these industrial end applications, sealing assemblies and their associated sealing rings need to meet various standards. For example, for sealing assemblies in vacuum piping, typical designs may be found as described in German Standard, DIN <NUM> (<NUM>) and/or in International Standard ISO <NUM> (<NUM>) and International Standard ISO <NUM> (<NUM>). As shown in <FIG>, a standard vacuum seal as in ISO <NUM> is shown having an O-ring <NUM>, two vacuum couplings or fittings <NUM>, an O-ring carrier or centering ring <NUM>, and clamps <NUM>. There are a variety of variations on such designs to accommodate different vacuum sealing assembly configurations. Such typical sealing configurations as shown in <FIG> are suitable for most applications with use temperatures from room temperature up to about <NUM>. Beyond <NUM>, typical prior art designs can result in damage to the seals, and potential failure. Further, there is also typically insufficient space in such assemblies for thermal expansion at higher temperatures.

Prior art sealing assemblies are guided by various existing industry specifications, including ISO <NUM>:<NUM>; ISO <NUM>:<NUM>; DIN <NUM>:<NUM>; DIN <NUM>: <NUM> and PNEUROP <NUM>: <NUM>. Such designs describe assemblies as shown, for example, in <FIG>. Such designs use a T-shaped metal centering ring (o-ring support) as a ring on the inner diameter of the elastomeric sealing ring for use in internal vacuum applications. These designs generally allow room for expansion of the seal at temperatures over about <NUM>, but do not allow for internal pressure conditions. Other designs as shown in <FIG> have a metal centering ring (o-ring support), overpressure rings and an elastomeric seal. Such designs generally have insufficient space for thermal expansion of the seal. This can cause damage to the seals, particularly when temperatures rise in the end application. Furthermore, these designs typically have a metal inner ring that is mostly rectangular in cross section causing increased exposure of the seal to process gasses. Such designs are useful from room temperature to about <NUM>. Beyond this temperature, damage can result to the seal which can lead to potential failure.

The present applicant has a double-lobed seal to improve sealing capability at higher temperatures and having only an inner ring (Greene, Tweed Seal No. <NUM>-<NUM>-SC513). Such assemblies are an improvement but the seal is still left exposed and there can still be impacts from thermal expansion.

<CIT> shows a vacuum sealing ring having an inner, compressible metal ring that is clamped upon installation in an apparatus. The inner, metal ring has a sideways and outwardly facing, U-shaped cross-sectional profile. The metal ring surrounds an outer elastomeric sealing O-ring having a circular cross-section. The sealing O-ring is compressed within the metal ring in use. The design does not have an outer ring on an exterior of the O-ring. The inner metal ring is shaped to seal the interior space from particulation from the elastomeric O-ring seal. A similar design having an outer seal shaped to complement the interior of the sideways U-shaped inner ring is shown in <CIT>. Upon compression, the outer elastomer sealing material filling the interior of the inner metal ring curves outwardly.

<CIT> teaches a metal and/or elastomer ring for a vacuum sealing assembly including vacuum flanges having V-notched receiving areas. The metal flange rings are also shaped on more of a V-shaped exterior surface which angles to a flat outer-facing surface. The modified V-angled portions engage V-notched receiving areas within the flanges. For use with an elastomer seal, the flange lips compress to give the desired seal against the interior sealing ring.

<CIT> shows a vacuum sealing assembly having a centering ring with a circumferential flange (O-ring support) for receiving an O-ring with a circular cross-sectional profile. The centering ring has upper and lower beveled surfaces on its exterior to seat within mating surfaces in the upper and lower vacuum fittings. A clamping ring is used to compress the elastomer.

<CIT> discloses a vacuum sealing assembly incorporating two elastomeric seals, one of which comprises a thermoplastic sacrificial protective collar surrounding the seal. The outer collar may be formed of polyetherether ketone (PEEK), polytetrafluoroethlene (PTFE), polyether sulfone (PES) or polyimide (PI), while the inner seal is formed of a fluoroelastomer. The assembly collar has two fingers that surround a portion of the outer surface of the O-ring seal and also help to seal the space in which the assembly is situated. The design is to provide a shielding effect on one side of the elastomer O-ring seal.

<CIT> teaches a semiconductor manufacturing chamber gate door that incorporates a seal having a cross-sectional view which has a generally parabolic cross-sectional design.

Korean Patent Publication No. <CIT> shows a seal for a vacuum assembly having a dovetail groove. The embodiments show modified seals having a more "barrel" shape as well.

Korean Patent No. <CIT>teaches a bonded seal. It has a metallic portion bonded to a perfluoroelastomer (FFKM) seal. The inner and outer rings 100a, 100b are almost a sideways pyramidal shape and are formed of FFKM. The connecting piece that spans between the two rings is formed of a fluorinated resin.

While such designs attempt to create ways to protect the sealing materials from damage and/or from contamination from the seals reaching the environment, a need in the art still exists for sealing assemblies for various sealing configurations between sealing members that provide sufficient space for thermal expansion of the sealing material in the sealing ring and prevent damage to the sealing ring at higher temperatures, while retaining a cohesive assembly upon installation and in use within industrial applications such as internal vacuum, internal pressure, and sanitary liquid sealing assemblies.

<CIT> and <CIT> disclose respectively a sealing assembly designed for providing protection from corrosive chemicals as exhaust gas and withstanding vacuum and positive pressure, and a sealing assembly for use in hydraulic systems, under pressure, particularly between pipe couplings. None of these documents provides a sealing assembly that protects a center elastomer seal while allowing for its thermal expansion at temperatures of about <NUM> to about <NUM>.

The invention is defined in the appended claims and relates to the use of a sealing assembly installed in a high temperature application having a service temperature of about <NUM> to about <NUM>, such as a vacuum sealing assembly for semiconductor manufacturing, the sealing assembly comprising:.

In one embodiment, a seal receiving area of the inner ring has a longitudinal cross-sectional profile of an outwardly facing truncated V and each outwardly facing projection of the inner ring is angled away from a transverse central axis through the inner ring and from each other and each forms an angle of about <NUM>° to about <NUM>° with the transverse central axis of the inner ring.

In one embodiment the high temperature application is a vacuum sealing assembly for use in semiconductor manufacturing.

In one embodiment the high temperature application includes a service temperature of about <NUM> to about <NUM>.

In one embodiment the elastomer is a fluoroelastomer or a perfluoroelastomer.

In one embodiment the inwardly facing projections (16a, 16b) of the outer ring are each spaced from each other and are each spaced from a longitudinal center of the interior surface of the outer ring by a distance of about <NUM>% to about <NUM>% of a height of the interior surface of the outer ring.

In one embodiment each inwardly facing projection of the outer ring forms an angle of about <NUM>° to about <NUM>° with the transverse central axis of the outer ring.

In one embodiment the outwardly facing projections of the inner ring are each spaced from each other and are each spaced from a longitudinal center of the exterior surface of the inner ring by a distance of about <NUM>% to about <NUM>% of a height of the exterior surface of the inner ring.

In one embodiment each outwardly facing projection of the inner ring forms an angle of about <NUM>° to about <NUM>° with the transverse central axis of the inner ring.

In one embodiment the inwardly facing projections of the outer ring are each spaced from each other and are each spaced from a longitudinal center of the interior surface of the outer ring by a distance of about <NUM>% to about <NUM>% of a height of the interior surface of the outer ring, and wherein the outwardly facing projections of the inner ring are each spaced from each other and are each spaced from a longitudinal center of the exterior surface of the inner ring by a distance of about <NUM>% to about <NUM>% of a height of the exterior surface of the inner ring.

In one embodiment the center sealing ring has a longitudinal cross-section that has a side-ways barrel shape.

In one embodiment the center sealing ring has a longitudinal cross-section that has a truncated side-ways tear drop shape with an inner facing side that is flat and an outer facing side that is curved, wherein the inner facing side is smaller than the outer facing side.

In one embodiment the center sealing ring has a longitudinal cross-section that has a truncated side-ways tear drop shape with an inner facing side that is curved and an outer facing side that is curved, and wherein the inner facing side is smaller than the outer facing side.

In one embodiment the center sealing ring has a longitudinal cross-section that has a truncated side-ways tear drop shape with an inner facing side that is flat and an outer facing side that is flat, and wherein the inner facing side is smaller than the outer facing side.

The foregoing summary, as well as the following detailed description of preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:.

The invention herein provides various configurations of sealing assemblies that offer solutions in the art to prevent seal damage and/or seal failure due to issues that arise in high temperature end applications both as due to the inability of prior art designs to accommodate sufficient thermal expansion of the assembly, particularly the inner sealing member and/or due to seal deterioration from the impact of aggressive reactants or the sealing environment, which impact can be further exacerbated in high temperature applications. Without intending to be limiting, the present assemblies provide for adequate thermal expansion space, maintain a cohesive sealing assembly in use in high temperature end applications and also protect the center sealing member.

Such sealing assemblies are useful in a wide variety of end applications in the fluid handling, aerospace and semiconductor fields, among others, and represent solutions to issues involved in such fields particularly where (i) sealing members of sealing assemblies are subject to damage and/or deterioration from aggressive process reactants or byproducts and/or from an aggressive process environment at any temperature service range and/or (ii) when sealing assemblies including sealing members are employed in a high temperature end applications, such as those over a service temperature of <NUM>. For example, such assemblies find particular usefulness in vacuum sealing assemblies employed in "subfab" areas of semiconductor manufacturing facilities, but are also useful in process equipment gates, doors, and the like.

As used herein, words such as "inner" and "outer," "upper" and "lower," "top" and "bottom," "left" and "right," "inwardly" and "outwardly" and words of similar import are intended to assist in understanding preferred embodiments of the invention with reference to the accompanying drawing Figures and with respect to the orientation of the sealing assemblies as shown in the Figures, and are not intended to be limiting to the scope of the invention or to limit the invention scope to the preferred embodiments shown in the Figures. The embodiments herein each use like reference numbers to refer to analogous features of the invention as described herein and as shown in the drawings, such that absent language to the contrary describing an alternative configuration for a particular feature, one skilled in the art would understand, based on this disclosure and the drawings attached hereto, that description of one such feature is applicable to an analogous feature in another embodiment herein unless otherwise specified.

The sealing assemblies herein present a sealing rings having custom cross-sectional configurations which, when combined with customized inner and outer rings in the assemblies, reduce seal volume, while increasing gland volume so as to create room for the sealing member to expand thermally and help to prevent damage to the sealing ring in use in aggressive and/or high temperature end applications. The custom profiles are also designed to keep the inner and outer rings and sealing member cohesive and together in use so as to aid in the ease of installation of the overall sealing assembly, for example, in piping components. The specialty inner and outer rings help to reduce the amount of direct process exposure of the center sealing ring.

In a first embodiment herein, shown with varying center sealing ring cross-sectional configurations in <FIG>, the invention includes a sealing assembly, generally referred to herein as assembly <NUM>. The assembly includes an outer ring <NUM> having an interior surface <NUM> and an exterior surface <NUM>. The interior surface <NUM> includes two inwardly extending projections <NUM>, identified independently as 16a, 16b, which together define a seal receiving area <NUM>. The projections preferably extend circumferentially around the entire outer ring, however, one skilled in the art would understand that it is within the scope of the invention, based on this disclosure, that a gap or opening or periodic openings may be provided if the end user elects to incorporate them, without departing from the invention. It is preferred that for achieving the best level of seal protection and for maintaining a cohesive assembly, the projections <NUM> extend around the entire outer ring <NUM>.

The exterior facing sides <NUM> of the projections <NUM> may be oriented with respect to a transverse central axis AOR through the outer ring in parallel or an angle. As shown, each exterior facing side 20a, 20b of respective projections 16a, 16b is in parallel to axis AOR. The interior facing sides <NUM> of the projections <NUM> may be similarly oriented, to the exterior facing sides, or more preferably as shown, each interior facing side 22a, 22b is angled at a respective angle α, α' with respect to the central transverse axis AOR of the outer ring. The angles are preferably the same, but may vary depending on sealing member design. As shown, they are the same.

The outer ring, as well as the inner ring, described below herein, are each preferably formed so as to include one or more of a metal, a metal alloy or either a heat-moldable or heat sinterable fluoropolymer. Thus, the outer ring and/or the inner ring may include various metals or alloys thereof for appropriate use in the designated end application. Suitable metals and metal alloys for use in semiconductor and/or high temperature processing applications include, but are not limited to, aluminum <NUM>, aluminum <NUM>, stainless steel <NUM>, and/or stainless steel <NUM>. Suitable fluoropolymers, include, without limitation, polytetrafluoroethylene (PTFE) as well as melt-processible fluoroplastic fluoropolymers such as copolymers of perfluoroalkylvinyl ether (PAVE) and tetrafluoroethylene (TFE), commonly known in the art as Teflon™ PFA, copolymers of hexafluoropropylene (HFP) and TFE such as Teflon™ FEP and other suitable melt-processible copolymers. Depending on the end use, other composite or polymeric molding materials may be suitable, including, without limitation, acrylonitrile-butadienestyrene (ABS), ethylene-propylene copolymers, polyethersulfones, polyolefins, polyvinyl chlorides, polyimides, polyetherimides, polyamides, polystyrene, polyethylene terephthalate and the like.

As used herein, when referencing high temperature end applications, it is the applicant's intention, that such term relates to service temperatures of about <NUM> to about <NUM>, and in other embodiments, to service temperatures of about <NUM> to about <NUM>. Such temperatures are considered in the art to be high temperature end applications, for example, for vacuum sealing assemblies for use in semiconductor manufacturing.

The outer ring will have dimensions configured to mate with an appropriately sized assembly flange and clamp fittings so as to be adaptable to existing piping or other fitted parts. Suitable outer ring dimensions include outer diameters (OD) of about <NUM> to about <NUM>. An inner diameter (ID) will vary somewhat depending on whether it is measured above or below the projections or within the seal receiving area <NUM> between the projections. On the portions of the outer ring above and below the projections (exterior to surfaces 20a, 20b), the ID is preferably about <NUM> to about <NUM>. Within the seal receiving area <NUM> as measured at the central transverse axis AOR, the ID is about <NUM> to about <NUM>. The outer ring may also have a varying height depending on end application, as measured longitudinally along the exterior of the outer ring, of about <NUM> to about <NUM>. The projections <NUM> of the outer ring <NUM> preferably create a seal receiving area that extends outwardly so as to go into the outer ring body while leaving the portions of the outer ring exterior to the projections thicker as noted above with respect to the ID dimensions. It will be understood by one skilled in the art, based on this disclosure that the projection angles, ring thickness and sizing can be varied within the scope of the invention.

The inner ring <NUM> for use with assembly <NUM> has an exterior surface <NUM> and an interior surface <NUM>. The exterior surface <NUM> preferably has two outwardly extending projections <NUM> (independently 30a, 30b) that together define a seal receiving area <NUM>. The projections <NUM> preferably extend circumferentially around the entire inner ring, however, one skilled in the art would understand that it is within the scope of the invention, based on this disclosure, that a gap or opening or periodic openings may be provided if the end user elects to incorporate them, without departing from the invention. It is preferred that for achieving the best level of seal protection and for maintaining a cohesive assembly, however, that the projections <NUM> extend around the entire inner ring <NUM>.

The exterior facing sides <NUM> (independently 34a, 34b) of the projections <NUM> may be oriented with respect to a transverse central axis AIR through the inner ring in parallel or at an angle. As shown, each exterior facing side 34a, 34b of respective projections 30a, 30b is in parallel to axis AIR. The interior facing sides <NUM> (independently 36a, 36b) of the projections <NUM> may be similarly oriented, to the exterior facing sides, or more preferably as shown, each interior facing side 36a, 36b is angled at a respective angle β, β' with respect to the central transverse axis AIR of the inner ring. The angles are preferably the same, but may vary depending on sealing member design. As shown, they are the same.

The inner ring <NUM> may be formed using any of the materials noted above with respect to the outer ring <NUM>. The inner ring will have dimensions configured to mate with an appropriately sized assembly flange and clamp fittings as well as so that the projections 30a, 30b of the inner ring <NUM> contact or mate with the projections 16a, 16b, respectively of the outer ring <NUM>. The inner ring dimensions, like the outer ring dimension should be varied so as to be adaptable to existing piping or other fitted parts. Suitable inner ring dimensions include inner diameters (ID) of about <NUM> to about <NUM>. An outer diameter (OD) will vary somewhat depending on whether it is measured above or below the projections 30a, 30b or within the seal receiving area <NUM> between the projections <NUM>. On the portions of the inner ring above and below the projections (exterior to surfaces 34a, 34b), the OD is preferably about <NUM> to about <NUM>. Within the seal receiving area <NUM> as measured at the central transverse axis AIR, the OD is about <NUM> to about <NUM>. The inner ring may also have a varying height depending on end application, as measured longitudinally along the exterior of the inner ring, of about <NUM> to about <NUM>. The projections <NUM> of the outer ring <NUM> preferably create a seal receiving area <NUM> that extends inwardly into the inner ring body from the exterior surface while leaving the portions of the inner ring exterior to the projections <NUM> thicker as noted above with respect to the OD dimensions. It will be understood by one skilled in the art, based on this disclosure that the projection angles, ring thickness and sizing can be varied within the scope of the invention.

In a preferred embodiment, the seal receiving area <NUM> of the outer ring <NUM> of the above-described assembly <NUM> has a longitudinal cross-sectional profile as shown in <FIG> of an inwardly facing truncated "V". The inwardly facing projections <NUM> of the outer ring <NUM> are preferably spaced from each other and each is preferably also spaced from a longitudinal center of the interior surface (the transverse longitudinal axis of the outer ring AOR) of the outer ring <NUM> by a distance of about <NUM>% to about <NUM>% of a height HOR of the interior surface <NUM> of the outer ring <NUM>. Each inwardly facing projection <NUM> of the outer ring <NUM> as discussed above may be angled away from the transverse central axis through the outer ring AOR and from each other, and each may form an angle α, α' respectively of about <NUM>° to about <NUM>° with the transverse central axis of the outer ring, and preferably an angle of about <NUM>° to about <NUM>° with the transverse central axis of the outer ring.

It is further preferred that the seal receiving area <NUM> of the inner ring <NUM> has a longitudinal cross-sectional profile of an outwardly facing truncated "V". The outwardly facing projections 30a, 30b of the inner ring <NUM> may be each spaced from each other and each spaced from a longitudinal center (i.e., the longitudinal axis) of the exterior surface of the inner ring AIR by a distance of about <NUM>% to about <NUM>% of a height HIR of the exterior surface of the inner ring <NUM>. Each outwardly facing projection 30a, 30b of the inner ring <NUM> may be angled away from the transverse central axis AIR through the inner ring <NUM> and from each other, and each preferably forms an angle β, β' of about <NUM>° to about <NUM>° with the transverse central axis AIR of the inner ring, more preferably an angle of about <NUM>° to about <NUM>° with the transverse central axis of the inner ring.

In a further preferred embodiment, both the seal receiving area of the outer ring and the seal receiving area of the inner have longitudinal cross-sectional profiles of an inwardly facing truncated "V" and an outwardly facing truncated "V" as shown in <FIG>, <FIG> and <FIG> and as described above with respect to each ring individually.

The assembly <NUM> further includes a center sealing ring <NUM> configured to be positioned within the seal receiving areas <NUM>, <NUM> of the outer ring <NUM> and the inner ring <NUM>, respectively. When the sealing assembly <NUM> is installed in a high temperature application, the elastomeric center sealing ring <NUM> is enclosed as shown (see <FIG>) within the outer ring <NUM> and the inner ring <NUM> so as to protect the center sealing ring <NUM> while allowing for thermal expansion of the center sealing ring <NUM>. As shown in <FIG>, the outer and inner rings are assembled around the center sealing ring <NUM> and are positioned between two mating parts, such as vacuum parts <NUM>. In position, the outer ring <NUM> sits so that its exterior ring body portion is outside of parts <NUM>, and the projections 16a, 16b extend inwardly between parts <NUM>. Parts <NUM> have mating flanges <NUM> configured to press against the contacting or mating projections <NUM>, <NUM> of the outer and inner rings assembled. The inner ring <NUM> is seated within the parts <NUM> so that the inner ring body is positioned inwardly to the mating flanges <NUM> and the projections <NUM> of the inner ring are within the mating flanges <NUM>. In use, a clamp of any suitable configuration as are known in the art may be used to press the flanges together so as to hold the sealing assembly in place.

The center sealing ring <NUM> is preferably formed of an elastomeric material (which may have various additives as are known in the art). For applications at high temperature and/or high pressure or employing aggressive environments or reactants, a fluoroelastomer (FKM) or a perfluoroelastomer (FFKM) are preferred. Suitable materials are available from a number of suppliers, including but not limited to Greene, Tweed, of Kulpsville, PA, Dyneon of Minneapolis, Minnesota, Daikin Industries, Ltd. , of Japan, Solvay, of Italy, and DuPont Elastomers, LLC of Wilmington, DE. For other end applications, other elastomers may be used including silicone elastomers, nitrile elastomers, and various diene elastomers, ethylene-propylene rubber and the like.

In this preferred embodiment, the center sealing ring <NUM> may have varying shapes. As shown in <FIG>, the center sealing ring <NUM> has a longitudinal cross-section that has a side-ways barrel shape. The center sealing ring <NUM> has an interior facing surface <NUM> and an exterior facing surface <NUM>. Each is a truncated flat surface which may have somewhat rounded or sharp edges as each meets the upper and lower surfaces <NUM>, <NUM>, respectively. The upper and lower surfaces have a curved bump extending outwardly in the upward and downward directions as shown best in <FIG>. The curved bump seals tightly against the contacting or mating projections <NUM>, <NUM> of the respective outer and inner rings <NUM>, <NUM>.

The barrel-shaped embodiment as shown preferably has an ID of about <NUM> to about <NUM> and an OD of about <NUM> to about <NUM>. The height of the seal at its largest dimension measured across the center of each upper and lower curved bump on the upper and lower surface <NUM>, <NUM> respectively is about <NUM> to about <NUM>. At the ID and OD, the height h<NUM> measures about <NUM> to about <NUM>. The size and angled configuration may be varied within the truncated sideways barrel embodiment to accommodate varying projection and ring designs within the scope of the invention.

As shown in <FIG>, an assembly <NUM> is provided having an outer ring <NUM> and an inner ring <NUM> which are essentially the same as the outer and inner rings <NUM>, <NUM> of assembly <NUM>, with the understanding that with a variation in center sealing ring configuration, one may adjust the outer and inner ring dimensions if desired. As shown in <FIG> and <FIG>, the assembly <NUM> has a center sealing ring <NUM> having a truncated side-ways tear drop shape with an inner facing side <NUM> that is flat and an outer facing side <NUM> that is curved, wherein the inner facing side <NUM> is preferably smaller in height than the outer facing side <NUM>. The height of such a design would decrease on both the upper side <NUM> and the lower side <NUM> of the center sealing ring <NUM> at a constant rate of decreasing height to provide the desired shape.

The truncated side-ways tear drop-shaped embodiment as shown preferably has an ID of about <NUM> to about <NUM> and an OD of about <NUM> to about <NUM>. The height h<NUM> of the seal on its OD at its largest dimension measured between the highest and lowest points on the exterior portion on each of the upper and lower surfaces <NUM>, <NUM>, respectively, is about <NUM> to about <NUM>. At the ID, the height h<NUM> measures about <NUM> to about <NUM>. The size and angled configuration may be varied within the truncated sideways tear drop shaped embodiment having a flat inner side and a rounded outer side to accommodate varying projection and ring designs within the scope of the invention.

As shown in <FIG>, a further an assembly <NUM> is provided having an outer ring <NUM> and an inner ring <NUM> which are also essentially the same as the outer and inner rings <NUM>, <NUM> of assembly <NUM>, with the understanding that with a variation in center sealing ring configuration, one may adjust the outer and inner ring dimensions if desired. As shown in <FIG> and <FIG>, the assembly <NUM> has a center sealing ring <NUM> having a truncated side-ways tear drop shape with an inner facing side <NUM> that is curved and an outer facing side <NUM> that is also curved, wherein the inner facing side <NUM> is preferably smaller in height than the outer facing side <NUM>. The height of such a design would decrease on both the upper side <NUM> and the lower side <NUM> of the center sealing ring <NUM> at a constant rate of decreasing height to provide the desired shape.

The truncated side-ways tear drop-shaped embodiment as shown in <FIG> preferably has an ID of about <NUM> to about <NUM> and an OD of about <NUM> to about <NUM>. The height h<NUM> of the seal at its OD is measured as the largest dimension between the highest and lowest points on the exterior portion on each of the upper and lower surfaces <NUM>, <NUM>, respectively, is about <NUM> to about <NUM>. At the ID, the height h<NUM> as measured along the highest and lowest points on the interior portion of the sealing ring measures about <NUM> to about <NUM>. The size and angled configuration may be varied within the truncated sideways teardrop embodiment with rounded sides to accommodate varying projection and ring designs within the scope of the invention.

As shown in <FIG>, a further embodiment of an assembly <NUM> is provided having an outer ring <NUM> and an inner ring <NUM> which are also essentially the same as the outer and inner rings <NUM>, <NUM> of assembly <NUM>, with the understanding that with a variation in center sealing ring configuration, one may adjust the outer and inner ring dimensions if desired. As shown in <FIG>, the assembly <NUM> has a center sealing ring <NUM> having a truncated side-ways tear drop shape with an inner facing side <NUM> that is generally flat and an outer facing side that is flat, by that incorporates beveled edges <NUM> on an exterior portion of the sealing ring as shown. The interior portion may also be beveled, slightly rounded or flat-edged. The inner facing side <NUM> is preferably smaller than the outer facing side <NUM>.

The center sealing ring <NUM> having the truncated side-ways tear drop-shaped with flat sides <NUM>, <NUM> shown in <FIG> in embodiment <NUM> as shown preferably has an ID of about <NUM> to about <NUM> and an OD of about <NUM> to about <NUM>. The height h<NUM> of the seal at its OD is measured as the largest dimension between the highest and lowest points on the exterior portion on each of the upper and lower surfaces <NUM>, <NUM>, respectively, which is about <NUM> to about <NUM>. At the ID, the height h<NUM> as measured along the highest and lowest points on the interior portion of the sealing ring and measures about <NUM> to about <NUM>. The size and angled configuration may be varied within the truncated sideways tear drop embodiment with flat sides to accommodate varying projection and ring designs within the scope of the invention.

In yet a further embodiment <NUM> herein, the invention includes a sealing assembly for a high temperature application having an outer ring <NUM> having an interior surface having two inwardly extending projections <NUM> defining a seal receiving area <NUM>. The outer ring is essentially the same as that of embodiment <NUM>. The assembly <NUM> includes a modified inner ring <NUM> having an exterior surface <NUM> and an interior surface <NUM>. The exterior surface <NUM> has an outwardly extending rectangular portion <NUM> on a central portion along a central transverse axis AIR and on the exterior surface of the inner ring. A further rounded projection <NUM> is positioned so as to be extending outwardly from the rectangular portion <NUM>.

The center sealing ring <NUM> has a longitudinal cross-section as shown best in <FIG> and <FIG> that is an inwardly facing and generally "C"-shaped profile. The "C"-shaped center sealing ring <NUM> defines an inner ring receiving area <NUM>. The center sealing ring <NUM> is configured to be positioned within the seal receiving area <NUM> of the outer ring <NUM> and to receive the outwardly extending rounded projection <NUM> of the inner ring <NUM> within the inner ring receiving area <NUM> as best shown in <FIG>. When the sealing assembly <NUM> is installed in a high temperature application, the elastomeric center sealing ring <NUM> is enclosed within the outer ring <NUM> and compressed against the inner ring <NUM> so as to protect the center sealing ring <NUM> while allowing for thermal expansion of the center sealing ring <NUM>.

The seal receiving area <NUM> of the outer ring <NUM> in this embodiment preferably has a longitudinal cross-sectional profile of an inwardly facing truncated "V" as with the outer ring <NUM> of embodiment <NUM>. The inwardly facing projections 416a, 416b of the outer ring <NUM> may each be spaced from each other and each spaced from a longitudinal center along the transverse center axis AOR of the interior surface <NUM> of the outer ring <NUM> by a distance of about <NUM>% to about <NUM>% of a height HOR' of the interior surface of the outer ring <NUM>. Each inwardly facing projection <NUM> of the outer ring <NUM> may be angled away from a transverse central axis AOR through the outer ring and from each other, and each preferably like embodiment <NUM> also forms an angle of about <NUM>° to about <NUM>° with the transverse central axis of the outer ring, and more preferably about <NUM>° to about <NUM>° with the transverse central axis of the outer ring.

The outer ring and/or the inner ring in this embodiment may be formed of the same materials used for embodiments <NUM>, <NUM>, <NUM> and <NUM>.

With respect to <FIG>, in yet a further embodiment <NUM> herein, the invention includes a bonded sealing assembly <NUM> for high temperature applications. This embodiment provides a sealing ring body <NUM> having a longitudinal cross-section having an outer ring portion <NUM>, an inner ring portion <NUM> and a central transversely extending bridge <NUM> that extends between the outer and the inner ring portions <NUM>, <NUM>. The outer ring portion <NUM> has an inwardly extending rectangular portion <NUM> and the inner ring portion has an inwardly extending rectangular portion <NUM>. Each of the rectangular portions <NUM>, <NUM> of the outer ring portion and the inner ring portion <NUM> are positioned so as to be longitudinally centered with respect to a central transverse axis ASRB through the sealing ring body. The bridge <NUM> has an upper surface <NUM> and a lower surface <NUM>. The outer and inner ring portions <NUM>, <NUM> together with and the bridge <NUM> further define an upper seal receiving area <NUM> and a lower seal receiving area <NUM>.

The embodiment further includes an upper seal lobe portion <NUM> and a lower seal lobe portion <NUM>, each seal portion, <NUM>, <NUM> is bonded respectively to the upper surface <NUM> and the lower surface <NUM> of the bridge <NUM>. Each lobe portion <NUM>, <NUM> is thus respectively located within each of the respective seal receiving areas <NUM>, <NUM> of the sealing ring body <NUM>. The upper and the lower seal lobe portions <NUM>, <NUM> each have respectively an upwardly extending and a downwardly extending generally parabolic longitudinal cross-section as best shown in <FIG>. As the sealing material approaches the bottom edges of the parabolic profile,troughs T form on the upper and lower portions for compression and expansion of the ring. The sealing material (see <FIG>) preferably extends along the interior of the sealing body <NUM> along the perimeter of the seal receiving areas <NUM>, <NUM>.

In this embodiment, the sealing ring body <NUM> may be formed of any of the metals, metal alloys and/or a fluoropolymers noted above with respect to prior embodiments. The upper and lower seal lobe portions preferably comprise elastomers.

The sealing ring body and the seal lobe portions may be chemically or mechanically bonded. In mechanically bonding the seal, small openings may be formed in the sealing ring body on the surfaces facing the seal receiving areas and upon molding and curing, the elastomeric material will vulcanize and expand to mechanically lock the sealing lobes into place. In chemically bonding, any chemical bonding agent known or to be developed in the art may be used that is compatible with the materials used to form the sealing lobes (which may be a variety of elastomers noted elsewhere herein) to the material used to form the sealing ring body.

It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.

Claim 1:
Use of a sealing assembly installed in a high temperature application having a service temperature of about <NUM> to about <NUM>, such as a vacuum sealing assembly for semiconductor manufacturing, the sealing assembly comprising:
an outer ring (<NUM>; <NUM>; <NUM>; <NUM>) having an interior surface (<NUM>) having two inwardly extending projections (16a, 16b) defining a seal receiving area (<NUM>);
an inner ring (<NUM>; <NUM>; <NUM>; <NUM>) having an exterior surface (<NUM>) having two outwardly extending projections (30a, 30b) defining a seal receiving area (<NUM>);
a center sealing ring (<NUM>) comprising an elastomer and configured to be positioned within the seal receiving areas (<NUM>, <NUM>) of the outer ring (<NUM>; <NUM>; <NUM>; <NUM>) and the inner ring (<NUM>; <NUM>; <NUM>; <NUM>),
wherein a seal receiving area (<NUM>) of the outer ring has a longitudinal cross-sectional profile of an inwardly facing truncated V and each inwardly facing projection (16a, 16b) of the outer ring (<NUM>) is angled away from a transverse central axis through the outer ring (<NUM>) and from each other, and each forms an angle (α, α') of about <NUM>° to about <NUM>° with the transverse central axis of the outer ring (<NUM>);
and wherein the elastomeric center sealing ring (<NUM>; <NUM>; <NUM>; <NUM>) is enclosed within the outer and the inner rings (<NUM>, <NUM>) to protect the center sealing ring (<NUM>; <NUM>; <NUM>; <NUM>) and allow for thermal expansion of the center sealing ring (<NUM>; <NUM>; <NUM>; <NUM>).