HEAD GASKET WITH IMPROVED ARMORING AND METHOD OF MAKING SAME

Abstract: A head gasket having a pair of armor assemblies (130, 150) with protective shim portions (132, 157) in the zone of adjacency between pairs of combustion openings. One armor's shim portion faces one main surface of a main body (10) of the gasket, and the other armor's shim portion faces the other main surface of the main body (10). The armor assemblies encapsulate the zone of adjacency thereby protecting against degradation and enhancing sealing in this zone. A method of making the head gasket by applying the armor assemblies from opposite sides of the main body is also disclosed.

Description: HEAD GASKET WITH IMPROVED ARMORING AND METHOD OF MAKING SAME Background of the Invention Cylinder head gaskets made with layers of facing material have been manuf ctured and used for decades . Such gaskets usually employ fire rings, such as U-shaped armors with or without wires, at the combustion openings to embrace the peripheral edges defining the combustion openings, thereby to protect the edges and enhance the sealing effect thereat . Sometimes the armors have been integrated so that the armors for pairs of adjacent or adjoining co oustion openings comprise a unitary assembly. In some instances one entire surface of the gasket is covered with the sheet material from which the armors are formed. The presence of integrating material at the zones of adjacency of pairs of combustion openings enhances the seal thereat, particularly where the combustion openings are very close to each other and the facing material is therefore weakened and fragile. Various sealing adjuncts have been provided for use at conventionally armored combustion openings and especially for use in the zones of adjacency of pairs of such openings. Thus, for example, multiple armors have been employed, with a second U-shaped armor simply overlying a first U-shaped armor. This, of course, enhances the seal to be effected thereat. In other instances metal shims have been placed under a leg of the U-shaped armor to provide for greater sealing stress. In some such cases, the shims for adjacent combustion openings are formed with, hence integrated with the armors in the zone of adjacency of a pair of combustion openings, thereby to enhance πhe sealing effect and to protect the facing layer or layers thereat. While all of these armoring techniques and adjuncts are of advantage, none is ideal. All of them tend to be sensitive to the conditions and loaαs at the combustion openings, such as excessive loads αue to thermal push, and tend to permit extrusion of facing layers when the gasKet is exposed to excessive clamp loads, sucn as because of thermal pusn. This tendency is most severe m the zones of adjacency of pairs of adjacent combustion openings. It would be of advantage to provide improved armoring and a method of making a gasket providing such improved armoring. Stxarmarv of the Invention In accordance with tne present invention, a head gasj-et having improved armoring s provided, together with a method of making such a gasKet To that end an improved head gasket comprises a main gasket body having at least one facing layer and defining a plurality of apertures, including at least one pair of adjacent combustion openings, and having first and second main surfaces, a first armor assembly comprising armors and having a joining shim portion covering the zone of adjacency of the pair of adjacent combustion openings on one of the main surfaces, each armor embracing the peripheral edge cf a combustion opening and having a first _eg formed w th tne joining shim portion and having a second leg confronting the other of the mam surfaces, a second armor assemDly comprising armors and having a joining shim portion covering the zone of adjacency of the pair of adjacent combustion openings on the other of the main surfaces, each armor embracing the peripheral edge of a comoustion opening and having a first leg confronting the one of the ma surfaces, whereby the zone of adjacency is encapsulated and resists degradation due to thermal push. The second armor assemDly may have a main body portion that overlies an entire ma surface and defines the second armor assembly joining smm portion. The first armor first leg may desirably project radially outwardly beyond the second armor first leg. In a preferred form the main gasket body includes a central core and a pair of facing layers, one on each surface of the central core. The facing layers may be compressed expanded graphite. Desirably the armors are U-shaped armors, each having a nose portion formed with legs confronting the main surfaces of the main gasket body. In a preferred form each armor of the second armor assembly has a second leg confronting the other of the main surfaces, and the second armor second leg projects radially outwardly beyond the first armor second leg, and the first armor first leg projects radially outwardly beyond the second armor first leg. In accordance with the present invention, a method of making an armored head gasket having at least one pair of adjacent combustion openings and improved sealing characteristics in the zone of adjacency of each pair of adjacent combustion openings is provided. It comprises the steps of providing a main gasket body defining a plurality of service openings and bolt holes, at least one pair of adjacent combustion openings, a pair of main surfaces, and having at least one facing layer, providing a first integrated inner armor assembly for embracing the peripheral edges of the pair of combustion openings, the inner armor assembly comprising a shim for overlying the gasket body in the zone of adjacency and an adjoining pair of armors, forming the armor assembly to embrace the peripheral edges of the combustion openings and to position the shims against one main surface of the gasket, providing a second integrated outer armor assembly for embracing the peripheral edges of the pair of combustion openings, the outer armor assembly comprising a second shim for underlying the gasket body in the zone of adjacency and an adjoining pair of armors, and forming the second armor assembly to embrace the peripheral edges of the combustion openings and to position the second shims aga st the other ma surface of the gasket, whereny each mam surface of the mam gasxet body m the zone of adjacency of the pair of combustion openings is sealed by a snim, and the zones cf adjacency between the adjacent pairs of combustion openings are encapsulated and resist degradation due to local operating conditions an engine . In one form of the method, the second armor assembly has a mam body portion that underlies the entire gasket body. In a preferred form the gasket body comprises a central core and a pair of facing layers, one on each mam surface of the gasKet body, and the facing layers are desirably of compressed expanded grapnite . Further objects, features and advantages of the present invention will become apparent from the following description and drawings. Brief Description of the Drawings Figure 1 is a plan view of a prior art armored head gasket; Figures 2 and 3 are cross-sectional views taken substantially along lines 2-2 and 3-3, respectively, of the prior art armored gasket of Figure 1; Figure 4 is a plan view of a furtner prior art armored head gasket; Figures 5 and 6 are cross-sectional views taken substantially along lines 5-5 and 6-6, respectively, of the prior art armored gasket of Figure 4 ; Figure 7 is a top plan view of an armored head gasket of the present invention; Figure 8 is a bottom plan view of the armored head gasket of Figure 7; Figures 9 and 10 are cross-sectional views taken substantially along lines 9-9 and 10-10, respectively, of Figure 7; Figure 11 is a schematic perspective view taken from a perspective similar to that cf Figure 9; Figure 12 is a load deflection curve showing how an armored head gasket of the type shown in Figure 7 differs from that of a prior art head gasket of the type represented by Figure 1; Figure 13 is a fragmentary top plan view of a further armored head gasket of the present invention; Figure 14 is a fragmentary bottom plan view of the armored head gasket of Figure 13; Figure 15 is a cross-sectional view taken substantially along line 15-15 of Figure 13; Figures 16-19 are representational views of a stepwise method of assembling an armored head gasket m accordance with Figure 7-n, and are shown at the cross- section represented by Figure 10. Detailed Description Referring first to the exemplary prior art armored head gasket shown in Figures 1-3, head gasket 10 comprises a main body 12 including a tanged core to which compressed expanded graphite facings are secured. The main gasket body 12 defines a plurality of apertures or openings, including conventional oil and water holes and bolt holes. Various sealing adjuncts such as prmted seals, protective coatings, etc. (not shown) may be provided as well. Gasket 10 also defines plural combustion openings 14, each of which is armored in accordance with a prior art practice. As seen in Figures 2 and 3, each combustion opening 14 is provided with a pair of inner and outer armors 16, 18, respectively, each of which is generally U-shaped (sometimes referred to as C-shaped) , and each of which embraces the peripheral edge of a combustion opening 14. The respective outer edges 20, 22 of the armors 16, 18 are typically in vertical alignment. In this prior art embodiment as shown in Figure 1 the armors are connected the zones of adjacency of pairs of combustion openings 14, but they do not cover, seal or effectively protect the zone of adjacency. Similarly, armors 18 are formed in a unitary assembly with connections in the zone of adjacency, but do not seal, cover or effectively protect the zone of adjacency. The armors 16, 18 simply provide enhanced sealing in the areas in wnich they are located, namely around the peripheral edges of the combustion openings 14. Referring now to another prior art armored head gasket, Figures 4-6 show a head gasket 40 comprising a main body 42 including a tanged core and facing layers, generally like body 12. Mam booy 42 defines a plurality of conventional openings, may employ conventional sealing adjuncts, and defines plural combustion openings 44, only one pair of which is illustrated. The combustion openings are armored accordance with yet another prior art practice . As seen in Figures 5 and 6, each of the pair of adjacent combustion openings 44 is provided with an armor 46 which armors are formed with a protective shim portion 48 m the zone of adjacency of co Dustion openings 44 Protective smm portion 48 overlies one major surface of the gasket body and protects the facing material _n the zone of adjacency. This is best seen from Figure 5. Additionally, a shim 50 for protecting the other side of the gasket the same zone of adjacency is provided. Shim 50 desirably comprises an assembly of mtegrated sections, each section surrounding a combustion opening 44, and which sections are captured and retained by the integrated armors 46, all as is apparent from Figures 5 and 6. However, αnder load, if the legs 52 of armors 46 tend to spread under excessive loading, the mam body 42 of the gasKet 40 will be exposed to gases and will tend to degrade. Referring now to Figures 7-11, an armored head gasket m accordance with the present invention comprises a head gasket 100 having a mam gasket body 110. Gasket body 110 defines a plurality of apertures such as suitable water and oil holes 112, bolt holes 114 and combustion openings 116. The mam gasket body 110 has two mam or major surfaces as seen m Figures 7 and 8. Body 110 includes a central tanged core 118 to which facing layers 120 of compressed expanded graphite are secured. The head gasket further comprises a first mner armor 130 for each combustion opening 116. Inner armors 130 are integrated mto a unitary assembly. Eacn adjacent pair of inner armors 130 is connected the zone of adjacency of a pair of combustion openings by a shim or connector 132. Each armor 130 is generally U-shaped in cross-section and has a pair of upper and lower legs, upper leg 134 and lower leg 136, respectively, and a nose 138 connecting the legs and enclosing the adjacent peripheral edge of the associated combustion opening 116. As will be apparent, the assembly of armors 130 is assembled with the mam gasket body 110 as a group. Typically, the lower legs 136 are initially formed to project vertically downwardly into the combustion openings, following wnich the lower legs are formed outwardly to lie against the lower major surface of the main body, as shown Dy Figures 9-11. The second outer armors 150 are, in this case, integrated with a metallic sheet 152 which confronts and overlies the entire surface of the lower graphite facing layer 120 defining the lower surface of the main body 110. Armors 150 include upper leg portions 154 as well as lower legs 156 which are continuous with the ma nody of sheet 152, and nose portions 158. The sheet 152 also provides a shim section 157 m the zone of adjacency of each pair of adjacent combustion openings (see Figures 9 and 11) . As is apparent from Figure 10, a preferred form the inner armor first leg 134 projects radially outwardly oeyond the second armor first leg 154. The armors 150 emorace the penpneral edges of the cotTLOUΞtion openings 116 as well as the first armor 130. For assemoly purposes they are initially formed at an angle which is generally perpendicular to the main dody 110 for association therewith. The armors 150 are inserted from the lower side (opposite to the upper side and direction from which the integrated first armors 130 were installed) until the sneet 152 lies against the lower surface of the main body 110. At that time, the legs 154 are clinched or formed outwardly to embrace the penpneral edges of the combustion openings, thereby to assume the reiationsnip shown Figures 9-11. It will be seen that at the zones of adjacency of pairs of combustion openings 116, the mam body 110 is encapsulated and protected against the adverse effects of combustion, such as aga st the effects of thermal push and of thermal expansion of the head and block at the locations at which those effects tend to be most pronounced and aggravated. Thus, at the lower surface, as seen in Figure 9, the ma oody 110 is protected aga st damage and against degradation due to the spreading of armor legs 136 (wnich is the tendency of prior art gaskets sucn as those shown by Figure 2) by the presence of the shim sections 157 of sneet 152 at the zones of adjacency. Similarly, the tendency to spread and to degrade is also resisted at the upper surface of the gasket wnere the inner armors 130 and armor shim 132 ensheath and protect the mam body 110. That is to be contrasted with prior art structures, as illustrated by Figures 5 and 6, where spreading of the armor legs will allow gases to enter and gam access to the mam body 42 of the gasKet at the peripheral edges of the combustion openings 44. The sealing characteristics are thus improved in the zones of adjacency of pairs of combustion openings. The relatively fragile gasket body at that zone is encapsulated. Exposure to forces tending to degrade tne body is limited. The density of the facing layers is also increased thereat and around the combustion openings by the armor construction, thereby improving the overall sealing characteristics around the combustion openings. Figures 12 shows how the armored head gasket of Figures 7-11 functions as compared to prior art gaskets of the type illustrated by Figures 1-3. In Figure 12, the solid line load deflection curve is representative of the operation of a gasket wnich has encapsulated zones of adjacency as illustrated by the gasket of Figures 7-11. At a point, as illustrated by Figure 12, prior art armored gaskets of the types represented by Figures 1-6 which are subjected to high loading will tend to follow the dotted line portion of the curve of Figure 12. A failure to seal adequately will result. A preferred gasket 100 comprises a mam gasket body formed of a cold rolled steel tanged core about 0.0083 inch thick and compressed expanded graphite layers about 0.035 men thick. The inner armor 130 may be of a tempered steel and of a thickness of 0.0091 to 0.0104 men, while the outer armor 150 may be of a tempered steel and of a thickness of about 0.0066 to 0.0076 inch. In Figure 10, the first inner leg 134 or heel, from the nose, is about 0.165 to 0.185 men, and the second armor first outer leg 154 or overlap is about 0.115 to 0.135 inch. The second leg heel and overlap 254 of the first armor 230 and the second leg heel and overlap 256 of the second armor in Figure 15 may be of similar dimensions. Other thicknesses and dimensions may be used as well. Additionally, other materials may also be used. For example, typical fiber-elastomer facing layers may be used mstead of compressed expanded graphite and the ma body may be laminated with a smooth, rather than a tanged, core m accordance with well known, art recognized principles. The gasket may oe coated with materials having lubricating and sealing characteristics, such as polytetrafluorethylene. A compressed expanded graphite which may be used is UCAR's Grafoil or Polycarbon's Calgraph A having a carbon content of about 93.5% and an ash content of 6.5%. Referring now to the embodiment of the present invention shown m Figures 13-15, the gasket may be very similar to that of Figures 7-11. One notable difference is that the lower surface of the gasket as shown Figure 14, rather than being a continuous sheet providing the outer armors, is instead an assembly of armors similar to that of the inner armors of Figures 7-11. Head gasket 200 as shown in Figures 13-15 has a main gasket body 210. Gasket body 210 defines a plurality of suitable water and oil holes 212, bolt holes 214 and combustion openings 216. The main gasket body 210 has two main or major surfaces. Body 210 includes a central tanged core 218 to which facing layers 220 of compressed expanded graphite are secured. Head gasket 200 further comprises a first armor 230 for each combustion opening 216. Armors 230 are integrated into a unitary assembly which may be identical to the armor assembly made up of armors 130. The second armors 250 are integrated and each include an upper leg 254, a lower leg 256, and a nose portion 258. In the zones of adjacency of pairs of adjacent combustion openings, the integrated armors define a shim 260. Figure 15 shows a cross-section taken on line 15-15 of Figure 13. A cross-section at the zone of adjacency is identical to that shown in Figure 9. In this embodiment it is seen that the second or lower leg 256 of the second armor preferably extends radially outwardly beyond the second leg 236 of the first armor 230 to provide enhanced sealing. Here again, the armors 250 embrace the peripheral edges of the combustion openings 216 and the first armor 230, and are initially formed at an angle whicn is generally perpendicular to the ma body 210 for association therewith. The armors 250 are inserted from the lower side (opposite to the upper side from which the mtegrated first armors 130 were installed) until legs 256 and shims 260 lie against the lower surface of the main body 210. At that time, the legs 254 are clinched or formed outwardly to embrace the peripheral edges of the combustion openings 216, to assume the relationship shown Figures 13-15. It will be seen that at the zones of adjacency of pairs of combustion openings the mam body 210 is encapsulated and protected against the adverse effects of combustion, such as due to thermal push and of thermal expansion of the head and block where those effects tend to be most pronounced and aggravated. Thus, at the lower surface, as seen in Figure 15, the ma body 210 is protected agamst degradation and agamst the spreading of armor legs 256 (which is the tendency of prior art gaskets such as those shown by Figure 2) by the presence of tne shim sections 260 in the zones of adjacency. Similarly, the tendency to spread and degradation at the top surface is also resisted at the upper surface where the inner armors 230 and armor shim 232 ensheath and protect the main body 210. That is to be contrasted with prior art structures as illustrated by Figures 5 and 6 where spreading of the armor legs will allow gases to enter and ga access to the mam body 42 of the gasket at the peripheral edges of the combustion openings 44. The method of assembling a gasket in accordance with the present invention is illustrated by Figures 16-19 in association with Figures 7-11. Referring first to Figures 16 and 10, a mam gasket body 110 is provided. It may be preformed with all of the plurality of service openings and holes, including oil and water openings, comr-ustion openings and bolt holes, and initially comprises the central core, such as the tanged core, and associated facing layers, such as the compressed expanded graphite layer disposed on each mam surface . The mam gasket body 110 defines a series of combustion openings, adjacent pairs of wnich define zones of adjacency between them, and a pair of ma or major surfaces. A first integrated inner armor assembly is provided. This includes the plurality of armors 130 and shim portions or shims 132 the zones of adjacency. Initially each first leg 134 terminates inwardly in an integral extension I which s disposed generally perpendicularly to leg 134. As so configured, the assembly of armors may be juxtaposed with body 110 with legs 134 and shims 132 lying agamst one mam surface, and with extensions I entering and projecting downwardly mto the combustion openings 116 closely adjacent to the peripheries of the combustion openings, as represented by Figure 16. Thereafter, in accordance with known practices, extensions I are formed outwardly to emDrace the penpneral edges of the combustion openings and to form second lower legs 136 wnich underlie the gasket body around the combustion opening and an enclosed nose section, as represented by Figure 17, all of which form the U-shaped armor configuration illustrated. A second integrated outer armor section is provided as well. To that end a plurality of second armors 150 and second sh m sections 157 for covering the other ma surface zones of adjacency of adjacent pairs of combustion openings are provided. Initially each first or lower leg 156 terminates inwardly an integral extension E which is disposed generally perpendicularly to leg 15 . As so configured, the assembly of armors 150 may be juxtaposed with body 110 with legs 156 and shim sections 157, as well as the remainder of sneet 152 lying against the other mam surface, and with extension E projecting upwardly into the combustion opening m a direction opposite to which the extension I projected, as represented by Figure 18. Thereafter, extension E is formed outwardly to embrace the peripheral edges of the combustion openings and to form second legs 154 which overlie the gasket body around the combustion opening and an enclosed nose section, as represented by Figure 19, all of which form the second U- shaped armor configuration shown. Thus, the zone of adjacency between each adjacent pair of comoustion openings is encapsulated, resists degradation due to thermal push, and has improved sealing and load/deflection characteristics. It w ll be noted that at times terms such as "underlying", "overlying, " "upwardly" and "downwardly" have been used to describe the assembly of the head gasket. This is intended to relate the fact that the armors are applied from opposite sides so that the shim portions cover opposite sides to assist in affecting the encapsulation of the zones of adjacency. Thus, the terms are to be understood in their relational senses, not m their absolute senses. Only several embodiments of the present invention have been described. It will be apparent to those skilled in the art that modifications may be made without departing from the spirit and scope of the invention. Accordingly, the invention is to be construed in light of the claims and is not to be limited by the specific embodiments described and illustrated.

Claims: What Is Claimed Is: 1. A head gasket comprising: a mam gasket body navmg at least one facing layer and defining a plurality of apertures, including at least one pair of adjacent cortioustion openings, and having first and second mam surfaces, a first armor assemDly comprising armors and having a joining shim portion covering the zone of adjacency of the pair of adjacent combustion openings on one of said mam surfaces, each said armor embracing the peripheral edge of a combustion opening and having a first leg formed with said joining snim portion and having a second leg confronting tne other of said ma surfaces, and a second armor assembly comprising second armors and having a joining shim portion covering the zone of adjacency of the pair of adjacent combustion openings on the other of said mam surfaces, each said second armor embracing the peripheral edge of a combustion opening and having a first leg confronting the one of said mam surfaces, whereby said zone of adjacency is encapsulated and resists degradation due to thermal push. 2. The head gasKet of claim 1, and where said second armor assembly has a mam body portion that overlies an entire ma surface and defines said second armor assembly joining shim portion. 3. The head gasket of claim 1, and wherein first armor first leg projects radially outwardly beyond said second armor first leg. 4. The head gasket of claim 1, and wherein said ma gasket body mcludes a central core and a pair of facing layers, one on each surface of said central core. 5. The head gasket of claim 4, and wherein said facing layers are compressed expanded graphite. 6. The head gasket of claim 1, and wherein said armors are U-shaped armors, each having a nose portion formed with legs confronting the mam surfaces of said mam gasket body. 7. The head gasket of claim 1, and wherein each armor of said second armor assembly has a second leg confronting the other of said mam surfaces, and said second armor second leg projects radially outwardly beyond said first armor second leg. 8. The head gasket of claim 7, and wherein said first armor first leg projects radially outwardly beyond said second armor first leg. 9. A method of making an armored head gasket having at least one pair of adjacent combustion openings, said armored head gasket having improved resistance to thermal push in the zone of adjacency of each sa d pair of adjacent combustion openings, comprising the steps of: providing a main gasket body defining a plurality of service openings and bolt holes, and at least one pair of adjacent combustion openings, said gasket body having a pair of ma surfaces and at least one facing layer, providing a first integrated inner armor assembly for embracing the peripheral edges of said pair of combustion openings, said inner armor assembly comprising a shim for overlying said gasket body said zone of adjacency and an adjoining pair of armors defining first legs for overlying said gasket body around said combustion openings and further defining integral extensions of the first legs disposed generally perpendicular to said first legs and entering said combustion openings closely adjacent to the peripheries of said combustion openings, forming said extensions to embrace the peripheral edges of the combustion openings and to form second legs joined to said first legs by a nose section to form generally U-shaped armors, providing a second integrated outer armor assembly for emDrac g the peripheral edges of said pair of combustion openings, said outer armor assembly comprising a second shim for underlying said gasket body n said zone of adjacency and an adjoining pair of armors including first leg portions for underlying said gasket body around said combustion openings and further defining integral second extensions of the first leg portions disposed generally perpendicular to said first leg portions and entering said combustion openings closely adjacent to the peripheries of said combustion openings, and forming said second extensions to emnrace the peripheral edges of the coiUDustion openings and to form second legs joined to said first leg portions by a nose section to form generally U-shaped armors embracing said first U-shaped armors and said peripheral edges, whereby each mam surface of said ma gasket body in the zone of adjacency of sa d pair of combustion openings is sealed by a shim, and the zones of adjacency between the adjacent pairs of combustion openings are encapsulated and resist degradation due to local operating conditions in an engine. 10. The metnod of claim 9, and wherein said second armor assembly has a ma body portion that underlies the entire gasKet body and defines said second armor shim and said second armor first leg portions. 11. The method of claim 9, and wherein said mam gasket body comprises a central core and a pair of facing layers, one on each ma surface of said gasket body. 12. The method of claim 11, and wherein said facing layers are compressed expanded graphite. 13. The method of claim 9, and wherein said first armor first legs project radially outwardly beyond said second armor first legs. 1 . A method of maκιng an armored head gasket having at least one pair of adjacent combustion openings, said armored head gasket having improved sealing characteristics in the zone cf adjacency of each said pair of adjacent combustion openings, comprising the steps of: providing a mam gasket body defining a plurality of service openings and bolt holes, and at least one pair of adjacent corτiDustion openings, said gasket body having a pair of mam surfaces and at least one facing layer and having a first mtegrated inner armor assembly embracing the peripheral edges of said pair of combustion openings, said inner armor assemoly comprising a shim overlying said gasket body m said zone of adjacency and an adjoining pair of armors defining first legs overlying said gasket body around said combustion openings and second legs joined to said first legs by a nose section to form generally U-shaped armors, said second legs underlying said gasket body around said combustion openings, providing a second integrated outer armor assembly for embracing the peripheral edges of said pair of combustion openings, said outer armor assembly comprising a second shim for underlying said gasket body in said zone of adjacency and an adjoining pair of armors mcludmg first leg portions for underlying said gasket body around said combustion openings and further defining integral second extensions of the first leg portions, and forming said second extensions to embrace the peripheral edges of the combustion openings and to form second legs joined to said first leg portions by a nose section to form generally U- shaped armors embracing said first U-shaped armors and said peripheral edges, whereby each ma surface of said mam gasket body in the zone of adjacency of said pair of combustion openings is sealed by a shim, and the zones of adjacency between the adjacent pairs of combustion openings are encapsulated and resist degradation. 15. The method of claim 14, and wherein said second armor assembly has a ma body portion that underlies the entire gasket body and defines said second armor shim and said second armor first leg portions. 16. The method of claim 14, and wherein said ma gasket body comprises a central core and a pair of facing layers, one on each mam surface of said gasket body. 17. The method of claim 16, and wherein said facing layers are compressed expanded graphite. 18. The method of claim 14 , and wherein said first armor first legs project radially outwardly oeyond said second armor first legs. 19. A method of making an armored head gasket having at least one pair of adjacent combustion openings, said armored head gasket having improved sealing characteristics in the zone of adjacency of each said pair of adjacent combustion openings, comprising the steps of: providing a main gasket body defining a plurality of service openings and bolt holes, and at least one pair of adjacent combustion openings, said gasket body having a pair of ma surfaces and at least one facing layer, providing a first integrated inner armor assembly for embracing the peripheral edges of said pair of combustion openings, said inner armor assembly comprising a shim for overlying said gasket body in said zone of adjacency and an adjoining pair of armors, applying said first armor assembly to embrace the peripheral edges of the combustion openings and to position said shims against one main surface of said gasket, providing a second mtegrated outer armor assembly for embracing the peripheral edges of said pair of combustion openings, said outer armor assembly comprismg a second shim for underlying said gasket body in said zone of adjacency and an adjoining pair of armors, and applying said second armor assembly to embrace the peripheral edges of the combustion openings and to position said second shims against the other main surface of said gasket, whereby each main surface of said main gasket body in the zone of adjacency of said pair of combustion openings is sealed by a shim, and the zones of adjacency between the adjacent pairs of combustion openings are encapsulated and resist degradation. 20. The method of claim 19, and wherein said second armor assembly has a main body portion that underlies the entire gasket body. 21. The method of claim 19, and wherein said main gasket body comprises a central core and a pair of facing layers, one on each main surface of said gasket body.

Inventors: WEST GREGORY C, WEST, GREGORY, C.
Applicants: FEL PRO INC, FEL-PRO INCORPORATED
Application year: 1996
Main classification: F16J15
IPC codes: F16J15