Abstract:
An elongated elastomeric gasket ( 10 ) seals a pair of opposing flanges ( 12, 14 ) against the passage of liquid without compressing the flanges ( 12, 14 ) together. A reinforcing spring ( 32 ) is embedded within the elastomeric gasket ( 10 ) and is shaped so as to react when deflected by the operation of installing the gasket ( 10 ) into an operative position between the flanges ( 12, 14 ). A strategically located U-shaped bend ( 34 ) formed in the reinforcing spring ( 32 ) causes, in a preferred embodiment, contact pressure to be increased between opposed sealing beads at the other end of the gasket. More specifically, lateral contact pressure between a first pair of sealing beads ( 24 ) and their associated contact faces ( 38 ) is increased as a direct result of the reinforcing spring ( 32 ) being displaced during the assembly process. Likewise, lateral contact pressure between a second pair of beads ( 28 ) and their respective contact faces ( 42 ) is increased in direct response to the lateral displacement of the reinforcing spring ( 32 ) in the region of the first beads ( 24 ) during assembly.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Divisional of U.S. patent application Ser. No. 11/839,056 filed Aug. 15, 2007, now U.S. Pat. No. 7,828,302. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     A three-part gasket system for sealing opposing flanges without compressing the flanges together, and more particularly a loose-piece gasket that maintains a liquid impervious seal through self-generated lateral contact pressure exerted on each of the opposing flanges. 
     2. Related Art 
     Gaskets are used in a wide variety of sealing applications. Typically, the gasket is compressed between opposing flanges to perfect a fluid impervious seal. The compression load is usually accomplished by spacing a plurality of bolts or other fastening devices around the gasket. For practical purposes, both the gasket and the opposing flanges must be designed and constructed out of sufficiently sturdy material so as to support the compression loads necessary to perfect the seal. As a result, the flange members tend to be heavily constructed, thereby adding to overall weight and cost. 
     U.S. Pat. No. 5,687,975 to Inciong, issued Nov. 18, 1997, describes a gasketed sealing assembly whose objective is to minimize the number of clamping bolts needed to establish an adequate compressive load between opposing flanges. While the Inciong &#39;975 patent represents a noteworthy advance in the art, it nevertheless remains dependent upon maintaining some compressive load between the opposing flanges to maintain a fluid tight seal. Thus, the flanges must be constructed of sufficiently sturdy (and heavy) material to withstand the compression loads. 
     A more recent example of a prior art attempt to reduce the compression load requirements between opposing flanges may be found in U.S. Publication No. 2006/0118073 to Bauer et al., published Jun. 8, 2006. This technique, while effective, may be considered expensive and not suited for all applications. In this design, the gasket feature is molded directly to one of the flange portions. The gasket member is of elastomeric construction with an embedded stabilizing core made of a rigid plastic material that increases lateral contact pressure on the opposing flange. 
     Accordingly, there exists a need in this field for a stand-alone gasket such as that used in a three-part system comprising the gasket and a pair of opposing flanges which are sealed together against the passage of liquid without compressing the flanges together. The stand-alone nature of the gasket component reduces overall system cost and facilitates low-cost repairs and maintenance. Therefore, a solution is needed that will enable light-weight flange constructions due to the avoidance of compressive loads. The solution must be low-cost, versatile, durable and easily adapted from one application to the next. 
     SUMMARY OF THE INVENTION 
     In accordance with a first aspect of this invention, a stand-alone, loose piece gasket is provided for sealing a pair of opposing flanges together against the passage of liquid without compressing the flanges together. The gasket comprises an elongated elastomeric gasket body defining a generally continuous length. The gasket body includes an integral first sealing member extending in a first lateral direction relative to the length, and an integral second sealing member extending in a second lateral direction opposite to the first lateral direction. Each of the first and second sealing members extend continuously and uninterrupted along the length of the gasket body. A first pair of opposing beads protrudes laterally from the first sealing member. The first opposing pair of beads extends continuously and uninterrupted along the length of the gasket for establishing a laterally directed contact seal against a first one of the opposing flanges. A second pair of opposing beads protrudes laterally from the second sealing member. The second opposing pair of beads extends continuously and uninterrupted along the length of the gasket for establishing a laterally directed contact seal against a second one of the opposing flanges. An elongated reinforcing spring is embedded within the gasket body and extends within each of the first and second sealing members. The reinforcing spring has at least one U-shaped bend for continuously urging the respective first and second pairs of beads laterally relative to the length to enhance the contact pressure of the beads against their respective opposing flanges. By this construction, the gasket maintains a fluid impervious seal between the opposing flanges through self-generated lateral contact pressure on each of the flanges without compressive force. 
     According to a second aspect of the invention, a three-part gasket system is provided for sealing a pair of opposing flanges together against the passage of liquid without compressing the flanges together. The three-part system consists of an elongated elastomeric body, along with first and second flanges. The elongated elastomeric gasket body defines a generally continuous length. The first and second flanges extend parallel to the gasket body, and each have a pair of oppositely facing contact faces. The gasket body includes an integral first sealing member extending laterally toward the first flange, and an integral second sealing member extending laterally toward the second flange. Each of the first and second sealing members extend continuously and uninterrupted along the length of the gasket body. A first pair of opposing beads protrudes laterally from the first sealing member. The first opposing pair of beads extends continuously and uninterrupted along the length for establishing laterally directed contact seals against the respective contact faces of the first flange. Likewise, the second pair of opposing beads is similarly structured and establishes a laterally directed contact seal against the respective contact faces of the second flange. An elongated reinforcing spring is embedded within the gasket body and extends within each of the first and second sealing members. The reinforcing spring has at least one U-shaped bend for continuously urging the respective first and second pairs of beads laterally relative to the length so as to enhance the contact pressure of the beads against the respective contact faces of the first and second flanges. The gasket maintains a liquid impervious seal between the first and second flanges through self-generated lateral contact pressure on each of the respective contact faces. 
     According to yet another aspect of the invention, a method is provided for maintaining a sealed interface between a pair of opposing flanges without compressing the flanges together. According to the method, first and second flanges are provided, each having a pair of oppositely facing contact faces. An elongated elastomeric body is interposed between the first and second flanges. A first pair of opposing beads on the gasket body bears in lateral pressing contact against the respective contact faces of the first flange. And likewise, a second pair of opposing beads on the gasket body bear in lateral pressing contact against the respective contact faces of the second flange. An elongated reinforcing spring is embedded within the gasket body and backs each of the first and second pairs of beads. The improvement is characterized by increasing the lateral contact pressure between the second pair of beads and the respective contact faces on the second flange in direct response to laterally displacing the reinforcing spring in the region of the first beads. This occurs simultaneously with the step of increasing the lateral contact pressure between the first pair of beads and the respective contact faces in the first flange in direct response to laterally displacing the reinforcing spring in the region of the second beads. Thus, according to the claimed method, the gasket maintains a liquid impervious seal between the first and second flanges through self-generated lateral contact pressure on each of the respective contact faces. 
     In accordance with each aspect of this invention, the shortcomings and disadvantages inherent in prior art approaches and teachings are overcome. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the present invention will become more readily appreciated when considered in connection with the following detailed description and appended drawings, wherein: 
         FIG. 1  is an exploded perspective view depicting an exemplary application of the subject invention in the form of an engine cylinder head, valve cover and valve cover gasket forming a three-part sealing assembly; 
         FIG. 2  is a fragmentary perspective view of a stand alone gasket according to a preferred embodiment of the subject invention; 
         FIG. 3  is a representational cross-sectional view of a prior art gasket construction compressed between opposing flanges; 
         FIG. 4  is a cross-sectional view of a gasket assembly according to a preferred embodiment of the subject invention; 
         FIG. 5  is a cross-sectional view as in  FIG. 4  depicting the multi-directional displacement of the embedded reinforcing spring caused by the shaped interfaces of the opposing first and second flanges; 
         FIG. 6  is a cross-sectional view depicting through imaginary force vectors the increase in lateral contact pressure exerted by each of the beads as a result of the reinforcing spring displacement shown in  FIG. 5 ; 
         FIG. 7  is a cross-sectional view as in  FIG. 4 , but illustrating a first alternative embodiment of the subject gasket assembly; and 
         FIG. 8  is a cross-sectional view as in  FIG. 4 , but illustrating a second alternative embodiment of the subject gasket assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, a sealing assembly according to the subject invention is exemplified in  FIG. 1  comprising a gasket, generally indicated at  10 , interposed between a first flange  12  and a second flange  14 . Although a gasket assembly according to this invention may find usefulness in a variety of applications, the exemplary embodiment described here portrays use in an automotive environment where the first flange  12  comprises the lower, peripheral edge of a valve or rocker cover  16 . The second flange  14  is here shown forming the upper peripheral edge of a cylinder head  18 . Of course, these specifically-named components are merely examples, and those of skill in the art will appreciate other components, both within and outside of the field of vehicular engines, with which to apply the teachings of this invention. 
     The gasket  10  as depicted in  FIG. 1  is formed as a continuous, i.e., looping or endless, member. In many applications, this form will be considered the norm. However, it is foreseeable that the gasket  10  may be of similar elongated construction yet have definite ends. In either event, the elongated, extrusion-like nature of the gasket body consistently defines a generally continuous length. 
     Referring now to  FIG. 2 , the length of the gasket  10  is established by the elongated body of the gasket  10  and indicated by a descriptive legend adjacent the drawing figure. The gasket body is here shown including an integral first sealing member  20  extending in a first lateral direction relative to the length. In this example, the first lateral direction is depicted as an upward pointing vector. All directional references, such as “lateral,” are relative to the length of the gasket body. Likewise, an integral second sealing member  22  extends in a second lateral direction that is generally opposite to the first lateral direction. Thus, in the example of  FIG. 2 , the second lateral direction is represented by a downwardly directed vector. Each of the first  20  and second  22  sealing members extend continuously and uninterrupted along the length of the gasket body. Thus, the gasket  10  maintains a generally consistent cross-section along its entire length, which length may be either endless or definite. 
     A first pair of opposing beads  24  protrude laterally from the first sealing member  20 . The lateral directions referred to here in relation to the beads  24  comprises third and fourth lateral directions. These third and fourth lateral directions are represented as vectors in  FIG. 2  that are generally perpendicular to the first and second lateral directions. The first pair of opposing beads  24  extend continuously and uninterrupted along the length of the gasket body for establishing a laterally directed contact seal against the first flange  12 . Thus, the first pair of beads  24  takes the form of ribs, or ridges, extending the entire length of the gasket  10 . In addition to the first pair of beads  24 , supplemental first beads  26  can be added, as needed. Thus, supplemental first beads  26  are optional and can be included in as many pairs and arrangements as may be appropriate for a given application. The supplemental beads  26 , like the first pair of beads  24  may or may not extend the continuous length of the gasket  10  and may be provided for enhanced sealing, enhanced retention, or other purposes. 
     A second pair of opposing beads  28  protrude laterally from the second sealing member  22 . Like the first pair of beads  24 , the second pair of beads  28  also face in the third and fourth lateral directions. By referring to the first  24  and second  28  pairs of beads as “opposing,” it is meant that the beads  24 ,  28  face in laterally opposite directions, i.e., the third and fourth lateral directions. In the case of the first pair of beads  24 , they are depicted as facing laterally away from or outwardly relative to one another. However, in the case of the second pair of opposing beads  28 , they are shown facing toward or inwardly relative to one another. In addition to the second pair of beads  28 , supplemental beads  30  can be provided for the same purposes as that described above in connection with the first pair of supplemental beads  26 . That is, the second pair of supplemental beads  30  may or may not be continuous and uninterrupted along the length of the gasket  10 , and may be provided for enhanced sealing, enhanced grip, locating purposes, or other useful objectives. 
     Preferably, the gasket  10  is made from a highly elastic, elastomeric material such as rubber. The term “rubber” is used in a more generic sense to refer to any compressible and highly resilient elastomeric material. More generally, however, any material known and used for gasketing applications can be used for the gasket  10 , provided it is elastomeric. 
     An elongated, reinforcing spring, generally indicated at  32 , is embedded within the elastomeric gasket body. The reinforcing spring  32  is preferably a unitary, sheet-like strip of metallic spring material like high carbon steel or other highly resilient alloy. The reinforcing spring  32  is shaped so as to extend within each of the first  20  and second  22  sealing members, backing the respective first  24  and second  28  pairs of opposing beads. The reinforcing spring  32  may be shaped in various configurations, but includes at least one U-shaped bend  34  for continuously urging the respective first  24  and second  28  pairs of opposing beads laterally (i.e., third and fourth dimensions) relative to the length of the gasket  10 . This lateral urging caused by the bent reinforcing spring  32  enhances the contact pressure of the beads  24 ,  28  against their respective opposing flanges  12 ,  14 , respectively. Through the strategic shape and embedment of the reinforcing spring  32 , the gasket  10  is enabled to maintain a liquid impervious seal between the opposing flanges  12 ,  14  through self-generated lateral contact pressure on each of the flanges  12 ,  14  without requiring compressive force to be maintained between the flanges  12 ,  14 . Thus, the structural composition of one or both flanges can be lightened since there are no, or minimal, compressive loads to sustain. 
     A side-by-side comparison of the subject gasket  10  and a prior art construction adapted for a similar application can be readily observed by reference to  FIGS. 3 and 4 . A preferred embodiment of the subject gasket  10 , as illustrated in  FIG. 4 , mates with the first flange  12  which is formed as a continuously extending trough  36  with a pair of oppositely facing contact faces  38  presenting laterally toward one another on opposing sides of the trough  36 . The second flange  14 , on the other hand, is defined by a continuously extending tongue  40  with a pair of oppositely facing contact faces  42  presenting laterally away from one another on opposite sides of the tongue  40 . In this case, the gasket body, as viewed in cross-section, possesses an inverted Y-shaped configuration with the first sealing member  21  inserted into the trough  36  and the second sealing member  22  having a generally U-shaped configuration overlapping both sides of the tongue  40 . As here shown, the resilient spring  32  likewise has a generally Y-shaped configuration, as viewed in cross-section taken perpendicularly through the length of the gasket  10 . This Y-shaped configuration of the resilient spring  32  is defined by a pair of diverging legs  44  embedded within the second sealing member  22  and a confluent stem  46  embedded within the first sealing member  20 . The U-shaped bend  34  spoken of previously is contained at the apex of the stem  46 , i.e., adjacent the upper most edge of the gasket  10 . In this configuration, it is shown that the first pair of opposing beads  24  protrudes laterally away from one another so as to engage the contact faces  38  in a lateral direction. The second pair of opposing beads  28  protrudes laterally toward one another, and are adapted for directly engaging the contact faces  42  of the tongue  40 . 
     In operation, the gasket  10  is dimensioned so as to provide an interference fit relationship between the respective beads  24 ,  28  and their respective contact faces  38 ,  42  on the flanges  12 ,  14 . Thus, as shown in  FIG. 5 , when the first sealing member  20  is inserted into the trough  36  in the first flange  12 , the interference fit between the first pair of beads  24  and the contact faces  38  displaces the stem  46  portion of the reinforcing spring  32 , thus squeezing it together as indicated by the imaginary directional arrows. Thus, with the U-shaped bend  34  acting somewhat like a living hinge, the diverging legs  44  are squeezed together, resulting in a seal reaction force as depicted in  FIG. 6 , wherein the second pair of beads  28  are squeezed ever more tightly against their respective contact faces  42  on the tongue  40 . A symbiotic relationship is established between the forced displacement of the reinforcing spring  32  associated with the first flange  12  that improves the sealing characteristics at the interface with the second flange  14 . In like manner, attachment of the second sealing member  22  to the tongue  40  displaces the diverging legs  44  of the reinforcing spring  32  outwardly, as depicted by directional arrows in  FIG. 5 , due to the interference fit between the second pair of beads  28  and the contact faces  42 . This, in turn, urges a spreading of the stem  46  via the hinge-like U-shaped bend  34 . The result, as depicted in  FIG. 6 , is a laterally outwardly directed seal reaction force tending to more tightly press the first pair of beads  24  (along with any supplemental beads  26 ) more tightly against the contact faces  38  in the trough  36 . Thus, the unique construction of the subject gasket  10  with the embedded reinforcing spring  32 , coupled with the novel construction of the first  12  and second  14  flanges, results in a gasket  10  better adapted to maintain a liquid impervious seal between the first  12  and second  14  flanges through self-generated lateral contact pressure on each of the respective contact faces  38 ,  42 . 
     Turning now to  FIG. 7 , a first alternative embodiment of the subject gasket  110  is shown and described. In this first alternative embodiment, reference numbers similar to those used above are offset by  100  and re-used to identify corresponding features for convenience. In this embodiment, the shape of the first sealing member  120  is mirrored with that of the second sealing member  122 , such that the resulting cross-sectional shape of the gasket  110  resembles the letter “H.” In this design, the reinforcing spring  132  is composed of first and second disjointed halves, each half containing a U-shaped bend  134  in the center connecting portion of the gasket body. The shape of the first flange  112  is modified accordingly, and now takes a form identical to that of the second flange  114  for proper mating with the configuration of this alternative gasket  110 . In all other respects, the gasket  110  functions the same as that described above in connection with the preferred embodiment. 
       FIG. 8  depicts a second alternative embodiment to the subject invention. In this example, in which reference numbers consistent with that of the preferred embodiment are off set by  200 , the second flange  214  has been modified to minor that of the first flange  212 . Likewise, the second sealing member  222  of the gasket  210  mirrors the first sealing member  220 , developing a cross-sectional configuration of the gasket  210  in the shape of a plus (+) sign. In this example, the reinforcing spring  232  is again formed in first and second halves one half each serving the first  220  and second  222  sealing members. The U-shaped bend  234  of each half of the reinforcing spring  232  is positioned near the apex, as in the preferred embodiment. Portions of the respective reinforcing spring halves may be bent in laterally outward directions (third and fourth dimensions) to stiffen the body of the gasket or otherwise enhance functionality as needed. 
     The foregoing invention has been described in accordance with the relevant legal standards, thus the description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiment may become apparent to those skilled in the art and fall within the scope of the invention. Accordingly the scope of legal protection afforded this invention can only be determined by studying the following claims.