EP0111546A4

EP0111546A4 - Resilient gasket having auxiliary resiliency means.

Info

Publication number: EP0111546A4
Application number: EP19830902209
Authority: EP
Inventors: Charles Martin Warren
Original assignee: Dow Chemical Co
Current assignee: Dow Chemical Co
Priority date: 1982-06-14
Filing date: 1983-06-06
Publication date: 1984-10-29
Also published as: ZA834233B; WO1984000058A1; KR840005528A; KR860001694B1; EP0111546A1

Abstract

Flexible, resilient gasketing material (2) with auxiliary resiliency means, such as ridges or beads (12) or internally-positioned spring means (6). The gaskets (2) may be straight or curved or made into continuous forms such as rectangles or circles. Preferably the gaskets are flanges (11).

Description

RESILIENT GASKET HAVING AUXILIARY RESILIENCY MEANS

BACKGROUND OF THE INVENTION

There are various types of process equipment which require seals or gaskets between two or more sections, wherein leak-proof joints are desired, that will withstand the environment in which they are used and which will adjust to the expansions and contractions of the sections.

There are various sealing putties and gasketing which have been used for these purposes, but for the most part, they tend to lose their resistance to ag¬ gressive environments_t or become brittle, or undergo compression-set to an extent that they lose resiliency and cannot continue to provide leak-proof joints between sections which undergo expansion and contraction.

I have now devised a gasketing arrangement which is ideally suitable for providing secure joints between sections of process equipment wherein a good seal is achieved, even though the sections undergo expansions and contractions. SUM ARY OF THE INVENTION

Substantially as illustrated in figures at¬ tached herewith, there is provided an elongate strip or elliptical tube of flexible resilient material having auxiliary resilience means along its length, said elongate strip or elliptical tube preferably having a flange portion along one or both edges thereof. The elongate strip may be straight, or curved, or may be embodied as a structure having the general overall shape of a triangle, square, rectangle, polygon, circle, or ellipse. The flange portions may lie in substantially the same general plane in which the elongate strip lies, or may be skewed from, or offset from the plane of the elongate sheet.

DETAILED DESCRIPTION

Figures 1-10, none of which are drawn to scale, are provided as visual aids in describing various embodiments of the present invention.

Figure 1 may be considered as a top view of a horizontally-positioned series of compartments (1) with gaskets or seals (2) between the compartments, or may be considered as a side view of a vertically-stacked series of compartments (1). The series of compartments is shown as being held in place between end members (8) by tensioned rods (7), though other suitable means for maintaining the positions of the compartments may be used.

Figure 2 is a view of Figure 1 taken along offset line A-A of Figure 1 and shows a rectangular shape of gasket (2) along an exposed edge of one of the compartments (1) which is, itself, shown to be of a "picture-frame" type of configuration. Holes (9) may be provided in a flanged portion (11) of gasket (2) for fastening purposes.

' Figure 3 is a enlarged cross-section view of a cutaway portion of Figure 1 to reveal in greater detail the positioning of an embodiment of gasket (2) between two compartments (1) and to show use of holes (9) for fastening gasket (2) in place along the outer perimeter of a surface of a compartment divider (5). When installed, the divider provides a space (4) which is distinct from spaces (3) within the compartments (1). The means for fastening the flanged portion of gasket (2) and divider (5) is shown as a bolt-means, though other means may be used.

Figure 4 is an enlarged cross-section view of a portion of gasket (2) to demonstrate positioning of metal spring means (6) which may be (and preferably are) used within an elliptically-shaped embodiment of gasket (2) having an elliptically-shaped centrally- located, opening (10) running the length of the gasket. The spring means (6) is described in Figure 5.

Figure 5 illustrates an end-view or cross- sectional view of a preferred metal spring means for use inside various embodiments of the resilient gaskets of the present invention to provide auxiliary resiliency. As illustrated, the springs represent two elongate strips of spring steel which are curved along their length with the concave surfaces facing each other, forming an elliptically shaped area between them. When under compression the curved surfaces are forced closer together. As shown, the curved strips have a small distance between their cooperating edges to expedite movement of the edges when the springs are compressed; other means or configurations for obtaining expedient movement of the edges may be used. Preferably, the metal spring means are made of "spring steel" though any material which will undergo numerous compression- decompression cycles may be used. Other metal spring configurations may be used.

Figure 6 illustrates, in cross-section, an embodiment wherein the gasket (2), having a flange-like extension (11) is provided with auxiliary resiliency means (12) as well an internal void area (10) and a stiffening edge (13) opposite the flange (11). The spring steel means of Figure 5 may also be used within the area (10) as an auxiliary resiliency means along with, or instead of, the auxiliary resiliency means (12). The auxiliary resiliency means (12) illustrate a plurality of resilient ridges or beads on the effective sealing surfaces of gasket (2). When used, the auxiliary means (12) may comprise a single ridge or bead, but preferably comprises a plurality of such ridges or beads which are parallel to each other. The ridges (12) may also be used, if desired, along the flange (11). The stiffening edge (13) may be used for structural purposes, such as for helping to avoid side-ways distortion of the gasket or as an aid in positioning the gasket during installation. The stif- fening edge (13} may be thick enough, itself, to augment the total area of seal when gasket (2) is totally compressed, but should not be. so thick that it will prevent the main effective portion of gasket (2) from

P being compressed the desired amount. Auxiliary rein¬ forcement means may be provided in the stiffening edge (13), if desired, and/or functional tabs or flanges may be attached to stiffening edge (13). The flanged portion (11) is illustrated as being an offset (bent) member attached obliquely, but it may also be a sub¬ stantially straight or flat member attached at a dif¬ ferent angle than that shown in Figure 6. Furthermore, the flanged portion (11) may be curved, as viewed in cross-section. .Various configurations of the flanged portion (11) may be used, depending on the process equipment in which it is to be used.

Figure 7 illustrates an embodiment wherein the only auxiliary resiliency means for gasket (2) is that of a plurality of ridges or beads (12) positioned on the effective seal-surfaces of gasket (2) and arranged parallel to each other. If desired, the ridges or beads (12) may also be positioned along flange (11). In some cases a single ridge or bead (12) may be used along each sealing surface, but a plurality of such ridges or beads is generally preferred. The ridges (12) do not have to be at right angles to gasket (2).

Figure 8 illustrates an embodiment wherein the gasket (2) is circular and has ridges or beads (12) concentrically-located along the effective sealing surfaces of the gasket. Here again, the flange (11) is illustrated as an off-set, oblique member, but other configurations may be used. The drawing is not to scale and it will be realized that the central open area within the gasket may be much larger, relative to the entire dimensions, than is illustrated. Figure 9 is a cross-sectional view of gasket (2) taken along line B-B of Figure 8 to more clearly show the ridges or beads (12) and to show the relative position of flange (11).

Figure 10 is a cross-sectional view of a gasket (2) having paired counter-biased ridges or beads (12) which are intentionally made to be at an acute angle to gasket (2). Along each side of gasket (2) are shown three pairs of counter-biased ridges (12) arranged so that they bend toward the central portion (14) of gasket (2) when the configuration becomes compressed between two compartments, each compressed ridge over¬ lapping the ridge toward which it bends. Only one such counter-biased pair of ridges along each side may be used, but a plurality of two or more such pairs is preferable.

In Figure 10, there is shown an angle _A) which is counter-biased to an angle (_LB) for the-out¬ side (i.e., the third) pair of ridges (12). Whereas the acute angle for the counter-biased pairs of ridges may effectively be any angle less than 90°, it is preferable that it be in the range of about 75° to about 80°. For angles L& and_LB, it is most preferred to use a value of about 11° ± 1°.

The present invention, then, provides re¬ silient gasketing material having auxiliary resiliency means comprising at least one of the following:

1. Resilient ridges or beads positioned along the effective sealing surfaces of the gasketing material, said ridges or beads being substantially parallel or concentric to each other; 2. Resilient ridges or beads positioned along the effective sealing surfaces of the gasketing material, said ridges or beads being substantially parallel or concentric to each other, said gasketing material containing a hollow portion (especially a hollow portion that is elliptical in cross-section) running internally through the gasketing material;

3. Spring members comprising elongate strips which are curved along their length, the curved portions forming, when viewed in cross-section, an elliptical shape, said spring members being positioned within a hollow portion of a gasket material which hollow portion conforms to the dimensions of said spring members; 4. Spring members positioned internally within an elongated gasket material, along the length of the gasket, said spring members responding resil- iently to compression and decompression forces acting on the gasket; 5. Resilient ridges or beads as in Item 2 above, along with spring members as in Item 3 or 4 above.

The resilient gasketing material may be made of natural or synthetic rubber or resilient polymers, taking into account the environment to which the gasket is to be exposed. Polychloroprene rubber is usually a good choice as it has the ability to withstand contact with a large number of chemicals and can withstand moderately high temperatures. Rubbery formulations based on polybutene, polybutadiene, polyisoprene, fluoropoly ers, polyvinylchloride, polysilicones, and the like may be used in many applications. The rubber formulations generally contain fillers or other additives to enhance their physical and chemical properties. Rubbery formulations covered with fluoropolymers or other flexible coatings or sheaths are within the purview of the present invention.

The resilient gasketing material can be pre¬ pared by molding-in the auxiliary resiliency means of the present invention. In some cases, it may be best to extrude, cast or mold the gasketing material as sections, including (if desired) the resilient ridges or beads, and then inserting the spring members between the sections and bonding the sections together. In other cases, the internally-positioned spring members may be included during the casting or molding operation. The flanges are preferably formed along with the gasket, but may be formed separately and then bonded to, or anchored to, the gasket. _*

The general configuration of the gasket can be that of straight gaskets or curved gaskets or may be continuous gaskets for use along triangular, square, rectangular, polygonal, circular, or elliptical surfaces.

While Figures 1-10 illustrate certain embodi¬ ments (not to scale) of the present invention, it will be understood that variations may be made without de¬ parting from the inventive concept expressed herein. For instance, more than one hollow portion may be used within the gasket and the internally-positioned spring members may be used in more than one area of the gasket.

Equipment in which these gaskets can be used may be, in size, from very small to very large and the concomitant gasket is conveniently sized for the par¬ ticular equipment. One of the greatest advantages of the present gaskets is that the gaskets, when used in very large structures are easily fastened in place by use of the flanges and a series of compartments can be more easily pressed together, horizontally, without having the gasket droop, sag, or slip out of place during the placement of the compartments. Furthermore the flanges can serve as gasketing for internal parts of the equip¬ ment, such as compartment dividers or separators, while serving to hold the main portion of the gasket in place.

The invention is limited only by the following claims.

OMPI

Claims

-in-

I CLAIM:

- 1 - A resilieftt gasket having auxiliary resiliency means, said auxiliary resiliency means comprising at least one of a) resilient ridges or beads positioned along the effective sealing surfaces of the gasket, said ridges or beads being substantially parallel or concentric to each other, b) resilient ridges or beads positioned

" along the effective sealing surfaces of the gasket, wherein the gasket contains a hollow portion running internally through the gasket along its length, c) spring members comprising elongate strips which are curved along their length, the curved strips forming, as viewed in cross-section, an elliptical shape, said spring members being positioned within a hollow portion running internally through the gasket along its length, and d) spring members positioned internally within an elongate gasket material, along the length of the gasket, said spring members responding resiliently to compression and decompression forces acting on the gasket. - 2 -

The gasket of Claim 1 wherein the gasket is provided with flange means along its length.

- 3 -

The gasket of Claim 1 wherein the auxiliary resiliency means comprises the resilient ridges or beads.

- 4 -

The gasket of Claim 1 wherein the auxiliary resiliency means comprises the spring member positioned within the gasket.

- 5 -

The gasket of Claim 1 wherein the auxiliary resiliency means comprises the internal spring means and the external ridges or beads.

- 6 -

The gasket of Claim 1 wherein the auxiliary resiliency means comprises the internal spring means and the gasket is provided with flange means along its length.

- 7 -

The gasket of Claim 1 wherein the auxiliary resiliency means comprises resilient ridges or beads which are counter-biased in pairs along each side of the gasket in a manner such, that each ridge or bead is biased toward a central portion of the gasket and, when under compression, will overlap the ridge or bead toward which it is biased. - 8 -

The gasket of Claim 7 wherein the counter- biased ridges or beads are each deposed at an acute angle from the gasket, at an angle of about 75° to about 80°.

- 9 -

The gasket of Claim 8 wherein the acute angles are about 79° ± 1°.

- 10 -

The gasket of Claim 7 wherein the gasket is provided with flange means along its length.

- 11 -

The gasket of Claim 1 wherein the auxiliary spring means comprises internal spring means along the length of the gasket, said spring means comprising elongate strips which are curved along their length, said curved strips forming, as viewed in cross-section, an elliptical shape.

- 12 -

The gasket of Claim 11 wherein the gasket is provided with flange means along its length.

- 13 -

The gasket of Claim 12 wherein the gasket is also provided with auxiliary resiliency means comprising resilient ridges or beads along the effective sealing surfaces, said ridges or beads being substantially parallel or concentric to each other.

OMPI -1^".-

- 14 -

The gasket of Claim 1 wherein the gasket is a continuous gasket enclosing an area.

- 15 -

The gasket of Claim 14 wherein the enclosed area is circular or oval.

- 16 -

The gasket of Claim 14 wherein the enclosed area is triangular, square, or rectangular.

- 17 -

The gasket of Claim 14 wherein the enclosed area is polygonal.

- 18 -

A gasket for sealing two mating surfaces of a container or vessel to maintain a fluid impervious seal therebetween comprising a resilient member having a general configu- ration matingly engagable with the mating surfaces and having at least one auxiliary and cooperative resilient element integral therewith consisting of a) at least one resilient protuberance extending from each side of said resilient member said protuberance being positioned substantially normal to the direction of the exertion of pressure of the fluid within said vessel; and, b) matingly opposed spring-like segments internally positioned within said member to coopera- tively exert resiliency, independent of said resiliency inherent in said member, toward the mating surfaces of the vessel. - 19 - A gasket capable of sealing a joint between two elements of a fluid container, thereby to maintain the contents of said container which may be under pressure internal of said container, comprising a resilient member having a shape substantially conforming to the surface configuration of the elements to be joined, said member having auxiliary resilient members integral therewith consisting essentially of at least one of a) resilient protuberences extending from the surface of said member and normal to the direction of pressure exerted by said fluid of said container, and b) two resilient convexical opposing halves of a spring-like assembly positioned internal of the member extending said member's surface against the surfaces of elements to be joined.

OMP