The present exemplary embodiment relates to a self adjusting gasket for pipe joints. It finds particular application in conjunction with pipe joints having an interface with a non-circular perimeter, and will be described with particular reference thereto. However, it is to be appreciated that the gasket is usable with generally circular pipe joints as well as other like applications.
Pipe systems are utilized to transfer fluids from one location to another. There are many types of pipe systems including, for example, sanitary, domestic water, steam, air, fuel/oil and storm drainage systems. Pipe systems include a series of elongated hollow pipe sections having many different sizes and cross sectional shapes such as rectangular, square, oval and circular. Generally, the pipe sections are manufactured in a factory, transported to a fluid transfer site and installed on site at the location where the fluid is to be transferred. Materials commonly used to manufacture pipe sections include concrete, metal, stone, polyvinyl chloride (PVC) and other thermoplastic polymers. Additionally, many pipe systems are installed underground and subject to both external forces from the environment and internal forces from the fluid being transferred.
Many pipe systems utilize gaskets between the joints of each pipe section to help prevent the leakage of fluid. The joints exist at an interface between a first pipe section and a second pipe section. In bell and spigot piping systems, the gasket is placed at the interface to abut both a spigot end of a first pipe section and a bell end of a second pipe section, the spigot end being received within the bell end. Gaskets are made of a flexible waterproof material and meant to prevent fluid from leaking at the joint while they are subject to various external forces and internal forces that act on the pipe system. The sealing effect of the gasket may be compromised due to the various forces acting thereon and misalignment of the pipe sections or inconsistent gaps between the surfaces along the interface.
To improve the alignment and sealing effect of the interface, one manufacturer provides gaskets including a profile having at least one projection extending from the body of the gasket to compressively abut a surface on the spigot end and a surface on the bell end. Another manufacturer provides gaskets including a profile having a generally hollow tube protruding from the gasket body with a layer of locking teeth and lubricant along the inner surface of the tube to aid in the self alignment of the gasket in the joint. Additionally, self aligning gaskets are known to include an internal cavity within the gasket body to hold a fluid and provide a dynamic seal at circular interfaces. There are many other types of gasket systems having similar features.
However, these known gaskets do not conform to the perimeter sections of pipe ends that transition between radial or angular portions along the joints due to stresses that are, in part, caused by the transition in joint geometry. Known gaskets fail to provide a consistent seal at the interface between the surfaces of the bell and spigot, especially along a transitioning joint geometry such as between lateral portions and corner or angled portions of the joint, such as rectangular or square joints.
Therefore, there remains a need for a self aligning gasket for improved sealing of pipe systems utilizing a bell and spigot type joint which better conforms to transitioning radial and linear portions of the joint geometry.
In one embodiment, the present disclosure pertains to a self adjusting gasket which retards leakage at a joint between an associated first pipe and an associated second pipe including a wedge shaped body made of a generally compressible, leak proof material. The wedge shaped body has a profile that includes a tapered front portion, a planar rear portion, a first contact surface, and an inclined second contact surface, including a first fin having a trailing edge oriented generally normal to the first contact surface and a second fin spaced from the first fin. A generally continuous annular cavity is located in the wedge shaped body wherein the cavity is not symmetrically shaped and a fluid disposed in the cavity.
In another embodiment of the present disclosure, provided is a method of retarding leakage at an interface of a spigot end of a first pipe and a bell end of a second pipe. The method includes mounting a self adjustable gasket to the spigot end of the first pipe, the gasket having a wedge shaped profile with a continuous annular cavity having a generally asymmetrical profile relative to the interface, the cavity holding a fluid. The bell end of the second pipe is positioned on the spigot end of the first pipe along the interface. The gasket is compressed against the bell end of the second pipe. The fluid is distributed within the annular cavity to balance a compressive force along the interface such that a continuous seal is established along the interface.
In still another embodiment of the present disclosure, a self adjusting gasket including a compressible wedge shaped body is provided. The wedge shaped body includes a contact surface having a plurality of compression ribs, an inclined surface extends from the contact surface at a tapered front portion, the inclined surface including at least one resilient sealing member extending away from the inclined surface. An abutment surface is located opposite the tapered front portion, said abutment surface being oriented generally normal to the contact surface. An annular cavity is located within the gasket that encloses an amount of fluid, the annular cavity having an orientation that is generally asymmetrical relative to the contact surface.
The present disclosure may take form in certain parts and arrangements of parts, several embodiments of which will be described in detail in the specification and illustrated in the accompanying drawings which form a part hereof and wherein:
It is to be understood that this detailed description and the figures are for purposes of illustrating exemplary embodiments only and are not intended to be limiting. Additionally, it will be appreciated that the drawings are not to scale and that portions of certain elements may be exaggerated for the purpose of clarity and ease of illustration.
The self adjusting gasket of the present disclosure is provided to mitigate deficiencies in the sealing and coupling of circular and especially non-circular piping systems utilizing a bell and spigot typed joint with a flexible gasket as the primary sealing element. Joint seals of bell and spigot type pipe systems are effective when, under compression, a gasket positioned between a surface of a spigot end and a surface of a bell end prevents leakage about the entire perimeter of the pipe joint. However, seal failures occur when the gasket is unable to seal the joint, for example, due to tolerances about angled or cornered edges, perimeter gaps, pipe installation misalignment or differential loading.
In accordance with the present disclosure, a self adjusting gasket has been developed to facilitate effective sealing in a piping system where a flexible, leak resistant joint is required. The self adjusting gasket finds particular application where coupling installation is subject to significant tolerance issues such as with large concrete piping systems having a non-circular cross section. In many of these instances, pipe installations require the use of cranes or other automatic lifting methods to properly position and align each pipe section. Variations in the alignment of such large heavy pipe sections necessitated the development of a more effective self adjusting gasket, as disclosed herein.
As illustrated in
The wedge shaped body 110 includes a profile having a tapered front portion 120, a planar rear portion 130, a first contact surface 140, and an inclined second contact surface 150. The planar rear portion 130 is an abutment surface that can be oriented generally normal to the first contact surface 140. In one embodiment, the first contact surface 140 includes a plurality of compression ribs 145 for an improved grip to an associated pipe surface. Additionally, the first contact surface 140 can be mounted to the associated pipe surface with an adhesive (see
The wedge shaped body 110 includes at least one protrusion or resilient sealing member such as a fin. In this illustrated embodiment, a first fin 160 extends from the inclined second contact surface 150 and includes a trailing edge 165 oriented generally normal to the first contact surface 140. The first fin 160 extends outwardly from the inclined second contact surface 150. A second fin 170 extends from the wedge shaped body 110 and is spaced from the first fin 160 such that the second fin 170 is oriented at an acute angle in relation to the first fin 160. The second fin 170 extends from the trailing edge 165 of the first fin 160 and includes a planar trailing surface 175 connected to an angled end surface 135 that extends from the planar rear portion 130.
Another way of looking at the gasket body 110 would be that the second contact surface 150 continues after the first fin 160 and that the second fin 170 begins at a vertical line (not shown) extending upwardly from the intersection of the planar trailing surface 175 with the angled end surface 135. In one embodiment, the second fin 170 extends past the planar rear portion 130 such that the planar trailing surface 175 has a greater length than the planar end surface 135. (see
The self adjusting gasket 100 also includes a generally continuous annular cavity 200 located in the wedge shaped body 110. A fluid 210 is disposed in the cavity 200 wherein the fluid 210 can be a gel type material. The fluid 210 can be a substantially incompressible fluid or gel material that is ideally stable in that it does not freeze or expand thermally under normal environmental conditions which are expected to be encountered in the field. Further disclosure concerning the fluid can be found in application Ser. No. 12/637,433 which is incorporated by reference hereinto in its entirety. Fluid 210 is injected within the annular cavity 200 through an injection port (not shown) and the injection port is then sealed. The cavity 200 is configured to accept and hold the fluid 210 when the gasket 100 is in both an uncompressed condition (see
Notably, the shape of the cavity 200 profile is not symmetrical. In one embodiment, the profile of the cavity 200 is non-symmetrical relative to the first contact surface 140 in the uncompressed condition. The profile of the cavity 200 can also be non-symmetrical relative to the surface 225 of the spigot end 220 of the first pipe 240 in the uncompressed condition. The asymmetry of the profile of the cavity 200 can be relative to the geometric shape and tolerance of the spigot surface 225 and the bell surface 235 along a portion of the perimeter of the coupled pipe sections. Additionally, various asymmetric shapes of the cavity 200 relative to the orientations of the planar rear portion 130, first fin 160 and second fin 170 are contemplated to efficiently distribute the fluid 210 within the cavity 200 to sufficiently balance the pressure along the interface 180 and create a secure seal.
As illustrated in
With reference to
With reference to
The second fin 170 and planar rear portion 130 of the compressed gasket 100 functions as a hydraulic seal that is energized by the compressing forces of the first pipe 240 and second pipe 250 and by hydrostatic pressure from the environment outside the pipe. In
In another embodiment of the present disclosure, as illustrated in
A cavity 600 of the gasket 500 of
Adhesive 790 can be applied between first contact surface 740 and the angled spigot surface 825 to mount the gasket 700 in place on the spigot. Additionally, planar rear portion 730 of gasket 700 extends past second fin 770 such that planar end surface 735 has a greater length than planar trailing surface 775. This configuration allows the second fin 770 to remain within the footprint of the first contact surface 740 when compressed within the interface 780 of the pipe joint.
With reference now to the embodiment of
The following description of the gasket is with particular reference to
Notably, geometric changes along the perimeter of the pipe ends are addressed externally by the shape of the wedge shaped body 110 and internally by the dynamic fluid 210 within the asymmetrical cavity 200. More particularly, the first fin 160 and second fin 170 extend outwardly from the wedge shaped body 110 and utilize static compression and hydraulic pressure to create a leak resistant, and preferably leak proof seal against the surface 225 of the spigot end 220 simultaneously to the surface 235 of the bell end 230 when under compression. The configuration of the first fin 160 extends from the inclined second surface 150 to create a sealed effect with the surface 235 of the bell end 230 as a compression sealing function. The configuration of the second fin 170 provides a hydraulic pressure sealing function that extends from the wedge shaped body 110 to create a sealed effect with the surface 235 of the bell end 230. The first and second fins 160, 170 provide a dynamic seal along the interface 180 to prevent leakage of fluid from within the pipe system and to prevent leakage of fluid from the environment into the pipe system.
Additionally, the cavity 200 within the gasket 100 has a particular shape and location within the body 110 that is adapted to allow the fluid gel material 210 to continuously flow within the entire length of the cavity 200 throughout the gasket 100 to balance out the various tension and compression forces acting thereon. The cavity 200 is configured, with optional combinations of asymmetric shapes (such as grooves 415 and 613 or enlarged areas 806 and 807) along the interior surface 205, for distributing the fluid 210 in response to contact pressure that the gasket 100 exerts against the surfaces of the spigot end 220 and bell end 230. The ability of the fluid 210 to move within the cavity 200 in a predetermined orientation allows for the gasket 100 to effectively seal along the interface 180 in situations such as where geometric transitions occur along the perimeter, where deflection of the interface 180 occurs or where the irregular gapping between the surfaces 225, 235 is a problem. Typically, during coupling, when one side of the interface 180 is narrowed along the perimeter, the opposing side is widened. The dimensional tolerances may be slight along the pipe interface 180, however, even slight tolerances can compromise a seal and introduce a leak. The apparatus and method of the present disclosure allows for reducing mass of the self adjusting gasket 100 in tighter/narrower areas along the interface 180 and increasing the mass of the gasket 100 in open/wider areas along the perimeter in other areas.
More particularly, in many instances, the spigot surface 225 and the bell surface 235 include a slope or a taper relative to an exterior surface of the first and second pipes 240, 250. The slope of the pipe ends is designed to ease manufacturing concerns as well as allowing for simpler coupling to opposing pipe ends. In one embodiment, the shape of the cavity 200 is non-symmetric relative to the first contact surface 140 of the wedge shaped body 110. The shape of the cavity 200 can be sloped relative to the spigot surface 225 and bell surface 235 but will react to the slope or taper of the intersection to allow for lower compression forces and accomplish a homing or a self-adjusted fitting of the pipe ends during coupling. The shape of the cavity 200 is based upon directing the pressure to the area of the joint that is most in need.
During coupling, the tapered front portion 120 of the wedge shaped body 110 compresses first and the pressure exerted on the gasket 100 is directed to the planar rear portion 130. At this point, coupling pressure can be directed in multiple directions towards the planar rear portion 130 and can be manipulated by the asymmetrical shape of the cavity 200. The shape of the cavity 200 and location of the cavity 200 relative to the first fin 160 and second fin 170, depends at least on the annular space, slope, and tightness of the joint area. The shape of the cavity 200, having an elongated asymmetrical profile with a combination of grooves and enlarged areas, is designed to force the fluid 210 into the area of least resistance and provide a pressure balancing of the gasket 100 against the bell surface 235 and the spigot surface 225.
The gasket of the present disclosure simplifies pipe section installation where insertion force and point loading during coupling occurs at non-circular locations (such as oval, square, rectangular) along the perimeter of the pipe end. The asymmetrically shaped fluid filled cavity relative to the first and second fin orientations allow the gasket to yield and distribute the load throughout a broader pattern on the joint face.
The exemplary embodiments of the disclosure have been described herein. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. Combinations of the various features can be combined in each embodiment. It is intended that the instant disclosure be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
This application is a Continuation-In-Part of U.S. patent application Ser. No. 12/637,433 which was filed on Dec. 14, 2009 and is still pending. That application claims priority from U.S. Provisional Application Ser. No. 61/122.976 which was filed on Dec. 16, 2008. Both applications are incorporated by reference hereinto in their entireties.test
Number | Date | Country | |
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61122976 | Dec 2008 | US |
Number | Date | Country | |
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Parent | 12637433 | Dec 2009 | US |
Child | 13267016 | US |