Enhanced stability gasket and coupling

Abstract

To provide a gasket and a coupling for joining pipe elements.SOLUTION: A coupling for joining pipe elements has cast segments attached end to end surrounding a central space. The segments define a channel that receives a gasket. Side surfaces within the channel have angularly oriented capture surfaces which are engaged by bulbous rims on the gasket which prevent the gasket from being dislodged from the channel when at least one pipe element is inserted into the central space. Side surfaces may also have support surfaces between the capture surfaces. The gasket supports the segments in a preassembled state where the segments are in spaced relation sufficient to permit insertion of one or more pipe elements while the segments are attached end to end.SELECTED DRAWING: None

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application is based on and claims priority to U.S. Provisional Application No. 63 / 251,082, filed October 1, 2021, which application is incorporated herein by reference.

[0002] FIELD OF THE INVENTION The present invention relates to couplings and gaskets for joining pipe elements. [Background technology]

[0003] (background) Mechanical pipe couplings are used to form piping networks by joining pipe elements to one another or to other components such as valves, fittings, and the like. Couplings comprising sections attached end-to-end around a central space may be obtained from a factory in what is known as a "pre-assembled" condition, in which the sections are supported in a sufficiently spaced relationship to allow a plurality of pipe elements, or at least one pipe element, to be inserted into the coupling without disassembling the coupling's sections from one another. In such "factory pre-assembled" couplings, it is convenient to use a gasket positioned within the central space and received in a channel defined by the sections to support the sections in the required spaced relationship. The gasket also provides the sealing function required to ensure a fluid-tight joint between the coupling and the pipe elements.

[0004] One challenge faced by coupling designers is how to prevent the gasket from falling out of the channel during insertion of a pipe element into the coupling in a pre-assembled state. FIG. 1 shows an exemplary prior art gasket 11 falling out of the channel 13 defined by the coupling section 15 upon insertion of a pipe element 17 into the coupling when in a pre-assembled state. The side of the gasket facing the inserted pipe element 17 tends to slide down the inner surface of the channel 13. This is believed to be due to the large draft angle 19 that exists as a result of the casting process used to mass-produce the section 15. A fallen gasket can present a problem in forming a fluid-tight joint because it may be impossible to insert another pipe element 21 so that it will seal properly. Furthermore, there is a risk that the gasket may be damaged upon insertion of a second pipe element. There is clearly an opportunity to improve mechanical pipe coupling and gasket designs for better stability and ease of assembling the joint from a pre-assembled state.

[0005] Another design challenge relates to the impact that material handling can have on factory-preassembled couplings during shipment. Factory-preassembled couplings are installed in bulk, often one on top of the other, multiple times within a shipping container. Following delivery to the point of final assembly, the couplings are positioned on pipe ends where one or several fasteners are tightened, and the fitting assembly is complete. This process requires that the spaced relationship of the sections, as ensured at the factory, be maintained during shipment to allow for the insertion of pipe elements during final installation. However, there is a potential for some coupling sections to be inadvertently displaced (compressed) toward one another due to contact with other couplings within the shipping container. Thus, at the point of use, some couplings may no longer be in the required spaced relationship established at the factory to ensure that one or more pipe elements can be easily inserted into the factory-preassembled coupling. In such cases, the installer may need to manually pull the housings apart to return the coupling sections to their intended spaced relationship. Although this action by the installer may improve handling issues, it would be advantageous to avoid this step in the assembly process. Summary of the Invention [Means for solving the problem]

[0006] (summary) The present invention relates to a coupling for joining pipe elements. In an exemplary embodiment, the coupling includes a plurality of sections attached to one another end-to-end around a central space for receiving the pipe elements. In this example, each section includes a casting having a back wall and first and second side walls attached to the back wall on opposite sides thereof, the back wall and side walls defining a channel, the back wall defining a back surface facing the central space, and the side walls defining respective first and second lateral surfaces facing the channel. Each lateral surface includes a capture surface adjacent to the back surface. In one example, each capture surface has an orientation angle of 10° or less, measured from a reference line extending radially from a longitudinal axis aligned coaxially with the section through the central space. Each section may further include first and second adjustable mounting assemblies located at opposite ends of the section for adjustably mounting the sections to one another in an end-to-end relationship.

[0007] In an exemplary embodiment, each section includes a undulating surface contiguous with the capture surface. The undulating surface has an orientation angle, measured from a reference line extending radially from the longitudinal axis, greater than 5°. Furthermore, in one example, the orientation angle of the capture surface is in the range of 10° to 1°. In a specific exemplary embodiment, the orientation angle of the capture surface is 5°. Furthermore, in one example, the orientation angle of the undulating surface is in the range of 5° to 10°. In an exemplary embodiment, the capture surface comprises 50% to 100% of the depth of each of the first and second sidewalls. In a specific example, the capture surface comprises 50% of the depth of each of the first and second sidewalls. In a further example, the undulating surface comprises 75% to 0% of the depth of each of the first and second sidewalls. In another example, the undulating surface comprises 50% of the depth of each of the first and second sidewalls.

[0008] An exemplary embodiment may include up to a first and a second compartment, wherein a first adjustable mounting assembly on the first compartment is in facing relationship with a first adjustable mounting assembly on the second compartment, and a second adjustable mounting assembly on the first compartment is in facing relationship with a second adjustable mounting assembly on the second compartment.

[0009] In an exemplary embodiment, each mounting assembly may include a respective knob defining an opening and a respective adjustable fastener received within the opening, the fastener extending between the knobs to adjustably attach the compartments to one another.

[0010] As a further example, each compartment may include a first contact surface positioned adjacent the first mounting assembly and a second contact surface positioned adjacent the second mounting assembly, wherein the first contact surface on the first compartment is in facing relationship with the first contact surface on the second compartment and the second contact surface on the first compartment is in facing relationship with the second contact surface on the second compartment. In an example, the first and second contact surfaces are angularly oriented and have opposite inclinations such that contact between the first and second contact surfaces causes the compartments to rotate in opposite directions about an axis of rotation perpendicular to the longitudinal axis.

[0011] An exemplary embodiment according to the present invention may further include a gasket. The exemplary gasket includes a web forming a circular loop received in the channel. A first spherical rim extends circumferentially around a first side of the web. The first spherical rim projects toward the back wall and the first side wall. A second spherical rim extends circumferentially around a second side of the web opposite the first side. The second spherical rim projects toward the back wall and the second side wall. A first lobe is attached to the first side of the web. The first lobe extends circumferentially around the loop and projects toward the central space. The first lobe defines a first sealing surface at its free end. The first sealing surface is engageable with one of the pipe elements received in the central space. A second lobe is attached to the second side of the web. The second lobe extends circumferentially around the loop and projects toward the central space. The second lobe defines a second sealing surface at its free end, which is engageable with one of the pipe elements received within the central space. The first spherical rim engages a capture surface on the first lateral surface, and the second spherical rim engages a capture surface on the second lateral surface, thereby supporting the sections in a factory pre-assembled state such that the sections are supported in a sufficiently spaced relationship to permit insertion of the pipe element into the central space while the sections are attached to each other end-to-end around the central space.

[0012] The gasket may further include a leg positioned between the first lobe and the second lobe. The leg protrudes from the web toward the central space. In an exemplary embodiment, the leg further includes a plurality of discrete tabs positioned on an inner periphery of the leg and protruding toward the central space. The tabs are arranged in a spaced relationship from one another along the inner periphery. In one exemplary embodiment, the tabs have a curved profile. Furthermore, in one example, the web has an outer peripheral surface facing away from the central space, and the outer peripheral surface is concave.

[0013] Additionally, as an example, the gasket may further include first and second glands extending from the first and second lobes, respectively. In an exemplary embodiment, the first and second spherical rims extend continuously about the first and second sides of the web, respectively.

[0014] According to an embodiment, each capture surface comprises a first and a second portion, the first capture surface portion being positioned proximate the first adjustable mounting assembly and the second capture surface portion being positioned proximate the second adjustable mounting assembly. As one example, the first capture surface portion may subtend an angle in the range of 25° to 45° and the second capture surface portion may subtend an angle in the range of 25° to 45° measured about the longitudinal axis.

[0015] In an exemplary coupling according to the present invention, each of the first and second side surfaces may further include respective first and second support surfaces adjacent to the rear surface. The first support surface is positioned between the first and second capture surface portions on the first side surface, and the second support surface is positioned between the first and second capture surface portions on the second side surface. The first support surface has an orientation angle that is different from the orientation angles of the first and second capture surface portions on the first side surface. The second support surface has an orientation angle that is different from the orientation angles of the first and second capture surface portions on the second side surface.

[0016] In an exemplary embodiment, the first and second bearing surfaces each have an orientation angle measured from respective first and second reference lines extending radially from the longitudinal axis that is in the range of 15° to 30°. Further, as an example, the first bearing surface may subtend an angle measured about the longitudinal axis that is in the range of 90° to 110°, and the second bearing surface subtends an angle measured about the longitudinal axis that is in the range of 90° to 110°.

[0017] In an exemplary embodiment, each capture surface includes a first and a second portion. The first capture surface portion is positioned adjacent to the first adjustable mounting assembly, and the second capture surface portion is positioned adjacent to the second adjustable mounting assembly. Each of the first and second side surfaces may further include respective first and second support surfaces adjacent to the rear surface. The first support surface is positioned between the first and second capture surface portions on the first side surface, and the second support surface is positioned between the first and second capture surface portions on the second side surface. The first support surface has an orientation angle that is different from the orientation angles of the first and second capture surface portions on the first side surface, and the second support surface has an orientation angle that is different from the orientation angles of the first and second capture surface portions on the second side surface.

[0018] Another exemplary coupling embodiment further includes a gasket, the gasket comprising a web forming a circular loop received in the channel. A first spherical rim extends circumferentially around a first side of the web. The first spherical rim projects toward the back wall and the first side wall. A second spherical rim extends circumferentially around a second side of the web opposite the first side. The second spherical rim projects toward the back wall and the second side wall. In one example, a first lobe is attached to the first side of the web. The first lobe extends circumferentially around the loop and projects toward the central space. The first lobe defines a first sealing surface at its free end. The first sealing surface is engageable with one of the pipe elements received in the central space. A second lobe is attached to the second side of the web. The second lobe extends circumferentially around the loop and projects toward the central space. The second lobe defines a second sealing surface at its free end, which in this embodiment is engageable with one of the pipe elements received within the central space.

[0019] In an exemplary embodiment, when the coupling is in a factory pre-assembled state, the web and first and second spherical rims engage the rear surface of the section along the first and second capture surface portions, the first lobe and first spherical rim engage the first support surface, and the second lobe and second spherical rim engage the second support surface. In this example, the engagement between the gasket and the sections supports the sections in the factory-assembled state such that the sections are maintained in a sufficiently spaced relationship to permit insertion into the central space of the pipe element, while the sections are attached end-to-end to one another surrounding the central space.

[0020] In an exemplary embodiment, the first and second support surfaces each have an orientation angle measured from respective first and second reference lines extending radially from the longitudinal axis that is in the range of 15° to 30°. Further, by way of example, the first capture surface portion subtends an angle in the range of 25° to 45°, and the second capture surface portion subtends an angle measured about the longitudinal axis that is in the range of 25° to 45°. In another exemplary embodiment, the first support surface subtends an angle measured about the longitudinal axis that is in the range of 90° to 110°, and the second support surface subtends an angle measured about the longitudinal axis that is in the range of 90° to 110°.

[0021] The present invention also includes a gasket. In an exemplary embodiment, the gasket comprises a web that forms a circular loop surrounding a central space. A first spherical rim extends circumferentially around a first side of the web. The first spherical rim projects both radially and axially relative to an axis that is coaxial with the circular loop. A second spherical rim extends circumferentially around a second side of the web opposite the first side. The second spherical rim projects both radially and axially relative to the axis. A first lobe is attached to the first side of the web. The first lobe extends circumferentially around the loop and projects toward the central space. The first lobe defines a first sealing surface at its free end. A second lobe is attached to the second side of the web. The second lobe extends circumferentially around the loop and projects toward the central space. The second lobe defines a second sealing surface at its free end.

[0022] In a further exemplary embodiment, the gasket according to the present invention includes a leg positioned between the first lobe and the second lobe. The leg protrudes from the web toward the central space. Also, as an example, the leg may further include a plurality of discrete tabs positioned on an inner periphery of the leg and protruding toward the central space. The tabs are arranged in a spaced relationship from one another along the inner periphery. In an exemplary embodiment, the tabs have a curved profile. Also, as an example, the web has an outer peripheral surface facing away from the central space, and the outer peripheral surface is concave. In an exemplary embodiment, first and second glands may extend from the first and second lobes, respectively. In a further example, first and second spherical rims may extend continuously about the first and second sides of the web, respectively. The present invention provides, for example, the following items. (Item 1) 1. A coupling for joining pipe elements, said coupling comprising: a plurality of compartments attached to one another end-to-end and surrounding a central space for receiving the pipe element; each said compartment comprising a casting; The casting is The back wall and first and second side walls attached to the back wall on opposite sides thereof; have the rear wall and the side walls define a channel, the rear wall defining a rear surface facing the central space, and the side walls defining respective first and second lateral surfaces facing the channel; each said side surface comprising a capture surface adjacent said back surface, each said capture surface having an orientation angle of 10° or less measured from a reference line extending radially from a longitudinal axis aligned coaxially with said compartment through said central space; Each of the sections further includes first and second adjustable mounting assemblies located at opposite ends of the section for adjustably mounting the sections to one another in end-to-end relationship. (Item 2) Item 1. The coupling of item 1, wherein each of the segments comprises an undulating surface contiguous with the capture surface, the undulating surface having an orientation angle, measured from a reference line extending radially from the longitudinal axis, of greater than 5°. (Item 3) Item 2. The coupling according to item 1, wherein the orientation angle of the capture surface is in the range of 10° to 1°. (Item 4) Item 2. The coupling according to item 1, wherein the orientation angle of the capture surface is 5°. (Item 5) 3. The coupling according to item 2, wherein the orientation angle of the undulating surface is in the range of 5° to 10°. (Item 6) Item 2. The coupling of item 1, wherein the capture surface comprises 50% to 100% of the depth of each of the first and second side walls. (Item 7) Item 10. The coupling of item 1, wherein the capture surface comprises 50% of the depth of each of the first and second side walls. (Item 8) 3. The coupling of claim 2, wherein the contoured surface comprises 75% to 0% of the depth of each of the first and second side walls. (Item 9) 3. The coupling of claim 2, wherein the contoured surface comprises 50% of the depth of each of the first and second side walls. (Item 10) 2. The coupling of claim 1, comprising up to first and second compartments, wherein the first adjustable mounting assembly on the first compartment is in a facing relationship with the first adjustable mounting assembly on the second compartment, and the second adjustable mounting assembly on the first compartment is in a facing relationship with the second adjustable mounting assembly on the second compartment. (Item 11) Each said mounting assembly comprises: a separate tab defining an opening; a separate adjustable fastener received within said opening; Equipped with Item 11. The coupling of item 10, wherein the fastener extends between the tabs for adjustably attaching the sections to one another. (Item 12) Each section further includes: a first contact surface positioned adjacent the first mounting assembly; a second contact surface positioned adjacent the second mounting assembly; and Equipped with the first contact surface on the first section is in facing relationship with the first contact surface on the second section, and the second contact surface on the first section is in facing relationship with the second contact surface on the second section; Item 1. The coupling of item 1, wherein the first and second contact surfaces are angularly oriented and have opposite inclinations such that contact between the first and second contact surfaces causes the compartments to rotate in opposite directions about an axis of rotation perpendicular to the longitudinal axis. (Item 13) Further comprising a gasket, the gasket comprising: a web forming a circular loop received within the channel; a first spherical rim extending circumferentially around a first side of the web, the first spherical rim projecting toward the back wall and the first side wall; a second spherical rim extending circumferentially around a second side of the web opposite the first side, the second spherical rim projecting toward the back wall and the second side wall; and a first lobe attached to the first side of the web, the first lobe extending circumferentially around the loop and projecting toward the central space, the first lobe defining a first sealing surface at a free end thereof, the first sealing surface being engageable with one of the pipe elements received within the central space; and a second lobe attached to the second side of the web, the second lobe extending circumferentially around the loop and projecting toward the central space, the second lobe defining a second sealing surface at a free end thereof, the second sealing surface being engageable with one of the pipe elements received within the central space; Equipped with 2. The coupling of claim 1, wherein the first spherical rim engages the capture surface on the first lateral surface and the second spherical rim engages the capture surface on the second lateral surface, thereby supporting the sections in a pre-assembled state at a factory such that the sections are supported in a sufficiently mutually spaced relationship to allow insertion of the pipe element into the central space, while the sections are attached to each other end-to-end around the central space. (Item 14) Item 14. The coupling of item 13, further comprising a leg positioned between the first lobe and the second lobe, the leg protruding from the web toward the central space. (Item 15) Item 15. The coupling of item 14, wherein the legs further include a plurality of discrete tabs positioned on an inner periphery of the legs and projecting toward the central space, the tabs arranged in a spaced-apart relationship from one another along the inner periphery. (Item 16) Item 16. The coupling of item 15, wherein the tab has a curved profile. (Item 17) Item 14. The coupling of item 13, wherein the web has an outer peripheral surface facing away from the central space, the outer peripheral surface being concave. (Item 18) Item 14. The coupling of item 13, further comprising first and second glands extending from the first and second lobes, respectively. (Item 19) Item 14. The coupling of item 13, wherein the first and second spherical rims extend continuously about the first and second sides of the web, respectively. (Item 20) 2. The coupling of claim 1, wherein each of the capture surfaces comprises a first and a second portion, the first capture surface portion being positioned proximate to the first adjustable mounting assembly and the second capture surface portion being positioned proximate to the second adjustable mounting assembly. (Item 21) 21. The coupling of claim 20, wherein the first capture surface portion subtends an angle in the range of 25° to 45° and the second capture surface portion subtends an angle measured about the longitudinal axis in the range of 25° to 45°. (Item 22) 21. The coupling of claim 20, wherein each of the first and second side surfaces further comprises respective first and second support surfaces adjacent the rear surface, the first support surface being positioned between the first and second capture surface portions on the first side surface, the second support surface being positioned between the first and second capture surface portions on the second side surface, the first support surface having an orientation angle different from the orientation angles of the first and second capture surface portions on the first side surface, and the second support surface having an orientation angle different from the orientation angles of the first and second capture surface portions on the second side surface. (Item 23) Item 23. The coupling of item 22, wherein the first and second bearing surfaces each have an orientation angle measured from respective first and second reference lines extending radially from the longitudinal axis, the orientation angle being in the range of 15° to 30°. (Item 24) Item 24. The coupling of item 23, wherein the first bearing surface subtends an angle measured about the longitudinal axis in the range of 90° to 110°, and the second bearing surface subtends an angle measured about the longitudinal axis in the range of 90° to 110°. (Item 25) each said capture surface comprising a first and second portion, said first capture surface portion being positioned proximate to said first adjustable mounting assembly and said second capture surface portion being positioned proximate to said second adjustable mounting assembly; 2. The coupling of claim 1, wherein each of the first and second side surfaces further comprises respective first and second support surfaces adjacent the rear surface, the first support surface being positioned between the first and second capture surface portions on the first side surface, the second support surface being positioned between the first and second capture surface portions on the second side surface, the first support surface having an orientation angle different from the orientation angles of the first and second capture surface portions on the first side surface, and the second support surface having an orientation angle different from the orientation angles of the first and second capture surface portions on the second side surface. (Item 26) Further comprising a gasket, the gasket comprising: a web forming a circular loop received within the channel; a first spherical rim extending circumferentially around a first side of the web, the first spherical rim projecting toward the back wall and the first side wall; a second spherical rim extending circumferentially around a second side of the web opposite the first side, the second spherical rim projecting toward the back wall and the second side wall; and a first lobe attached to the first side of the web, the first lobe extending circumferentially around the loop and projecting toward the central space, the first lobe defining a first sealing surface at a free end thereof, the first sealing surface being engageable with one of the pipe elements received within the central space; and a second lobe attached to the second side of the web, the second lobe extending circumferentially around the loop and projecting toward the central space, the second lobe defining a second sealing surface at a free end thereof, the second sealing surface being engageable with one of the pipe elements received within the central space; Item 26. The coupling according to item 25, comprising: (Item 27) When the coupling is in a pre-assembled state at the factory, the web and the first and second spherical rims engage the rear surface of the compartment along the first and second capture surface portions; the first lobe and the first spherical rim engage the first support surface, and the second lobe and the second spherical rim engage the second support surface; 27. The coupling of claim 26, wherein the engagement between the gasket and the sections supports the sections in the factory-assembled state so that the sections are maintained in a sufficiently mutually spaced relationship to allow insertion of the pipe element into the central space, while the sections are attached to each other end-to-end, surrounding the central space. (Item 28) Item 26. The coupling of item 25, wherein the first and second bearing surfaces each have an orientation angle measured from respective first and second reference lines extending radially from the longitudinal axis, the orientation angle being in the range of 15° to 30°. (Item 29) Item 26. The coupling of item 25, wherein the first capture surface portion subtends an angle in the range of 25° to 45° and the second capture surface portion subtends an angle measured about the longitudinal axis in the range of 25° to 45°. (Item 30) 26. The coupling of claim 25, wherein the first bearing surface subtends an angle measured about the longitudinal axis in the range of 90° to 110°, and the second bearing surface subtends an angle measured about the longitudinal axis in the range of 90° to 110°. (Item 31) A gasket, the gasket comprising: a web surrounding the central space to form a circular loop; a first spherical rim extending circumferentially around the first side of the web, the first spherical rim projecting both radially and axially relative to an axis aligned coaxially with the circular loop; a second spherical rim extending circumferentially around a second side of the web opposite the first side, the second spherical rim projecting both radially and axially relative to the axis; and a first lobe attached to the first side of the web, the first lobe extending circumferentially around the loop and projecting toward the central space, the first lobe defining a first sealing surface at a free end thereof; a second lobe attached to the second side of the web, the second lobe extending circumferentially around the loop and projecting toward the central space, the second lobe defining a second sealing surface at a free end thereof; A gasket comprising: (Item 32) Item 32. The gasket of item 31, further comprising a leg positioned between the first lobe and the second lobe, the leg protruding from the web toward the central space. (Item 33) Item 33. The gasket of item 32, wherein the legs further include a plurality of discrete tabs positioned on an inner periphery of the legs and projecting toward the central space, the tabs arranged in a spaced-apart relationship from one another along the inner periphery. (Item 34) Item 34. The coupling of item 33, wherein the tab has a curved profile. (Item 35) Item 32. The gasket of item 31, wherein the web has an outer peripheral surface facing away from the central space, the outer peripheral surface being concave. (Item 36) Item 32. The gasket of item 31, further comprising first and second glands extending from the first and second lobes, respectively. (Item 37) Item 32. The gasket of item 31, wherein the first and second spherical rims extend continuously about the first and second sides of the web, respectively. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a partial cross-sectional view of a prior art pipe coupling and gasket.

[0024] [Figure 2] FIG. 2 is an axial view of an exemplary pipe coupling according to the present invention shown in a pre-assembled state.

[0025] [Figure 3] FIG. 3 is an isometric view of an exemplary pipe coupling section in accordance with the present invention.

[0026] [Figure 4] FIG. 4 is a cross-sectional view of the exemplary compartment shown in FIG.

[0027] [Figure 4A] FIG. 4A is a partial cross-sectional view on an enlarged scale taken from FIG.

[0028] [Figure 5] FIG. 5 is an axial view of an exemplary gasket according to the present invention.

[0029] [Figure 5A] FIG. 5A is an isometric view of another example gasket in accordance with the present invention.

[0030] [Figure 6] FIG. 6 is a cross-sectional view of the exemplary gasket shown in FIG. 5 or 5A.

[0031] [Figure 7] 7-9 are cross-sectional views showing exemplary couplings and gaskets in use according to the present invention. [Figure 8] 7-9 are cross-sectional views showing exemplary couplings and gaskets in use according to the present invention. [Figure 9] 7-9 are cross-sectional views showing exemplary couplings and gaskets in use according to the present invention.

[0032] [Figure 10] FIG. 10 is an axial view showing another exemplary embodiment of a coupling according to the present invention.

[0033] [Figure 11]FIG. 11 shows a cross-sectional view of an exemplary coupling section taken at a point proximate to the adjustable mounting assembly.

[0034] [Figure 12] FIG. 12 shows a cross-sectional view of an exemplary coupling section taken at a point approximately midway between the ends of the section.

[0035] [Figure 13] FIG. 13 shows a cross-sectional view of an exemplary coupling section and gasket taken at a point proximate to the adjustable mounting assembly.

[0036] [Figure 14] FIG. 14 shows a cross-sectional view of an exemplary coupling section and gasket taken at a point approximately midway between the ends of the section. DETAILED DESCRIPTION OF THE INVENTION

[0037] (Detailed explanation) FIG. 2 illustrates an exemplary coupling 10 for joining pipe elements. The coupling 10 includes multiple sections, in this example, first and second sections 12 and 14, attached end-to-end to one another and surrounding a central space 16 for receiving the pipe elements. As shown in FIG. 3, each section (12 is shown) includes a rear wall 18 and first and second side walls 20, 22 attached to the rear wall on opposite sides thereof. The rear wall 18 and side walls 20, 22 define a channel 24, and the rear wall defines a rear surface 26 facing the central space 16. As shown in FIG. 4, the side walls 20 and 22 define respective first and second side surfaces 28, 30 facing the channel 24. Each side surface 28, 30 includes a capture surface 32 adjacent the rear surface 26. 4A , each capture surface 32 has an orientation angle 34 of 10° or less, measured from a reference line 36 extending radially from a longitudinal axis 38 that is coaxially aligned with the sections 12, 14 through the central space 16. In practical exemplary embodiments, the orientation angle 34 of the capture surfaces 32 may range from about 10° to about 1°. An orientation angle 34 of about 5° is expected to be beneficial. Because the sections 12 and 14 are advantageously cast for economical mass production, a relatively small orientation angle 34 of the capture surfaces 32 has been shown to improve gasket stability while providing adequate molding draft during insertion of the pipe elements, as described below.

[0038] As shown in Figure 4, each side surface 28, 30 may also include an undulating surface 40 contiguous with the capture surface 32. As shown in Figure 4A, the undulating surface 40, if present, advantageously has an orientation angle 42 greater than 5°, measured from a reference line 36 extending radially from the longitudinal axis 38. The orientation angle 42 of the undulating surface 40 advantageously ranges from about 15° to about 30° and, coordinated with the orientation angle 34 of the capture surface 32, provides a "lead-in" for ease of coupling assembly, as described below.

[0039] As suggested by FIG. 4 , the capture surface and undulating surfaces 32 and 40 can occupy a range of portions of the side surfaces 28 and 30, measured as a proportion of the depth 33 of the first and second side walls 20 and 22. In an exemplary embodiment, the capture surface 32 can include approximately 50% of the side surface depth 33 (as shown) to 100% of the depth 33 (without the undulating surface). A capture surface that includes 50% of the side wall depth 33 is expected to be advantageous. The undulating surface 40 interferes with the capture surface 32 with respect to the proportionate depth of the side surfaces 28 and 30; thus, the undulating surface can include 0% to approximately 75% of the side wall depth 33. In cooperation with the capture surface 32, a undulating surface 40 that includes 50% of the side wall depth 33 is expected to be advantageous.

[0040] As shown in Figures 3 and 4, sections 12 and 14 (12 is shown) may also include first and second arcuate wedges 46 and 48 arranged on opposite sides of the sections. The wedges 46 and 48 engage circumferential grooves in the pipe elements to provide a positive mechanical engagement when forming a joint. As shown in Figures 2 and 3, each section 12, 14 further includes first and second adjustable mounting assemblies 50 and 52 located at opposite ends of the section for adjustably mounting the sections to one another in an end-to-end relationship about the central space 16. As shown in Figure 2, the first adjustable mounting assembly 50 on the first section 12 is in a facing relationship with the first adjustable mounting assembly 50 on the second section 14, and the second adjustable mounting assembly 52 on the first section 12 is in a facing relationship with the second adjustable mounting assembly 52 on the second section 14. In the exemplary embodiment, each mounting assembly 50, 52 includes a respective knob 54 that defines an opening 56. As shown in FIG. 2, the openings 56 receive respective adjustable fasteners 58, which in this example include a nut 60 and a bolt 62. The fasteners 58 extend between the knobs 54 to adjustably attach the sections 12, 14 to one another.

[0041] 3, it is advantageous if each section (12 is shown) further comprises a first contact surface 64 positioned adjacent the first mounting assembly 50 and a second contact surface 66 positioned adjacent the second mounting assembly 52. ​​As shown in FIG. 2, the first contact surface 64 on the first section 12 is in facing relationship with the first contact surface 64 on the second section 14, and the second contact surface 66 on the first section 12 is in facing relationship with the second contact surface 66 on the second section 14. The first and second contact surfaces 64 and 66 are angularly oriented and have opposite slopes, such that when the sections are extended toward each other, the resulting contact between the first contact surface 64 and the second contact surface 66 causes the sections 12 and 14 to rotate in opposite directions relative to each other about a rotation axis 68 perpendicular to the longitudinal axis 38 (see FIG. 3). Contact surfaces 64 and 66 are used when it is desired to provide a more raised joint, as described in US Pat. No. 4,611,839 (hereby incorporated by reference).

[0042] As shown in Figures 2 and 5, a coupling according to the present invention may further include a gasket 70. In the exemplary embodiment shown in Figure 5, the gasket 70 includes a web 72 that forms a circular loop 74 that is received within the channel 24 (see Figures 3 and 4). As shown in Figure 6, the gasket 70 includes a first spherical rim 76 that extends circumferentially around a first side of the web 72 and a second spherical rim 78 that extends circumferentially around a second side of the web opposite the first side. The spherical rims 76 and 78 advantageously extend contiguously about the first and second sides of the web 72. Furthermore, as shown in Figure 6, each spherical rim 76 and 78 projects radially, as defined by arrow 77, and in opposite axial directions, as defined by arrow 79. Directions 77 and 79 are defined relative to a longitudinal axis 38 that is aligned coaxially with compartments 12, 14 through central space 16, as shown in Figures 3, 4, and 6. As shown in Figure 5, axis 38 is also coaxial with circular loop 74 when gasket 70 is positioned within channel 24 (see also Figures 2 and 3). As can be determined from Figure 4, the protrusion of spherical rims 76 and 78 in radial direction 77 can also be described as protruding toward rear wall 18 when gasket 70 is within channel 24. Similarly, the protrusion of spherical rims 76 and 78 in axial direction 79 can also be described as protruding toward first and second side walls 20 and 22 when gasket 70 is within channel 24.

[0043] As shown in FIG. 6, a first lobe 80 is attached to a first side of the web 72. The first lobe 80 extends circumferentially around the loop 74 (see also FIG. 5) and projects toward the central space 16. The first lobe 80 defines a first sealing surface 82 at a free end 84 thereof. The first sealing surface 82 is engageable with one of the pipe elements received within the central space 16, as described below.

[0044] A second lobe 86 is attached to a second side of the web 72. The second lobe 86 extends circumferentially around the loop 74 shown in FIG. 5 and projects toward the central space 16. As shown again with reference to FIG. 6, the second lobe 86 defines a second sealing surface 88 at its free end 90. Like the first sealing surface 82, the second sealing surface 88 is also engageable with one of the pipe elements received within the central space 16. The seal of the gasket 70 may be enhanced through the use of first and second glands 92 and 94 extending from the first and second lobes 80 and 86, respectively. The glands 92 and 94 allow internal pressure within the central space 16 to act on the pipe elements and pressurize the sealing surfaces 82 and 88 against them, resulting in a higher-pressure seal.

[0045] As shown in FIGS. 5 and 6 , the gasket 70 may further include a leg 96 positioned between the first lobe 80 and the second lobe 86. The leg 96 protrudes from the web 72 toward the central space 16 and acts as a stop surface to ensure that a pipe element inserted into the central space is inserted to a desired depth. As shown in FIG. 5A , the leg 96 may further include a plurality of discrete tabs 97 positioned on the inner periphery 99 of the leg. The tabs 97 protrude toward the central space 16 and are arranged in a spaced-apart relationship with one another along the inner periphery 99. The tabs 97 provide positive and reliable alignment within the coupling 10 for pipe elements having beveled ends. It is considered advantageous for the tab 97 to have a curved profile. The curved profile of the tab 97 minimizes the area of ​​engagement between the leg 96 and the pipe element while still providing sufficient engagement for proper pipe element alignment within the coupling 10. The less engagement between the legs 96 and the pipe elements results in less pressure head loss within the pipe elements at the joint created by the coupling 10 because the entire inner periphery 99 does not extend into the fluid flow path and create turbulence and resistance to flow. Any intrusion is limited to the portion of the tab 97. As shown in FIG. 6 , the web 72 may also have an outer periphery surface 98 facing away from the central space 16. In this exemplary embodiment, the outer periphery surface 98 is concave.

[0046] Figures 7, 8, and 9 show a portion of coupling 10 in a "pre-assembled state." In this configuration, sections 12 and 14 (14 is shown) are joined together end-to-end using mounting assemblies 50 and 52 on each section (see Figure 2), but are held in a sufficiently spaced-apart relationship to allow pipe elements 100, 102 to be inserted into central space 16 (see Figures 8 and 9). In this exemplary embodiment, gasket 70 is used to support sections 12 and 14 in the pre-assembled state (see also Figure 2). As shown in FIG. 7, the first spherical rim 76 engages the first capture surface 32 of the first side surface 28 and the second spherical rim 78 engages the capture surface 32 of the second side surface 30, thereby supporting the sections (14 shown) in a pre-assembled state such that the sections are supported in a sufficiently spaced relationship to allow insertion into the central space 16 of the pipe element while the sections are attached end-to-end to one another surrounding the central space (see FIG. 2).

[0047] As shown in FIG. 8 , unlike the prior art configuration depicted in FIG. 1 , dislodgement of the gasket 70 upon insertion of the first pipe element 100 is substantially prevented in the coupling 10 according to the present invention because the first and second spherical rims 76 and 78 engage the respective capture surfaces 32 on the compartment's first and second side walls 20 and 22. It has been found that the contact between the spherical rims 76 and 78 and the capture surfaces 32, along with their angular orientation 34, acts as an anti-rotation feature, thereby inhibiting dislodgement of the gasket upon pipe insertion. The combination of the gasket 70 and the coupling 10 achieves significantly greater stability upon pipe element insertion, allowing both pipe elements to be easily inserted into the coupling 10 when in a pre-assembled state. The respective contoured surfaces 40, when present on the side surfaces 20 and 22, along with their greater orientation angle, act to guide the gasket 70 into the desired engagement, achieving the pre-assembled state. 9 shows both pipe elements 100 and 102 inserted into the central space 16, with sections 12 and 14 (14 shown) stretched with their wedges 46 and 48 engaging circumferential grooves 104 and 106 to provide mechanical engagement. The gasket 70 is compressed between sections 12, 14 (14 shown) and the pipe elements 100, 102, with the sealing surfaces 86, 88 engaging the pipe elements to result in a fluid-tight seal. The deformation of the gasket 70 is accommodated by a cavity 108 extending along the back wall 18, and the concave shape of the web 72 is deformed to a convex shape, thereby allowing the legs 96 to retract from between the pipe elements 100, 102 and not enter the fluid flow path.

[0048] FIG. 10 illustrates another exemplary embodiment of a coupling 110 according to the present invention, comprising segments 132 and 134. As shown in FIGS. 10 and 11, the capture surface 32 of the coupling 110 comprises first and second portions 112, 114. The first capture surface portion 112 is positioned proximate the first adjustable mounting assembly 50, and the second capture surface portion 114 is positioned proximate the second adjustable mounting assembly 52 (only the capture surface portion 112 is illustrated in FIG. 11). In this exemplary embodiment, the first capture surface portion 112 extends from an end of the coupling segment 132 and defines an angle 116 along the segment's arc length that is in the range of about 25° to about 45°. Similarly, the second capture surface portion 114 extends from the opposite end of the segment 132 and defines an angle 118 along the segment's arc length that is in the range of about 25° to about 45°. The defined angles 116 , 118 are measured about the longitudinal axis 38 .

[0049] As shown in Figures 10 and 12, the first and second side surfaces 28 and 30 further include respective first and second support surfaces 120 and 122. The support surfaces 120 and 122 are positioned adjacent the compartment rear surface 26. As shown in Figure 10, the first support surface 120 is positioned between the first and second capture surface portions 112 and 114 on the first side surface 28. Similarly, the second support surface 122 is positioned (not visible) between the first and second capture surface portions on the second side surface 30. In the exemplary embodiment, the first support surface 120 subtends an angle 128 measured about the longitudinal axis 38, the angle being in the range of about 90° to about 110°. Similarly, second bearing surface 122 may also subtend an angle, measured about longitudinal axis 38, ranging from about 90° to about 110°. As shown in a comparison of Figures 11 and 12, first bearing surfaces 120, 122 have respective orientation angles 124 and 126 that are different from the orientation angles of first and second capture surface portions 112, 114 (see Figure 4A for comparison). In the exemplary embodiment, first and second bearing surfaces 120, 122 each have respective orientation angles 124, 126 that are measured from respective first and second reference lines extending radially from longitudinal axis 38 and ranging from about 15° to about 30°. Although not explicitly described above, section 134 may also be identical to section 132.

[0050] 13 and 14 are cross-sectional views of section 132 illustrating the engagement of the capture surface portion (112 shown) of gasket 70 with support surfaces 120 and 122 when the coupling is in a factory pre-assembled state, such that sections 132, 134 are maintained in a sufficiently spaced-apart relationship to permit insertion into central space 16 of one or more pipe elements while the sections are attached end-to-end to one another, surrounding central space 16, as shown in FIG. 10. As shown in FIG. 13, web 72 and first and second spherical rims 76, 78 of gasket 70 engage rear surfaces 26 of rear walls 18 of sections 132, 134 (132 shown) along first and second capture surface portions 112 and 114 (112 shown). The cross section of Figure 13 is taken near the mounting assembly 50 within the arc length of angle 116 subtended by capture surface portion 112. Gasket 70 is substantially seated within sections 132, 134 across these regions of coupling 110, preventing dislodgement of the gasket upon insertion of the pipe element, as discussed above. Figure 14 is a cross section taken between the ends of sections 132 or 134 within the arc length of angle 128 subtended by bearing surfaces 120, 122. In this region, first lobe 80 and first spherical rim 76 of gasket 70 engage first bearing surface 120, and second lobe 86 and second spherical rim 78 engage second bearing surface 122. This engagement with bearing surfaces 120 and 122 of gasket 70 is expected to maintain sections 132 and 134 of coupling 110 in a spaced apart relationship during shipping and handling, even when the coupling is compressed by the weight of other couplings, even within a shipping container.

[0051] All embodiments of the claimed invention described herein are expressly provided by way of example only. Numerous variations and modifications may be made to the exemplary embodiments described herein without departing from the concepts of the disclosure. Additionally, the scope of the disclosure is intended to encompass all modifications and combinations of all elements, features, and aspects described in the specification and claims and shown in the drawings. All such modifications and combinations are intended to be within the scope of the disclosure.

Claims

1. A gasket, comprising: a web surrounding a central space to form a circular loop; a first spherical rim extending circumferentially around the first side of the web, the first spherical rim projecting both radially and axially relative to an axis coaxially aligned with the circular loop; a second spherical rim extending circumferentially around a second side of the web opposite the first side, the second spherical rim projecting both radially and axially relative to the axis; and a first lobe attached to the first side of the web, the first lobe extending circumferentially around the loop and projecting toward the central space, the first lobe defining a first sealing surface at a free end thereof; a second lobe attached to the second side of the web, the second lobe extending circumferentially around the loop and projecting toward the central space, the second lobe defining a second sealing surface at a free end thereof; A gasket comprising:

2. A gasket as described in claim 1, further comprising a leg positioned between the first lobe and the second lobe, the leg protruding from the web toward the central space.

3. A gasket as described in claim 2, wherein the leg further comprises a plurality of discrete tabs positioned on the inner circumference of the leg and protruding toward the central space, the tabs being arranged in a spaced-apart relationship from one another along the inner circumference.

4. A coupling as described in claim 3, wherein the tab has a curved outer shape.

5. A gasket as described in claim 1, wherein the web has an outer peripheral surface facing away from the central space, and the outer peripheral surface is concave.

6. A gasket as described in claim 1, further comprising first and second glands extending from the first and second lobes, respectively.

7. A gasket as described in claim 1, wherein the first and second spherical rims extend continuously about the first and second sides of the web, respectively.

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