Coupling having rotation limited segments

Abstract

To provide a favorable coupling having rotation limited segments.SOLUTION: A pipe coupling has two segments with angularly oriented action surfaces in a facing relationship. The action surfaces induce relative rotation between the segments when the segments are drawn together to engage pipe elements being joined. Attachment elements on each segment, in the form of lugs, provide adjustable fasteners which draw the segments together when tightened. Angularly oriented support surfaces on the lugs engage one another and counteract the fastener force. Stop surfaces are positioned on the lugs adjacent to the support surfaces. Engagement between the stop surfaces limits the relative rotation between the segments.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This application is based on and claims the benefit of priority to U.S. Provisional Application No. 63 / 110,433, filed November 6, 2020, which is hereby incorporated by reference in its entirety.

[0002] FIELD OF THEINVENTION The present invention relates to a mechanical coupling for joining pipe elements. [Background technology]

[0003] (background) It is advantageous to use angularly oriented contact surfaces between sections of a mechanical coupling for grooved pipe, rotating the sections relative to one another so that a "key" of the coupling locks into a circumferential groove in the pipe elements to form a stronger joint in bending and twisting between them. U.S. Patent No. 4,639,020 to Rung et al., incorporated herein by reference, discloses an example of such a coupling.

[0004] While such prior art couplings are very effective in producing stronger joints, they can present challenges during installation, for example, in ease of assembly and lack of a consistent and uniform visual indication that the coupling is properly installed in all intended conditions. An opportunity clearly exists to improve such mechanical couplings, thus facilitating assembly and providing a consistent and unambiguous visual indication that confirms proper installation. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Pat. No. 4,639,020 Summary of the Invention [Means for solving the problem]

[0006] (overview) The present invention relates to a coupling for joining pipe elements in an end-to-end relationship. In an exemplary embodiment, the coupling comprises a first section and a second section attached to each other at opposite ends, surrounding a central space for receiving the pipe elements. Each section comprises a first lug extending from its first end and a second lug extending from its second end. The first and second lugs of the first section align with the first and second lugs of the second section, respectively. A first adjustable fastener extends between the first lugs and a second adjustable fastener extends between the second lugs. Each section further comprises a first working surface positioned between the central space and the first lug and a first support surface positioned on the first lug. A first fastener is positioned between the first working surface and the first support surface. The first working surface and the first support surface are oriented at a first angle transverse to a longitudinal axis of the first fastener. The second working surface is positioned between the central space and the second lug, and the second support surface is positioned on the second lug. The second fastener is positioned between the second working surface and the second support surface. The second working surface and the second support surface are oriented at a second angle transverse to a longitudinal axis of the second fastener. The second angle has an opposite inclination to the first angle. At least one first stop surface is positioned on the first lug adjacent to the first support surface. The first stop surface is oriented at a third angle having an opposite inclination to the first angle. At least one second stop surface is positioned on the second lug adjacent to the second support surface. The second stop surface is oriented at a fourth angle having an opposite inclination to the second angle. Upon adjustment of the first and second fasteners to draw the first and second segments toward one another, engagement between the first acting surfaces at the first ends of the segments and engagement between the second acting surfaces at the second ends of the segments causes the first and second segments to rotate in opposite directions relative to one another, and engagement between at least one of the first stop surfaces on the first lug and the second stop surface on the second lug limits the rotation.

[0007] In an exemplary embodiment, the first lug defines a first opening surrounding a first axis positioned between a first working surface and a first support surface oriented perpendicular to the longitudinal axis of the first fastener. The first opening may extend through the first lug. Further, by way of example, the second lug defines a second opening surrounding a second axis positioned between a second working surface and a second support surface oriented perpendicular to the longitudinal axis of the second fastener. The second opening may extend through the second lug.

[0008] In an exemplary embodiment, each of the first and second adjustable fasteners comprises a nut and a bolt. Further, by way of example, each of the segments comprises a first and a second arcuate lobe positioned on opposite sides of the segments. Each of the arcuate lobes faces the central space. Each of the arcuate lobes is engageable within a circumferential groove in the pipe element when the segments are drawn toward each other by the adjustable fasteners. The exemplary embodiment may further comprise a seal positioned within the central space. The seal supports the segments in a sufficiently spaced relationship to allow insertion of the pipe element into the central space without disassembling the coupling. In a practical example, the first angle has a slant of 45°, and may also have a slant in the range of 30° to 60°. By way of example, the second angle has a slant equal to but opposite to the first angle.

[0009] The present invention further encompasses a coupling for joining pipe elements in an end-to-end relationship. An exemplary coupling embodiment includes a first section and a second section attached to each other at opposite ends, surrounding a central space for receiving the pipe elements. Each section includes a first lug extending from its first end and a second lug extending from its second end. The first and second lugs of the first section align with the first and second lugs of the second section, respectively. A first adjustable fastener extends between the first lugs, and a second adjustable fastener extends between the second lugs. Each section further includes a first working surface positioned between the central space and the first lug, and a first support surface positioned on the first lug. The first fastener is positioned between the first working surface and the first support surface. The first working surface is oriented perpendicular to the longitudinal axis of the first fastener, and the first support surface is oriented at a first angle transverse to the longitudinal axis of the first fastener. The second working surface is positioned between the central space and the second lug, and the second support surface is positioned on the second lug. The second fastener is positioned between the second working surface and the second support surface. The second working surface is oriented perpendicular to the longitudinal axis of the second fastener, and the second support surface is oriented at a second angle transverse to the longitudinal axis of the second fastener. The second angle has an opposite inclination to the first angle. At least one first stop surface is positioned on the first lug adjacent to the first support surface. The first stop surface is oriented at a third angle having an opposite inclination to the first angle. At least one second stop surface is positioned on the second lug adjacent the second support surface. The second stop surface is oriented at a fourth angle having an opposite inclination to the second angle. Upon adjustment of the first and second fasteners to draw the first and second sections toward one another, engagement between at least one of the first stop surfaces on the first lug and the second stop surface on the second lug prevents rotation of the sections relative to one another.

[0010] In an exemplary embodiment, the first lug defines a first opening surrounding a first axis positioned between a first working surface and a first support surface, oriented perpendicular to the longitudinal axis of the first fastener. The first opening may extend through the first lug. Further, by way of example, the second lug defines a second opening surrounding a second axis positioned between a second working surface and a second support surface, oriented perpendicular to the longitudinal axis of the second fastener. The second opening may extend through the second lug. In a specific exemplary embodiment, each of the first adjustable fastener and the second adjustable fastener comprises a nut and a bolt.

[0011] In an exemplary embodiment, each of the sections includes a first arcuate lobe and a second arcuate lobe positioned on opposite sides of the section, each of the arcuate lobes facing the central space, each of the arcuate lobes engageable within a circumferential groove in the pipe element when the sections are drawn toward one another by the adjustable fastener.

[0012] Exemplary embodiments may further include a seal positioned within the central space. The seal supports the sections in a sufficiently spaced relationship to permit insertion of the pipe elements into the central space without disassembling the coupling. In practical examples, the first angle has a slope of 45° and may have a slope in the range of 30° to 60°. In specific exemplary embodiments, the second angle has a slope equal to but opposite to the first angle.

[0013] The present invention also encompasses a coupling for joining pipe elements in an end-to-end relationship. In an exemplary embodiment, the coupling comprises a first section and a second section attached to each other at opposite ends, surrounding a central space for receiving the pipe elements. Each section comprises a first lug extending from its first end. The first lug of the first section aligns with the first lug of the second section. A first adjustable fastener extends between the first lugs. Each section further comprises a second end. The second ends of the sections are respectively arranged opposite the first ends. Each second end is connected to a hinge that joins the first and second sections to each other. The hinge defines a hinge axis oriented perpendicular to a longitudinal axis of the first fastener. The first and second sections are pivotable about the hinge axis. As an example, each section further comprises a first working surface positioned between the central space and the first lug, and a first support surface positioned on the first lug. The first fastener is positioned between the first working surface and the first support surface. The first working surface is oriented perpendicular to the longitudinal axis of the first fastener, and the first support surface is oriented at a first angle transverse to the longitudinal axis of the first fastener. A first stop surface is positioned on the first lug adjacent to the first support surface. The first stop surface is oriented at a third angle having an opposite inclination to the first angle. When the first fastener is adjusted to pivot the first and second sections, thereby drawing them toward each other, the engagement between the first stop surfaces on the first lug prevents rotation of the sections relative to each other.

[0014] In an exemplary embodiment, the first lug defines a first opening surrounding a first axis positioned between the first working surface and the first support surface, the first axis being oriented perpendicular to a longitudinal axis of the first fastener. The first opening may extend through the first lug. In a practical example, the first adjustable fastener comprises a nut and a bolt.

[0015] By way of example, each of the segments includes a first arcuate lobe and a second arcuate lobe positioned on opposite sides of the segment. Each of the arcuate lobes faces the central space. Each of the arcuate lobes is engageable within a circumferential groove in the pipe element when the segments are drawn toward one another by the adjustable fastener. The coupling according to the present invention may further include a seal positioned within the central space. The seal supports the segments in a sufficiently spaced relationship to permit insertion of the pipe element into the central space without disassembling the coupling.

[0016] In a practical embodiment, the first angle has a tilt of 45° and may have a tilt in the range of 30° to 60°. The present specification also provides, for example, the following items: (Item 1) 1. A coupling for joining pipe elements in an end-to-end relationship, said coupling comprising: a first section and a second section attached to each other at opposite ends surrounding a central space for receiving the pipe element, each of the sections having a first lug extending from a first end thereof and a second lug extending from a second end thereof, the first lug and the second lug of the first section respectively aligning with the first lug and the second lug of the second section; a first adjustable fastener extending between the first lugs and a second adjustable fastener extending between the second lugs; each of the sections comprises: a first working surface positioned between the central space and the first lug, and a first support surface positioned on the first lug, the first fastener being positioned between the first working surface and the first support surface, the first working surface and the first support surface being oriented at a first angle transverse to a longitudinal axis of the first fastener; a second working surface positioned between the central space and the second lug, and a second support surface positioned on the second lug, the second fastener being positioned between the second working surface and the second support surface, the second working surface and the second support surface being oriented at a second angle transverse to a longitudinal axis of the second fastener, the second angle having an opposite slope to the first angle; at least one first stop surface positioned on the first lug adjacent the first support surface, the first stop surface being oriented at a third angle having an opposite slope to the first angle; at least one second stop surface positioned on the second lug adjacent the second support surface, the second stop surface being oriented at a fourth angle having an opposite inclination to the second angle; wherein upon adjustment of the first fastener and the second fastener to draw the first and second segments toward one another, engagement between the first acting surfaces at the first ends of the segments and the second acting surfaces at the second ends of the segments rotate the first and second segments in opposite directions relative to one another and engagement between at least one of the first stop surfaces on the first lug and the second stop surface on the second lug limits the rotation. (Item 2) 2. The coupling of claim 1, wherein the first lug defines a first opening surrounding a first axis positioned between the first working surface and the first support surface that is oriented perpendicular to the longitudinal axis of the first fastener. (Item 3) 3. The coupling of claim 2, wherein the first opening extends through the first lug. (Item 4) 3. The coupling of claim 2, wherein the second lug defines a second opening surrounding a second axis positioned between the second working surface and the second support surface that is oriented perpendicular to the longitudinal axis of the second fastener. (Item 5) 5. The coupling of claim 4, wherein the second opening extends through the second lug. (Item 6) 2. The coupling of claim 1, wherein the first adjustable fastener and the second adjustable fastener each comprise a nut and a bolt. (Item 7) 2. The coupling of claim 1, wherein each of the segments includes a first arcuate protrusion and a second arcuate protrusion positioned on opposite sides of the segments, each of the arcuate protrusions facing the central space, and each of the arcuate protrusions engageable within a circumferential groove in the pipe element when the segments are drawn toward each other by the adjustable fastener. (Item 8) 2. The coupling of claim 1, further comprising a seal positioned within the central space, the seal supporting the sections in a sufficiently spaced relationship to permit insertion of the pipe element into the central space without disassembly of the coupling. (Item 9) 2. The coupling of claim 1, wherein the first angle has a tilt of 45°. (Item 10) 2. The coupling according to item 1, wherein the first angle has a tilt in the range of 30° to 60°. (Item 11) 2. The coupling of claim 1, wherein the second angle is equal to the first angle but has an opposite slope to the first angle. (Item 12) 1. A coupling for joining pipe elements in an end-to-end relationship, said coupling comprising: a first section and a second section attached to each other at opposite ends surrounding a central space for receiving the pipe element, each of the sections having a first lug extending from a first end thereof and a second lug extending from a second end thereof, the first lug and the second lug of the first section being aligned with the first lug and the second lug of the second section, respectively; a first adjustable fastener extending between the first lugs and a second adjustable fastener extending between the second lugs; each of the sections comprises: a first working surface positioned between the central space and the first lug, and a first support surface positioned on the first lug, the first fastener being positioned between the first working surface and the first support surface, the first working surface being oriented perpendicular to a longitudinal axis of the first fastener, and the first support surface being oriented at a first angle transverse to the longitudinal axis of the first fastener; a second working surface positioned between the central space and the second lug, and a second support surface positioned on the second lug, the second fastener being positioned between the second working surface and the second support surface, the second working surface being oriented perpendicular to a longitudinal axis of the second fastener, and the second support surface being oriented at a second angle transverse to the longitudinal axis of the second fastener, the second angle having an opposite slope to the first angle; at least one first stop surface positioned on the first lug adjacent the first support surface, the first stop surface being oriented at a third angle having an opposite slope to the first angle; at least one second stop surface positioned on the second lug adjacent the second support surface, the second stop surface being oriented at a fourth angle having an opposite inclination to the second angle; and wherein when the first fastener and the second fastener are adjusted to draw the first and second segments toward one another, engagement between at least one of the first stop surfaces on the first lug and the second stop surface on the second lug prevents rotation of the segments relative to one another. (Item 13) Item 13. The coupling of item 12, wherein the first lug defines a first opening surrounding a first axis positioned between the first working surface and the first support surface that is oriented perpendicular to the longitudinal axis of the first fastener. (Item 14) Item 14. The coupling of item 13, wherein the first opening extends through the first lug. (Item 15) Item 14. The coupling of item 13, wherein the second lug defines a second opening surrounding a second axis positioned between the second working surface and the second support surface that is oriented perpendicular to the longitudinal axis of the second fastener. (Item 16) Item 16. The coupling of item 15, wherein the second opening extends through the second lug. (Item 17) Item 13. The coupling of item 12, wherein the first adjustable fastener and the second adjustable fastener each comprise a nut and a bolt. (Item 18) Item 13. The coupling of item 12, wherein each of the segments includes a first arcuate projection and a second arcuate projection positioned on opposite sides of the segments, each of the arcuate projections facing the central space, each of the arcuate projections engageable within a circumferential groove in the pipe element when the segments are drawn toward one another by the adjustable fastener. (Item 19) Item 13. The coupling of item 12, further comprising a seal positioned within the central space, the seal supporting the sections in a sufficiently spaced relationship to permit insertion of the pipe element into the central space without disassembly of the coupling. (Item 20) Item 13. The coupling according to item 12, wherein the first angle has a slope of 45°. (Item 21) Item 13. The coupling according to item 12, wherein the first angle has a tilt in the range of 30° to 60°. (Item 22) Item 13. The coupling of item 12, wherein the second angle is equal to the first angle but has an opposite slope to the first angle. (Item 23) 1. A coupling for joining pipe elements in an end-to-end relationship, said coupling comprising: a first section and a second section attached to each other at opposite ends surrounding a central space for receiving the pipe element, each of the sections having a first lug extending from a first end thereof, the first lug of the first section being aligned with the first lug of the second section; a first adjustable fastener extending between the first lugs; and each of the segments further comprising a second end, the second ends of the segments being respectively arranged opposite the first ends, each of the second ends being connected to a hinge interconnecting the first and second segments, the hinge defining a hinge axis oriented perpendicular to a longitudinal axis of the first fastener, the first and second segments being pivotable about the hinge axis, and each of the segments comprising: a first working surface positioned between the central space and the first lug, and a first support surface positioned on the first lug, the first fastener being positioned between the first working surface and the first support surface, the first working surface being oriented perpendicular to the longitudinal axis of the first fastener, and the first support surface being oriented at a first angle transverse to the longitudinal axis of the first fastener; a first stop surface positioned on the first lug adjacent the first support surface, the first stop surface being oriented at a third angle having an opposite inclination to the first angle; and wherein upon adjustment of the first fastener to pivot the first and second segments, thereby drawing the first and second segments toward one another, engagement between the first stop surfaces on the first lug prevents rotation of the segments relative to one another. (Item 24) 24. The coupling of claim 23, wherein the first lug defines a first opening surrounding a first axis positioned between the first working surface and the first support surface that is oriented perpendicular to the longitudinal axis of the first fastener. (Item 25) Item 25. The coupling of item 24, wherein the first opening extends through the first lug. (Item 26) Item 24. The coupling of item 23, wherein the first adjustable fastener comprises a nut and bolt. (Item 27) Item 24. The coupling of item 23, wherein each of the segments includes a first arcuate projection and a second arcuate projection positioned on opposite sides of the segments, each of the arcuate projections facing the central space, each of the arcuate projections engageable within a circumferential groove in the pipe element when the segments are drawn toward one another by the adjustable fastener. (Item 28) 24. The coupling of claim 23, further comprising a seal positioned within the central space, the seal supporting the sections in a sufficiently spaced relationship to permit insertion of the pipe element into the central space without disassembly of the coupling. (Item 29) 24. The coupling according to claim 23, wherein the first angle has a slope of 45°. (Item 30) Item 24. The coupling according to item 23, wherein the first angle has a tilt in the range of 30° to 60°. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is an isometric view of an exemplary mechanical coupling according to the present invention shown in a factory-assembled condition.

[0018] [Diagram 2] FIG. 2 is an end view of the coupling shown in FIG.

[0019] [Diagram 3] 3 and 4 show end views of an exemplary coupling during installation. [Figure 4] 3 and 4 show end views of an exemplary coupling during installation.

[0020] [Diagram 5] FIG. 5 is an isometric view of another exemplary mechanical coupling according to the present invention shown in a factory-assembled condition.

[0021] [Figure 6] FIG. 6 is an end view of the coupling shown in FIG.

[0022] [Figure 7] 7 and 8 show end views of an exemplary coupling during installation. [Figure 8] 7 and 8 show end views of an exemplary coupling during installation.

[0023] [Figure 9] FIG. 9 is a front view of another exemplary embodiment of a coupling according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] (Detailed Description) FIG. 1 illustrates an exemplary coupling 10 according to the present invention for joining pipe elements (not shown) in an end-to-end relationship. In this embodiment, the coupling 10 comprises a first section 12 and a second section 14. The sections 12 and 14 are attached to each other at opposite ends to surround and define a central space 16 for receiving the pipe elements. The coupling 10 is designed to join pipe elements having circumferential grooves at their ends, so that each of the sections 12 and 14 comprises a first arcuate projection 18a and a second arcuate projection 18b (see also FIG. 2), also known as "keys," positioned on opposite sides 20 and 22 of the sections 12 and 14. The arcuate projections 18a and 18b face the central space 16 and are engageable within the circumferential groove in the pipe elements when the sections are drawn toward each other to form the joint. A seal 24 is positioned within the central space 16. Seal 24 is advantageously a ring gasket made from an elastomer such as EPDM and can support sections 12 and 14 in the spaced apart relationship as shown, a distance sufficient to permit insertion of the pipe elements into central space 16 without disassembly of coupling 10. Couplings according to the present invention can also be used with plain end pipes, shouldered pipes, or other formed pipe ends known in the art.

[0025] 1, each section 12, 14 includes a first lug 26 extending from a first end 28 thereof. A second lug 30 extends from a second end 32 of each section. The first lug 26 and the second lug 30 of the first section 12 align with the first lug 26 and the second lug 30 of the second section 14, respectively. A first adjustable fastener 34 extends between the first lugs 26 of each section 12 and 14, and a second adjustable fastener 36 extends between the second lugs 30 of each section. In this embodiment, the first adjustable fastener 34 and the second adjustable fastener 36 include a nut 38 and a bolt 40.

[0026] Each section 12 and 14 further comprises a first working surface 42 positioned between the central space 16 and the first lug 26. A first support surface 44 is positioned on the first lug 26 of each section 12 and 14. The first fastener 34 is positioned between the first working surface 42 and the first support surface 44 of the sections 12 and 14. As shown in Figs. 1 and 2, the first working surface 42 and the first support surface 44 are oriented at a first angle 46 transverse to a longitudinal axis 48 of the first fastener 34. The first angle 46 may have an inclination in the range of 45° to 70°, with an inclination of 60° being considered advantageous. As shown in Fig. 1, a second working surface 50 is positioned on each section 12 and 14 between the central space 16 and the second lug 30. A second bearing surface 52 is positioned on the second lug 30 of each of the segments 12 and 14. The second fastener 36 is positioned between the second working surface 50 and the second bearing surface 52 of the segments 12 and 14. The second working surface 50 and the second bearing surface 52 are oriented at a second angle 54 transversely to a longitudinal axis 56 of the second fastener 36. The second angle 54 of the second working surface 50 and the second bearing surface 52 has an opposite inclination to the first angle 46 of the first working surface 42 and the first bearing surface 44. It is also advantageous if the inclinations of the first angle 46 and the second angle 54 are equal in magnitude and opposite in sign. In the embodiments disclosed herein, the first working surface 42 and the second working surface 50 have the same angular orientation as the first support surface 44 and the second support surface 52, respectively, although practical designs may advantageously have working surfaces with orientation angles that differ from the orientation angles of their adjacent associated support surfaces.

[0027] At least one first stop surface 58 is positioned on the first lug 26 of each segment 12 and 14 adjacent the first support surface 44. The first stop surface 58 is oriented at a third angle 60 (see FIG. 1 ) having an opposite inclination to the inclination of the first angle 46. At least one second stop surface 62 is positioned on the second lug 30 of each segment 12, 14 adjacent the second support surface 52. The second stop surface 62 is oriented at a fourth angle 64 having an opposite inclination to the second angle 54.

[0028] Advantageously, the first lug 26 may define a first opening 27 surrounding a first axis 29 positioned between the first working surface 42 and the first support surface 44, oriented perpendicular to the longitudinal axis 48 of the first fastener 34. In a practical embodiment, the first opening 27 extends through the first lug 26. The bending stiffness of the first lug 26 may be adjusted to a desired value by appropriately sizing the first opening 27. Similarly, the second lug 30 may define a second opening 31 surrounding a second axis 33 positioned between the second working surface 50 and the second support surface 52, oriented perpendicular to the longitudinal axis 56 of the second fastener 36. In a practical embodiment, the second opening 31 extends through the second lug 30. The bending stiffness of the second lug 30 may be adjusted to a desired value by appropriately sizing the second opening 31.

[0029] Operation of the coupling 10 will be described with reference to Figures 1-4. Figures 1 and 2 show the exemplary coupling 10 in a factory assembled configuration, with the sections 12 and 14 supported in spaced apart relationship on the seal 24 at a distance from each other sufficient to allow a pipe element (not shown) to be inserted into the central space 16. In this factory assembled embodiment, the fasteners 34 and 36 are sufficiently tightened to hold the sections against the seal. The pipe elements are inserted into the central space 16 with their circumferential grooves aligned with the arcuate projections 18a and 18b on the opposite sides 20 and 22 of the sections 12 and 14. The fasteners 34 and 36 are then further tightened to draw the sections 12 and 14 toward each other. Figure 3 shows the point in time when the first and second working surfaces 42 and 50 (42 shown) on the sections 12 and 14 engage each other. Advantageously, the support surfaces 44 and 52 (44 shown) on each section engage at approximately the same time. Arcuate projections 18a and 18b (not visible in the figure) are likewise engaged within grooves in the pipe elements at this point. During correct installation of coupling 10, engagement of bearing surfaces 44 and 52 between sections 12 and 14 provides the first visual indication that correct installation is proceeding.

[0030] The angular orientation and opposing inclination of the working surfaces 42 and 50 and the support surface 44 on the first end 28 of the segments and the support surface 52 on the second end 30 cause the segments 12 and 14 to rotate in opposite directions relative to one another as the fasteners 34 and 36 are further tightened. FIG. 1 illustrates the axis of rotation 66 of the segments as the paired working surfaces 42 and 50 on each segment engage one another. The purpose of this rotation is to force the arcuate projections 18a and 18b into firm contact with the side walls and / or floors of the grooves of the pipe elements with which they engage, thereby increasing the strength of the joint in bending, axial loading, and torsion. It should be noted, however, that the working surfaces 42 and 50 do not have features that limit the degree of relative rotation between the segments 12 and 14 as the fasteners are tightened. Features that limit relative rotation between the segments 12 and 14 are provided by the stop surfaces 58 and 62 on the lugs 26 and 30, respectively. As shown in FIG. 4, these stop surfaces (58 shown) engage as the fastener is further tightened. The geometry of the working surfaces 42 and 50, the support surfaces 44 and 52, and the stop surfaces 58 and 62, their lengths, locations on the segments, and orientation angles cooperate with the arcuate projections 18a and 18b such that when the first stop surface 58 and the second stop surface 62, respectively, engage or nearly engage as depicted in FIG. 4, the projections are effectively arrested within the circumferential groove of the pipe element. Thus, the engagement of both stop surfaces 58 and 62 on the opposite ends of the segments 12 and 14 provides visual confirmation that the coupling 10 is properly seated. The stop surfaces 58 and 62 provide this confirmation throughout the tolerance range imposed on the circumferential groove in the pipe element. At one end of the groove tolerance range, the segments 12 and 14 rotate about axis 66 to the limit imposed by the respective engagement between the first stop surface 58 and the second stop surface 62. At the other end of the groove tolerance range, engagement between one or both of the projections 18a and 18b and their respective circumferential grooves imposes a limit on rotation of the segments. It is contemplated that when engagement between the projections 18a and 18b and the grooves limits the relative rotation of the segments, one or both of the first stop surface 58 and the second stop surface 62 do not engage.However, the lugs 26 and 30 at the opposite ends of the sections 12 and 14 are designed to deform as the fasteners 34 and 36 are tightened once the rotational limits imposed by the engagement between the projections 18a and 18b and their circumferential grooves are reached to allow the stop faces 58 and 62 to engage. The deformation is controlled in part by the size of the openings 27 and 29 extending through the lugs 26 and 30. Thus, regardless of where the circumferential grooves in the pipe elements lie on the tolerance spectrum, the engineer need only tighten the fasteners 34 and 36 until the stop faces 58 and 62 on the respective lugs 26 and 30 at the opposite ends 28 and 32 of the sections 12 and 14 engage. This engagement provides a final visual confirmation that the coupling 10 is properly seated.

[0031] In addition to being easily visually inspected to confirm proper jointing, the coupling 10 according to the present invention is also relatively insensitive to the installation procedure, providing greater ease of assembly. Although the preferred installation practice is to partially tighten each fastener in a series of alternating steps, this practice need not necessarily be followed. Instead, a technician may fully tighten one fastener with a power impact wrench and then fully tighten the other fastener. However, in the case of the coupling 10 according to the present invention, this practice does not result in over-rotation of the coupling sections, which is prevented by the engagement of the stop surface on the side of one fastener that is tightened first. The technician may then apply torque to tighten the other fastener, bringing the stop surface on the opposite end of the coupling into engagement to complete the installation. The geometry of the coupling is such that the projections 18a and 18b are securely engaged within their respective circumferential grooves in contact with the side walls and / or floors of the grooves to form a robust joint, so long as both sets of stop surfaces 58 and 62 are in contact.

[0032] 5-8 illustrate another exemplary embodiment of a coupling 70 according to the present invention. The coupling 70 is the same as the coupling 10 as described above, except for the orientation of the working faces 42 and 50. In the coupling 70, the first working face 42 is oriented substantially perpendicular to the longitudinal axis 48 of the first fastener 34, and the second working face 50 is oriented substantially perpendicular to the longitudinal axis 56 of the second fastener 36. Due to the different orientations of the working faces 42 and 50, the coupling sections 12 and 14 do not rotate about the axis 66 in response to their engagement when the fasteners 34 and 36 are tightened to direct the sections towards each other and couple the pipe elements together. The coupling 70 is advantageous when a more flexible pipe connection is desired. However, when fasteners 34 and 36 are tightened, friction between the torqued fasteners and their respective lugs tends to rotate the coupling segments relative to one another, thereby causing undesirable engagement between projections 18a and 18b and the grooves in the pipe element. As shown in Figures 7 and 8, this undesirable effect is mitigated by engagement between one or both of the stop surfaces 58 and 62 on lugs 26 and 30 because the geometry of support surfaces 44 and 52 and stop surfaces 58 and 62, their lengths, locations on the segments, and orientation angles cooperate with arcuate projections 18a and 18b such that the projections do not get stuck in the circumferential grooves of the pipe element when first and second stop surfaces 58 and 62, respectively, engage. The engagement between the stop surfaces and support surfaces may also serve as a final visual confirmation that coupling 70 is properly seated.

[0033] FIG. 9 illustrates another exemplary embodiment of a coupling 72 according to the present invention. The coupling 72 shares many of the features of the coupling embodiments 10 and 70 as described above, but substitutes a hinge for the second lug 30. The second end 32 of each segment 12 and 14 is connected to a hinge 74 arranged opposite the first end 28 and joining the first and second segments to one another. The hinge 74 defines a hinge axis 76 oriented perpendicular to the longitudinal axis 48 of the first fastener 34. The first segment 12 and the second segment 14 are pivotable about the hinge axis 76. Adjusting the first fastener 34 pivots the first segment 12 and the second segment 14, thereby drawing them toward one another, and the engagement between the first stop surfaces 58 on the first lug 26 (see FIG. 8) prevents rotation of the segments relative to one another about the axis 66. In this exemplary embodiment, hinge 74 includes bearings 78 (shown) and 80 (hidden) that are rotatably joined by hinge pin 82. Other forms of hinge joints are also practical.

[0034] With respect to coupling 70, the first working surface 42 of coupling 74 is oriented substantially perpendicular to the longitudinal axis 48 of the first fastener 34. Due to the perpendicular orientation of the working surface 42, the coupling sections 12 and 14 do not rotate relative to one another about axis 66 in response to their engagement when the fastener 34 is tightened to direct the sections toward one another and join the pipe elements together. As with coupling 70, coupling 74 is advantageous when a more flexible pipe joint is desired. When the fastener 34 is tightened, friction between the torqued fasteners and their respective lugs tends to rotate the coupling sections relative to one another, thereby causing undesired engagement between the projections 18a and 18b and the grooves in the pipe elements. As with coupling 70, and as shown in Figures 7 and 8 (which also show lug 26 of coupling 74), this undesirable effect is mitigated by the engagement between one or both of the stop surfaces 58 on lug 26 because the geometry of support surface 44 and stop surface 58, their length, location on the section, and orientation angle cooperate with arcuate projections 18a and 18b such that when first stop surface 58 engages, the projections do not get stuck in the circumferential groove of the pipe element. The engagement of the stop surfaces also prevents undesirable torsional loading on the hinge about an axis perpendicular to axis of rotation 76. The engagement between the stop surface and the support surface may also serve as a final visual confirmation that coupling 74 has been properly seated. The stop surfaces provide this confirmation throughout the tolerance range imposed on the diameter of the circumferential groove in the pipe element.

[0035] With respect to couplings 10 and 70, the first lug 26 of the coupling 74 defines a first opening 27 surrounding a first axis 29 oriented perpendicular to a longitudinal axis 48 of the first fastener 34. The axis 48 and fastener 34 are positioned between the first working surface 42 and the first support surface 44. In the exemplary embodiment shown, the first opening 27 extends through the first lug 26. In a practical embodiment, the first adjustable fastener 34 may include a nut 38 and a bolt 40.

[0036] It is anticipated that a coupling according to the present invention will enable a strong and flexible joint to be easily and reliably formed while reducing the coupling's susceptibility to poor installation techniques.

Claims

1. A method of providing a coupling for joining pipe elements in an end-to-end relationship, said coupling comprising: a first section and a second section attached to each other at opposite ends surrounding a central space for receiving the pipe element, each of the sections having a first lug extending from a first end thereof and a second lug extending from a second end thereof, the first lug and the second lug of the first section respectively aligning with the first lug and the second lug of the second section; a first adjustable fastener extending between the first lugs and a second adjustable fastener extending between the second lugs; a first action surface positioned between the central space and the first lug and a first stop surface positioned on the first lug, the first adjustable fastener being positioned between the first action surface and the first stop surface; a second action surface positioned between the central space and the second lug and a second stop surface positioned on the second lug, the second adjustable fastener being positioned between the second action surface and the second stop surface; Equipped with The method comprises: tightening the first adjustable fastener until the first stop surfaces contact each other; thereafter, tightening the second adjustable fastener until the second stop surfaces contact each other. A method comprising:

2. Tightening the first adjustable fastener so that the first working surfaces contact each other before the first stop surfaces contact each other; thereafter, continuing to tighten the first adjustable fastener until the first stop surfaces contact each other; thereafter, tightening the second adjustable fastener such that the second application surfaces contact one another before the second stop surfaces contact one another; thereafter, continuing to tighten the second adjustable fastener until the second stop surfaces contact each other. The method of claim 1 further comprising:

3. The method of claim 1, wherein each of the first adjustable fastener and the second adjustable fastener comprises a nut and bolt, and the tightening step includes applying a torque to one of the nut or the bolt.

4. The method of claim 1, wherein each of the sections has a first arcuate protrusion and a second arcuate protrusion positioned on opposite sides of the section, each of the arcuate protrusions facing the central space, and each of the arcuate protrusions engageable within a circumferential groove in the pipe element when the sections are drawn toward each other by the adjustable fastener.

5. The method of claim 1, further comprising positioning a seal within the central space, the seal supporting the sections in a sufficiently spaced relationship to permit insertion of the pipe elements into the central space without disassembling the coupling prior to the tightening step.

6. A method of providing a coupling for joining pipe elements in an end-to-end relationship, the coupling comprising: a first section and a second section attached to each other at opposite ends surrounding a central space for receiving the pipe element, each of the sections having a first lug extending from a first end thereof and a second lug extending from a second end thereof, the first lug and the second lug of the first section being aligned with the first lug and the second lug of the second section, respectively; a first adjustable fastener extending between the first lugs and a second adjustable fastener extending between the second lugs; Equipped with Each of the sections comprises: a first working surface positioned between the central space and the first lug and a first support surface positioned on the first lug, the first adjustable fastener being positioned between the first working surface and the first support surface, the first working surface and the first support surface being oriented at a first angle transverse to a longitudinal axis of the first adjustable fastener; a second working surface positioned between the central space and the second lug and a second support surface positioned on the second lug, the second adjustable fastener being positioned between the second working surface and the second support surface, the second working surface and the second support surface being oriented at a second angle transverse to a longitudinal axis of the second adjustable fastener, the second angle having an opposite slope to the first angle; a first stop surface positioned on the first lug adjacent the first support surface, the first stop surface being oriented at a third angle having an opposite inclination to the first angle; a second stop surface positioned on the second lug adjacent the second support surface, the second stop surface being oriented at a fourth angle having an opposite inclination to the second angle; Further equipped with The method comprises: tightening the first adjustable fastener until the first stop surfaces contact each other; thereafter, tightening the second adjustable fastener until the second stop surfaces contact each other. A method comprising:

7. Tightening the first adjustable fastener so that the first working surfaces contact each other before the first stop surfaces contact each other; thereafter, continuing to tighten the first adjustable fastener such that the first support surfaces contact each other before the first stop surfaces contact each other; thereafter, continuing to tighten the first adjustable fastener until the first stop surfaces contact each other; thereafter, tightening the second adjustable fastener such that the second application surfaces contact one another before the second stop surfaces contact one another; thereafter, continuing to tighten the second adjustable fastener such that the second support surfaces contact each other before the second stop surfaces contact each other; thereafter, continuing to tighten the second adjustable fastener until the second stop surfaces contact each other. The method of claim 6 further comprising:

8. The method of claim 6, wherein each of the first adjustable fastener and the second adjustable fastener comprises a nut and bolt, and the tightening step includes applying a torque to one of the nut or the bolt.

9. The method of claim 6, wherein each of the sections has a first arcuate protrusion and a second arcuate protrusion positioned on opposite sides of the section, each of the arcuate protrusions facing the central space, and each of the arcuate protrusions engageable within a circumferential groove in the pipe element when the sections are drawn toward each other by the adjustable fastener.

10. The method of claim 6, further comprising positioning a seal within the central space, the seal supporting the sections in a sufficiently spaced relationship to permit insertion of the pipe elements into the central space without disassembling the coupling prior to the tightening step.

11. A method of providing a coupling for joining pipe elements in an end-to-end relationship, said coupling comprising: a first section and a second section attached to each other at opposite ends surrounding a central space for receiving the pipe element, each of the sections having a first lug extending from a first end thereof and a second lug extending from a second end thereof, the first lug and the second lug of the first section being aligned with the first lug and the second lug of the second section, respectively; a first adjustable fastener extending between the first lugs and a second adjustable fastener extending between the second lugs; Equipped with Each of the sections comprises: a first working surface positioned between the central space and the first lug and a first support surface positioned on the first lug, the first adjustable fastener being positioned between the first working surface and the first support surface; a second working surface positioned between the central space and the second lug and a second support surface positioned on the second lug, the second adjustable fastener being positioned between the second working surface and the second support surface; a first stop surface positioned on the first lug adjacent the first support surface; a second stop surface positioned on the second lug adjacent the second support surface; and Further equipped with The method comprises: tightening the first adjustable fastener until the first stop surfaces contact each other; thereafter, tightening the second adjustable fastener until the second stop surfaces contact each other. A method comprising:

12. Tightening the first adjustable fastener so that the first working surfaces contact each other before the first stop surfaces contact each other; thereafter, continuing to tighten the first adjustable fastener such that the first support surfaces contact each other before the first stop surfaces contact each other; thereafter, continuing to tighten the first adjustable fastener until the first stop surfaces contact each other; thereafter, tightening the second adjustable fastener such that the second application surfaces contact one another before the second stop surfaces contact one another; thereafter, continuing to tighten the second adjustable fastener such that the second support surfaces contact each other before the second stop surfaces contact each other; thereafter, continuing to tighten the second adjustable fastener until the second stop surfaces contact each other. The method of claim 11 further comprising:

13. The method of claim 11, wherein each of the first adjustable fastener and the second adjustable fastener comprises a nut and bolt, and the tightening step includes applying a torque to one of the nut or the bolt.

14. The method of claim 11, wherein each of the sections has a first arcuate protrusion and a second arcuate protrusion positioned on opposite sides of the section, each of the arcuate protrusions facing the central space, and each of the arcuate protrusions engageable within a circumferential groove in the pipe element when the sections are drawn toward each other by the adjustable fastener.

15. The method of claim 11, further comprising positioning a seal within the central space, the seal supporting the sections in a sufficiently spaced relationship to permit insertion of the pipe elements into the central space without disassembling the coupling prior to the tightening step.

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