Joint assembly, v-clamp, and end flanges

A v-clamp provides an enhanced axial load to tubular body end flanges in order to establish a fluid-tight joint therebetween. The v-clamp, according to an example, has a v-angle that varies in value over a section or more of a band of the v-clamp. The varying v-angle has been shown to effect an axial load that is more evenly and uniformly applied around a circumference of the v-clamp and to the underlying tubular body end flanges. Furthermore, in an example, the tubular body end flanges have a partially spherical shape.

TECHNICAL FIELD

This disclosure relates generally to v-clamps for joining tubular bodies.

BACKGROUND

V-clamps are typically used to join tubular bodies that have end flanges extending outwardly from the main structures of the tubular bodies. These types of tubular bodies are employed in a wide range of applications including, but not limited to, automotive, aerospace, agriculture, and oil and gas. Previous end flanges have angled and planar walls, and previous v-clamps have bands that exhibit a cross-sectional profile configuration that remains unchanged along the band's extent. When the v-clamps are tightened on the tubular bodies, the bands receive the end flanges and radial and axial forces exerted on the end flanges establish a fluid-tight joint at the end flanges.

SUMMARY

According to an implementation, a v-clamp may include a band. The band extends in a circumferential direction from a first end to a second end. The band has a first side wall and a second side wall. The first and second side walls establish a v-angle therebetween in sectional profile. The v-angle has a first value at a first circumferential position of the band and has a second value at a second circumferential position of the band. The first circumferential position is nearer to a closure mechanism of the v-clamp than the second circumferential position. The first value is greater than the second value.

According to another implementation, a joint assembly may include a first tubular body end flange, a second tubular body end flange, and a v-clamp. The v-clamp can be placed over the first and second tubular body end flanges. The v-clamp may include a band. The band extends in a circumferential direction from a first end to a second end. The band has a first side wall and a second side wall. The first and second side walls establish a v-angle therebetween in sectional profile. One or more of the first tubular body end flange, second tubular body end flange, and/or v-clamp has a change in shape over a portion or more of a circumferential extent thereof. The change in shape effects a generally even application of axial load to the first and second tubular body end flanges from the v-clamp over the portion or more of the circumferential extent.

According to yet another implementation, an end flange assembly may include a first tubular body end flange and a second tubular body end flange. The first tubular body end flange has a generally partially spherical shape. And the second tubular body end flange has a generally partially spherical shape.

DETAILED DESCRIPTION

With reference toFIGS.1-3E, a first embodiment of a v-clamp10is presented that furnishes an improved axial load applied to a first and a second tubular body end flange12,14in order to establish a fluid-tight joint therebetween. The improved axial load is more evenly and uniformly applied around a circumference of the v-clamp10and to the first and second tubular body end flanges12,14than previously demonstrated. In this embodiment, sliding frictional effects experienced amid a tightening action are accommodated via a v-angle of the v-clamp10that varies in value over a section or more of the v-clamp's band, via the end flanges12,14exhibiting a partially spherical profile, or a combination of both. The varied v-angle and partially spherical end flanges, when taken individually or together, provide a level of control and management—lacking in past v-clamps—over an orientation of the force ultimately applied to the underlying end flanges12,14. The v-clamp10hence converts contact forces between the v-clamp10and the underlying end flanges12,14more efficiently and effectively than previously shown. Moreover, a tightening force needed to effect the improved force and establish the fluid-tight joint is minimized compared to past tightening forces. The v-clamp10is suitable for use in a wide range of applications including, but not limited to, automotive (e.g., joints adjacent a turbocharger, exhaust components, etc.), aerospace, agriculture, and oil and gas applications, and is particularly suitable in applications involving high temperatures, stringent leak requirements, and tight packaging demands.

Furthermore, as used herein, the words axially, radially, and circumferentially, and their related grammatical forms, are used in reference to the generally circular and cylindrical shape of the shown v-clamp. In this sense, axially refers to a direction that is generally along or parallel to a central axis of the circular and cylindrical shape, radially refers to a direction that is generally along or parallel to a radius of the circular and cylindrical shape, and circumferentially refers to a direction that is generally along or in a similar direction as a circumference of the circular and cylindrical shape.

Turning now toFIGS.1and2, the v-clamp10can be employed in applications involving fluid-flow through a first tubular body16and a second tubular body18. The first tubular body16has the first end flange12, and the second tubular body18has the second end flange14. The first and second end flanges12,14can be unitary extensions of their respective tubular bodies, or can be initially discrete components that are subsequently fixed to the tubular bodies. The first and second end flanges12,14span circumferentially around the respective first and second tubular bodies16,18, and span radially outboard of the respective tubular body16,18. In assembly and installation, the first and second end flanges12,14come together for abutment and could have a gasket seated therebetween. In the example of the gasket, one or both of the end flanges12,14could have a circumferential channel residing in a confronting face15(FIG.3B) thereof in which the gasket would be seated; the gasket would establish a seal against potential leakage at the surface-to-surface confrontation of the first and second end flanges12,14.

The first and second end flanges12,14can have different configurations in different embodiments. In the embodiment ofFIGS.1-3E and8, the first and second end flange12,14have a configuration that accounts for a v-angle that varies and an accompanying contact angle between the v-clamp's band and the end flanges12,14that correspondingly varies; in this regard, the configuration of the end flanges can differ according to differing v-angles in other embodiments. With particular reference toFIGS.2and8, here, the first end flange12has a generally partially spherical shape. An exterior surface20of the first end flange12is correspondingly partially circular in shape, and lacks the angled and planar surfaces of previous end flanges. A sectional profile of the first end flange12ofFIG.2is depicted inFIGS.3A-3Eand demonstrates a partially spherical profile of the first end flange12. Similarly, the second end flange14has a generally partially spherical shape. An exterior surface22of the second end flange14is correspondingly partially circular in shape, and lacks the angled and planar surfaces of previous end flanges. As before, the sectional profile of the second end flange14demonstrates a partially spherical profile of the second end flange14. The sectional profiles of the first and second end flanges12,14, presented inFIG.8is similar to those presented inFIG.2, but have somewhat planar base portions21,23transitioning from the first and second tubular bodies16,18to their partially spherical portions; their partially spherical portions provide similar effects to those ofFIG.2. Moreover, other embodiments of flanges could have partially spherical portions only at the locations of the flanges that are engaged by the v-clamp. Still, in other embodiments that lack specific depiction in the figures, the end flanges could exhibit other configurations, as set forth below. In certain embodiments, the first and second end flanges could have angled and planar walls. This is depicted inFIG.9. First and second end flanges312,314have first and second planar walls313,315. The first and second planar walls313,315are angled at about forty degrees (40°) with respect to the vertical direction ofFIG.9(i.e., the radial direction). The first and second end flanges12,14, together with the v-clamp10, constitute a joint assembly.

The v-clamp10is set in place over and around the first and second end flanges12,14and is tightened to assist in the establishment of a fluid-tight joint therebetween. The v-clamp10can have various designs, constructions, and components in different embodiments; its exact design, construction, and components can be dictated in part or more by the application in which the v-clamp will be employed and the design and construction of the end flanges in which it will be tightened down upon. In the embodiment presented byFIGS.1-3E, the v-clamp10includes a band24and a closure mechanism (not depicted). Still, in other embodiments, the v-clamp10could include more, less, and/or different components than those of the figures.

The band24constitutes the main structure of the v-clamp10. The band24can be made from a metal material such as stainless steel. The band24can take different forms in different embodiments. With reference toFIGS.1and3, the band24has a first end26at one of its circumferential terminations, and has a second end28at its other and opposite circumferential termination. The band24can extend circumferentially continuously from the first end26to the second end28, and/or can have a hinged structure or some other discontinuity in its circumferential extent between the first and second ends26,28. In one example, the band24has a pair of band segments bridged together at a circumferential position that lies 180° from the closure mechanism. At its axial boundaries, the band24has a first axial end30and a second axial end32. On a radially-inboard facing side, the band24has an inner surface34(FIG.3A). On the first and second ends26,28, the band24can have various formations dictated in part or more by the design and construction and components of the closure mechanism. InFIGS.1and3, for example, the band24has first and second band flanges36,38extending radially-outboard of the main circular body of the band24. The first and second band flanges36,38can each have a hole for receiving insertion of a fastener of the closure mechanism. In other embodiments, the band24could have first and second loops on the respective first and second ends26,28that are formed by the band24being folded back onto itself and spot-welded in place; this type of end formation can be used with a T-bolt type tightening assembly; still, other formations are possible.

It has been found that certain past v-clamps applied an axial load to underlying end flanges in an uneven and non-uniform way. The axial load applied, testing has shown, was much higher at the tightening hardware and much lower at a location of the v-clamp's band opposite the tightening hardware. The graph ofFIG.4evidences this somewhat poorly distributed axial load around the v-clamp's circumference. Line100represents a past v-clamp having a band with a cross-sectional profile configuration that remains unchanged along the extent of its band. A point110on the line100is a location of the v-clamp's band next to the tightening hardware, and a point120, on the other hand, is a location of the v-clamp's band opposite the tightening hardware and about one-hundred-and-eighty degrees (180°) from the tightening hardware relative to the full circumference of the v-clamp's band (for demonstrative purposes, the points110,120and their related locations are indicated inFIG.3). Points on the line100in-between the points110and120represent respective locations along the v-clamp's band. In the graph, the axial load applied at the point110is greater than three-hundred-and-fifty newtons (350 N), while the axial load applied at the point120is below one-hundred-and-fifty newtons (150 N), evidencing a loss of more than one-half of the axial load applied from the tightening hardware to opposite the tightening hardware. And the axial load applied progressively decreases from the point110to the point120. As a consequence, these past v-clamps and their established joints might be more vulnerable to leakage at locations farther away from the tightening hardware. Furthermore, it has been found that the loss of axial load is due in large part to sliding frictional effects generated amid tightening and rundown actions between the v-clamp's band and underlying end flanges. The sliding frictional effects work to dissipate band tension at increased amounts farther from the tightening hardware. The axial load that would otherwise be applied is lost through friction and the attendant reduction in band tension. To counteract the axial load losses, past tightening forces have been increased. This also often meant a larger-sized fastener and thicker band needed to withstand the increased tightening force. Skilled artisans should appreciate that the graph ofFIG.4is the result of analytical modeling, and that similar modeling may yield differing results.

The band24presented by the figures has been designed and constructed to resolve the drawbacks of the past v-clamps. In this embodiment, and referring now to the sectional profiles ofFIGS.3A-3E, the band24has a shape that changes along a circumferential extent taken between the first and second ends26,28. The precise change in shape itself can differ in different embodiments. Here, the change in shape is mirrored and symmetrical about a diametric centerline40(FIG.3). The band24has a base wall42, a first side wall44extending from the base wall42, and a second side wall46extending from the base wall42. Because of the change in shape, the base wall42transitions from a somewhat planar configuration (FIG.3E) at a location farthest away from the closure mechanism, to a more rounded and more pointed configuration (FIG.3A) at a location nearest to the closure mechanism. The transitional configuration at the base wall42occurs gradually, as can be observed fromFIGS.3A-3E. As it transitions, the base wall42gradually grows in size and axially widens from the location atFIG.3Ato the location atFIG.3E, as can be observed by a review ofFIGS.3A-3E. As but one non-limiting example, the base wall42can widen in size from the location atFIG.3Bto the location atFIG.3Dby approximately 1.5 millimeters (mm); in other examples, the widening can be more or less than this value. The first side wall44depends radially-inboard and axially-outward of the base wall42, and likewise the second side wall46depends radially-inboard and axially-outward of the base wall42. Together, the base wall42and first and second side walls44,46establish a generally concave shape when viewed from the interior of the v-clamp10. A channel48(FIG.3E) is defined at the underside of the band24by the base wall42and first and second side walls44,46and receives the first and second end flanges12,14in assembly and installation.

Still referring toFIGS.3A-3E, the change in shape of the band24in this embodiment is a v-angle50that varies along the circumferential extent of the band24. The v-angle50is established between the first and second side walls44,46and defined thereby. In general, the side walls44,46spread apart and the v-angle50grows wider closer to the closure mechanism, and the side walls44,46come together and the v-angle50grows narrower and sharper farther away from the closure mechanism. The v-angle50steadily and continuously increases over the band's extent from the location denoted by the point120inFIG.3and to the first end26and closure mechanism. Conversely, the v-angle50steadily and continuously decreases over the band's extent from the first end26and closure mechanism and to the location denoted by the point120inFIG.3. For demonstrative purposes, the sectional view ofFIG.3Acan constitute a first circumferential position of the band24. The v-angle50at the first circumferential position in this example has a value of approximately seventy-eight degrees (78°); of course, other values of the v-angle are possible in other examples. The sectional view ofFIG.3Bcan constitute a second circumferential position of the band24, and the v-angle50at the second circumferential position in this example has a value of approximately sixty-nine degrees (69°); of course, other values of the v-angle are possible at this circumferential position in other examples. The sectional view ofFIG.3Ccan constitute a third circumferential position of the band24, and the v-angle50at the third circumferential position in this example has a value of approximately fifty-six degrees) (56°; of course, other values of the v-angle are possible at this circumferential position in other examples. The sectional view ofFIG.3Dcan constitute a fourth circumferential position of the band24, and the v-angle50at the fourth circumferential position in this example has a value of approximately forty-three degrees (43°); of course, other values of the v-angle are possible at this circumferential position in other examples. Still further, the sectional view ofFIG.3Ecan constitute a fifth circumferential position of the band24, and the v-angle50at the fifth circumferential position in this example has a value of approximately thirty-one degrees (31°); of course, other values of the v-angle are possible at this circumferential position in other examples. The precise rate-of-change of the change in shape of the band24can vary in different embodiments and can be dictated by the coefficient of friction experienced between the band24and the end flanges12,14and by the tightening force of the closure mechanism.

The closure mechanism is used to tighten and loosen the v-clamp10and bring the first and second ends26,28toward and away from each other. The closure mechanism is situated at the first and second ends26,28and can be held by the first and second band flanges36,38. The closure mechanism can take different forms in different embodiments. In one example, the closure mechanism includes a fastener or screw and a nut. The screw is inserted through the holes in the first and second band flanges36,38and the nut is threaded over the end of screw for tightening. In an example of a T-bolt type tightening assembly, the closure mechanism includes a trunnion and a fastener with a T-bolt and a nut. One example of a T-bolt type closure mechanism can be found in U.S. Pat. No. 7,441,311 owned by the applicant of this disclosure.

The varying v-angle50of the band24, as described, furnishes an improved axial load that is more evenly and uniformly applied fully around the circumferential extents of the v-clamp10and to the first and second end flanges12,14. The improved axial load is the result of a force applied via clamping with radial and axial force components. The sliding frictional effects generated at locations closer to the closure mechanism, such as at the first and second circumferential positions, are decreased due to the wider v-angle thereat, resulting in a lower and more tepid dissipation in band tension thereat and hence at locations farther from the closure mechanism such as at the fourth and fifth circumferential positions. Increased band tension, it has been found, produces increased conversion to axial load. Moreover, because the v-angle50is sharper farther from the closure mechanism, the resulting normal force (Fn) exerted by the band24thereat is orientated and directed more in the axial direction relative to the circular shape of the v-clamp10than closer to the closure mechanism—this means that a greater proportion of the forces applied to the first and second end flanges12,14is employed to impart axial loading. In other words, a sharper v-angle50has been found to exert an increased axial load.

With reference again to the graph ofFIG.4, a line130evidences the improved axial load. The line130represents a v-clamp such as the v-clamp10described and depicted herein with the band24having the varying v-angle50. As before, the point110is a location of the band24next to the closure mechanism, and the point120is a location of the band24opposite the closure mechanism. In the graph, and unlike the line100of past v-clamps, the axial load applied at the point110is approximately the same as the axial load applied at the point120, evidencing no measurable loss in the axial load applied from the tightening hardware to opposite the tightening hardware. And the axial load applied remains substantially steady between the points110and120. The line100demonstrates an example of a more evenly and uniformly applied axial load and a generally even application of axial load, as described herein; still, other examples apart from the line100can exist. In the example presented in the graph, the axial load applied at the point110(e.g., a first axial load) has a value that is within about ten percent (%) of a value of the axial load applied at the point120(e.g., a second axial load). Satisfying this relationship, it is thought, in at least an embodiment brings about an improved axial load; still, an improved axial load can arise even absent the relationship. Moreover, because of this improved axial load of the v-clamp10, the tightening and screw force of the closure mechanism employed to tighten the band24around the end flanges12,14can be reduced. Indeed, in the example ofFIG.4, the tightening force used for the past v-clamp of the line100was approximately five Kilonewtons (5 kN), and the tightening force used for the v-clamp10of the line130was approximately three-and-one-half Kilonewtons (3.5 kN). Even with the reduced tightening force, the v-clamp10can furnish a suitable axial load that establishes a fluid-tight joint. By reducing the tightening force, a smaller-sized fastener of the closure mechanism and a thinner band can be used for the v-clamp10than would otherwise be possible. Indeed, testing has shown that the v-clamp10may facilitate the use of a fastener of the closure mechanism that exhibits about 30% lower strength than that of past fasteners commonly employed.

Moreover, testing was conducted in order to prove the efficacy of a v-clamp with a varying v-angle, as set forth. The testing involved v-clamps with bands of two styles: i) a band with a varying v-angle, and ii) a standard band with an invariable or constant w-angle. The band with the varying v-angle had similarities to that described with reference toFIGS.3A-3E. The v-angle grew wider closer to its closure mechanism, and grew narrower farther away from the closure mechanism and closer to the 180° circumferential position of the band. The v-angle steadily and continuously increased over the band's extent from the 180° circumferential position and to the closure mechanism. At a circumferential position approximating that taken atFIG.3B, the v-angle had a value of approximately 69°. Also, at this circumferential position, the band's base wall had a planar configuration with an axial width of approximately 6.43 mm. At a circumferential position approximating that taken atFIG.3C, the v-angle had a value of approximately 56° and the band's base wall had an axial width of approximately 7.23 mm. Lastly, at a circumferential position approximating that taken atFIG.3D, the v-angle had a value of approximately 43° and the band's base wall had an axial width of approximately 8.04 mm. Further, the band had a first foot and a second foot, described below, that remain mostly constant and unchanged in shape. The standard band with the invariable v-angle, on the other hand, had a v-angle with a value of approximately 39° and a base wall with an axial width of approximately 7.9 mm. The testing also involved end flanges of two styles: i) end flanges with a partially spherical profile, and ii) standard end flanges with planar walls angled at 40°. The end flanges with the partially spherical profile resembled that depicted inFIG.8, and the standard end flanges with planar walls angled at 40° resembled those depicted inFIG.9.

A total of four groups were tested: 1) a standard band and standard end flanges, 2) a varying v-angle band and standard end flanges, 3) a standard band and partially spherical end flanges, and 4) a varying v-angle band and partially spherical end flanges. Three samples in each of the four groups were tested. The graphs ofFIG.10present certain testing results. Skilled artisans should appreciate that similar testing may yield differing results. Axial load in newtons (N) is plotted on the y-axis, and torque in newton-meters (Nm) is plotted on the x-axis. Testing results for group 1) are presented in the graph residing in the upper-lefthand quadrant; testing results for group 2) are presented in the graph residing in the upper-righthand quadrant; testing results for group 3) are presented in the graph residing in the lower-lefthand quadrant; and testing results for group 4) are presented in the graph residing in the lower-righthand quadrant. Dashed line A inFIG.10represents measurements of axial load at a circumferential position approximating that taken atFIG.3B. Solid line B represents measurements of axial load at the circumferential position ofFIG.3B, but on an opposite side of the full v-clamp band and on the other side of the closure mechanism. And dashed line C represents axial load measurements at a circumferential position approximating that taken atFIG.3Eand that lies 180° from the closure mechanism. As can be observed from the graphs, results for groups 1) and 3) involving the standard band show a measurable and not insignificant loss in axial load among lines A and B closer to the closure mechanism, compared to line C farther from the closure mechanism. The results for groups 2) and 4), on the other hand, involving the varying v-angle band show minimal-to-no loss in axial load among lines A and B compared to line C. The bar graphs ofFIG.11also present certain testing results. Skilled artisans should appreciate that similar testing may yield differing results. Total axial load in kilonewtons (kN) is plotted on the y-axis, and a screw force of 13 Nm of torque was applied. Testing results for group 1) are presented in the upper-lefthand bar graph D; testing results for group 2) are presented in the upper-righthand bar graph E; testing results for group 3) are presented in the lower-lefthand bar graph D; and testing results for group 4) are presented in the lower-righthand bar graph E. As can be observed from the bar graphs, there was a loss of total axial load of about 6 kN between groups 1) and 2), and there was a loss of total axial load of about 1 kN between groups 3) and 4). These losses of total axial load were deemed suitable.

With reference now toFIGS.5-7E, a second embodiment of a v-clamp210is presented that, like the previous embodiment, furnishes an improved axial load applied to the first and second tubular body end flanges12,14. The second embodiment is similar to the first embodiment in some respects, and not all of the similarities will be repeated here in this description of the second embodiment. As before, the improved axial load provided by the v-clamp210is more evenly and uniformly applied around a circumference of the v-clamp210. The first and second end flanges12,14each exhibit a partially spherical profile in cross-section, as depicted in the sectional views ofFIGS.7A-7Ebut could have another configuration, as previously set forth, such as the angled and planar walls ofFIG.9.

The v-clamp210includes a band224and the closure mechanism as described with reference to the first embodiment. The band224has a base wall242, a first side wall244extending from the base wall242, and a second side wall246extending from the base wall242. A channel248(FIG.7E) is defined at the underside of the band224by the base wall242and first and second side walls244,246and receives the first and second end flanges12,14in assembly and installation. Similar to the first embodiment, the band224of this second embodiment has a shape that changes along a circumferential extent, and the change in shape is constituted in part by a v-angle250that varies over the band's circumferential extent. As before, the v-angle250grows wider closer to the closure mechanism and, conversely, the v-angle250grows narrower and sharper farther away from the closure mechanism. The v-angle250steadily and continuously increases over the band's extent from the location denoted by the point120inFIG.6and to the closure mechanism. Conversely, the v-angle250steadily and continuously decreases over the band's extent from the closure mechanism and to the location denoted by the point120inFIG.6. The v-angle250at a first circumferential position ofFIG.7Ain this example has a value of approximately seventy-seven degrees (77°). The v-angle250at a second circumferential position ofFIG.7Bin the example has a value of approximately sixty-nine degrees (69°). Further, the v-angle250at a third circumferential position ofFIG.7Cin the example has a value of approximately fifty-six degrees (56°), and the w-angle250at a fourth circumferential position ofFIG.7Din the example has a value of approximately forty-three degrees (43°). Lastly, the v-angle250at a fifth circumferential position ofFIG.7Ein the example has a value of approximately thirty-two degrees (32°). Of course, other values of the v-angle are possible at these circumferential positions in other examples.

Dissimilar to the first embodiment, the band224in this second embodiment has a pair of feet residing at its first and second axial ends230,232in order to augment stiffness properties of the band224. Turning now to all ofFIGS.7A-7E, a first foot260spans from the first side wall244and constitutes a terminal extremity thereof. Indeed, the first axial end230of the band224is located at the first foot260. Since the feet undergo a change in shape along with the band224, as subsequently set forth, the first foot260depends somewhat radially-inboard of the first side wall244at certain locations, and depends somewhat radially-outboard of the first side wall244at other locations. And the first foot260depends somewhat axially-outward of the first side wall244. Further, a second foot262spans from the second side wall246and constitutes a terminal extremity thereof. Indeed, the second axial end232of the band224is located at the second foot262. Like the first foot260, the second foot262depends somewhat radially-inboard of the second side wall246at certain locations, and depends somewhat radially-outboard of the second side wall246at other locations. The second foot262depends somewhat axially-outward of the second side wall246.

In the second embodiment, the first and second feet260,262have shapes that change along the entire circumferential extent of the band224between the band's first and second ends226,228. The precise change in shape can differ in different embodiments. Here, the change in shape is mirrored and symmetrical about a diametric centerline240(FIG.6). In general, the first and second feet260,262grow and become more pronounced farther away from the closure mechanism, and the feet260,262recede and become less pronounced closer to the closure mechanism. With more specificity, the first and second feet260,262project radially outboard to an increased degree over the band's extent from the first end226and closure mechanism and to the location denoted by the point120inFIG.6. Also, the first and second feet260,262steadily and continuously increase in length in general axially-outward directions F, G (FIG.7E) over the band's extent from the first end226and closure mechanism and to the location denoted by the point120inFIG.6. The axially-outward direction F is with respect to the first side wall244, and the axially-outward direction G is with respect to the second side wall246. These changes in shapes, as described, can be observed in part from the sectional views taken fromFIG.7AtoFIG.7E.

In this second embodiment, the more pronounced feet260,262furnish greater stiffness to the band224. For instance, the band224exhibits a greater stiffness at its first and second side walls244,246at the circumferential position marked by the sectional view ofFIG.7Ethan at the circumferential position marked by the sectional view ofFIG.7B. In other words, the stiffness of the band224varies over the band's circumferential extent. It has been found that bending moments experienced by the band224at the first and second side walls244,246become greater as the v-angle250grows narrower. The bending moment experienced atFIG.7E, for example, is greater than that experienced atFIG.7B. The side walls244,246are urged apart (i.e., axially-outwardly) by a larger extent at circumferential positions farther away from the closure mechanism due in part to the accompanying narrowing v-angle250. Furthermore, a moment arm established by a loading point of contact between the end flanges12,14and side walls244,246can be longer at circumferential positions farther away from the closure mechanism—this is demonstrated in the example by loading points H inFIG.7Band H′ inFIG.7E. And, material stresses experienced by the band224at the first and second side walls244,246become greater as the v-angle250grows narrower. As a consequence, in some cases the side walls244,246can be urged apart by a larger extent than wanted farther from the closure mechanism, potentially thwarting the intended control and management over the orientation of the applied force. The feet260,262and their attendant stiffness work to counteract these unwanted consequences and help maintain the intended orientation of the applied force.

As an alternative to the second embodiment, the band224could have the feet260,262that grow and become more pronounced farther away from the closure mechanism and as presented inFIG.6andFIGS.7A-7E, but the band224could have a v-angle250that does not vary over the band's circumferential extent and instead maintains a constant and unchanged angle value over the band's circumferential extent. In this alternative, the first and second end flanges12,14would still each exhibit a partially spherical profile in cross-section, as previously described. Here, the control and management over the orientation of the applied force is established via the varying feet260,262and the attendant varying stiffness. The band's side walls244,246are urged apart and deflect in response to the tightening actions from the closure mechanism by varying amounts according to the varying stiffness. For instance, deflection can be greater at circumferential locations of the band224having less stiffness, and can be less at circumferential locations of the band224having more stiffness. Since the v-angle250is unchanged, having the feet260,262recede and become less pronounced closer to the closure mechanism provides greater deflection of the band224closer to the closure mechanism. And conversely, having the feet260,262grow and become more pronounced farther away from the closure mechanism provides less deflection of the band224farther from the closure mechanism. Accordingly, as with previous embodiments, sliding frictional effects are decreased closer to the closure mechanism, resulting in a lower and more tepid reduction in band tension at locations farther from the closure mechanism. Still, in yet another embodiment, the feet260,262could reside on the band224with the v-angle250that varies over the band's circumferential extent, as described, but the feet260,262could themselves lack a change in shape and instead could remain constant and unchanged in shape over the band's circumferential extent.

In a third embodiment, an improved axial load applied to the first and second tubular body end flanges12,14is furnished in larger part by the end flanges themselves. The first and second tubular body end flanges12,14in this embodiment each have a shape that changes over their circumferential extents, while the v-clamp's band has a w-angle that does not vary and instead maintains a constant and unchanged angle value over the band's circumferential extent. In this third embodiment, the band also lacks the changing feet of the second embodiment. Here, the control and management over the orientation of the applied force is established via the varying shape of the first and second tubular body end flanges12,14. In this third embodiment, instead of the first and second tubular body end flanges12,14exhibiting partially spherical profiles in cross-section, in order to effect the change in shape each of the first and second tubular body end flanges12,14has an exterior wall and surface that is planar like that shown inFIG.9. The planar exterior walls and surfaces vary their orientation with respect to a center axis of the respective first and second tubular body16,18. As in previous embodiments, the varying orientation is mirrored and symmetrical about the diametric centerline (40,240).

The planar exterior walls and surfaces define an acute angle with respect to the center axis of the respective first and second tubular body16,18. The acute angle narrows and becomes smaller closer to the closure mechanism with respect to the installation position of the v-clamp on the end flanges12,14and, conversely, widens and becomes larger farther away from the closure mechanism. The acute angle steadily and continuously decreases over the flanges' extent from the location denoted by the point120inFIG.6and to the closure mechanism, again relative to the installation position of the v-clamp on the end flanges12,14. Conversely, the acute angle steadily and continuously increases over the flanges' extent from the closure mechanism and to the location denoted by the point120, again relative to the installation position of the v-clamp on the end flanges12,14. While the v-clamp's band has an unchanged v-angle in this third embodiment prior to installation and tightening, the v-angle does indeed vary upon installation and tightening of the v-clamp due to the varying acute angle of the planar exterior walls and surfaces of the first and second tubular body end flanges12,14. In this embodiment, the v-angle varies in a manner that is akin to the varying v-angle of the first embodiment. The v-angle grows wider closer to the closure mechanism and, conversely, grows narrower farther away from the closure mechanism. And as before, because the acute angle is larger farther from the closure mechanism and the v-angle concomitantly sharper farther from the closure mechanism, the resulting normal force (Fn) exerted by the v-clamp's band thereat is oriented and directed more in the axial direction than closer to the closure mechanism. Accordingly, a greater proportion of the forces applied to the first and second end flanges12,14is employed to impart axial loading.

In yet another embodiment, the band24has the v-angle50that varies along the circumferential extent of the band24, and the tubular body end flanges12,14have the planar exterior walls and surfaces that vary their orientation with respect to the center axis of the respective tubular body16,18. In essence, this embodiment combines and incorporates the designs and constructions of the first and third embodiments. The varying v-angle50and varying acute angle, as previously described, work together to furnish the improved axial load applied to the first and second tubular body end flanges12,14. The control and management over the orientation of the applied force is hence established via the combined varying v-angle50and varying acute angle of the tubular body end flanges12,14. Upon installation and tightening, the band's v-angle50grows wider closer to the closure mechanism and, conversely, grows narrower farther from the closure mechanism. As before, the resulting normal force (Fn) exerted by the v-clamp's band24is oriented and directed more in the axial direction farther from the closure mechanism than closer to the closure mechanism, and hence a greater proportion of the forces applied to the end flanges12,14is employed to impart axial loading.