US2969995A - Sectional gasket ring with radially extending flange to prevent axial separation of sections - Google Patents

Description

Jan. 31, 1961 R. c. BOUGHTON 2,969,995

SECTIONAL GASKET RING WITH RADIALLY EXTENDING FLANGE TO PREVENT AXIAL SEPARATION OF SECTIONS Filed June 17, 1957 4 Sheets-Sheet l f/GL/ {I60 25 M\\ A T TO/PNEYS 2,969,995 LANGE Jan. 31, 1961 R. c. BOUGHTON SECTIONAL GASKET RING WITH RADIALLY EXTENDING F TO PREVENT AXIAL SEPARATION OF SECTIONS 1957' 4 Sheets-Sheet 2 Filed June 17,

INVENTOR. ROGER C. BOUGH TON BY @W W M ATTORNEYS Jan. 31, 1961 R. c. BOUGHTON 2,969,995

SECTIONAL GASKET RING WITH RADIALLY EXTENDING FLANGE TO. PREVENT AXIAL SEPARATION OF SECTIONS Filed June 17, 195'? 4 Sheets-Sheet 3 INVENTOR. ROGER C. BOUGHTON ,wewa ww A 7' TO/PNEYS Jan. 31, 196k Q BOUGHTON 2,969,995

SECTIONAL GASKET RING WITH RADIALLY EXTENDING FLANGE TO PREVENT AXIAL SEPARATION OF SECTIONS Filed June 17, 195'? 4 Sheets-Sheet 4 f/GJE f? I n 4 A INVENTOR. ROGER C. BOUGHTO/V A T TOPNEVS United States Patent O SECTIONAL GASKET RING WITH RADIALLY EX- TENDING FLANGE TO PREVENT AXIAL SEPA- RATION OF SECTIONS Roger C. Boughton, Alhambra, Califi, assignor to Joslyn nMlgg. & Supply Co., Chicago, Ill., a corporation of Filed June 17, 1957, Ser. No. 665,888

3 Claims. (Cl. 285413) This invention relates to a clamp for sealing the annular opening between the pipes in a bell and spigot joint, and is a continuation in part of application Serial No. 142,675, filed February 6, 1950, now abandoned.

One object of the invention is the provision of improved clamping means for a bell and spigot pipe joint to insure against leakage, particularly in the case of large diameter pipes in which the clamping ring for engagement with the gasket is in a plurality of sections.

Another object of the invention is the provision of means for accurately and effectively sealing large pipe joints in the order of those of from 10" to 36" in diameter without sacrificing the adjustability required for pipes of relatively large tolerances.

Other objects and advantages will be obvious from the description and drawings.

In the drawings, Fig. 1 is an enlarged fragmentary view, part sectional and part in elevation showing a portion of a pipe joint. I

Fig. 2 is an elevational view showing one side of a sectional spigot n'ng assembled except for the bolts.

Fig. 3 shows one of the sections of the ring of Fig. 2 including the adjacent ends of sections connected therewith, and also having dot-dash lines showing the different forces occurring in the tightening of the sections of a spigot ring against a gasket.

Fig. 4 is an enlarged sectional view taken along line fl-4 of Fig. 2.

Fig. 5 is a sectional view taken along line 55 of Fig. 2.

Fig. 6 is a sectional view taken along line 6-6 of Fig. 2 with the bolt connecting the sections being indicated in dot-dash lines.

Fig-7 is a sectional view taken along line 77 of Fig. 2 with the bolt connecting the adjacent sections being indicated in dot-dash lines.

Fig. 8 is a fragmentary elevational view at the joint between adjacent sections of the spigot ring as seen from the side opposite to that shown in Fig. 2.

Fig. 9 is an enlarged exploded fragmentary section of the structure at adjacent ends of the adjacent segments of the spigot ring as seen from the same side of the ring as shown in Figs. 2 and 3.

Fig. 10 is a fragmentary side elevational view of the bell ring of the clamp.

Figs. 11, 12 are semi-diagrammatic views illustrating the action that tends to occur in a sectional spigot ring in tightening it against the gasket.

Fig. 13 is a fragmentary exploded elevational view similar to that of Fig. 9 showing the joint between the ends of the adjacent segments of a spigot ring but omitting a portion of the structure that is shown in Fig. 9.

Fig. 14 is a sectional view taken through the adjacent ends of the adjacent segments of a spigot ring of the type illustrated in Fig. 13, when the segments are bolted together.

The present invention is adapted to be employed with a conventional bell and spigot joint for connecting pipes ice 1, 2 (Figs. 1, 11, 12). The pipe 1 is provided with a bell end generally designated 3 for receiving the end of the spigot pipe 2 and a ring of oakum 7 is inserted and caulked into the space 8 between the pipe 2 and the bell 3. Lead 9 is then poured and caulked into the remainder of the space up to the face 6 as shown in Fig. 1.

In the present instance an annular gasket 10 surrounds the spigot pipe 2 and engages the face 6 of the bell 3 as shown in Fig. 1. Gasket 10 has an annular axially facing surface 11 for engaging the face 6 of the bell and also for filling the open end of the seam or space 8 through which leakage would otherwise occur. Adjacent to the surface 11 and in engagement with the outer side of spigot pipe 2 gasket 10 is provided with a cylindrical. radially inwardly facing surface 12 that is perpendicular" to surface 11. The outer surface 13 of gasket 10 that is. opposite to the surface 12 is shorter in width or in direction axially of the gasket than surface 12 and is inclinedi: toward said axis from the outer edge of surface 11 to form a conical but radially outwardly directed surface.. Opposite to the bell engaging surface 11 of the gasket, the latter is formed with a generally axially facing sur-- face 14 that is inclined radially from its juncture with. surface 13 in a direction away from the hell 3.

The gasket 10, in cross section, comprises two por tions 15, 16 of resilient material, such as rubber, which; sections are integrally united. Portion 15 is substantial-- ly a quarter round piece in cross sectional contour, andl is formed of relatively soft rubber, preferably having aa durometer hardness of about 50. This portion is adjacent; to the corner at the intersection of surfaces 11, 12, and; its fiat sides extend approximately equal distances along said surfaces from their line of intersection so that the open end of space 8 is completely covered by said portion. The round or curved side of portion 15 is the side that is integrally united with portion 16.

The remainder or portion 16 of gasket 10 is formed of hard rubber of a durometer hardness of about for resisting cold flow. The portions 15, 16 of the gasket are molded and cured together at the same time so that the resulting gasket is a unitary member and is not two previously cured portions cemented together. This is an important distinction, since portions that are cemented together are not consistently satisfactory.

In normal practice, the lead 9 is usually flush with the surface 6 of the hell 3, but where there is a space, or recess due to the lead not reaching the plane of said surface, the material of portion 15 of the gasket will completely fill the recess and will extend over a portion of surface 6 when the spigot ring is tightened against the gasket to move it toward and against the bell.

Heretofore in conventional gaskets, this result has not occurred, but instead, the gasket has merely bulged into the recess for a limited distance if the gasket has been sufficiently hard to resist cold flow thereof under pressure. Of course, should the width of the space or recess in direction axially of the pipe be greater than say about an eighth of an inch, it is usually filled with some material such as plaster of Paris before the gasket is tightened. Otherwise, the possibility of the spigot ring engaging the bell end of the pipe would exist, which would result in limiting the sealing effect of the gasket and the joint would be defective. Obviously, a hard or relatively hard gasket along the corner that material 15 oocupies, would not fill any recess at the open end of space 8.

The spigot ring, generally designated 20, surrounds thespigot pipe 2, and is adapted to compress the gasket 10 between said ring and the face 6 of the bell 3, and to force the portion 15 of the gasket into any recess that. might be left between lead 9 and face 6 of the bell. In. cross-sectional contour, the spigot ring, for the majoL' portion of its length, comprises an annular web 21 (Figs. 1, 4, 5) disposed in a plane approximately perpendicular to the axis of the pipes although preferably slanted slightly from a point adjacent to the outer side of gasket t0 the outer edge of the web in a direction away from bell 3.

A flange 22 integral. with the web 21 extends axially outwardly of the web in a direction toward hell 3 when the spigot ring is installed (Fig. l). The flange 22 and the inner marginal portion 24 of the web 21 thus provide a pair of gasket engaging walls, the inner surface of flange 22 engaging the surface 13 of the gasket and the axially facing surface of marginal portion 24 engaging the surface 14 of the gasket. These gasket engaging surfaces have substantially the same inclination as the surfaces 13, 14. of the gasket.

On the. side of web 21 opposite to the flange 22 are a pair-of radially spaced circular flanges 25, 26 ('Figs. 4, 5) which stiffen: the web. 21 against bending.

Integral with the spigot ring at spaced points around the periphery thereof are radially outwardly extending lugs 27 (Fig. 4) which are provided with holes 28 for bolting the spigot ring to the bell ringas will hereafter be. described. The web 21v is also reinforced by ribs; 29 extending radially from each opening (Fig. 8') and stiffening ribs 30 (Fig. 2) radially from opposite sides of each hole 28 to flange 22 on the side of the ring that is adjacent to the bell 3.

Spigot ring 29 is formed in segments adapted to be secured together at their ends. In Fig. 2 four such segments A, B, C and D are shown, such as would be employed for pipes having large diameters above say 20". Smaller diameter pipes of say from 12 to 16" diameters would preferably have only three segments. However, the connections between the segments would be identical.

The ends of an adjacent pair of segments A and B are shown in Fig. 9 and these ends are adapted to be releasablysecured together in overlapping relationship to form a joint. It is to be understood that the joints between segments B, C and C, Band D, A are identical to the joint shown in Fig. 9.

The web 21 of segment A is provided with a longitudinally extending extension at one end generally designated 35, which extension is integral with web 21 and which is adapted to axially overlie a complimentarily formed extension generally designated 36 cast integrally with web 21 of segment B, and at one end of the latter. These extensions 35, 36 are formed so that the gasket engaging flange 2 2 is continuous across the joint except for the slight crack necessarily existing between the mating portions of the joint.

The extension 36 is provided with a hole 38 that is elongated in direction circumferentially. of the segment, and which hole is adapted to register with hole 37' in segment A for receiving a bolt 41 (Fig. 7 in dot-dash line). Similarly, a second hole 39 is formed in extension 35 but outwardly of flange 22, and a hole 40 is formed in extension 36 for receiving bolt 42' (Fig. 6.). This hole 40 is elongated circumferentially of the segment.

Upon tightening the bolts 42, 41 by means. of nuts 43; 44 the extensions 35, 36 may be rigidly but releasably secured together. The head 45 (Fig. 7) of each bolt 41 is preferably elongated to fit each rectangular depression 46 (Fig. 9) in extension 35 of each segment. As seen in Fig. 7 the top of the head 45 isbiased to conform to. the slant of the gasket engaging wall 24 of web 21,, with which it is flush.

The thickness of extension 36' is increased adjacent to its outer edge to provide an axially projecting or raised elongated portion 50 extending circumferentially of the segment to a point about centrally between the ends of, extension 36. This portion 50 is provided with a circumferentially extending row of radially inwardly projecting teeth-51 which are adapted to mesh with the radially outwardly projecting. teeth 52 of a circurnferentiallyextend- 4 ing row formed in extension. 35. While rows of teeth 51, 52 are described as extending circumferentially of the segments, the rows themselves are actually straight and not curved.

It is pertinent to note that the teeth 51, 52 when in engagement with each other positively prevent circumferential relative movement between the adjacent segments of the ring when the ring is assembled and bolts 41, 42 are tightened, but the adjacent ends of the segments may be adjusted to enable the ring to be accommodated to variations in the outside diameter of the spigot pipe.

The description of the spigot ring to this point is applicable to the spigot ring of Figs. 1, 2 to 9 and 11 to 14, there being no differences, hence the same numbers are used in Figs. 9 and 13 and in Figs. 7 and 14 to identify identical parts.

Heretofore the principal difficulty encountered inthe use of spigot rings is the tendency of one or more of the segments to tilt out of the plane of the ring in tightening the bolts that connect the spigot ring with the bell ring, such bolts being indicated at 49. Fig. ll illustrates the. tendency with respect to the top segment when the nuts on the bolts connecting the top segment are behind the nuts of the remainder of the nuts in a tightening operation. In this instance the segment will tend to be rotated about axis IJ (Fig. 3) relative to the adjacent segments, and when the condition of Fig. 12 occurs, and the nuts on the top segment are ahead of the others, the axis of rotation of the segment that is so tightened will tend to be along the axis G, H of Fig. 3. Actually no such rotation occurs in the present clamp, but the tendency to so rotate clearly would place so great a strain on the segments at their ends as to either cause the segments to bend (as they are of malleable iron) or else to overstress the bolts connecting the segments unless the structure is such as to prevent this occurrence.

The relationship between the rows of teeth 51, 52' and the bolts 41, 42 is such as to prevent any overstressing of the bolts as would occur were only single bolts used or were they circumferentially in line with each other. Thus the bolt openings for bolts 41 are positioned radially inwardly of the rows of teeth and in radial alignment with the rows, while the other openings for bolts 42 are spaced from the openings for bolts 41 in a direction circumferentially of the spigot ring and are also spaced from one of the ends, of each pair of rows of intermeshing teeth substantially in alignment with said rows longi tudinal'ly of the latter.

As seen in Fig. 3 the bolts 41, 42 are offset from both of the axes HG and I] and on moment arms that extend substantially at right angles to said axes so that the bolts provide the greatest possible resistance tobeing overstressed, and the teeth cooperate with each other to also resist the tendency of one segment to rotate about either of said axesrelative to the adjacent segments. In other words the segments would have to fulcrum about the ends of the teeth in order to tilt and this would put the bolts in shear-where no overstressing could occur.

This relationship between the bolts that connect the segments and the teeth is very important, and virtually makes a single unitary ring out of the segments, which is the end desired. Obviously in large diameter pipe the clamping-rings must be in segments for the purpose of installation and replacement, and also to compensate for variations in the pipe diameters. If the spigot ring were not tightened against a resilient gasket, the above features would not be important, but it is the fact that one segment may move ahead of another or may lag behind the others in a tightening operation that causes the difiiculty, and that makes it essential to construct the spigot ringso that there will be no overstressing of the bolts connecting the adjacent segments nor a breakage of the segments at their ends.

The employment of the radially directed teeth instead;

for example, of axially directed teeth, is quite important for the reason that the unthreaded central portions of the bolts function to hold the segments together against radial separation. Once the clamp is properly in position and the gasket tightly closes the seam, the joint will he covered by the earth and will normally remain in position for the lifeof the weakest part. Were the segments to-have axially directed engaging teeth the segments would separate when the nuts on the segment connecting bolts failed, but where the teeth are axially directed and in engagement, it is the unthreaded central portion of the bolt that holds the segments, the bolts being in shear stress rather than depending on the nuts. In the bolt making art it is a well known fact that the weakest point in a bolt is the threaded section since the threads are stressed in manufacturing, and the life of the unthreaded body will exceed that of the threaded portion by five times. Thus the installations that employ the radially directed teeth 51, 52 will have a much longer life from the standpoint of corrosion than where the stressed threaded ends of the bolts are solely relied upon to hold the segments together.

It may be mentioned at this point that in segmental spigot clamp structures heretofore employed, in which attempts to use bolts have been made, it has been quite common for segments to be tilted, as seen in Figs. 11, 12 due to overstressing the bolts, and this overstressing has been due to designs that failed to prevent it. When the bolts are overstressed in the manner shown in Fig. 12 to the point where the tilted segment engages the bell of the pipe, there is no remedy except to remove the entire spigot clamp and start over again, which is a very costly procedure.

The structure shown in Figs. 1 to 9 distinguishes from the structure of Figs. l3, 14 only in one feature that materially adds to the advantages of the spigot ring.

A comparison between Figs. 7 and 14 clearly shows that the portion 50 having the radially inwardly projecting row of teeth 51 terminates at one end of the teeth in the structure shown in Fig. 14. In Fig. 7 it is seen that a radially inwardly extending flange 48 extends over the ends of the teeth 51, 52 that are on the gasket engaging side of the ring so that teeth 51, 52 are enclosed.

In assembling the ring on the pipe the bolts 42 may be called the pivot bolts since these are spaced from outwardly of one end of the rows of teeth, and enable the segments to be pivoted thereabout in connecting the segments. They are tightened only after the clamp has been assembled about the spigot pipe and adjusted, and thereafter the bolts 41 are inserted and tightened.

Thus when the ring is assembled and is tightened, the segments are locked together by the flange 48 and the wall of extension 36 that is opposed thereto against axial movement of the segments relative to each other and furthermore the flange 48 also contributes to strengthening the connections between the segments against tilting of one relative to the others. The bolts will truly be in shear (instead of longitudinal tension) so that ultimate corrosion of the threaded and weakened ends will be of even less concern than in the structure of Figs. 13, 14.

The bell ring, generally designated 60 (Fig. 10) comprises the same number of segments as there are in the spigot ring, and they are formed with bolt lugs 61 in a similar manner to lugs 27, which lugs have openings 67 therein for bolts 49. Projections 62 at spaced points around the inner periphery of the bell ring are adapted to engage the shoulder of hell 3 (Fig. l). The segments of the bell ring overlap at the adjacent ends of adjacent segments and may be connected by suitable bolts.

Bolts 49, as has already been explained, connect the bell ring and the spigot ring.

Insofar as the gasket is concerned, it is important that the harder portion 16 contact both the outer cylindrical surface of pipe 2 and the flat axially facing sur- 6 face 6-of the bell and that the softer portion 15 extend across and slightly beyond the seam or space 8 and also engage the cylindrical outer surface of the pipe 2.

When the spigot ring is tightened against the gasket, the gasket will, of course, react against the spigot ring tending to urge the segments of the latter radially outwardly and axially, and the teeth 50, 51 will clearly resist any tendency to radial separation, and flange 48 will resist axial separation. The bolts 41, 42 cooperate with the teeth and flange 48.

I claim:

1. A spigot ring for engagement with the seam sealing gasket at the bell and spigot ends of pipe comprising; a plurality of circumferentially extending segments, one of the adjacent ends of each adjacent pair of segments being formed with a recess for receiving the other end of said adjacent ends in laterally overlapping relationship, said recess having an axially projecting side wall overlying an edge of said other end and complementarily formed recesses and projections on said side wall and along said edge providing a pair of rows of corresponding radially inwardly and radially outwardly facing, axially extending teeth respectively on said axially projecting side wall and along said edge of said other end, said rows extending circumferentially of said segments and the teeth of said rows being adapted to interfit when said segments are in circumferential alignment to secure said segments against circumferential movement relatively, said adjacent ends of said segments including said teeth thereon being radially movable apart and together free from axial movement relative to each other prior to bolting said adjacent ends together whereby said adjacent ends may be moved circumferentially of said ring relative to each other in the plane of said ring to different adjusted positions and said rows of teeth may then be moved radially into interfitting engaging relation when said adjacent ends are in the desired adjusted position, and bolts extending axially of said ring and removable therefrom for bolting said adjacent ends together in said adjusted position.

2. A spigot ring for engagement with the seam sealing gasket at the bell and spigot ends of pipe comprising; a plurality of circumferentially extending segments with the adjacent ends of each adjacent pair of segments having fiat opposed surfaces perpendicular to the axis of said ring in laterally overlapping relationship, a pair of bolts extending through each pair of said adjacent ends spaced circumferentially and radially of said ring for securing said ends together, and a pair of rows radially outwardly and radially inwardly facing, axially extending interfitting teeth extending generally circumferentially of said segments formed on said overlapping ends along the radially outer portions of said flat opposed surfaces for holding said overlapping ends against relative movement circumferentially of said ring and to permit relative movement radially between adjacent ends of each pair for movement of said rows of teeth to and from such intermeshing relationship when said flat surfaces are together, and before bolting said ends together, an axial projection on one of each of said lapping ends extending laterally over the other lapping end and having the row of radially inwardly facing teeth thereon, one bolt of each pair thereof being spaced radially inwardly of each pair of said rows of teeth in radial alignment with each such pair of rows and the other bolt of each pair thereof being spaced circumferentially of said ring from one of the ends of each pair of rows of teeth and substantially in alignment with each such pair of rows longitudinally of the latter, the teeth of each pair of interfitting rows thereof having substantial width axially of the ring with substantially engaging axially extending surfaces cooperating with each pair of bolts to resist tilting of each segment relative to the adjacent segments about an axis extending through the ends of each segment.

3. A spigot ring having a radially inner portion for 17 a engagement with the sealing asket in a bell and spigot pipe joint and a radially outer portion having axially extending holes for reception of clamping bolts comprising: a plurality of adjacent pairs of corresponding segments in which the adjacent ends of the segments of said pairs are in axially lapping engaging relation to form the ring, one of said adjacent ends being formed with a radially inwardly opening recess having side walls perpendicular to the axis of said ring and radially inwardly facing, axially extending teeth on the bottom wall of 10 said recess directed toward the radially inwardly opening side of said recess and the other of said adjacent ends being adapted to enter said radially inwardly open side upon relative movement between said adjacent ends radially of said ring, said other of said adjacent ends having radially outwardly facing teeth extending into the open side of said recesses and in mesh with the teeth in said recess, and bolts extending axially of said ring conne'cfing' thesaid adjacent ends oi the segments of said adjacent pairs thereof for preventing radial movement of said se ments relative to each other.

References Cited in thefile of this patent UNITED STATES PATENTS 539,617 Harrington e May 21, 1895 940,098 Wehrle NOV. 16, 1909 1,856,788 Seaberg May 3, 1932 1,916,968 Davis July 4, 1933 1,951,034 Norton Mar. 13, 1934 2,037,184 Teet'or Apr. 14, 1936 2,415,753 Newell Feb. 11, 1947 FCREIGN PATENTS 319,124 Great Britain -Sept. 19, 1929 462,425 Great Britain Mar. 9, 1937

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