Pipe coupling with gasket locating means

A side-outlet pipe coupling having a split housing surrounding split-ring gasket means is provided. Lugs formed at the free ends of the gasket means position said gasket means within the coupling housing such that abutting free ends of the gasket means are off-set from the plane of splitting of the housing.

FIELD OF THE INVENTION 
This invention relates to pipe couplings used for the joining of pipes, and 
more particularly to improvements in the gasketing employed in such 
couplings. 
BACKGROUND AND SUMMARY OF THE INVENTION 
In the coupling of grooved-end pressure pipes, two basic designs of 
couplings are commonly known. In the first design, a full-ring resilient 
gasket of generally C-shaped cross-section is used to surround the joint, 
two half-round housing segments being clamped together around the gasket. 
In a variation of this design, the two housing segments are hinged 
together at one side of the joint, and clamped together at the other side. 
In the second known design, a split-ring gasket is employed within the 
housing segments. Such gasket may be formed in one piece, with a single 
break in its circular continuity defining two free ends, or may be formed 
of several arcuate sections each having two free ends, the several 
sections together defining a circle. 
Both of these known coupling designs have undesirable limitations. For 
example, the grooving of the pipe ends used in conjunction with these 
couplings is carried out through either roll-forming or cut-grooving. The 
full-ring gasket must be forced over the grooved pipe-ends when assembling 
the coupling, as the inside sealing diameter of the full-ring gasket is 
normally smaller than the pipe diameter. It is, therefore, desirable to 
have the pipe-end surface uniform in diameter and free of sharp edges. 
However, contrary to this requirement, the roll-grooving process tends to 
flare the pipe-end diameter and most methods used in cutting the pipes to 
length tend to leave sharp end edges, thus increasing the degree of 
difficulty in urging the full-ring gasket over the adjoining pipe-ends, 
and also increasing the danger of damaging the internal sealing lips of 
the full-ring gasket. 
Another limiting factor of full-ring couplings is the difficulty of their 
assembly. First, the adjoining pipe-ends must be set apart to allow the 
assembler to position the gasket before pushing it over the first 
pipe-end. Then, the second pipe-end must be brought into alignment to 
receive the other side of the gasket. This procedure can be quite 
laborious for large diameter pipes, with cranes and other mechanical 
assistances often being necessary. This procedure negates the desired 
procedure of pre-positioning a full line of pipe-lengths in ceiling-hung 
or surface-laid systems. Also, removal or replacement of the coupling, as 
where the gasketing is damaged by fire, becomes difficult, as it may be 
necessary to disassemble a large number of pipe-lengths to change one 
coupling. The split-ring gasket coupling is preferable over its full-ring 
counterpart in that it overcomes the limitations listed above. 
In addition, where a side-outlet is incorporated into a full-ring gasket 
coupling, the gasket must provide for an opening into the main piping and 
maintain the sealing integrity of the coupling housing at the side-outlet. 
Providing for such side-outlet in the wall of a full-ring gasket requires 
molding techniques more complicated than those necessary to produce a 
similar split-ring gasket. The result is higher production costs for the 
full-ring side-outlet gasket. While split-ring gasket couplings offer 
obvious advantages over full-ring gasket couplings, they have serious 
limitations of their own. Foremost among these is their succeptability to 
leakage along the axially extending sealing lines defined by abutting free 
ends of the gasket sections. In the known designs of split-ring gasket 
couplings, the axially extending sealing lines are aligned with the plane 
of contact of the opposed ends of the housing segments, or, where the 
housing segments do not actually touch, they are aligned with the space 
between the opposed ends of the housing segments. There is, therefore, 
nothing in such designs to prevent cold-flow of the gasketing material 
outwardly between the ends of the housing segments. Fluid-flow along the 
axially-extending sealing line is also possible, as there is no inner wall 
surface of a housing segment to impede its progress. 
It is a general object of the present invention to provide an improved 
split-ring gasket pipe coupling which overcomes the disadvantages 
associated with the prior art. Accordingly, it is an object of the present 
invention to provide a coupling having novel means for positioning a 
split-ring gasket within the coupling to promote better sealing better 
abutting free ends of the split-ring gasket. 
A further object of the present invention is to provide an improved 
split-ring gasket coupling of the side-outlet type. The known types of 
pipe couplings provide cumbersome nut and bolt locking means which require 
considerable dexterity on the part of the assembler. Typically, the nut 
must be removed from the bolt before the coupling housing can be closed, 
and then must be replaced and tightened. This is usually carried out while 
holding the housing segment in alignment under adverse conditions, such as 
on scaffolding. It is, therefore, a further object of the invention to 
provide a pipe coupling having a simple, inexpensive locking means which 
allow for the closing of the housing segments without the need for removal 
and replacement of the nut and bolt assemblies. 
The above and further objects and novel features of the invention will more 
fully appear in the following description, when the same is read in 
conjunction with the accompanying drawings. It is to be expressly 
understood, however, the drawings are for the purpose of illustration 
only, and are not intended as a definition of the limits of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to the drawings, the pipe coupling device comprises two arcuate 
housing segments 10 and 10', each segment having opposable ends 11. The 
housing segments, which may be made of cast or forged metal, PVC plastic, 
or other suitable material, are movable from an open position (FIGS. 2a 
and 2b) to a closed position (FIGS. 1, 4, 5 and 6) in which the opposable 
ends 11 are brought into opposition, thereby defining a coupling housing, 
designated by the general reference numeral 14, of generally circular 
configuration. The housing 14 engages the pipes 15 to be coupled by means 
of arcuate flanges 16 located at axially opposite ends of each housing 
segment 10, 10'. Each housing segment has a continuous inner wall surface 
12, (see FIG. 2b), which, in the preferred embodiment, has slanting side 
walls 13. 
The coupling housing 14 has fitted within it arcuate gasket means 17, which 
has free ends 18, 18' adapted to abut along an axially extending sealing 
line 19 (see FIG. 4). It will be understood that the gasket means may have 
a one-piece construction with a single break in its circular continuity, 
in which case there are two free ends and one axially extending sealing 
line, or, as shown in the drawings, the gasket means may be composed of 
one or more arcuate gasket sections, with each section having two free 
ends. In the preferred embodiment shown, there are two gasket sections 
with two sealing lines 19, 19'. As shown, the gasket means 17 is generally 
C-shaped cross-section, with outer 20, and side 21 surfaces, together 
defining an interior of said gasket means. The outer surface 20 of each 
gasket section is generally complimentary to the continuous inner wall 
surface 12 of the corresponding arcuate coupling housing segment 10, 10'. 
Side surfaces 21 of the gasket means are formed at the axially opposite 
ends of the outer surfaces 20, and slant radially inwardly in an axially 
outwardly direction as shown, so as to be accurately received within 
slanting side walls 13 of the coupling housing segment 10 and 10'. Inner 
surfaces 22, adapted for sealing with the pipes 15, are formed at the 
axially opposite ends of the interior of the gasket means. In the 
preferred embodiment shown, the side surfaces comprise a sealing lip 
having a first axially extending portion 22a, which is parallel to the 
axis of the coupling 14, and a second radially extending portion 22b, 
which extends radially inwardly from the axial inward end of the first 
portion 22a. The first portion 22a lies flat on the surface of the pipe 
15, exerting a compressive force against that surface in the closed 
position. The second portion 22b, is angled radially inwardly in the 
relaxed or non-compressed condition and is pushed outwardly into alignment 
with the first portion when the coupling 14 is closed, thereby applying 
pressure against the surface of the pipe 15. The upper surface 23 of the 
second portion is acted upon by internal pressures in the coupling, 
thereby resulting in an additional sealing load against the pipes 15. 
It will be appreciated that upon outward deflection of the second portion 
22b of the sealing lip into alignment with the first portion 22a, there 
will occur a circumferential retraction of the said second portion in the 
region of the abutting free ends 18 of the gasket sections 10, 10'. Such 
retraction of the second section 22b results in a gap in the gasketing 
material in the region of the axially extending sealing line 19. To 
compensate for this circumferential retraction, a projection 24 of the 
second radially extending portion 22b, which extends circumferentially 
from the general surface of the free ends 18, 18' of the gasket means, is 
provided. In the preferred embodiment shown, each of said second sections 
features an equal circumferential extension. However, other arrangements 
are considered to be within the scope of this invention. For example, 
either free end 18 or 18' of an arcuate gasket section may have no such 
projection, while the abutting free end of the opposed gasket section may 
present a projection which alone counteracts the retraction. 
The coupling of the present invention provides novel means for the 
positioning of the gasket means within the coupling housing such that, in 
the closed position of the housing segments 10, 10', the radially outer 
side of the sealing line 19 is spaced circumferentially from the opposed 
ends 11, 11' of the housing segments and is in contact with the continuous 
inner wall surface 12 of one of the said housing segments. By such means, 
the invention overcomes the problems of cold-flow and leakage associated 
with known split-ring gasket couplings. These means comprise a recess, 
which, in the closed position of the housing segments 10, 10', is defined 
by adjoining radially outwardly extending depressions 27, in the end 
region of the inner wall surface 12 of said opposing housing segments. The 
said means additionally comprise radially outwardly projecting lugs 25, 
25' adjacent to and co-extensive with abutting enlarged free ends 18, 18' 
of the gasket means 17, the projecting lugs 25, 25' of abutting enlarged 
free ends 18, 18' completely occupying the recess. 
The radially outwardly projecting lugs 25, 25' are generally rectangular in 
cross-section, having a shoulder 28 with their circumferentially free ends 
being co-incident with the enlarged free ends 18, 18' of the gasket 
sections. Thus, the lugs 25, 25', in addition to their locating function, 
aid in the sealing between opposed gasket sections by providing a radially 
extended surface of abutment on the free ends 18, 18'. It will be seen 
from FIGS. 2a, 3a, 3b and 9 that one lug 25 of each gasket section is 
shorter in circumferential length than the opposite lug of the same gasket 
section 25'. The two gasket sections are mirror images of each other, and 
are brought into opposition in the closed position so that the free end 11 
of the shorter lug 25 of one section is opposed to the free end 11 of the 
longer lug 25' of the other section. The depressions 27 have a shoulder 
29, which demarcates their inner circumferential limits. Each depression 
is generally rectangular in shape and of equal dimensions to the adjoining 
depression. As the abutting lugs 25 and 25' of unequal circumferential 
length completely occupy the recess defined by the two equally sized 
depressions 27, 27', it will be appreciated that the axially extending 
sealing line 19 will be spaced circumferentially from the opposed ends of 
the housing segments 10, 10', and furthermore, the said sealing line 19 
will be in contact with the continuous inner wall surface 12 of one of the 
housing segments 10 or 10'. In FIG. 4, it will be seen that the sealing 
line 19' at the right of FIG. 4 is in contact with the continuous inner 
wall 12 of the upper housing segment 10, while the sealing line 19 to the 
left of FIG. 4 is in contact with the continuous inner wall 12 of the 
lower housing segment 10'. 
Preferably, the lugs 25 and 25' are oversized with respect to the recess. 
That is, the two lugs together define a composite lug element having a 
volume greater than the volume of the recess. This oversizing creates 
additional compressive loading along the axially extending sealing line 
19, thereby increasing the effectiveness of sealing between abutting free 
ends 18, 18'. 
The housing depression shoulders 29 also aid in this sealing by acting as a 
stop to retain much of the compressive loading in the lug regions adjacent 
to the free ends 18, 18' of the gasket sections. 
The coupling of the present invention provides releasable locking means, 
designated by the general reference numeral 45. These locking means 
cooperate with the housing segments 10, 10' to lock the segments together 
in the closed position, as shown in FIG. 1. While any known form of 
locking means may be used, novel means are herein disclosed which provide 
a simple, low-cost and effective locking device which eliminates loose 
parts and permits the coupling housing to be closed around the pipes 15, 
15' with a minimum of effort and dexterity by the assembler. The novel 
locking means comprise first 46 and second 46' opposing bolt pads on the 
two housing segments 10, 10', respectively, each of said bolt pads having 
a radially extending open-ended slot 48, 48', a nut 47 and a bolt 49 
having a threaded shaft 50 and a head 51 which is retained on the slot 48 
of the first opposed bolt pad 46 by a resilient cylindrical ferrule 53 
engaging the threaded shaft 50 of the bolt 49 in the head region and 
having one end engaging resiliently an adjacent side surface 55 of the 
slot 48 of the first opposing bolt pad 46. The bolt 49 used in this 
locking means assembly is of the standard oval track neck type and the 
assembly utilizes the narrow section of the oval neck 52 to locate the 
bolt 49 in the slot 48 of the first bolt pad 46. FIG. 4 shows in solid 
lines the bolt 49 in place with the neck 52 in the slot 48 and a soft 
rubber ferrule 53 pushed into position on the threaded shaft 50 of the 
bolt 49 with the end closest to the head engaging the adjacent side 
surface 55 of the slot 48 of the first bolt pad 46. In this position, the 
ferrule 53 prevents the bolt from sliding out of the slot 48, but allows 
the bolt/nut assembly to pivot outwards (dotted lines) sufficiently for 
nut 47 to ride past the extreme edge of the second opposed bolt pad 46' 
before slipping into the slot 48' of the second bolt pad 46'. In the 
preferred embodiment illustrated, there is provided an inclined cam 
surface 56' on both sides of the second bolt pad 46' which contacts the 
end of the assembled nut 47 during closing of the housing segments 10, 
10', thereby causing the outward pivoting of the nut 47 and bolt 49 to the 
position shown in broken lines in FIG. 4. On further closure movement, the 
compressive action of the rubber ferrule 53, when pivoting the bolt 49, 
acts to return the bolt to its vertical position, as shown in solid lines 
in FIG. 4, so facilitating the rapid assembly of the coupling 14 on the 
pipes 15 and frequently permitting the coupling to be assembled around the 
pipe using only one hand. Once in the vertical position shown in the solid 
lines of FIG. 4, the nut is tightened to lock the two housing segments 10, 
10' together in the closed position. The length of the rubber ferrule 53 
is such that when in the secured position of FIG. 4, it engages the last 
two or three threads of bolt 49, thus preventing the ferrule from sliding 
back up the bolt during the compressive action of the bolt pivoting. 
It is also an object of the present invention to incorporate the novel 
features hereinbefore described in a pipe coupling having one or more 
side-outlets for attachment of branch pipes. Accordingly, the preferred 
embodiment of pipe coupling illustrated in FIGS. 1, 2a, 2b, 5, 6 and 7 has 
located upon the upper housing segment 10, at a substantially central 
position, an upwardly extending hollow boss 32, said hollow boss being in 
communication with the interior 33 of the coupling housing 14. Means are 
provided on the hollow boss 32 for the connection of a side-outlet pipe. 
The means shown comprise internal threading 36 of the hollow boss 32 for 
mating with a branch pipe which is correspondingly threaded. Any other 
known means of connecting branch pipes to the hollow boss 32 may be used. 
An upwardly projecting recess 34, defined by a generally conical side 
surface 34a, and a generally half-circular upper surface 34b, is provided 
in the inner wall surface 12 of the housing segment 10. The recess as 
shown is annular, surrounding the opening of the hollow boss 32 into the 
interior 33 of the coupling housing 14. The purpose of this recess will 
become apparent from the description below. 
The gasket means 17 has formed on its outer surface 20 a hollow outwardly 
extending resilient boss, generally designated by the reference numeral 
37. This resilient boss 37 is positioned on the outer surface 20 such that 
its axis is in alignment with the axis of the hollow boss 32 of the 
housing segment 10 when the coupling is in the closed position (see FIGS. 
4 and 5). The resilient boss 37 is comprised of an other side-wall 38 and 
an inner side-wall 39. 
The outer side-wall 38 of the resilient boss 37 is generally complimentary 
to and adapted to be received within the upwardly projecting recess 34 of 
the housing segment 10. The outer 38 and inner 39 side-walls terminate at 
their outer axial extents in an annular sealing lip 40, which, under 
compression in the closed position, forms a seal between itself and the 
confronting complimentary surface of the upwardly projecting recess 34. In 
the preferred embodiment, the confronting complimentary surface of the 
recess 34 comprises the generally half-circular upper surface 34b. 
To increase effective sealing around the side-outlet opening the inner 
side-wall 39 may be provided with a circumferential groove, generally 
designated by the reference numeral 42, defined by an upper face 43a and a 
lower face 43b. The upper portion of the resilient boss 37, comprising 
that portion of the resilient boss above the lower face 43b, is 
deflectable from the uncompressed condition (FIG. 7) to the compressed 
condition (FIG. 6) upon closure of the coupling housing segments 10, 10'. 
In the compressed condition the upper face 43a is in partial contact with 
the lower face 43b. This deflection of the upper portion of the resilient 
boss 37 results in additional compressive forces being exerted by the 
annular sealing lip 40 against the generally half-circular upper surface 
34b and by the outer side-wall 38 against the generally conical side 
surface 34a and the exposed portion of the lower face 43b can be acted on 
by positive fluid pressures, thus augmenting the sealing action. 
The opposable end 11 of the housing segments 10, 10' may be brought into 
opposition by any well-known means, such as nut and bolt assemblies at 
both ends of the housing segment. However, as previously outlined, such 
arrangements are cumbersome, consisting of many loose parts, which require 
substantial dexterity on the part of the assembler. Therefore, to provide 
for a coupling that is both easy and quick to assemble and disassemble, 
the preferred embodiment has the two housing segments 10, 10', pivoted 
together at one end and provided with releasable locking means 45, at the 
end opposite the pivoting end. The two housing segments 10, 10' may be 
pivoted together by means of a pivot pin 44 which engages opposing ears 26 
formed at the free ends 11 of the respective housing segments. 
Another modified embodiment of the pipe coupling and gasket means used 
therein is shown in FIGS. 8a and 8b. This embodiment includes the features 
already described in a coupling capable of joining two main pipes 15, 15' 
of different outside diameters. In addition, this coupling is equipped 
with an upwardly extending hollow boss 32, 32' on each of the two housing 
segments, 10, 10'. It will be noted that the hollow bosses are bored and 
tapped to accept branch pipes of unequal outside diameters. This 
embodiment differs further from the preferred embodiment of FIGS. 1, 2a, 
2b, 4 and 5 in that the outer 38 and inner 39 side-walls of each resilient 
hollow boss increase gradually in axial dimensions from a minimum, to the 
left of FIG. 8a to a maximum, at the right of FIG. 8b, so as to 
accommodate the decreased outside diameter of the pipe 15'. The dimensions 
of the annualar sealing lip 40, and of the upper 43a and lower 43b faces 
remain constant. Also, the outer main side-walls 54, 54' of both coupling 
segments 10, 10' are axially extended to accommodate the decreased outside 
diameter of pipe 15', and each of said side-walls terminates in a flange 
16' said flanges together defining a diameter smaller than that defined by 
the axially opposite flanges 16, 16'. This change in flange diameter 
necessitates an inward slanting of the continuous inner wall surface 12 of 
the coupling segments 10, 10', and a corresponding inward slanting of the 
outer surface 20 of each gasket section (see FIG. 8b). In all other 
respects, the dimensions and arrangement of the various components 
correspond to those of the preferred embodiment. 
FIGS. 9 and 10 show further modifications of the gasket means 17 of the 
present invention. 
In FIG. 9, two circumferential ribs 30 have been added to the outer surface 
20 of the gasket means 17. The gasket section is in all other respects 
identical to that shown in FIG. 3a. These ribs have been found to enhance 
the sealing at the inner surfaces 22, 22' especially when excessive radial 
deflection of the pipes 15 occurs. 
FIG. 10 shows a section of gasket means 17, having a main arcuate extent of 
generally C-shaped cross-section. This gasket section is similar to the 
gasket sections shown in FIGS. 2a, 3a, and 3b, with the exception that the 
free end 18' of the section forms a solid end wall 31' for abutment 
against a second solid end wall (not shown) of an opposing gasket section. 
It will be noted that the radially inner part of the solid end wall 31' 
extends upwardly beyond the general plane of the wall 31' to provide 
circumferentially extending projections, similar to and having the same 
purpose as, the projections 24, 24' of the second portions 22b, 22b' of 
the axially opposite inner surfaces 22, 22' of the embodiment described 
above with reference to FIGS. 3a and 3b. 
Although only a limited number of embodiments of the invention have been 
illustrated in the accompanying drawings and described in the foregoing 
specification, it is to be especially understood that various changes, 
such as in the relative dimensions of the parts, materials used, the 
number and placement of side outlets, and the like, as well as the 
suggested manner of use of the apparatus of the invention, may be made 
therein without the parting from the spirit and scope of the invention, as 
will be apparent to those skilled in the art.