U.S. patent application number 16/509951 was filed with the patent office on 2019-10-31 for split ring coupling and fitting.
The applicant listed for this patent is Victaulic Company. Invention is credited to Matthew A. Bowman.
Application Number | 20190331265 16/509951 |
Document ID | / |
Family ID | 68292205 |
Filed Date | 2019-10-31 |
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United States Patent
Application |
20190331265 |
Kind Code |
A1 |
Bowman; Matthew A. |
October 31, 2019 |
Split Ring Coupling and Fitting
Abstract
A pipe fitting has housing portions attached in spaced relation
to define non-coaxial receptacles that receive pipe elements. The
housing portions are supported on split rings received within
grooves in each housing portion. The housing portions are supported
in spaced relation in a preassembled state to permit insertion of
pipe elements into the receptacles without disassembly of the
fitting. The grooves in the housing portions have a floor surface
with three surface portions. Two of the surface portions on each
groove of each housing portion engage the split rings when the
housing portions are supported in spaced relation.
Inventors: |
Bowman; Matthew A.; (Palmer,
PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Victaulic Company |
Easton |
PA |
US |
|
|
Family ID: |
68292205 |
Appl. No.: |
16/509951 |
Filed: |
July 12, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15267735 |
Sep 16, 2016 |
10371295 |
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16509951 |
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14574984 |
Dec 18, 2014 |
10100957 |
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15267735 |
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61920138 |
Dec 23, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16L 43/00 20130101;
F16L 17/04 20130101; F16L 21/08 20130101; F16L 37/088 20130101;
F16L 21/065 20130101; F16L 37/091 20130101 |
International
Class: |
F16L 21/06 20060101
F16L021/06; F16L 37/091 20060101 F16L037/091; F16L 37/088 20060101
F16L037/088; F16L 17/04 20060101 F16L017/04 |
Claims
1. A fitting for connecting at least two pipe elements together,
said fitting comprising: first and second housing portions attached
to one another in spaced apart relation and defining at least first
and second receptacles for receiving said pipe elements, said first
and second receptacles respectively surrounding first and second
axes, said first axis oriented coaxially with said first
receptacle, said second axis oriented coaxially with said second
receptacle, said first axis being angularly oriented with respect
to said second axis, said housing portions further defining a fluid
path extending between said first and second receptacles, each of
said housing portions comprising: a first groove extending
circumferentially about said first receptacle and a second groove
extending circumferentially about said second receptacle, each of
said grooves defined by two side surfaces arranged in spaced
relation and a floor surface extending therebetween, each said
floor surface comprising first and second surface portions arranged
respectively at opposite ends of each said groove, and a third
surface portion positioned therebetween, said first and second
surface portions each having a greater radius of curvature than
said third surface portion; a first split ring positioned within
said first groove and a second split ring positioned within said
second groove, said first and second split rings engaging said
first and second surface portions of said floors in said first and
second grooves.
2. A fitting for connecting at least two pipe elements together,
said fitting comprising: first and second housing portions attached
to one another in spaced apart relation and defining at least first
and second receptacles for receiving said pipe elements, said first
and second receptacles respectively surrounding first and second
axes, said first axis oriented coaxially with said first
receptacle, said second axis oriented coaxially with said second
receptacle, said first axis being angularly oriented with respect
to said second axis, said housing portions further defining a fluid
path extending between said first and second receptacles, each of
said housing portions comprising: a groove extending
circumferentially about said first receptacle, said groove defined
by two side surfaces arranged in spaced relation and a floor
surface extending therebetween, said floor surface comprising first
and second surface portions arranged respectively at opposite ends
of said groove and a third surface portion positioned therebetween,
said first and second surface portions each having a greater radius
of curvature than said third surface portion; a split ring
positioned within said groove, said split ring engaging said first
and second surface portions of said floor surface.
3. A fitting for connecting at least two pipe elements together,
said fitting comprising: first and second housing portions attached
to one another in spaced apart relation and defining at least first
and second receptacles for receiving said pipe elements, said first
and second receptacles having respective first and second back
walls respectively surrounding first and second axes, said first
axis oriented coaxially with said first receptacle, said second
axis oriented coaxially with said second receptacle, said first
axis being angularly oriented with respect to said second axis,
said housing portions further defining a fluid path extending
between said first and second receptacles, each of said housing
portions comprising: a first groove extending circumferentially
about said first receptacle and a second groove extending
circumferentially about said second receptacle, each of said
grooves defined by two side surfaces arranged in spaced relation
and a floor surface extending therebetween, said floor surface of
said first groove facing said first axis, said floor surface of
said second groove facing said second axis; a first split ring
positioned within said first groove and a second split ring
positioned within said second groove, at least one of said first
and second split rings engaging at least one of said floor surfaces
in one of said first and second grooves and thereby supporting said
housing portions in said spaced apart relation; wherein, for at
least one of said housing portions: a distance between said first
back wall and said floor surface of said first groove, as measured
along a radially projecting line extending from said first axis, is
a first value at a first point midway between opposite ends of said
first groove, and a second value at a second point proximate to one
of said ends of said first groove, said first value being greater
than said second value.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation of U.S. patent
application Ser. No. 15/267,735, filed Sep. 16, 2016, which
application is a Continuation in Part of and claims benefit of
priority to U.S. patent application Ser. No. 14/574,984, filed Dec.
18, 2014, now U.S. Pat. No. 10,100,957, issued Oct. 16, 2018, which
patent is a non-provisional of and claims benefit of priority to
U.S. Provisional Patent Application No. 61/920,138, filed Dec. 23,
2013, all aforementioned applications and patent being hereby
incorporated by reference herein.
FIELD OF THE INVENTION
[0002] This invention relates to mechanical pipe couplings and
fittings for joining pipe elements.
BACKGROUND
[0003] Prior art mechanical couplings and fittings for joining pipe
elements together end-to-end comprise interconnectable segments or
housing portions that are positionable circumferentially
surrounding the end portions of co-axially aligned pipe elements.
The term "pipe element" is used herein to describe any pipe-like
item or component having a pipe-like form. Pipe elements include
pipe stock, pipe fittings such as elbows, caps and tees as well as
fluid control components such as valves, reducers, strainers,
restrictors, pressure regulators and the like.
[0004] Each mechanical coupling segment or housing portion has
arcuate surfaces which project radially inwardly and engage plain
end pipe elements, shoulder end pipe elements, shoulder and bead
pipe elements or circumferential grooves that extend around each of
the pipe elements to be joined. Engagement between the arcuate
surfaces and the pipe elements provides mechanical restraint to the
joint and ensures that the pipe elements remain coupled even under
high internal pressure and external forces. The segments and
housing portions define an annular channel that receives a sealing
element, typically an elastomeric ring which engages the ends of
each pipe element and cooperates with the segments or housing
portions to provide a fluid tight seal. The segments and housing
portions have connection members, typically in the form of lugs
which project outwardly from the segments and housing portions. The
lugs are adapted to receive fasteners, such as nuts and bolts,
which are adjustably tightenable to draw the segments or housing
portions toward one another.
[0005] To ensure a good fit between the couplings or fittings and
the pipe elements, the arcuate surfaces according to the prior art
have a radius of curvature that is substantially matched to the
radius of curvature of the outer surface of the pipe element that
it is intended to engage. For couplings or fittings used with
grooved pipe elements, the radii of curvature of the arcuate
surfaces are smaller than the radii of curvature of the outer
surfaces of the pipe elements outside of the grooves so that the
arcuate surfaces fit within and engage the grooves properly.
[0006] This geometrical relation between the arcuate surfaces of
the couplings or fittings and the outer surfaces of the pipe
elements according to the prior art results in a time consuming
installation process when mechanical couplings or fittings are
used. Typically, the coupling or fitting is received by the
technician with the segments or housing portions bolted together
and the sealing element captured within the segments or housing
portions. The technician first disassembles the coupling or fitting
by unbolting it, removes the sealing element, lubricates it (if not
pre-lubricated) and places it around the ends of the pipe elements
to be joined. Installation of the sealing element requires that it
be lubricated and stretched significantly to accommodate the pipe
elements, an often difficult and messy task, as the sealing element
is usually stiff and the lubrication makes manual manipulation of
the seal difficult. With the sealing element in place on both pipe
elements, the segments or housing portions are then placed one at a
time straddling the ends of the pipe elements and capturing the
sealing element against them. During placement, the segments or
housing portions engage the sealing element, the arcuate surfaces
are aligned with the grooves when present, or with alignment marks
made on the outside surfaces of the pipe elements, the bolts are
inserted through the lugs, the nuts are threaded onto the bolts and
tightened, drawing the coupling segments or housing portions toward
one another, compressing the sealing element and engaging the
arcuate surface within the grooves.
[0007] As evident from the previous description, installation of
mechanical pipe couplings and fittings according to the prior art
requires that the technician typically handle at least seven
individual piece parts (and more when the coupling has more than
two segments), and must totally disassemble and reassemble the
coupling or fitting. Significant time, effort and expense would be
saved if the technician could install a mechanical pipe coupling or
fitting without first totally disassembling it and then
reassembling it, piece by piece.
SUMMARY
[0008] The invention concerns a fitting for connecting at least two
pipe elements together. In one example embodiment the fitting
comprises first and second housing portions attached to one another
in spaced apart relation and defining at least first and second
receptacles for receiving the pipe elements. The first and second
receptacles respectively surround first and second axes. The first
axis is oriented coaxially with the first receptacle, the second
axis is oriented coaxially with the second receptacle. The first
axis is angularly oriented with respect to the second axis. The
housing portions further define a fluid path extending between the
first and second receptacles. By way of example each of the housing
portions comprise a first groove extending circumferentially about
the first receptacle, and a second groove extending
circumferentially about the second receptacle. Each of the grooves
is define by two side surfaces arranged in spaced relation and a
floor surface extending therebetween. Each floor surface comprises
first and second surface portions arranged respectively at opposite
ends of each the groove, and a third surface portion positioned
therebetween. The first and second surface portions each have a
greater radius of curvature than the third surface portion. A first
split ring is positioned within the first groove and a second split
ring is positioned within the second groove. The first and second
split rings engage the first and second surface portions of the
floors in the first and second grooves.
[0009] In an example embodiment the first and second split rings
support the housing portions in the spaced apart relation. By way
of further example at least one of the split rings has an outer
radius of curvature and an inner radius of curvature. The inner
radius of curvature is at least equal to an outer radius of one of
the pipe elements. In an example embodiment, the radius of
curvature of the first and second surface portions on at least one
of the housing portions is equal to the outer radius of curvature
of the at least one split ring. In a further example, at least one
of the split rings supports the housing portions in a preassembled
state in spaced apart relation sufficient to allow the pipe
elements to be inserted into the first and second receptacles. By
way of example, at least one split ring has sufficient stiffness to
maintain the housing portions in the preassembled state through
handling of the fitting during insertion of the pipe elements.
[0010] In an example embodiment at least one of the first and
second surface portions has a length extending from about 5% to
about 30% of a total length of at least one of the grooves. In a
particular example embodiment at least one of the split rings has a
rectangular cross sectional shape. By way of example, at least one
of the split rings comprises a plurality of teeth arranged in
spaced relation to one another and extending circumferentially
around the at least one split ring. The teeth project toward one of
the first and second axes.
[0011] An example fitting further comprises a first seal positioned
within the first receptacle, a second seal positioned within the
second receptacle, and a tube extending within the housing portions
between the first and second seals. By way of example the first and
second seals each comprise a flexible, resilient ring having ring
inner surfaces adapted to engage outer surfaces of the pipe
elements. The ring inner surfaces have a diameter sized to receive
the pipe elements upon insertion of the pipe elements into the
first and second receptacles. By way of example, the housing
portions comprise adjustably tightenable connection members for
drawing the housing portions toward one another. In an example
embodiment, the adjustably tightenable connection members include a
plurality of fasteners. The fasteners extends between the housing
portions and holding the housing portions together in a
preassembled state.
[0012] In an example fitting, at least a first angularly oriented
surface is located on the first housing portion. At least a second
angularly oriented surface is located on the second housing
portion. The first and second angularly oriented surfaces are in
facing relation and slide over one another when the fasteners are
tightened to bring the first and second angularly oriented surfaces
into contact. Sliding motion between the first and second angularly
oriented surfaces causes the first and second housing portions to
rotate in opposite directions relatively to one another.
[0013] The invention encompasses a fitting for connecting at least
two pipe elements together. In an example embodiment the fitting
comprises first and second housing portions attached to one another
in spaced apart relation and defining at least first and second
receptacles for receiving the pipe elements. The first and second
receptacles respectively surround first and second axes. The first
axis is oriented coaxially with the first receptacle, and the
second axis oriented coaxially with the second receptacle. The
first axis is angularly oriented with respect to the second axis.
The housing portions further define a fluid path extending between
the first and second receptacles. By way of example, each of the
housing portions comprise a groove extending circumferentially
about the first receptacle. The groove is defined by two side
surfaces arranged in spaced relation and a floor surface extending
therebetween. The floor surface comprises first and second surface
portions arranged respectively at opposite ends of the groove and a
third surface portion positioned therebetween. The first and second
surface portions each have a greater radius of curvature than the
third surface portion. A split ring is positioned within the
groove. The split ring engages the first and second surface
portions of the floor surface.
[0014] In an example embodiment, the split ring supports the
housing portions in the spaced apart relation. By way of further
example the split ring has an outer radius of curvature and an
inner radius of curvature. The inner radius of curvature is at
least equal to an outer radius of one of the pipe elements. In an
example embodiment, the radius of curvature of the first and second
surface portions on at least one of the housing portions is equal
to the outer radius of curvature of the split ring. By way of
example, the split ring supports the housing portions in a
preassembled state in spaced apart relation sufficient to allow one
of the pipe elements to be inserted into the first receptacle.
[0015] In a specific example embodiment, at least one of the first
and second surface portions has a length extending from about 5% to
about 30% of a total length of the groove. By way of further
example, a first seal is positioned within the first receptacle, a
second seal positioned within the second receptacle, and a tube
extending within the housing portions between the first and second
seals. In a specific example embodiment, the first and second seals
each comprise a flexible, resilient ring having a ring inner
surface adapted to engage outer surfaces of the pipe elements. The
ring inner surfaces have a diameter sized to receive the pipe
elements upon insertion of the pipe elements into the first and
second receptacles. In a further example, the housing portions
comprise adjustably tightenable connection members for drawing the
housing portions toward one another.
[0016] The invention encompasses a fitting for connecting at least
two pipe elements together. In an example embodiment the fitting
comprises first and second housing portions attached to one another
in spaced apart relation and defining at least first and second
receptacles for receiving the pipe elements. The first and second
receptacles have respective first and second back walls
respectively surrounding first and second axes. The first axis is
oriented coaxially with the first receptacle, and the second axis
is oriented coaxially with the second receptacle. The first axis is
angularly oriented with respect to the second axis. The housing
portions further define a fluid path extending between the first
and second receptacles. By way of example each of the housing
portions comprise a first groove extending circumferentially about
the first receptacle and a second groove extending
circumferentially about the second receptacle. Each of the grooves
is defined by two side surfaces arranged in spaced relation and a
floor surface extending therebetween. The floor surface of the
first groove faces the first axis, the floor surface of the second
groove faces the second axis. A first split ring is positioned
within the first groove and a second split ring positioned within
the second groove. At least one of the first and second split rings
engage at least one of the floor surfaces in one of the first and
second grooves and thereby support the housing portions in the
spaced apart relation. In this example, for at least one of the
housing portions, a distance between the first back wall and the
floor surface of the first groove, as measured along a radially
projecting line extending from the first axis, is a first value at
a first point midway between opposite ends of the first groove, and
a second value at a second point proximate to one of the ends of
the first groove, the first value being greater than the second
value.
[0017] In an example embodiment, the first and second split rings
support the housing portions in the spaced apart relation. By way
of example, at least one of the split rings has an outer radius of
curvature and an inner radius of curvature. The inner radius of
curvature is at least equal to an outer radius of one of the pipe
elements. Further by way of example, a radius of curvature of the
floor surface proximate to the one end of the first groove on the
at least one housing portion is equal to the outer radius of
curvature of the at least one split ring. In an example embodiment,
the at least one split ring supports the housing portions in a
preassembled state in spaced apart relation sufficient to allow the
pipe elements to be inserted into the receptacles. By way of
example, the at least one split ring has sufficient stiffness to
maintain the housing portions in the preassembled state through
handling of the fitting during insertion of the pipe elements. In a
particular example, a distance between the first back wall and the
floor surface of the first groove, as measured along a radially
projecting line extending from the first axis, is a third value at
a third point proximate to another one of the ends of the first
groove, the third value being equal to the second value.
[0018] In a specific example, at least one of the split rings has a
rectangular cross sectional shape. Further by way of example, at
least one of the split rings comprises a plurality of teeth
arranged in spaced relation to one another and extending
circumferentially around the at least one split ring. The teeth
project toward one of the first and second axes. By way of further
example, a first seal is positioned within the first receptacle, a
second seal is positioned within the second receptacle, and a tube
extends within the housing portions between the first and second
seals. In an example embodiment, the first and second seals each
comprise a flexible, resilient ring having ring inner surfaces
adapted to engage outer surfaces of the pipe elements. The ring
inner surfaces have a diameter sized to receive the pipe elements
upon insertion of the pipe elements into the first and second
receptacles. By way of example, the housing portions comprise
adjustably tightenable connection members for drawing the housing
portions toward one another. In a specific example embodiment, the
adjustably tightenable connection members include a plurality of
fasteners. The fasteners extend between the housing portions and
hold the housing portions together in a preassembled state.
[0019] By way of example, a fitting further comprises at least a
first angularly oriented surface located on the first housing
portion, and at least a second angularly oriented surface located
on the second housing portion. The first and second angularly
oriented surfaces being in facing relation and sliding over one
another when the fasteners are tightened to bring the first and
second angularly oriented surfaces into contact. Sliding motion
between the first and second angularly oriented surfaces causes the
first and second housing portions to rotate in opposite directions
relatively to one another.
[0020] The invention encompasses a fitting for connecting at least
two pipe elements together. By way of example, the fitting
comprises first and second housing portions attached to one another
in spaced apart relation and defining at least first and second
receptacles for receiving the pipe elements. The first and second
receptacles have respective first and second back walls
respectively surrounding first and second axes. The first axis is
oriented coaxially with the first receptacle, the second axis
oriented coaxially with the second receptacle, and the first axis
is angularly oriented with respect to the second axis. The housing
portions further defining a fluid path extending between the first
and second receptacles. In an example embodiment, each of the
housing portions comprise at least one groove extending
circumferentially about the first receptacle. The at least one
groove is defined by two side surfaces arranged in spaced relation
and a floor surface extending therebetween. The floor surface of
the at least one groove faces the first axis. A split ring is
positioned within the at least one groove. The split ring engages
the floor surface of the at least one groove proximate to opposite
ends of the at least one groove and supports the housing portions
in the spaced apart relation. In an example embodiment, for at
least one housing portion, a distance between the back wall and the
floor surface of the at least one groove, as measured along a
radially projecting line extending from the first axis, is a first
value at a first point midway between opposite ends of the at least
one groove, and a second value at a second point proximate to one
of the ends of the at least one groove, the first value being
greater than the second value.
[0021] In an example embodiment, the split ring has an outer radius
of curvature and an inner radius of curvature. The inner radius of
curvature is at least equal to an outer radius of one of the pipe
elements. By way of example, a radius of curvature of the floor
surface proximate to the one end of the first groove on the at
least one housing portion is equal to the outer radius of curvature
of the split ring. In an example embodiment, the split ring
supports the housing portions in a preassembled state in spaced
apart relation sufficient to allow one the pipe element to be
inserted into the first receptacle. In a particular example, the
split ring has sufficient stiffness to maintain the housing
portions in the preassembled state through handling of the fitting
during insertion of the pipe elements.
[0022] In an example embodiment, a distance between the first back
wall and the floor surface of the first groove, as measured along a
radially projecting line extending from the first axis, is a third
value at a third point proximate to another one of the ends of the
first groove, the third value being equal to the second value. In a
particular embodiment, the split ring has a rectangular cross
sectional shape. By way of further example, the split ring
comprises a plurality of teeth arranged in spaced relation to one
another and extending circumferentially around the split ring. The
teeth project toward the first axis.
[0023] An example fitting further comprises a first seal positioned
within the first receptacle. A second seal is positioned within the
second receptacle, and a tube extends within the housing portions
between the first and second seals. By way of example, the first
and second seals each comprise a flexible, resilient ring having
ring inner surfaces adapted to engage outer surfaces of the pipe
elements. The ring inner surfaces have a diameter sized to receive
the pipe elements upon insertion of the pipe elements into the
first and second receptacles. By way of example, the housing
portions comprise adjustably tightenable connection members for
drawing the housing portions toward one another. In a specific
example the adjustably tightenable connection members include a
plurality of fasteners. The fasteners extend between the housing
portions and hold the housing portions together in a preassembled
state.
[0024] An example fitting further comprises at least a first
angularly oriented surface located on the first housing portion. At
least a second angularly oriented surface located the second
housing portion. The first and second angularly oriented surfaces
are in facing relation and slide over one another when the
fasteners are tightened to bring the first and second angularly
oriented surfaces into contact. Sliding motion between the first
and second angularly oriented surfaces cause the first and second
housing portions to rotate in opposite directions relatively to one
another.
[0025] The invention encompasses a fitting for connecting at least
two pipe elements together. In an example embodiment, the fitting
comprises first and second housing portions attached to one another
in spaced apart relation and defining at least first and second
receptacles for receiving the pipe elements. The first and second
receptacles respectively surround first and second axes. The first
axis is oriented coaxially with the first receptacle, the second
axis is oriented coaxially with the second receptacle, and the
first axis is angularly oriented with respect to the second axis.
The housing portions further define a fluid path extending between
the first and second receptacles. By way of example, each of the
housing portions comprise a first groove extending
circumferentially about the first receptacle and a second groove
extending circumferentially about the second receptacle. Each of
the grooves is defined by two side surfaces arranged in spaced
relation and a floor surface extending therebetween. Each floor
surface comprises first and second surface portions arranged
respectively at opposite ends of the grooves and a third surface
portion positioned therebetween. The first and second surface
portions each have a center of curvature offset from a center of
curvature of the third surface portion. A first split ring is
positioned within the first groove and a second split ring
positioned within the second groove. The first and second split
rings engage the first and second surface portions of the floors in
the first and second grooves and supporting the housing portions in
the spaced apart relation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is an axial view of an example pipe coupling
according to the invention;
[0027] FIG. 1A is an isometric exploded view of the pipe coupling
shown in FIG. 1;
[0028] FIG. 2 is an isometric view of a segment from the pipe
coupling shown in FIG. 1;
[0029] FIG. 3 is a partial cross sectional view of the pipe
coupling shown in FIG. 1;
[0030] FIG. 3A is a partial cross sectional view of an example
embodiment of a pipe coupling according to the invention;
[0031] FIG. 3B is an isometric view of a segment from the pipe
coupling shown in FIG. 3A;
[0032] FIGS. 3C, 3D and 3E are cross sectional views of example
embodiments of coupling segments according to the invention;
[0033] FIGS. 4 and 5 are axial views of another example embodiment
of a pipe coupling according to the invention;
[0034] FIG. 5A is a longitudinal sectional view of the pipe
coupling shown in FIGS. 4 and 5;
[0035] FIGS. 6 and 7 are isometric views of example seals used with
the pipe couplings according to the invention;
[0036] FIGS. 8-10 are longitudinal sectional views illustrating a
method of using the pipe couplings according to the invention;
[0037] FIG. 11 is an axial view of an example coupling according to
the invention;
[0038] FIG. 12 is an isometric view of an example fitting according
to the invention;
[0039] FIG. 13 is an exploded isometric view of the fitting shown
in FIG. 12;
[0040] FIGS. 14 and 14A are an isometric views of example housing
portions used with the fitting of FIG. 1;
[0041] FIG. 15 is a side view of a toothed split ring;
[0042] FIG. 16 is an exploded isometric view of a sealing
element;
[0043] FIG. 17 is a rear view of the fitting shown in FIG. 12;
[0044] FIG. 18 is an isometric view of an example fitting forming a
pipe joint;
[0045] FIG. 19 is a plan sectional view of a fitting forming a pipe
joint;
[0046] FIGS. 20 and 21 are longitudinal sectional views taken at
lines 20-20 of FIG. 19;
[0047] FIG. 22 is a longitudinal sectional view of a portion of an
example fitting;
[0048] FIGS. 23-25 are cross sectional views of example embodiments
of fittings; and
[0049] FIG. 26 is an isometric view of a housing portion of an
example fitting.
DETAILED DESCRIPTION
[0050] FIGS. 1 and 1A show an example coupling 10 according to the
invention. Coupling 10 comprises a plurality of segments, in this
example, two segments 12 and 14 attached to one another end to end
surrounding a central space 16. As shown in FIG. 2, each of the
segments 12 and 14 (12 shown) has a channel 20 that extends between
the ends 22 and 24 of the segments. Each segment 12 and 14 also has
first and second grooves 26 and 28. Grooves 26 and 28 extend
between ends 22 and 24 of the segments and are positioned in spaced
relation from one another on opposite sides of the channel 20. Each
groove 26 and 28 is defined by two side surfaces 30 and 32,
arranged in spaced relation, and a floor surface 34 that extends
between the side surfaces. As shown in FIGS. 2 and 3, floor surface
34 comprises three surface portions 36, 38 and 40. The first and
second surface portions 36 and 38 are arranged, respectively, at
opposite ends 22 and 24 of the segments 12 and 14. The third
surface portion 40 is positioned between the first and second
surface portions 36 and 38. Each of the first and second surface
portions 36 and 38 has a respective radius of curvature 42 and 44,
and these radii are larger than the radius of curvature 46 of the
third surface portion 40. The first and second surface portions 36
and 38 advantageously have a length from about 5% to about 30% of
the total length of one of the grooves 26, 28.
[0051] As shown in FIGS. 1, 1A and 3, coupling 10 includes first
and second split rings 48 and 50. Split ring 48 is positioned
within groove 26 and split ring 50 is positioned within groove 28
of the segments 12 and 14. With reference to FIG. 3, the split
rings (48 being shown) have an outer radius of curvature 52 and an
inner radius of curvature 54. In their undeformed state, the outer
radii of curvature 52 of the split rings is sized so that the split
rings 48 and 50 engage the first and second surface portions 36 and
38 of floor surface 34 and thereby support the segments 12 and 14
in spaced apart relation sufficient to permit pipe elements to be
inserted into the central space 16 as described in detail below.
This spaced configuration of the segments (shown in FIGS. 1 and 3)
is known as the "preassembled state", and the stiffness of the
split rings 48 and 50 is sufficient to maintain the segments 12 and
14 in this preassembled state during shipping, handling and
assembly of the joint. It is advantageous that the radii of
curvature 42 and 44 of the first and second surface portions 36 and
38 of the floor surface 34 of the grooves 26 and 28 be
substantially equal to the radii of curvature of the split rings 48
and 50 in their undeformed state. Further to this end, when in
their undeformed state, the inner radii of curvature 54 of the
split rings 48 and 50 are sized to be at least as large as the
maximum radius of the pipe elements that the coupling 10 is
intended to join. This permits insertion of the pipe elements into
the central space 16 when the coupling 10 is in its preassembled
state as described below.
[0052] In the preassembled state, the segments 12 and 14 are
attached to one another end to end surrounding the central space 16
and are supported in spaced relation to one another as shown in
FIG. 1, the spacing being sufficient to permit pipe elements to be
inserted between the segments 12 and 14 into the central space 16.
Interconnection of the segments 12 and 14 is effected by connection
members, preferably in the form of lugs 56 and 58 shown in FIGS. 1
and 2. The lugs are preferably positioned at each end of each
segment and project outwardly from the segments. Lugs 56 and 58 are
positioned in facing relation to one another and adapted to receive
fasteners, preferably in the form of bolts 60 and nuts 62 which are
adjustably tightenable and cooperate with the lugs 56 and 58 for
adjustably connecting the coupling segments to one another as
discussed in further detail below. The stiffness of the split rings
48 and 50, while sufficient to support the segments 12 and 14 in
the spaced relation of the preassembled state, is not so great that
it prevents the use of hand tools to tighten the bolts 60 and nuts
62 to draw the segments 12 and 14 toward the central space 16,
thereby deforming the split rings to the point where their outer
radii of curvature 52 are smaller and substantially equal to the
radii of the third surface portion 40 of the grooves 26 and 28. The
inner radii of curvature 54 also become smaller as the split rings
deform to permit them to engage grooves in pipe elements and
provide mechanical engagement between the coupling 10 and the pipe
elements to retain the pipe elements to the coupling against
externally applied forces as well as forces due to internal
pressure within the pipe elements that would tend to cause
separation of the joint. (Other types of pipe elements, for
example, shouldered and shoulder and bead pipe elements may also be
effectively engaged by the inner radii of curvature 54.) When used
with grooved pipe elements it is advantageous that the split rings
have a rectangular cross sectional shape (as shown in FIG. 1A) so
as to provide substantially continuous engagement within the
grooves. In an another coupling embodiment 64, shown in FIGS. 4, 5
and 5A, the split rings 66 comprise a plurality of teeth 68. Teeth
68 are arranged in spaced relation to one another and extend
circumferentially around the split rings 66. Split rings 66 are
used advantageously with plain end pipe elements. The teeth 68
project toward the center 70 of the central space 16 and are forced
into engagement with the outer surface of the plain end pipe when
the split rings 66 are deformed by tightening the bolts 60 and nuts
62 to draw segments 12 and 14 toward the central space 16. The
teeth bite into the pipe elements to provide the desired mechanical
engagement to secure the pipe elements to the coupling. Use of
either type of split ring (toothed or rectangular cross section) is
expected to provide pipe couplings with exceptional stiffness. The
segments are advantageously formed of metal, such as iron, and the
split rings may be formed of spring steel, stainless steel,
beryllium copper, as well as polymers including plastics such as
nylon and acrylonitrile butadiene styrene (ABS).
[0053] FIGS. 3A and 3B show another example coupling 11 according
to the invention. Similar to coupling 10, coupling 11 comprises a
plurality of segments, in this example, two segments 13 and 15
attached to one another end to end surrounding a central space 17.
As shown in FIG. 3B, each of the segments 13 and 15 (13 shown) has
a channel 21 that extends between the ends 23 and 25 of the
segments. Each segment 13 and 15 also has first and second grooves
27 and 29. Grooves 27 and 29 extend between ends 23 and 25 of the
segments and are positioned in spaced relation from one another on
opposite sides of the channel 21. Each groove 27 and 29 is defined
by two side surfaces 31 and 33, arranged in spaced relation, and a
floor surface 35 that extends between the side surfaces. As shown
in FIGS. 3A and 3B, floor surface 35 comprises three surface
portions 37, 39 and 41. The first and second surface portions 37
and 39 are arranged, respectively, at opposite ends 23 and 25 of
the segments 13 and 15. The third surface portion 41 is positioned
between the first and second surface portions 37 and 39. Each of
the first and second surface portions 37 and 39 has a respective
center of curvature 43 and 45, and these centers of curvature are
offset from (i.e., not coincident with) the center of curvature 47
of the third surface portion 41. The first and second surface
portions 37 and 39 advantageously have a length from about 5% to
about 30% of the total length of one of the grooves 27, 29.
[0054] Similar to coupling 10, coupling 11 includes first and
second split rings 49 and 51 (49 shown). Split ring 49 is
positioned within groove 27 and split ring 51 is positioned within
groove 29 of the segments 13 and 15 (see FIG. 3B). With reference
to FIG. 3A, the split rings (49 being shown) have an outer radius
of curvature 53 and an inner radius of curvature 55. In their
undeformed state, the outer radii of curvature 53 of the split
rings is sized so that the split rings 49 and 51 engage the first
and second surface portions 37 and 39 of floor surface 35 and
thereby support the segments 13 and 15 in spaced apart relation
sufficient to permit pipe elements to be inserted into the central
space 17 as described in detail below. This spaced configuration of
the segments (shown in FIG. 3A) is known as the "preassembled
state", and the stiffness of the split rings 49 and 51 is
sufficient to maintain the segments 13 and 15 in this preassembled
state during shipping, handling and assembly of the joint. It is
advantageous if the radii of curvature of the first and second
surface portions 37 and 39 of the floor surface 35 of the grooves
27 and 29 are substantially equal to the radii of curvature of the
split rings 49 and 51 in their undeformed state. Further to this
end, when in their undeformed state, the inner radii of curvature
55 of the split rings 49 and 51 are sized to be at least as large
as the maximum radius of the pipe elements that the coupling 11 is
intended to join. This permits insertion of the pipe elements into
the central space 17 when the coupling 11 is in its preassembled
state as described below. Note that for coupling 11, the radii of
curvature of the first and second surface portions 37 and 39 have
no required relationship to the radius of curvature of the third
surface portion 41, unlike coupling 10, wherein the radii of
curvature 42 and 44 of surface portions 36 and 38 are greater than
the radius of curvature 46 of the third surface portion 40.
[0055] As shown in FIG. 3C, example coupling segments 93 according
to the invention may also be described by the geometric relation
between the back wall 91 extending between the ends of the segment
and defining the channel 69, and the floor surface 67 of the groove
29 that receives the split rings (not shown). The geometric
relation which permits the split rings to support the segments 93
in spaced relation as described above relates to a first distance
95, measured between the surface of back wall 91 and the floor
surface 67 of groove 29 along a radially projecting line 97 between
a central axis 35 (for example, the longitudinal axis of pipe
elements being joined by the segment) and a point 63 midway between
the ends of the segment 93, and a second distance 61, measured
between the surface of back wall 91 and the floor surface 67 of
groove 29 along a radially projecting line 59 between central axis
35 and a point 57 proximate to one end of the segment 93. The value
of the first distance 95 is greater than the value of the second
distance 61 for segments according to the invention.
[0056] This geometric condition may be accomplished, for example as
shown in FIG. 3C by continuously changing the curvature of the
floor surface 67 as it traverses between the points 63 and 57. In
another example, shown in FIG. 3D, the curvature of floor surface
67 is changed abruptly in the regions proximate to the ends of
segment 93. FIG. 3E shows floor surface 67 formed of faceted,
straight segments in the regions proximate to the ends of the
segments to receive the split rings for support of the segments in
spaced relation.
[0057] FIGS. 6 and 7 show examples of seals used with couplings 10,
11 and 64 according to the invention. Seal 72 (FIG. 6) is
preferably a flexible, resilient ring formed from elastomeric
material. The seal may have lips 74 that use the internal pressure
within the pipes to increase the sealing force between the seal and
the outer surfaces of the pipe elements. As shown in FIG. 7,
another seal embodiment 76 may also have a tongue 78 positioned
between the lips 74, the tongue extending circumferentially around
the seal and projecting radially inwardly. Tongue 78 provides a
stop surface that engages the ends of pipe elements to ensure
proper positioning of the seal 76 relatively to the pipe elements.
Engagement of the pipe elements with tongue 78 also effects
alignment of the pipe engaging surfaces with the grooves (if
present), or with alignment marks on the outside surface of the
pipe elements. Seals 72 and 76 are received within channels 20 (see
FIGS. 1A and 2) of the couplings 10 and 64.
[0058] Assembly of a pipe joint is illustrated in FIGS. 8-10. After
both pipe elements 80 and 82 are inserted into coupling 10 as shown
in FIGS. 8 and 9, nuts 62 are tightened (see also FIG. 1). The nuts
62 cooperate with their bolts 60 to draw the segments 12 and 14
toward the central space 16. Tightening of the nuts exerts a force
on the lugs 56 and 58 which compresses the split rings 48 and 50
and causes them to deform such that they engage the outer surfaces
of the pipe elements 80 and 82 within grooves 84 and 86. For plain
end pipe (see FIGS. 4 and 5), compression of the split rings 66
causes their teeth 68 to bite into the outer surface of the pipe
elements. Deformation of the split rings 48 and 50 is preferably
substantially elastic, allowing them to spring back substantially
to their original shape when the nuts 62 are loosened, thereby
permitting the coupling 10 to be reused in the manner according to
the invention as described herein. The split rings may also be
designed to have significant plastic deformation, wherein the
deformation imparts a permanent set to the rings. For practical
couplings, there will generally be some degree of both plastic and
elastic deformation occurring in the split rings as a result of
tightening the fasteners. The seal 72 is also deformed by this
process, with the lips 74 coming into full engagement with the pipe
element outer surfaces. Because the seal 72 is substantially
volumetrically incompressible, it must be provided with space into
which it may expand when radially compressed by the segments.
[0059] The joint stiffness may be increased using coupling segments
71 and 73 as shown in FIG. 11. In addition to having the grooves
and split rings as described above, segments 71 and 73 also have
angularly oriented surfaces 75 (on segment 71) and 77 (on segment
73). Surfaces 75 and 77 in this example are located adjacent to the
connection members 79 and 81. Surfaces 75 on segment 71 are in
respective facing relation with surfaces 77 on segment 73. As the
nuts 83 are tightened on bolts 85 the segments 71 and 73 are drawn
toward one another and into contact so that the surfaces 75 engage
and slide over surfaces 77. As the slopes of the surfaces 75 and 77
are opposite to one another on opposite ends of the couplings the
sliding motion between the surfaces causes the segments 71 and 73
to rotate in opposite directions relatively to one another about
axis 87 and force the split rings (not shown) to engage the side
surfaces of the grooves in which they are received, thereby adding
rigidity to the joint.
[0060] As shown in FIGS. 1 and 3, for the preassembled coupling 10,
it is advantageous to hold nuts 62 in a position on bolts 60 that
will maintain the segments 12 and 14 in the desired spaced apart
relation as determined by contact between the segments and the
split rings 48 and 50.
[0061] FIGS. 12 and 13 show an example embodiment of a fitting 90
for connecting pipe elements 92 and 94. Fitting 90 is shown as a
90.degree. elbow fitting by way of example, but other elbow angles
as well as "Tee" fittings joining three pipe elements are also
contemplated. Fitting 90 comprises first and second housing
portions 96 and 98 and is shown in FIG. 1 in a "preassembled state"
where the housing portions are attached to one another in spaced
apart relation. As explained below, it is advantageous to hold the
housing portions 96 and 98 in spaced apart relation sufficient to
allow pipe elements 92 and 94 to be inserted into the fitting. The
housing portions 96, 98 are advantageously formed of metal, such as
ductile iron.
[0062] Housing portions 96 and 98 define first and second
receptacles 100 and 102 which receive respective pipe elements 92
and 94 upon insertion. First and second receptacles 100 and 102
surround respective first and second axes 104 and 106. First axis
104 is oriented coaxially with receptacle 100 and second axis 106
is oriented coaxially with receptacle 102. Axes 104 and 106 are
angularly oriented with respect to one another. In this example the
orientation angle 108 between axes 104 and 106 is 90.degree.; other
orientation angles are of course feasible. Housing portions 96 and
98 define a fluid path 110 between the receptacles 100 and 102.
[0063] As shown in FIGS. 13 and 14 the housing portions 96 and 98
each comprise a first groove 112 which extends circumferentially
around the first receptacle 100 and a second groove 114 which
extends around the second receptacle 102. As shown in FIG. 14, each
groove 112, 114 is defined by two side surfaces 116, 118 arranged
in spaced relation. A floor surface 120 extends between the side
surfaces. Floor surface 120 comprises first and second surface
portions 122 and 124 located at opposite ends of each groove 112,
114. A third surface portion 126 is positioned between the first
and second surface portions 122 and 124 of each groove 112 and 114.
One or both surface portions 122, 124 have a greater radius of
curvature 128 than the radius of curvature 130 of the third surface
portion 126. One or both surface portions 122, 124 may have a
length that extends from about 5% to about 45% of the total length
of a groove 112, 114 in one housing portion.
[0064] As shown in FIGS. 12 and 13, a first split ring 132 is
positioned within the first groove 112 surrounding receptacle 100
and a second split ring 134 is positioned within the second groove
114 surrounding the receptacle 102. Split rings 132 and 134 may
have a rectangular cross sectional shape as shown and may be formed
of spring steel, stainless steel, beryllium copper, as well as
polymers including plastics such as nylon and acrylonitrile
butadiene styrene (ABS). Split rings 132 and 134 are used to join
grooved end pipe elements as described below. For joining plain end
pipe elements a toothed split ring 136, shown in FIG. 15, is used.
Toothed split ring 136 comprises a ring 138 having a plurality of
teeth 140 arranged in spaced relation to one another. Teeth 140
extend circumferentially around the ring 138 and project toward
axes 104 and 106 when the toothed split rings 136 are in respective
grooves 112 and 114. The teeth are forced into engagement with the
outer surface of the plain end pipe when the split rings 136 are
deformed during formation of a joint. The teeth bite into the pipe
elements to provide the desired mechanical engagement to secure
them to the fitting 90. Use of either type of split ring (toothed
or rectangular cross section) is expected to provide fittings 90
with exceptional stiffness.
[0065] FIG. 13 also shows the sealing element 142 for fitting 90.
Sealing element 142 comprises a first seal 144 positioned within
the first receptacle 100, a second seal 146 positioned within the
second receptacle 102, and a tube 148 which extends within the
housing portions 96 and 98 along the fluid path 110 between the
first and second seals 144 and 146. In the example embodiment shown
in FIG. 13, each seal 144, 146 comprises a flexible, resilient ring
150 having a ring inner surface 152 adapted to engage the outer
surfaces of pipe elements 92 and 94 (see FIG. 12). Ring inner
surfaces 152 have a diameter sized to receive the pipe elements
upon their insertion into receptacles 100 and 102 as described
below. The ring inner surfaces 152 sealingly engage the pipe
elements when the sealing element 142 is compressed between the
housing portions 96 and 98. In example sealing element 142, rings
150 are integrally formed with the tube 148. Sealing element 142
may be formed from an elastomeric material. In another example
sealing element 154, shown in FIG. 16, the rings 150 are formed
separate from the tube 148. In this embodiment, rings 150 are
formed of an elastomeric material and tube 148 may be formed from a
harder, less resilient material against which ring sealing surfaces
156 may seal when the rings 150, 152 of sealing element 154 are
compressed between the housing portions 96 and 98.
[0066] As shown in FIGS. 12 and 13, each housing portion 96 and 98
comprises a plurality of adjustably tightenable connection members
158 (in this example, 3). In this example connection members 158
include lugs 160 on each housing portion which receive fasteners
162 that extend between the housing portions 96 and 98. Connection
members 158 permit the housing portions 96 and 98 to be drawn
toward one another when the fasteners 162 are tightened. As shown
in FIG. 17, engagement between the housing portions 96 and 98 may
be guided by projections 164 which extend from each housing portion
and are received in recesses 166 in each housing portion. The
stiffness of the joint formed between the pipe elements may also be
determined by interfacing surfaces on each housing portion 96, 98.
As shown in FIGS. 12, 13 and 14, housing portion 96 has angularly
oriented surface portions 168 and 170 in facing relationship with
respective mating angularly oriented surface portions 172 and 174
on housing portion 98. As the fasteners 162 are tightened the
surfaces are brought into engagement. Because the slopes of the
surfaces 168, 172 and 170, 174 are opposite to one another on
opposite ends of the fitting 90 sliding motion between the surfaces
is engendered which causes the housing portions 96, 98 to rotate in
opposite directions relatively to one another about axis 176 (see
FIG. 12) and force the split rings 132, 134 to engage the side
surfaces of the grooves in which they are received, thereby adding
rigidity to the joint. As shown in FIG. 14A, a more flexible joint
is achieved if the interfacing surfaces 178 near the connection
members 158 on the housing portions 96 and 98 (98 shown) are not
angularly oriented.
[0067] As shown in FIG. 13, the split rings 132, 134 have an outer
radius of curvature 180 and an inner radius of curvature 182. In
their undeformed state, the outer radius of curvature 180 of the
split rings is sized so that the split rings 132 and 134 engage the
first and second surface portions 122 and 124 of floor surface 120
(see FIG. 14) and thereby cooperate with the seals to support the
housing portions 96 and 98 in the presassembled state, in spaced
apart relation sufficient to permit pipe elements to be inserted
into the receptacles 100 and 102 as described in detail below. It
is advantageous if the combined stiffness of one or both split
rings 132 and 134 as well as the sealing element 142 or sealing
element 145 is sufficient to maintain the housing portions 96 and
98 in this preassembled state during shipping, handling and
assembly of the joint. It is further advantageous if the radii of
curvature 128 of the first and second surface portions 132 and 134
of the floor surface 120 of the grooves 112 and 114 is
substantially equal to the outer radii of curvature 180 of the
split rings 132 and 134 in their undeformed state. Further to this
end, when in their undeformed state, the inner radii of curvature
182 of the split rings 132 and 134 are sized to be at least as
large as the maximum radius of the pipe elements that the fitting
90 is intended to join. This permits insertion of the pipe elements
into the receptacles 100 and 102 when the fitting 90 is in its
preassembled state.
[0068] The stiffness of the split rings 132 and 134, while
sufficient to support the housing portions 96 and 98 in the spaced
relation of the preassembled state, is not so great that it
prevents the use of hand tools to tighten the fasteners 162 to draw
the housing portions 96 and 98 toward one another, thereby
deforming the split rings to the point where their outer radii 180
are smaller and substantially equal to the radius 130 of the third
surface portion 126 of the grooves 112 and 114. The inner radii 182
also become smaller as the split rings deform to permit them to
engage grooves in pipe elements and provide mechanical engagement
between the fitting 90 and the pipe elements to retain the pipe
elements to the fitting against externally applied forces as well
as forces due to internal pressure within the pipe elements that
would tend to cause separation of the joint. (Other types of pipe
elements, for example, shouldered and shoulder and bead pipe
elements may also be effectively engaged by the inner radii
182.)
[0069] Assembly of a pipe joint is illustrated in FIGS. 18-21. With
the fitting 90 in the preassembled state (FIG. 18) both pipe
elements 92 and 94 are inserted into receptacles 100 and 102 (FIG.
19). The outer surfaces of the pipe elements 92 and 94 engage the
ring inner surfaces 152 of rings 150 and contact an end of tube
148, which serves as a stop to locate the pipe elements within the
receptacles. As shown in FIG. 19, respective circumferential
grooves 92a and 94a on pipe elements 92 and 94 align with
respective split rings 132, 134 in grooves 112 and 114. The split
rings are in their undeformed shape, thus, as shown in FIG. 20, the
inner radii 182 of the spilt rings 132, 134 are at least equal to
or greater than the outer radii of the pipe elements 92 and 94
(only 92 shown) thereby enabling the pipe elements to pass through
the split rings upon insertion. Fasteners 162 of the connection
members 158 (see FIG. 18) are tightened. Adjustable tightening of
the connection members 158 draws housing portions 96 and 98 toward
one another thereby compressing the split rings 132 and 132. As
shown in FIG. 21, the split rings deform such that they engage the
outer surfaces of the pipe elements 92 and 94 (92 shown) within
grooves 92a and 94a. For plain end pipe (see FIGS. 15 and 22),
compression of the toothed split rings 136 causes their teeth 140
to bite into the outer surface of the pipe elements (94 shown).
[0070] Deformation of the split rings 132, 134 and 136 is
preferably substantially elastic, allowing them to spring back
substantially to their original shape when the fasteners 162 are
loosened, thereby permitting the fitting 90 to be reused in the
manner according to the invention as described herein. The split
rings may also be designed to have significant plastic deformation,
wherein the deformation imparts a permanent set to the rings. For
practical fittings, there will generally be some degree of both
plastic and elastic deformation occurring in the split rings as a
result of tightening the fasteners. The sealing element 142 is also
deformed by this process, with the ring inner surfaces 152 coming
into full engagement with the pipe element outer surfaces (see FIG.
20).
[0071] As shown in FIGS. 23-25, housing portions 96 and 98 (98
shown) may also be described by the geometric relation between back
walls 184, 186 (see also FIG. 14) respectively surrounding axes 104
and 106, and the floor surfaces 120 of the grooves 112, 114 that
receives the split rings (not shown). The geometric relation which
permits the split rings to support the housing portions 96 and 98
in spaced relation as described above relates to a distance 188,
measured between the surface of back walls 184, 186 and the floor
surface 120 of grooves 112, 114. The geometric relation is
described below for one back wall 186 and one floor surface 120 of
groove 114 on one housing portion 98, it being understood that the
relation may also apply to both receptacles 100, 102 on both
housing portions 96 and 98.
[0072] As shown in FIG. 23, distance 188 is measured along a
radially projecting line 190 extending from axis 106. Distance 188
is a first value at a first point 192 midway between opposite ends
of the groove 114, and a second value at a second point 194
proximate to one end of the groove 114. The first value is greater
than the second value. Distance 188 may also be measured along line
190 at a third point 196 proximate to the other end of groove 114.
It is advantageous for distance 188 at the third point 196 to have
a third value equal to the second value to symmetrically support
the housing portions 96 and 98 in spaced apart relation on the
split rings 132, 134.
[0073] This geometric condition between floor surfaces 120 and back
walls 184, 186 may be accomplished, for example as shown in FIG. 23
by continuously changing the curvature of the floor 120 as it
traverses between the points 194, 192 and 196. In another example,
shown in FIG. 24, the curvature of floor 120 is changed abruptly in
the regions proximate to the ends of groove 114. FIG. 25 shows
floor 120 formed of faceted, straight segments in the regions
proximate to the ends of the groove 114 to receive the split rings
for support of the housing portions in spaced relation.
[0074] Yet another way of describing the geometry of the floor
surfaces 120 so that the split rings 132, 134 support the housing
portions 96 and 98 is illustrated in FIG. 26. As described above,
floor surfaces 120 each comprise three surface portions 122, 124
and 126. The first and second surface portions 122 and 124 are
arranged, respectively, at opposite ends of the grooves 112 and
114. The third surface portion 126 is positioned between the first
and second surface portions 122 and 124. Each of the first and
second surface portions 122 and 124 has a respective center of
curvature 198 and 200, and these centers of curvature are offset
from (i.e., not coincident with) the center of curvature 202 of the
third surface portion 126. As shown in FIG. 26, the centers of
curvature 198 and 200 of the first and second surface portions 122
and 124 can be coincident which results in symmetric support of the
housing portions 96 and 98 by the split rings 132, 134.
[0075] Fittings 90 according to the invention are expected to
provide improved performance, for example, withstand higher
internal pressures and external forces while also reducing the time
and effort required to form a joint because the fittings are
provided in the preassembled state.
* * * * *