Abstract
A grooved-ended resilient expansion joint is disclosed. The expansion joint has a resilient expansion member with a central resilient portion and two resilient axially disposed cylindrical ends. Each cylindrical end has a radially outwardly raised distal cylindrical gasket portion with at least one inside shoulder having an inner diameter sized substantially the same as an outer diameter of a pipe to be joined. A pair of pre-assembled pipe couplings are provided for joining the expansion joint to a pair groove-ended pipe segments without disassembling the coupling.
Claims
1. A grooved-ended resilient pipe expansion joint and pipe coupling combination, comprising: an expansion joint further comprising a resilient expansion member having a central resilient portion and two resilient axially disposed cylindrical ends; each end having a radially outwardly raised distal cylindrical gasket portion with at least one inside shoulder having an inner diameter sized substantially the same as an outer diameter of a grooved ended pipe; each end having a neck portion between the central resilient portion and the radially outwardly raised distal cylindrical gasket portion the neck portion having an outer diameter substantially the same as an inner diameter of a grooved pipe nipple; and a pipe coupling for engaging one of the pair of grooved ended pipes and the grooved pipe nipple, the coupling further comprising upper and lower arcuate housing segments and left and right bridge segments disposed between the upper and lower arcuate housing segments, each bridge segment having at least first and second sets of dihedrally angled faces that engage corresponding faces each in the upper and lower arcuate housing segments such that drawing the upper and lower arcuate housing segments inwardly together along a first axis presses each bridge segment inward along a second axis roughly tangential to the first axis, wherein the first set of dihedrally angled faces have a line of intersection with the second set of dihedrally angled faces.
2. The combination of claim 1, further comprising the pipe coupling having axially inward projecting lands that mate with an end groove in the pipe.
3. The combination of claim 1, wherein the pipe coupling is loosely fastened around one of the cylindrical ends of the expansion joint and the end groove in the pipe, the end groove in the pipe disposed inside the inside shoulder of the cylindrical gasket portion of the expansion member, and the cylindrical gasket portion is thus disposed within an interior gasket receiving portion of the coupling.
4. The combination of claim 1, the cylindrical gasket portion further comprising a second inside shoulder, the second inside shoulder sized to receive the grooved pipe nipple, wherein the grooved pipe nipple is disposed inside the second inside shoulder of the cylindrical gasket portion.
5. The combination of claim 1, wherein the cylindrical gasket portion is formed into a trapezoid shape to fit the interior gasket receiving portion of the coupling.
6. The combination of claim 1, the resilient expansion member further comprising a plurality of central portions.
7. The combination of claim 6, wherein at least one of the plurality of central portions is roughly spherical.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] FIGS. 1A-1B are a front elevation of a conventional assembled pipe coupling and a schematic partial section of a conventional pipe gasket.
[0054] FIGS. 2A-2C are perspective partial sectional views of: a rubber expansion joint formed of rubber bellows with rubber flanges; a bellows reinforced with layers of nylon fabrics or steel braiding; and a flange installation requiring welding.
[0055] FIG. 3 is a schematic partial section of the disclosed pipe coupling.
[0056] FIGS. 4A-E are front elevations of disclosed assembled pipe couplings.
[0057] FIGS. 5A-D are schematic perspective and partial sections of disclosed pipe couplings.
[0058] FIG. 6 is a front elevation of a disclosed pre-assembled pipe coupling.
[0059] FIG. 7 is an exploded perspective of a disclosed pipe coupling.
[0060] FIGS. 8A-C are side, plan and detail views of disclosed cooping bridge pieces.
[0061] FIG. 9 is a perspective partial sectional view of a flange installation with special adapters.
[0062] FIG. 10 is a perspective partial sectional view of a disclosed rubber expansion joint.
BEST MODE
[0063] Turning now to the drawings, the invention will be described in various forms by reference to the numerals of the drawing figures wherein like numbers indicate like parts.
[0064] FIGS. 1A and 1B illustrate typical features of some conventional pipe couplings. Coupling 10 has upper and lower arcuate segments 1 and 2, both enclosing gasket 3, and fastened together by bolts 5 and nuts 4. Pipe 20 fitted with end grooves 22 is shown for comparison of diameters with gasket 3. Conventional pipe gasket 3, especially if provided as a one-piece gasket, has an inner diameter B that is less than the outer diameter OD of pipe 20. This has been reported to optimize sealing of gasket 3 on pipe 20. The problem is that gasket 3 must first be stretched onto the end of pipe 20, with attendant effort and risk of tearing or gouging or dropping gasket 3, and with potential insurmountable difficulty when at least one pipe end is already in a hard to reach location.
[0065] FIG. 2A illustrates a conventional rubber expansion joint 13 which includes rubber bellows 12 and a pair of steel flange reinforcements 11. FIG. 2B illustrates conventional rubber expansion joint 26 with conventional bellows rubber 28 reinforced with layers of nylon fabric or steel braiding 23, and a steel flange 24. FIG. 2C illustrates the necessity of high temperature welding 31 to install a flange on a conventional pipe end.
[0066] FIG. 9 illustrates the use of special adapters 41 to install a flanged rubber expansion joint in a grooved piping system.
[0067] In FIG. 10, rubber expansion joint 103 has rubber bellows 140 and grooved pipe nipple 150. The axial outer ends of joint 103 have a neck portion 143 and a seal portion 142, desirably in roughly trapezoidal (section) form. Pipe nipple 150 is seated on neck portion 143. Seal portion 142 engages pipe 120 in pipe grove 129 and all is connected firmly with couplings 130. Coupling 130 can advantageously be coupling 100 (see FIGS. 6 and 7).
[0068] FIG. 3 shows an unconventional comparison of diameters with pipes 20 and gasket 110 inside of pipe coupling 100. Gasket 110 has an inner diameter B (measured at or near the base of sealing lips 112, not at the tips of the lips) that is greater than the outer diameter OD of pipe 20 to optimize quick insertion and quick fit of pipe 20 into gasket 110, without any sacrifice of sealing effectiveness. Abutment of pipes 20 with pipe stop 113 inside gasket 110 is schematically illustrated as well. FIG. 3 schematically illustrates the pipe insertion phase of the process, with coupling lands 122 not yet engaged or mated with pipe end groove 22. That happens during the coupling tightening phase. (See generally FIG. 5.)
[0069] FIG. 4 illustrates disclosed variants of a novel pre-assembled pipe coupling. Each alternative embodiment differs principally from the others only in design and placement of the various bridge segments 121-125. In general each coupling 100 has upper housing segment 101, lower housing segment 102, fastened (in FIG. 4—FIG. 4E is not yet fastened or locked, but rather in pre-assembled state) with bolts 105 and nuts 104. Both bridge segments 121 are shown driven fully inward by the tightening action of the bolts compressing upper and lower segments 101, 102 together, such that all four segments are fully and roughly equally providing circumferential pressure to gasket 110 and to the pipes (not generally shown in FIG. 4).
[0070] FIG. 5 illustrates, among other details, the four way compressing action provided by the combination of upper and lower housing segments and bridge segments 121 between them. After pipes 20 are inserted into coupling 100 (FIG. 5B), with pipe ends abutting and stopped by pipe stop 113 of gasket 110, and sealing lips 112 flexed inward and sealing against the pipe OD, segment lands 122 are not yet engaged in pipe grooves 22.
[0071] In FIG. 5A, when the bolts are tightened, a compressive force is generated generally along axis 33, which in turn, because of the complementary angular faces 126, 127 of bridge segments with their corresponding upper and lower segment faces 106, 107 (see FIG. 7), drives bridge segments 121 generally inward along axis 32, believed to be at least roughly tangential to axis 33.
[0072] In FIGS. 5C-D, bolts are fully tightened, there is generally in gap now between upper and lower housing segments (as there is in FIG. 5A), and bridge segments 121 are fully driven inward along axis 32 to compress against the gasket and the pipe. Coupling lands 122 are now fully engaged in pipe grooves 22.
[0073] FIGS. 6 & 7 show an embodiment of the disclosed pre-assembled coupling in both pre-assembled and exploded perspective views. Schematically, pipe 20 is shown inserted into coupling 100 in FIG. 6. Bolts and nuts are loose, and coupling 100 is uncompressed and bridge segments 121 have not yet been driven in.
[0074] FIG. 7's exploded view of the uncompressed but pre-assembled coupling 100 affords a more detailed view of aspects of bridge segments 121, as does FIG. 8. In perspective, dihedral faces 126, and second face set 127 can be better seen, as can be corresponding face 107 in lower segment 102 set at an angle complementary to the lower face 127 of segment 121. Face 106 corresponding to face 126 and set at complementary angle to face 126 is not illustrated, but it is believed those skilled in the art will appreciate already where such a face will lie, given the rest of this disclosure.
[0075] FIGS. 8A-C illustrate details of disclosed coupling bridge segments 121 in side and plan views respectively. Bridge segments 121 operate and function as described in more detail above with reference to upper 101 and lower 102 coupling housing segments, particularly with respect to applying nearly uniform circumferential radially inward pressure to the joined pipe segments 20, or at least 4-way inward pressure to the pipe joint. Each bridge segment 121 desirably has a pair of lands 122 for mating with and applying pressure to corresponding end grooves 22 in pipe segments 20. When present, lands 122 on bridges 121 have a geometry similar to or at least complementary to the geometry of lands 122 on the housing segments 101, 102.
[0076] Bridge 121 has at least one dihedral set of faces 126. This face set 126 is comprised of two planar faces disposed to one another at dihedral angle A. In preferred embodiments this angle A is about 90 degrees. It can also be exactly 90 degrees, or can vary with good function from about 75 to 105 degrees. In FIG. 8b the dotted circular phantom line schematically illustrates the position of bolt 105 when bridge 121 is assembled into coupling 100. It can be seen that much of face set 126 can be cut away, such as illustrated by the cut-away for belt 105 or by faces 128, and still properly function. In preferred embodiments, there are additional face sets 127, which may or may not be dihedral face sets, depending on the relationship between angle A and angle C. For the case A=C, faces 127 are also simple dihedral faces. If angle C does not equal angle A, then faces 127 form a more complex spatial planar angle with each other. Preferred embodiments have values for C that are close to or identical to A. Also, in preferred embodiments, faces 127 are not co-planar with faces 126 (though that is an option in the case A=C) but are instead, with respect to faces 126, swept back from faces 126 at dihedral angle D (detail FIG. 8C).
[0077] In compliance with the statute, the invention has been described in language more or less specific as to structural features. It is to be understood, however, that the invention is not limited to the specific features shown, since the means and construction shown comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims, appropriately interpreted in accordance with the doctrine of equivalents.
