Pipe joints or couplings – With fluid pressure seal – Flexible lip
Reexamination Certificate
1998-06-18
2001-01-09
Browne, Lynne H. (Department: 3629)
Pipe joints or couplings
With fluid pressure seal
Flexible lip
C285S915000
Reexamination Certificate
active
06170884
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a segmented pipe coupling comprised of two or more coupling segments that are secured to each other in end-to-end relationship by traction bolts that extend through bolting pads of the coupling segments.
Segmented pipe couplings are employed for interconnecting lengths of pipe with each other or for connecting a fitting to a length of pipe, the segmented pipe coupling encompassing a sealing gasket that is held in compressed relationship within the segmented pipe coupling upon tightening of the coupling down onto the pipes or fittings.
BACKGROUND OF THE INVENTION
Segmented pipe couplings are well-known in the art, the respective coupling segments of such couplings being comprised of castings of a ductile iron.
The sealing gaskets that are to be positioned within the segmented pipe coupling commonly are formed from an elastomeric material, and include sealing lips, and if desired, a centrally located radially extending stem to be trapped between the adjacent ends of the pipes to be coupled by the coupling.
More commonly, the coupling segments include circumferentially extending keys at their respective opposite sides, the keys being for reception within grooves cut or otherwise formed in the exterior circumference of the pipes, the keys acting to resist axial stresses that are generated in the pipes, those axial stresses being absorbed by the coupling as a tensile or a compressive stress.
Other forms of such couplings have been proposed, in which the keys are separate from the coupling and are mechanically affixed to the external surface of the pipes, the keys then being received within grooves provided in the respective coupling segments.
Each of those constructions is encumbered with the disadvantage that either the pipes must be provided with cut or rolled grooves in their outer periphery, with the expense attendant thereon, or, the keys must be affixed mechanically to the pipe periphery, again with the expenses attendant thereon.
Such coupling segments are considered to be of minimal utility in the interconnection of pipes that have not been provided with grooves, or which have not been provided with mechanically attached keys, the reason being that the casting operation employed in the manufacture of the coupling segments, and, the material from which the coupling segments are cast are not conducive to the provision of sharp edges of a sufficient hardness for them to bite into the pipe exterior, in order to provide the required positive, as opposed to frictional, interconnection between the coupling and the respective pipes or fittings.
SUMMARY OF THE INVENTION
The present invention has for its object to provide a segmented pipe coupling formed from coupling segments that can be castings of ductile iron, and which can be employed in the assembly of a segmented pipe coupling specifically intended for use in coupling plain ended pipes or fittings, i.e., pipes or fittings that are devoid of grooves for the reception of keys, or which are devoid of keys mechanically affixed to the pipes or fittings. In an alternative form, the present invention can also provide a segmented pipe coupling formed from coupling segments that can be castings of ductile iron, and which can be employed in the assembly of a segmented pipe coupling specifically intended for use in coupling plain ended pipes or fittings to grooved pipes or fittings.
According to the present invention, coupling segments for assembly into a segmented pipe coupling to be employed with plain ended pipe, are formed for castings of a ductile iron, and, include circumferentially extending recesses in their inner periphery for the reception of hardened steel cutter members having cutting edges that extend radially inwardly of the inner periphery of the coupling segments.
The cutter members are secured within the coupling segments by crimping the adjacent walls of the coupling segment in order to securely trap the cutter members within their associated recesses or by the use of acrylic adhesive or other affixation means adhering adjacent cutter members to each other and to the walls of the recesses.
The cutter members, at their radially innermost edges are provided with a sharp cutting edge that has been formed on the cutter members by a grinding operation, the cutter members at the respective opposite sides of the coupling segment being inclined towards each other to produce a biting action on the periphery of plain ended pipe that is resistive to axial forces applied to the pipe, and which additionally is resistive to angling or bending forces that may be exerted on the pipes or fittings.
The alternative form of the invention employs a coupling with cutter members as previously described to secure a plain ended pipe or fitting and a projection or key fitting within the groove of a grooved pipe or fitting to secure it.
REFERENCES:
patent: 2225208 (1940-12-01), Crickmer
patent: 3116078 (1963-12-01), Scherer
patent: 3174386 (1965-03-01), Lewis
patent: 3423111 (1969-01-01), Elsner
patent: 3444775 (1969-05-01), Hills
patent: 4146254 (1979-03-01), Turner et al.
patent: 4842306 (1989-06-01), Zeidler et al.
patent: 5058931 (1991-10-01), Bowsher
patent: 5911446 (1999-06-01), McLennan et al.
Victaulic Mechanical Piping Systems General Catalog, Vitaulic Company of America, p. 73, 1988.*
Brown Dennis R.
Dole Douglas R.
McLennan William Ross
Abelman ,Frayne & Schwab
Binda Greg
Browne Lynne H.
Victaulic Company of America
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