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A pipe sealing gasket is shown which is designed to be received within a raceway provided within a socket end of a female bell plastic pipe end which is assembled with a mating male pipe end to form a plastic pipe joint. The raceway in the female bell plastic pipe end is preformed during manufacture

A pipe sealing gasket is shown which is designed to be received within a raceway provided within a socket end of a female bell plastic pipe end which is assembled with a mating male pipe end to form a plastic pipe joint. The raceway in the female bell plastic pipe end is preformed during manufacture and the gasket is installed thereafter. The gasket has a rubber body portion which is reinforced by a hard plastic band formed as a series of integral, spaced wedges which are interconnected by a flexible ribbon. The hard plastic band acts to prevent extrusion of the gasket during a variety of pressure conditions as well as preventing displacement during field assembly.

대표청구항 ▼

1. A method of forming a sealed joint in a pipeline formed of sections of plastic pipe where a gasket with an embedded reinforcing hard plastic band is installed within a gasket receiving raceway provided within the belled end of a female pipe member, the raceway being arcuate with a forward facing

1. A method of forming a sealed joint in a pipeline formed of sections of plastic pipe where a gasket with an embedded reinforcing hard plastic band is installed within a gasket receiving raceway provided within the belled end of a female pipe member, the raceway being arcuate with a forward facing slope region when viewed in cross section, and wherein the raceway has been previously formed during the manufacture of the pipe and the gasket is installed thereafter, the female bell socket end having a given internal diameter which is designed to receive a mating male thermoplastic pipe end to form a pipe joint, the male thermoplastic pipe end having a given outer diameter, the method comprising: installing a sealing gasket within the gasket receiving raceway by bending the gasket to temporarily transform the gasket from a cylindrical shape to a elliptical shape, placing the gasket within the gasket receiving groove and releasing the gasket, whereby the gasket returns to the cylindrical shape;wherein the gasket is formed as a ring shaped elastomeric body having a main body portion formed of rubber which, when viewed in cross section, includes a leading nose region, a lower compression region and a trailing tail region, the leading nose region facing towards the female socket end of the pipe once the gasket is inserted within the pipe;wherein the leading nose region of the main body portion of the gasket is reinforced by a hard plastic band formed as a series of integral and discrete, spaced wedges interconnected by a flexible ribbon, the hard plastic band being embedded within the leading nose region of the main body portion of the gasket during gasket manufacture by molding the same therein, rather than being a separate bonded piece, the wedges each having a front edge, a rear edge and opposing side edges when viewed in isometric view, the opposing side edge of one selected wedge being connected to a side edge of a next adjacent wedge by a portion of the flexible ribbon;wherein the hard plastic band is formed of a synthetic plastic material having a durometer which is greater than the durometer of the main body portion of the gasket while being flexible enough to allow the gasket to accept inverse curvature during installation into the groove provided in the female, socket end of the thermoplastic pipe; andwherein the wedges on the hard plastic band act in concert with the forward facing slope region of the arcuate raceway to wedge between the outer diameter of the male thermoplastic pipe end and the internal diameter of the female bell socket end, whereby hydraulic fluid due to fluid in the pipeline acts upon the wedges on the hard plastic band to push the wedges into tighter engagement with the mating male and female pipe members to prevent extrusion of the gasket from the raceway provided in the female bell socket end of the thermoplastic pipe once a spigot end of a mating male pipe is installed to from a pipe joint and the pipe is conveying fluid. 2. The method of claim 1, wherein the opposing side edges of the wedges slope evenly from the rear edge to the front edge thereof, as viewed in isometric view. 3. The method of claim 2, wherein the main body portion of the gasket is formed of a rubber selected from the group consisting of styrene butadiene rubber, ethylene propylene diene monomer rubber and nitrile rubber. 4. The method of claim 1, wherein the hard plastic band is embedded within the leading nose region of the main body portion of the gasket during manufacture by placing the hard plastic band in a mold and injecting rubber about the band, rather than being bonded as a separate piece. 5. The method of claim 1, wherein the main body portion of the gasket is formed of a natural or synthetic rubber. 6. The method of claim 1, wherein the synthetic plastic material is a modified polyphenylene ether. 7. The method of claim 1, wherein the lower compression region of the gasket includes a series of circumferential engagement grooves for engaging the mating male spigot pipe end. 8. The method of claim 1, wherein the main gasket body has an outer bulbous region which is also provided with a series of circumferential engagement grooves for engaging the female socket end of the pipe. 9. A method of installing a gasket with an embedded reinforcing hard plastic band within a gasket receiving raceway provided within the belled end of a female pipe member so as to form a sealed pipe joint in a pipeline formed of sections of plastic pipe, the belled end having a mouth opening which is engageable with a spigot end of a mating male plastic pipe section to form the pipe joint, the method comprising the steps of: providing a plastic pipe section having a preformed female belled end opening with a gasket receiving raceway, the raceway being arcuate with a forward sloping region when viewed in cross sectional view;installing a sealing gasket within the gasket receiving raceway by bending the gasket to temporarily transform the gasket from a cylindrical shape to a elliptical shape, placing the gasket within the gasket receiving groove and releasing the gasket, whereby the gasket returns to the cylindrical shape;wherein the gasket is formed as a ring shaped elastomeric body having a main body portion formed of rubber which, when viewed in cross section, includes a leading nose region, a lower compression region and a trailing tail region, the leading nose region facing towards the female socket end of the pipe once the gasket is inserted within the pipe;wherein the leading nose region of the main body portion of the gasket is reinforced by a hard plastic band formed as a series of integral, spaced wedges interconnected by a flexible ribbon, the hard plastic band being embedded within the leading nose region of the main body portion of the gasket during gasket manufacture by molding the same therein, the wedges each having a front edge a rear edge and opposing side edges, as viewed in isometric view, the opposing side edge of one selected wedge being connected to a side edge of a next adjacent wedge by a portion of the flexible ribbon; andwherein hydraulic pressure due to fluid in the pipe acts upon the wedges on the hard plastic band to push the wedges into tighter engagement with the mating male and female pipe members to prevent extrusion of the gasket from the raceway provided in the female socket end of the thermoplastic pipe once a spigot end of a mating male pipe is installed to form a pipe joint and the pipe is conveying fluid. 10. A method of installing a gasket with an embedded reinforcing hard plastic band within a gasket receiving raceway provided within the belled end of a female pipe member so as to form a sealed pipe joint in a pipeline formed of sections of plastic pipe, the belled end having a mouth opening which is engageable with a spigot end of a mating male plastic pipe section to form the pipe joint, the method comprising the steps of: providing a plastic pipe section having a preformed female belled end opening with a gasket receiving raceway, the raceway being arcuate with a forward sloping region when viewed in cross sectional view;installing a sealing gasket within the gasket receiving raceway by bending the gasket to temporarily transform the gasket from a cylindrical shape to a elliptical shape, placing the gasket within the gasket receiving groove and releasing the gasket, whereby the gasket returns to the cylindrical shape;wherein the gasket is formed as a ring shaped elastomeric body having a main body portion formed of rubber which, when viewed in cross section, includes a leading nose region, a lower compression region and a trailing tail region, the leading nose region facing towards the female socket end of the pipe once the gasket is inserted within the pipe;wherein the leading nose region of the main body portion of the gasket is reinforced by a hard plastic band formed as a series of integral, spaced wedges interconnected by a flexible ribbon, the hard plastic band being embedded within the leading nose region of the main body portion of the gasket during gasket manufacture by molding the same therein, the wedges each having a front edge a rear edge and opposing side edges, as viewed in isometric view, one of the selected wedges being connected to a next adjacent wedge by a portion of the flexible ribbon; andwherein hydraulic pressure due to fluid in the pipe acts upon the wedges on the hard plastic band to push the wedges into tighter engagement with the mating male and female pipe members to prevent extrusion of the gasket from the raceway provided in the female socket end of the thermoplastic pipe once a spigot end of a mating male pipe is installed to form a pipe joint and the pipe is conveying fluid.