Patent ID: 6918618
Filing Date: 2005-07-19
Classification: F16L

Abstract:
1. A PVC-pipe, axially-tensioned joint comprising: a first PVC pipe having an axial direction, a spigot end and a first axial opening at the spigot end, wherein the spigot end has an outside diameter and an outer surface, and wherein there is a circumferential groove in and circumferentially around the outer surface of the spigot end, such that the groove has a bottom surface, a length in the axial direction, a forward radial edge and a trailing radial edge, wherein the forward radial edge is closer to the first axial opening of the first PVC pipe than is the trailing radial edge and wherein the forward radial edge of the groove forms a substantially radial shoulder circumferentially around and in the spigot end of the first PVC pipe; an inner ring having a bottom surface corresponding substantially to the bottom surface of the groove in the spigot end of the first PVC pipe, an outside diameter substantially the same as the outside diameter of the spigot end of the first PVC pipe and an outer surface, wherein the inner ring is fitted into the groove in an axial location in the axial direction in the spigot end of the first PVC pipe, and a forward radial edge of the inner ring abuts against the radial shoulder around and in the spigot end of the first PVC pipe and wherein the inner ring has a rearward radial edge which forms a substantially radial shoulder circumferentially around the inner ring; a second PVC pipe having an axial direction and a bell end, wherein the bell end has an inside diameter greater than the outside diameter of the spigot end of the first PVC pipe, wherein the bell end of the second PVC pipe is fitted onto the spigot end of the first PVC pipe in substantially the same axial direction as the axial direction of the first PVC pipe, wherein there is a plurality of angularly-spaced-apart holes extending radially through the bell end of the second PVC pipe; a set of radial fasteners wherein each given one of the radial fasteners extends through one of the plurality of angularly-spaced-apart holes extending radially in the bell end of the second PVC pipe such that a first end portion of the fastener abuts against the shoulder of the inner ring; and an outer ring having an inside diameter substantially the same as or greater than the outside diameter of the bell end of the second PVC pipe, wherein the outer ring is fitted onto the bell end of the second PVC pipe in substantially the same axial location as the axial location of the inner ring, wherein there is a set of angularly-spaced-apart holes extending radially through the outer ring, and wherein the radial holes extending through the outer ring are aligned axially and angularly to correspond with the holes in the bell end of the second PVC pipe, and wherein each given one of the radial fasteners extends through the corresponding radial holes in the outer ring.