Grooved-ended resilient expansion joint and method of resiliently joining together a pair of grooved-ended pipes

1. A grooved-ended resilient expansion joint 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 pipe to be joined; each end having a neck portion between the central resilient portion and the radially outwardly raised distal cylindrical gasket portion and sized to receive a grooved-ended pipe nipple;

the grooved pipe nipple set around the neck portion, the grooved pipe nipple having the same outer diameter as the pipe to be joined, and grooved to mate with a selected mechanical pipe coupling connector; and

a mechanical pipe coupling connector having axially inward projecting lands that mate with the end groove in the pipe to be joined and with the groove in the pipe nipple set around the neck portion;

wherein the mechanical pipe coupling connector is fastened around the grooved pipe nipple and the end groove in the pipe to be joined, the end groove in the pipe to be joined is disposed inside the inside shoulder of the cylindrical gasket portion, and the cylindrical gasket portion is thus disposed within an interior gasket receiving portion of the connector.

2. The grooved-ended resilient expansion joint 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 nipple is disposed inside the second inside shoulder of the cylindrical gasket portion.

3. The grooved-ended resilient expansion joint of claim 1 , further comprising a pair of grooved double ended pipe nipples mechanically coupled into the groove-ended resilient expansion joint.

4. The grooved-ended resilient expansion joint of claim 1 , wherein the cylindrical gasket portion is formed into a trapezoid shape to fit the interior gasket receiving portion of the connector.

5. The grooved-ended resilient expansion joint of claim 1 , the resilient expansion member further comprising a plurality of central portions.

6. The grooved-ended resilient expansion joint of claim 5 , wherein at least one of the plurality of central portions is roughly spherical.

7. A method of resiliently joining together a pair of grooved ended pipes, the method comprising the following steps:

providing first and second grooved-ended pipes, each of the first and second groove ended pipes having a pipe end, the pipe end having a groove formed thereon;

providing an expansion joint 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 an associated one of said first and second grooved ended pipes; each end having a neck portion between the central resilient portion and the radially outwardly raised distal cylindrical gasket portion and sized to receive a grooved pipe nipple;

disposing a first grooved pipe nipple around a first neck portion of a resilient expansion member, where the first grooved pipe nipple and the first grooved-ended pipe have the same outer diameter and groove configuration;

placing first and second mechanical pipe coupling connectors on the first and second grooved pipe nipple and the grooved ends of the first and second grooved-ended pipes;

fastening the first mechanical pipe coupling connector around the first grooved pipe nipple and the first grooved-ended pipe; and

fastening the second mechanical pipe coupling connector around the second grooved pipe nipple and the second grooved-ended pipe.

8. The method of claim 7 , further comprising:

in the resilient expansion member, axially outward from the neck portion, a first resilient cylindrical gasket portion having a first inside shoulder, and

in the resilient expansion member, axially outward from the neck portion, a second resilient cylindrical gasket portion having a second inside shoulder; and

disposing the grooved-end of the first grooved-ended pipe inside the first inside shoulder of the cylindrical gasket portion; and

disposing the grooved-end of the second grooved-ended pipe inside the second shoulder of the cylindrical gasket portion.