Patent ID: 6105972
Filing Date: 2000-08-22
Classification: F16L

Abstract:
A pipe sealing gasket designed for receipt within a groove provided within a socket end of a thermoplastic pipe, the gasket having an improved low insertion geometry, the gasket comprising:a ring shaped elastomeric body which, when viewed in cross section, includes a leading nose region and a lower compression region, the leading nose region being joined to the lower compression region by a leading curved surface region which defines an angle .alpha. with respect to a horizontal axis drawn parallel to a central axis of the pipe, the lower compression region being joined to a secondary seal surface by a trailing curved surface region which defines a second angle .beta. with respect to the horizontal axis drawn parallel to the central axis of the pipe;wherein the angles .alpha. and .beta. are selected to minimize the insertion force required when inserting the male spigot end within the female socket end while maintaining a compression seal between the pipe sections;wherein the angle .alpha. is selected to be less than about 60 degrees and the angle .beta. is selected to be greater than about 45 degrees; andwherein the insertion force required to insert the male spigot end within the female socket end to make up a pipe joint can be resolved into an x-component of force and a y-component of force and wherein the angles .alpha. and .beta. are selected to decrease the x-component of force without appreciably altering the y-component of force when inserting the male spigot end within the female socket end, the x-component of force being decreased by at least 40% while the y-component of force is decreased by less than 10%.