Abstract: A pipe joint is disclosed, along with a pipe for use with such a joint. The pipe has a double wall construction with support ribs connecting the two walls of the pipe. The pipe also includes at least one end wall having a routed groove formed therein, wherein the groove is dimensioned to receive a coupling member. A locking entrance lip is formed within the groove. The pipe joint includes two pipe sections and a coupling member that is received into the respective grooves of each pipe section and is locked into place by the locking entrance lips. The joint is fluid tight, locks the pipe sections in place, and is smooth on both the interior and exterior surfaces of the two connected pipes. In addition, the disclosed pipe joint construction is very easy to assemble, and is particularly suited for use in sewer relining operations.

Abstract: A coupling member includes a ring is formed with a predetermined draft angle. A gasket is provided for creating a seal between the ring and the end grooves of the conduit. The gasket comprises first and second walls which define an interior cavity for receiving the ring. The first and second walls have differential thicknesses so as to accommodate the draft angle of the ring. A plurality of fins are formed integrally on the exterior of the gasket for creating an interference fit with the end grooves.In the preferred embodiment, the first wall is substantially thicker than the second wall and the fins exterior to the first wall are thicker than the fins on the second wall. Also, the thicknesses of the first and second walls are preferably tapered so as to define an interior cavity having a draft angle equal to that of the ring.

Abstract: A force-transmitting joint formed between two pipe sections is provided that is particularly suited for an extruded, plastic pipe having a variable wall thickness. The joint has a smooth outer surface and a constant gap in which a sealing member is retained. The pipe section has an outer wall including an outer surface and an inner surface with a variable wall thickness defined therebetween. A first end of the pipe section includes a first joint member comprising a first support surface having a constant width. The first joint member further comprises an outwardly extending sealing leg having a variable width. A second end of the pipe includes a second joint member comprising a second support surface having a constant width which is less than the width of the first support surface. The second joint member further comprises a recess having a variable thickness. An annular sealing member is assembled onto the sealing leg.

Abstract: A seal for use in rotating machinery such as a gas turbine engine comprises two pole pieces attached to the engine casing and defining a gap in which a magnetic powder is held by a magnetic field generated by a permanent magnet, electro-magnet or a combination of the two. The non-magnetic fins of the adjacent rotor (e.g. turbine blades), extend into the gap and distort the magnetic field so that while there is a small clearance between the fin and the powder, this small clearance can be maintained approximately the same whatever the position of the fin in the gap. A seeding tube allows magnetic powder to be supplied to the gap to make good any loss of powder.