PIPE COUPLING

摘要

A coupling assembly (10) for plastic pipes (12) including a nut (14), a body (20), a grip-ring (16) and a seal (18). The nut (14) can engage the body (20) through appropriate threads (28) and includes a hooked projection (36) having a sloping surface (46) adapted to abut against and provide a force on a corresponding surface (48) of the grip ring (16) within the body (20). A pipe (12) is inserted through the nut (14), grip-ring (16) and seal (18) into the body (20). Tightening of the nut (14) causes its sloped surface (46) to engage and the grip ring (16) to be forced both radially and longitudinally. Radial compression results in the grip-ring (16) engaging the pipe (12) whilst longitudinal force causes it to be forced into the body (20) simultaneously abutting against and compressing the seal (18) whilst dragging the pipe (12) further into the body (20). The nut (14) and the body (20) may further have tapered surfaces (46) that are brought together as the grip ring (14) is forced into the body (20). The physical connection between the body (20) and the nut (14) provides reinforcing for the nut (14), a feature especially useful when dealing with soft plastics. Further features include a lip (70) on the grip ring (16) that provides an additional support for the grip ring (16) when compressed as well as an abutment shoulder (56) on the nut (14) preventing the grip ring (16) from being pulled out of the body (20).