US Patent 7140557 Emitter tube for irrigation system

The invention provides an emitter tube for an irrigation system, the tube being of resiliently flexible material having a base inlet end adapted to be mounted and a free outlet end adapted to be unmounted, the arrangement being such that, with liquid flowing at a sufficient rate through the emitter tube, hydraulic forces exerted by the flowing liquid on the tube cause the outlet end continuously to move about, further having a base section and an end section downstream from the base section when the end section is of greater flexibility than the base section.