Patent attributes
A drip irrigation hose includes a plurality of emitter elements secured to a tube at longitudinally-spaced locations to define, with an inner surface of the tube, a plurality of labyrinths each having an inlet in communication with the interior of the tube, and an outlet in communication with a tube outlet for discharging water from the tube outlet at a slow rate. The labyrinths are defined by a continuous strip of a relatively inelastic material bonded to the inner surface of the tube, and a formation of a relatively elastic material shaped to define at least the tips of a group of teeth for each of the emitter elements producing, with the inner surface of the tube a turbulent flow passageway at each of the longitudinally spaced locations along the length of the tube. In some embodiments the drip irrigation hose is formed with a clearance between the inner surface of the tube and the teeth normally bypassing at least a part of each labyrinth in the non-pressurized condition of the tube, which clearance is closed in the pressurized condition of the tube to render the labyrinths effective to regulate the flow therethrough in response to pressure.