Patent ID: 7735758
Filing Date: 2010-06-15
Classification: A01G,Y02A

Abstract:
1. A drip irrigation hose, comprising: a tube for conducting pressurized water through its interior and formed with a plurality of outlets for emitting water at longitudinally-spaced locations along the length of the tube; and a plurality of flow-control elements fixed with respect to the inner surface of said tube at longitudinally-spaced locations thereof to define, with said inner surface, a plurality of labyrinths each having an inlet communicating with the interior of the tube and an outlet communicating with a tube outlet for emitting water there from at a slow rate; said labyrinth including a bottom wall of an elastomeric material constructed to produce, adjacent to said bottom wall, a significant laminar flow of water in which the laminar flow decreases, and thereby turbulent flow increases, with an increase in the water pressure within the tube to thereby provide pressure-compensation for the water flow through the respective tube outlet; wherein said labyrinth further includes a plurality of teeth in spaced, staggered relationship to each other; at least some of said teeth being constructed with an expanded root where joined to the bottom wall to produce significant laminar flow adjacent to said bottom wall; said bottom wall being dimensioned such that an increase in said water pressure deforms the bottom wall in a manner to decrease the laminar flow through said labyrinth and thereby to increase the pressure drop through the respective portion of said labyrinth; and wherein said teeth, including said expanded roots, are joined to said bottom wall by a juncture formed with a curve or an obtuse angle with respect to said bottom wall, such that said juncture tends to increase the laminar flow adjacent to the bottom wall, but said water pressure applied to said bottom wall tends to deform said juncture to decrease the laminar flow adjacent to said bottom wall, and thereby to increase the turbulent flow through said labyrinth.