Drip irrigation hose with pressure compensation and method for its manufacture

Abstract

A laminar flow section and a turbulent flow section are formed contiguous to each other along the length of a flow regulating passage in a drip irrigation hose. Responsive to the pressure in a water supply passage of the drip irrigation hose, the cross-sectional area of the laminar flow section is reduced as the pressure increases so as to compensate for the effect of pressure changes on the drip flow rate of the hose. The water supply passage is formed by a continuous strip of plastic film sealed together at its margins, and the flow regulating passage has longitudinal side walls extending inwardly from the strip. The base portion of the side walls has chevron shaped surfaces that form the turbulent flow section and the remainder of the side walls has smooth surfaces that form the laminar flow section. The cross-sectional area of the laminar flow section is reduced responsive to pressure by a continuous strip of deflectable plastic film that seals the side walls such that the smooth surfaces are adjacent thereto. The deflectable plastic film is deflected toward the chevron shaped surfaces as the pressure increases to reduce the cross sectional area of the laminar flow section.

Dependencies are inferred from the claim text.