Drip irrigation hose and method and apparatus for making same

A drip irrigation hose, comprising:

• a tube for conducting pressurized water through its interior and formed with a plurality of outlets for discharging the water at longitudinally-spaced locations along the length of the tube;
• and a plurality of emitter elements secured to said tube at longitudinally-spaced locations along its length to define a plurality of labyrinths each in communication with the interior of the tube for discharging water from a tube outlet at a slow rate;
• each of said emitter elements including a relatively elastic material shaped to define at least a part of a labyrinth and a relatively inelastic material underlying said relatively elastic material and bonding same to the inner face of the tube;
• said relatively inelastic material being in the form of a continuous strip extending the length of said tube.

A drip irrigation hose, comprising:

• a tube for conducting pressurized water through its interior and formed with a plurality of outlets for discharging the water at longitudinally-spaced locations along the length of the tube;
• and a plurality of emitter elements secured to said tube at longitudinally-spaced locations along its length to define a plurality of labyrinths each in communication with the interior of the tube for discharging water from a tube outlet at a slow rate;
• said labyrinths being defined by a continuous strip of a relatively inelastic material having a relatively elastic material applied thereto and shaped to define a group of teeth for each of said emitter elements producing turbulent flow passageways with respect to said tube at each of said longitudinally spaced locations along the length of said continuous strip;
• said drip irrigation hose being formed with a clearance between said tube and said teeth normally bypassing at least a part of each labyrinth in the non-pressurized condition of the hose and being closed in the pressurized condition of the hose to render said labyrinths effective to regulate the flow therethrough in response to pressure.

A method of making a drip irrigation hose, comprising:

• extruding a continuous strip of a relatively inelastic material;
• applying to said continuous strip of relatively inelastic material a relatively elastic material to occupy discrete, longitudinally-spaced locations along the length of said continuous strip, said relatively elastic material being shaped at each of said longitudinally-spaced locations to define at least a part of an emitter element having a turbulent flow passageway, an inlet end thereto, and an outlet end therefrom;
• extruding a continuous tube over said continuous strip;
• bonding said continuous strip to the inner surface of said extruded tube such that the interior of the tube communicates with the inlet end of each of said emitter elements;
• and
• perforating said extruded tube with a plurality of holes at longitudinally-spaced locations, each hole aligned with the outlet end of one of said emitter elements.

A method of making a drip irrigation hose, comprising:

• extruding a continuous strip of a relatively inelastic material;
• applying over said continuous strip of relatively inelastic material a mixture of two liquids capable of being cured by cross-linking to form a relatively elastic material;
• shaping said relatively elastic material into at least a part of a plurality of emitter elements spaced longitudinally along the length of said continuous strip of relatively inelastic material, with each emitter element having a turbulent flow passageway, an inlet end thereto, and an outlet end therefrom;
• extruding a continuous tube over said continuous strip;
• bonding said continuous strip to the inner surface of said extruded tube such that the interior of the tube communicates with the inlet end of each of said emitter elements;
• and
• perforating said extruded tube with a plurality of holes at longitudinally-spaced locations, each hole aligned with the outlet end of one of said emitter elements.