Method of manufacture of a drip irrigation hose

• US 6,936,126 B2
• Filed: 07/11/2002
• Issued: 08/30/2005
• Est. Priority Date: 07/19/1994
• Status: Expired due to Fees

• Current Assignee: John Deere Water Incorporated
• Original Assignee: T-Systems International Incorporated (Deere & Company)
• Inventors: DeFrank, Michael, Teegardin, David L., Marchetti, David
• Primary Examiner(s): Yao, Sam Chuan
• Assistant Examiner(s): Musser, Barbara J.
• Application Number:
  US10/192,959
• Publication Number:
  US 20020174944A1
• Time in Patent Office: 1,146 Days
• Field of Search: 156/203, 156/252, 156/466, 156/513, 237/542, 237/533.3, 833/32, 833/43, 834/25, 836/76, 83/30, 83/57, 833/31
• US Class Current: 156/203
• CPC Class Codes: A01G 25/02 Watering arrangements located above the soil which make use of perforated pipe-lines or pipe-lines with dispensing fittings, e.g. for drip irrigation
• CPC Class Codes: F16L 11/12 with arrangements for particular purposes, e.g. specially profiled, with protecting layer, heated, electrically conducting F16L11/11 takes precedence
• CPC Class Codes: Y02A 40/22 Improving land use; Improving water use or availability; Controlling erosion
• CPC Class Codes: Y10T 156/1013 and edge-joining of one piece blank to form tube
• CPC Class Codes: Y10T 156/1056 Perforating lamina
• CPC Class Codes: Y10T 156/1064 Partial cutting [e.g., grooving or incising]
• CPC Class Codes: Y10T 156/1067 Continuous longitudinal slitting
• CPC Class Codes: Y10T 156/1082 Partial cutting bonded sandwich [e.g., grooving or incising]
• CPC Class Codes: Y10T 156/1087 Continuous longitudinal slitting
• CPC Class Codes: Y10T 156/1304 Means making hole or aperture in part to be laminated

Abstract

A drip irrigation hose of the continuous emitter type in which the outlets from the regulating passage each comprise a single longitudinal slit. By controlling the length of the slits and the flexibility of the film, water drips from the outlets when the hose is pressurized without clogging when the hose is depressurized. The slits are sufficiently long and the film is sufficiently flexible so the water drips from the outlets when the hose is pressurized. The slits are sufficiently short and the film is sufficiently rigid so the outlets close completely when the hose is depressurized. An outlet forming wheel has a knife blade on its periphery. A backing wheel engages the outlet forming wheel to establish a first nip therebetween. The backing wheel has on its periphery a circumferential slot into which the knife blade fits at the first nip. A rib forming wheel has around its periphery impressions that define a desired track pattern for the ribs. The outlet forming wheel and the rib forming wheel are mounted on a common shaft to operate in synchronism. A continuous strip of plastic film is directed in a path that reverses direction four times to accommodate these wheels.

Claims

1. A method for making drip irrigation hose comprising:

rotating an outlet forming wheel having a knife blade on its periphery;

positioning a backing wheel to engage the outlet forming wheel and establish a nip, the backing wheel having a circumferential slot into which the knife blade fits as the outlet forming wheel rotates;

moving a strip of plastic film through the nip to form single slit outlets repeatedly along the strip as the knife blade rotates;

forming on the strip an elongated flow regulating passage; and

forming inlets to the flow regulating passage that are spaced from the outlets to form a substantial path length from each inlet to a corresponding outlet, wherein the outlets couple the flow regulating passage to the exterior of the hose.

2. The method of claim 1, wherein the strip of plastic film has first and second margins, and wherein the method further comprises overlapping and sealing the first and second margins to form a tube from the strip of plastic film.

3. The method of claim 2, wherein the flow regulating passage lies between the overlapping margins.

4. The method of claim 1, wherein the step of forming a flow regulating passage overlaps and seals margins of the strip between the inlets and the outlets, wherein the outlets couple the flow regulating passage to the exterior of the hose.

5. The method of claim 1, in which the outlet forming wheel is rotated such that the knife blade forms slits that close completely when the hose is depressurized.

6. The method of claim 5, in which the strip is flexible, additionally comprising partially wrapping the strip around one of the wheels as the strip moves through the nip.

7. The method of claim 1, in which the strip is flexible, additionally comprising partially wrapping the strip around one of the wheels as the strip moves through the nip.