Method and apparatus for making a drip irrigation hose

• US 6,464,816 B1
• Filed: 08/04/1998
• Issued: 10/15/2002
• Est. Priority Date: 07/19/1994
• Status: Expired due to Term

• 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): Ball, Michael W.
• Assistant Examiner(s): Musser, Barbara J.
• Application Number:
  US09/128,770
• Time in Patent Office: 1,533 Days
• Field of Search: 156/203, 156/252, 156/466, 156/513, 239/542, 239/533.13
• 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;

maintaining a continuous moving strip of plastic film having first and second longitudinal margins in contact with the wheel to form slit outlets repeatedly along the first margin of the strip as the knife blade rotates;

forming an elongated flow regulating passage and inlets to the flow regulating passage on one margin of the strip, the inlets being spaced from the outlets to form a substantial path length from each inlet to outlet;

folding the strip to overlap the first and second margins so the first margin overlies the second margin and the flow regulating passage lies between the overlapping margins; and

sealing the overlapping margins and the flow regulating passage to form a water supply passage, the inlets coupling the water supply passage to the flow regulating passage and the outlets coupling the flow regulating passage to the exterior of the hose.

2. A method for making drip irrigation hose comprising:

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

maintaining a continuous moving strip of plastic film having first and second margins in contact with the wheel to form slit outlets repeatedly in the surface of the strip as the knife blade rotates;

forming an elongated flow regulating passage on one margin of the strip;

folding the strip to overlap, close the flow regulating passage, and form a water supply passage;

sealing the overlapping margins; and

repeatedly forming inlets from the water supply passage to the flow regulating passage to form a substantial path length from each inlet to outlet.

3. Apparatus for making drip irrigation hose comprising:

a rotating outlet forming wheel having a knife blade on its periphery capable of forming single slit outlets;

a backing wheel that forms a nip with the outlet forming wheel for maintaining a continuous moving strip of plastic film having first and second margins in contact with the wheel to form single slit outlets repeatedly in the first margin of the strip as the knife blade rotates, wherein the strip has a general direction of movement;

means for forming an elongated flow regulating passage on the first margin of the strip over the outlets;

means for folding the strip to overlap the margins so the flow regulating passage lies between the margins;

means for sealing the overlapping margins to form a water supply passage adjacent to the flow regulating passage; and

means for repeatedly forming inlets from the water supply passage to the flow regulating passage to form a substantial path length from each inlet to outlet.

4. The apparatus of claim 3, in which the means for forming a flow regulating passage comprises means for extruding a bead of molten plastic onto the surface of the strip at one margin, a rotating pattern wheel for repeatedly forming a desired track pattern in the bead, means for coupling the pattern wheel to the outlet forming wheel so the pattern and outlet forming wheels rotate in synchronism, and means for pressing the margins together to form the flow regulating passage.

5. The apparatus of claim 4, in which the coupling means comprises a shaft connected between the pattern and outlet forming wheels.

7. The apparatus of claim 3, in which the means for forming inlets forms inlets in the second margin.

8. The apparatus of claim 3, in which the means for forming inlets forms slit inlets in the second margin.

9. The apparatus of claim 4, in which the means for forming inlets forms interruptions in the track pattern of the pattern wheel.

10. The apparatus of claim 3, in which the knife blade is mounted on the periphery of the outlet forming wheel.

11. The apparatus of claim 10, in which the backing wheel has a circumferential slot into which the knife blade fits as it passes through the nip.

12. The apparatus of claim 11, in which the strip is wrapped around the backing wheel such that it moves in the general direction of movement before it passes through the nip and opposite the general direction of movement after it passes through the nip.

13. The apparatus of claim 12, additionally comprising a direction changing wheel around which the strip is wrapped such that it moves in the general direction of movement after it leaves the direction changing wheel.

14. The apparatus of claim 13, in which the strip is wrapped around the outlet forming wheel after it leaves the direction changing wheel such that the strip moves opposite the general direction of movement after the strip leaves the outlet forming wheel.

15. The apparatus of claim 14, additionally comprising a further direction changing wheel around which the strip is wrapped such that it moves in the general direction of movement after it leaves the further direction changing wheel.

16. The apparatus of claim 3, in which the means for forming a flow regulating passage comprises an extruder that deposits one or more molten beads on the first margin of the strip and a rotating molding wheel having a pattern of depressions that forms the pattern of the flow regulating passage in the one or more beads.

17. The apparatus of claim 16, additionally comprising means for synchronizing the molding wheel to the outlet forming wheel.

18. The apparatus of claim 17, in which the synchronizing means comprises a rotating shaft connecting the molding wheel to the outlet forming wheel.

19. The apparatus of claim 17, in which the synchronizing means comprises a first coupling wheel connected to the molding wheel, a second coupling wheel connected to the outlet forming wheel, and a rotation transmitting belt between the first and second coupling wheels.

20. The apparatus of claim 19, in which the wheels are designed so the angular velocity of the molding wheel is a multiple of the outlet forming wheel.

21. The apparatus of claim 18, in which the molding wheel is laterally displaced from the outlet forming wheel.

22. The apparatus of claim 17, in which the knife blade is mounted on the periphery of the outlet forming wheel.

23. The apparatus of claim 22, in which the backing wheel has a circumferential slot into which the knife blade fits as it passes through the nip.

24. The apparatus of claim 23, in which the strip is wrapped around the backing wheel such that it moves in the general direction of movement before it passes through the nip and opposite the general direction of movement after it passes through the nip.

25. The apparatus of claim 24, additionally comprising a direction changing wheel around which the strip is wrapped such that it moves in the general direction of movement after it leaves the direction changing wheel.

26. The apparatus of claim 25, in which the strip is wrapped around the outlet forming wheel after it leaves the direction changing wheel such that the strip moves opposite the general direction of movement after the strip leaves the outlet forming wheel.

27. The apparatus of claim 26, additionally comprising a further direction changing wheel around which the strip is wrapped such that the strip moves in the general direction of movement into contact with the outlet forming wheel after it leaves the further direction changing wheel.

28. The apparatus of claim 3, in which the strip moves in a given direction while in contact with the outlet forming wheel, the means for forming a flow regulating passage comprises a rotating passage forming wheel, the apparatus additionally comprising a rotating shaft between the wheels to synchronize their rotation, and a film path between the wheels for reversing the direction of movement of the strip between the wheels so the strip moves across the passage forming wheel in the given direction.

29. The apparatus of claim 3, in which the strip moves in a given direction while in contact with the outlet forming wheel, the means for forming a flow regulating passage comprises a rotating passage forming wheel, the apparatus additionally comprising a first coupling wheel connected to the passage forming wheel, a second coupling wheel connected to the outlet forming wheel, a rotation transmitting belt between the first and second coupling wheels synchronize their rotation, and a film path between the wheels for reversing the direction of movement of the strip between the wheels so the strip

6. Apparatus for making drip irrigation hose comprising:

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

a backing wheel that forms a nip with the outlet forming wheel for maintaining a continuous moving strip of plastic film having first and second longitudinal margins in contact with the wheel to form slit outlets repeatedly along the first margin of the strip as the knife blade rotates, wherein the strip has a general direction of movement;

means for forming an elongated flow regulating passage and inlets to the flow regulating passage on one margin of the strip, the inlets being spaced from the outlets to form a substantial path length from each inlet to outlet;

means for folding the strip to overlap the first and second margins so the first margin overlies the second margin and the flow regulating passage lies between the overlapping margins;

means for sealing the overlapping margins and the flow regulating passage to form a water supply passage, the inlets coupling the water supply passage to the flow regulating passage to form a water supply passage, the inlets coupling the water supply passage to the flow regulating passage and the outlets coupling the flow regulating passage to the exterior of the hose.