Claims
- 1. An apparatus for fabricating drip irrigation tape, comprising:
- extruding means for extruding a heated strip of flexible material;
- a pair of opposing shaping drums for shaping the heated strip of flexible material to form an indented groove of predetermined, serpentine shape extending along one side edge portion of the strip, a first one of the shaping drums having a smooth annular rim surface and a mandrel projecting outwardly from said rim surface adjacent one side edge of said first drum, the mandrel being shaped to correspond to the desired serpentine shape of the indented groove, the second one of the shaping drums having a smooth annular rim surface opposing the smooth rim surface of said first shaping drum and an annular channel on said rim surface adjacent one side edge of said rim surface and extending inwardly from said smooth rim surface for receiving the mandrel as the drum rotates, the annular channel comprising a straight, linear channel having a width substantially equal to the maximum width of the projecting serpentine mandrel;
- the opposing smooth annular rim surfaces of the shaping drums comprising means for guiding the heated strip between the drums and the projecting mandrel and opposing annular channel comprising means for deforming a portion of the strip located between the mandrel and channel out of the plane of the remainder of the strip to form the indented groove;
- a folding device for folding the strip lengthwise with the opposite side edge portions of the strip overlapping to cover the groove and form a first conduit within the folded strip;
- a sealing device for joining the overlapping edge portions together in face-to-face contact at least along opposite sides of the groove;
- and port forming means for providing a series of inlet ports between the first conduit and a secondary conduit defined by the groove, and a series of outlet ports between the secondary conduit and the exterior of the tape.
- 2. The apparatus as claimed in claim 1 wherein the serpentine configuration is continuous around the periphery of the drum.
- 3. The apparatus as claimed in claim 1, wherein the serpentine configuration comprises a series of separate serpentine segments formed around the circumference of the mandrel for forming a series of separate serpentine channel segments along the side edge of the strip.
- 4. The apparatus as claimed in claim 1, wherein the port forming means comprises means for piercing orifices through the side edge portions of the strip in regions corresponding to the inner and outer walls of the secondary conduit.
- 5. The apparatus as claimed in claim 1, wherein the sealing device comprises an ultrasonic welding device.
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 08/015,080, filed Feb. 8, 1993 which was a continuation application Ser. No. 07/722,535 filed Jun. 27, 1991 (abandoned), which was a divisional of application Ser. No. 07/485,778 filed Feb. 22, 1990 (abanoned), which was a continuation of application Ser. No. 07/332,588 filed Apr. 3, 1989 (abandoned), which was a continuation-in-part of appliation Ser. No. 07/156,413 filed Feb. 16, 1988 (abandoned).
U.S. Pat. No. 4,722,759 of Roberts et al. and U.S. Pat. No. 4,807,668 of Roberts are related to this application.
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0196763 |
Aug 1986 |
EPX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
485778 |
Feb 1990 |
|
Continuations (3)
|
Number |
Date |
Country |
Parent |
15080 |
Feb 1993 |
|
Parent |
722535 |
Jun 1991 |
|
Parent |
332588 |
Apr 1989 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
156413 |
Feb 1988 |
|