U.S. patent application number 12/084350 was filed with the patent office on 2009-07-09 for drip irrigation apparatus.
This patent application is currently assigned to NAAN-DAAN IRRIGATION SYSTEM (C.S.) LTD.. Invention is credited to Tomer Cohen, Eldad Dinor, Izhak Gal, Moshe Gorney, David Sol.
Application Number | 20090173811 12/084350 |
Document ID | / |
Family ID | 38006294 |
Filed Date | 2009-07-09 |
United States Patent
Application |
20090173811 |
Kind Code |
A1 |
Gorney; Moshe ; et
al. |
July 9, 2009 |
Drip Irrigation Apparatus
Abstract
Drip irrigation apparatus including a main water flow channel
having associated therewith along a length thereof a plurality of
pressure-controlled drip irrigation emitter units and at least one
secondary water flow channel extending generally parallel to the
main water flow channel and receiving water from at least one of
the plurality of pressure-controlled drip irrigation emitter units,
the at least one secondary water flow channel having water outlets
disposed along the length of the main water flow channel,
intermediate the plurality of pressure-controlled drip irrigation
emitter units.
Inventors: |
Gorney; Moshe; (Kibbutz
Naan, IL) ; Dinor; Eldad; (Kibbutz Naan, IL) ;
Sol; David; (Kibbutz Naan, IL) ; Cohen; Tomer;
(Even Yehuda, IL) ; Gal; Izhak; (Kibbutz Naan,
IL) |
Correspondence
Address: |
Husch Blackwell Sanders, LLP;Husch Blackwell Sanders LLP Welsh & Katz
120 S RIVERSIDE PLAZA, 22ND FLOOR
CHICAGO
IL
60606
US
|
Assignee: |
NAAN-DAAN IRRIGATION SYSTEM (C.S.)
LTD.
Naan
IL
|
Family ID: |
38006294 |
Appl. No.: |
12/084350 |
Filed: |
November 1, 2006 |
PCT Filed: |
November 1, 2006 |
PCT NO: |
PCT/IL06/01265 |
371 Date: |
February 10, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60732611 |
Nov 1, 2005 |
|
|
|
Current U.S.
Class: |
239/542 |
Current CPC
Class: |
Y02A 40/22 20180101;
A01G 25/023 20130101; Y02A 40/237 20180101 |
Class at
Publication: |
239/542 |
International
Class: |
B05B 1/30 20060101
B05B001/30 |
Claims
1. Drip irrigation apparatus comprising: a main water flow channel
having associated therewith along a length thereof a plurality of
pressure-controlled drip irrigation emitter units; and at least one
secondary water flow channel extending generally parallel to said
main water flow channel and receiving water from at least one of
said plurality of pressure-controlled drip irrigation emitter
units, said at least one secondary water flow channel having water
outlets disposed along the length of said main water flow channel,
intermediate said plurality of pressure-controlled drip irrigation
emitter units.
2. Drip irrigation apparatus according to claim 1 and wherein said
at least one secondary water flow channel comprises at least one of
a weeping hose and a sweat irrigation hose.
3. Drip irrigation apparatus according to claim 1 and wherein said
at least one secondary water flow channel has associated therewith
at least one pressure reducing pathway, having outlets which
correspond to said water outlets.
4. Drip irrigation apparatus comprising: a main water flow channel
having associated therewith along a length thereof a plurality of
pressure-controlled drip irrigation emitter units; at least one
secondary water flow channel extending generally parallel to said
main water flow channel and receiving water from at least one of
said plurality of pressure-controlled drip irrigation emitter
units; and at least one pressure-reducing pathway associated with
each of said at least one secondary water flow channel and
distributed therealong, said at least one pressure-reducing pathway
having outlets disposed along the length of said main water flow
channel, intermediate said plurality of pressure-controlled drip
irrigation emitter units.
5. Drip irrigation apparatus according to claim 4 and wherein said
outlets are defined by welding.
6. Drip irrigation apparatus according to claim 4 and wherein said
at least one pressure reducing pathway comprises a series of
discrete labyrinths each having an inlet and an outlet.
7. Drip irrigation apparatus according to claim 6 and wherein said
discrete labyrinths are realized by embossing of said at least one
secondary water flow channel.
8. Drip irrigation apparatus according to claim 6 and wherein said
discrete labyrinths are realized by attaching discrete labyrinth
elements to said at least one secondary water flow channel.
9. Drip irrigation apparatus according to claim 4 and wherein said
at least one pressure reducing pathway comprises a generally
continuous series of non-mutually communicating labyrinths, each
having an inlet and an outlet.
10. Drip irrigation apparatus according to claim 9 and wherein said
non-mutually communicating labyrinths are realized by embossing of
said at least one secondary water flow channel.
11. Drip irrigation apparatus according to claim 9 and wherein said
inlet faces said at least one secondary water flow channel and said
outlet faces away from said at least one secondary water flow
channel.
12. Drip irrigation apparatus according to claim 4 and wherein said
at least one pressure reducing pathway comprises a generally
continuous labyrinth, having multiple inlets and multiple
outlets.
13. Drip irrigation apparatus according to claim 12 and wherein
said multiple outlets are generally evenly spaced on either side of
each of said multiple inlets.
14. Drip irrigation apparatus according to claim 12 and wherein two
of said multiple outlets are provided for each of said multiple
inlets.
15. Drip irrigation apparatus according to claim 12 and wherein
said multiple inlets face said at least one secondary water flow
channel and said multiple outlets face away from said at least one
secondary water flow channel.
16. Drip irrigation apparatus according to claim 4 and wherein at
least one of said plurality of pressure-controlled drip irrigation
emitter units includes a low pressure leakage prevention
feature.
17. Drip irrigation apparatus according to claim 4 and wherein at
least one of said plurality of pressure-controlled drip irrigation
emitter units comprises: an inlet aperture; a raised wall having a
rim, said raised wall and said rim surrounding said inlet aperture;
and an elastic element operative to be displaced when water
pressure in said main water flow channel exceeds a predetermined
threshold, and to be in sealed engagement with said rim of said
raised wall when water pressure in said main water flow channel
does not exceed said predetermined threshold.
18. Drip irrigation apparatus according to claim 4 and wherein at
least one of said plurality of pressure-controlled drip irrigation
emitter units comprises two mutually sealed portions.
19. Drip irrigation apparatus according to claim 18 and wherein: a
first one of said two mutually sealed portions comprises: a
circumferential raised elongate portion; and an internal raised
elongate portion extending between two sections of said at least
one pressure-reducing pathway; and a second one of said two
mutually sealed portions comprises: a circumferential elongate
recess; and an internal elongate recess, said two mutually sealed
portions being sealed by engagement of said raised elongate
portions with said elongate recesses.
20. Drip irrigation apparatus according to claim 19 and wherein
said raised elongate portions have a generally triangular cross
section, and said elongate recesses have a generally rectangular
cross section.
21. Drip irrigation apparatus according to claim 19 and wherein
said two mutually sealed portions are sealed ultrasonically.
22. Drip irrigation apparatus according to claim 21 and wherein
said two mutually sealed portions are sealed ultrasonically along
said raised elongate portions and said elongate recesses.
23. Drip irrigation apparatus according to claim 22 and wherein at
least one of said two mutually sealed portions and said at least
one pressure reducing pathway is not deformed by ultrasonic sealing
of said raised elongate portions and said elongate recesses.
24. Drip irrigation apparatus according to claim 22 and wherein
dimensions of at least one of said two mutually sealed portions and
said at least one pressure reducing pathway are not changed by
ultrasonic sealing of said raised elongate portions and said
elongate recesses.
25. Drip irrigation apparatus according to claim 18 and wherein
said at least one pressure reducing pathway maintains its
functionality even when sealing between inwardly facing sides of
said two mutually sealed portions is incomplete.
26. Drip irrigation apparatus according to claim 19 and wherein
said first one of said two mutually sealed portions includes a
circumferential raised wall and an internal raised wall having a
protrusion therebetween, said protrusion being operative to at
least partially prevent particular matter from flowing into said at
least one pressure reducing pathway.
27. Drip irrigation apparatus according to claim 17 and wherein
said raised wall comprises a non-circular wall, and said rim is
configured such that at a predetermined threshold pressure across
said elastic element, said elastic element transitions from
generally complete circumferential disengagement with said rim to
generally complete circumferential engagement with said rim.
28. Drip irrigation apparatus according to claim 27 and wherein
said rim is configured such that at a second predetermined
threshold pressure across said elastic element, said elastic
element transitions from generally complete circumferential
engagement with said rim to generally complete circumferential
disengagement with said rim.
29. Drip irrigation apparatus according to claim 27 and wherein
said rim of said non-circular wall is non-planar.
30. Drip irrigation apparatus according to claim 1 and wherein said
main water flow channel is defined by welding of one elongate edge
of a sheet to an interior location therealong.
31. Drip irrigation apparatus according to claim 30 and wherein
said at least one secondary water flow channel is defined by
welding of another elongate edge of said sheet to a labyrinth
defining strip which is welded to said sheet at an exterior
location therealong.
32. Drip irrigation apparatus according to claim 1 and wherein said
main water flow channel is defined by welding of first and second
elongate edges of a first sheet at a seam location.
33. Drip irrigation apparatus according to claim 32 and wherein
said at least one secondary water flow channel is defined by
welding of a first elongate edge of a second sheet to said first
elongate edge of said first sheet at said seam location and by
welding a second elongate edge of said second sheet to a labyrinth
defining strip which is welded to said first sheet at an exterior
location therealong.
34. Drip irrigation apparatus according to claim 1 and wherein said
main water flow channel is defined by an elongate tube.
35. Drip irrigation apparatus according to claim 34 and wherein
said at least one secondary water flow channel is defined by
welding of a first elongate edge of a sheet to said elongate tube
at a first exterior location therealong and by welding of a second
elongate edge of said sheet to a labyrinth defining strip which is
welded to said elongate tube at a second exterior location
therealong.
36. Drip irrigation apparatus according to claim 34 and wherein
said at least one secondary water flow channel is defined by
welding of a first elongate edge of a sheet to said elongate tube
at a first exterior location therealong and by welding of a second
elongate edge of said sheet to said elongate tube at a second
exterior location therealong, said sheet having a labyrinth
defining strip welded at a surface thereof which faces an exterior
surface of said elongate tube.
37. Drip irrigation apparatus according to claim 34 and wherein
said at least one secondary flow channel is defined by a second
elongate tube surrounding said elongate tube, said second elongate
tube having welded at a first location of an interior surface
thereof a labyrinth defining strip and being welded at a second
location of said interior surface thereof to an outer surface of
said elongate tube.
38. Drip irrigation apparatus according to claim 30 and wherein
said main water flow channel has welded at an interior location
therealong at least one of said plurality of pressure-controlled
drip irrigation emitter unit.
39. Drip irrigation apparatus according to claim 30 and wherein
said at least one secondary water flow channel includes material
having at least one of weeping hose functionality and sweat
irrigation functionality.
40. A pressure-controlled drip irrigation emitter element
comprising: a water inlet; an inlet control chamber receiving water
from said water inlet via an inlet aperture; a pressure reducing
pathway receiving water from said inlet control chamber; an outlet
control chamber receiving water from said pressure reducing
pathway; an elastic element separating said inlet control chamber
and said outlet control chamber; and a non-circular wall
surrounding said inlet aperture and having a rim, said rim being
configured such that at a predetermined threshold pressure across
said elastic element, said elastic element transitions from
generally complete circumferential disengagement with said rim to
generally complete circumferential engagement with said rim.
41. A pressure-controlled drip irrigation emitter element
comprising: a water inlet; an inlet control chamber receiving water
from said water inlet via an inlet aperture; a pressure reducing
pathway receiving water from said inlet control chamber; an outlet
control chamber receiving water from said pressure reducing
pathway; and an elastic element separating said inlet control
chamber and said outlet control chamber, said inlet control
chamber, said outlet control chamber and said pressure reducing
pathway being defined by ultrasonic sealing of first and second
emitter element portions in a manner such that the dimensions of
said pressure reducing pathway are not affected.
42. A pressure-controlled drip irrigation emitter element according
to claim 41 and wherein said inlet aperture is surrounded by a
non-circular wall having a rim, said rim being configured such that
at a predetermined threshold pressure across said elastic element,
said elastic element transitions from generally complete
circumferential disengagement with said rim to generally complete
circumferential engagement with said rim.
43. A pressure-controlled drip irrigation emitter element according
to claim 40 and wherein said rim is configured such that at a
second predetermined threshold pressure across said elastic
element, said elastic element transitions from generally complete
circumferential engagement with said rim to generally complete
circumferential disengagement with said rim.
44. A pressure-controlled drip irrigation emitter element according
to claim 40 and wherein said rim of said non-circular wall is
non-planar.
45. A pressure-controlled drip irrigation emitter element according
to claim 41 and wherein one of said first and second emitter
element portions includes a raised elongate portion and another of
said first and second emitter element portions includes a
corresponding elongate recess, said raised elongate portion and
said elongate recess being ultrasonically welded together.
46. A pressure-controlled drip irrigation emitter element according
to claim 45 and wherein said raised elongate portion has a
generally triangular cross section and said elongate recess has a
generally rectangular cross section.
47. A pressure-controlled drip irrigation emitter element according
to claim 45 and wherein said one of said first and second emitter
element portions also includes an internal raised elongate portion
extending between two sections of said pressure-reducing pathway,
and said another of said first and second emitter element portions
also includes a corresponding internal elongate recess, said
internal raised elongate portion and said internal elongate recess
being ultrasonically welded together.
48. A pressure-controlled drip irrigation emitter element according
to claim 47 and wherein said internal raised elongate portion has a
generally triangular cross section and said internal elongate
recess has a generally rectangular cross section.
49. A pressure-controlled drip irrigation emitter element according
to claim 41 and wherein said pressure reducing pathway maintains
its functionality even when sealing between inwardly facing sides
of said two mutually sealed portions is incomplete.
50. A pressure-controlled drip irrigation emitter element according
to claim 41 and wherein one of said first and second emitter
element portions includes a circumferential raised wall and an
internal raised wall having a protrusion therebetween, said
protrusion being operative to at least partially prevent particular
matter from flowing into said pressure reducing pathway.
51. A pressure-controlled drip irrigation emitter element disposed
along an interior wall of a water supply tube comprising: a water
inlet coupled to said interior wall of said water supply tube; an
inlet control chamber receiving water from said water inlet via an
inlet aperture; a pressure reducing pathway receiving water from
said inlet control chamber, said pressure reducing pathway being
separated from said interior wall of said water supply tube; an
outlet control chamber receiving water from said pressure reducing
pathway via a pressure reducing pathway outlet passage; and an
elastic element separating said inlet control chamber and said
outlet control chamber, said pressure reducing pathway outlet
passage extending from said pressure reducing pathway, along a
pathway extending between said emitter element and said interior
wall of said water supply tube, and to said outlet control
chamber.
52. A pressure-controlled drip irrigation emitter element according
to claim 51 and wherein said inlet aperture is surrounded by a
non-circular wall having a rim, said rim being configured such that
at a predetermined threshold pressure across said elastic element,
said elastic element transitions from generally complete
circumferential disengagement with said rim to generally complete
circumferential engagement with said rim.
53. A pressure-controlled drip irrigation emitter element according
to claim 52 and wherein said rim is configured such that at a
second predetermined threshold pressure across said elastic
element, said elastic element transitions from generally complete
circumferential engagement with said rim to generally complete
circumferential disengagement with said rim.
54. A pressure-controlled drip irrigation emitter element according
to claim 52 and wherein said rim of said non-circular wall is
non-planar.
55. A pressure-controlled drip irrigation emitter element according
to claim 51 and wherein said inlet control chamber, said outlet
control chamber and said pressure reducing pathway are defined by
ultrasonic sealing of first and second emitter element portions in
a manner such that the dimensions of said pressure reducing pathway
are not affected.
56. A pressure-controlled drip irrigation emitter element according
to claim 55 and wherein one of said first and second emitter
element portions includes a raised elongate portion and another of
said first and second emitter element portions includes a
corresponding elongate recess, said raised elongate portion and
said elongate recess being ultrasonically welded together.
57. A pressure-controlled drip irrigation emitter element according
to claim 56 and wherein said raised elongate portion has a
generally triangular cross section and said elongate recess has a
generally rectangular cross section.
58. A pressure-controlled drip irrigation emitter element according
to claim 56 and wherein said one of said first and second emitter
element portions also includes an internal raised elongate portion
extending between two sections of said pressure-reducing pathway,
and said another of said first and second emitter element portions
also includes a corresponding internal elongate recess, said
internal raised elongate portion and said internal elongate recess
being ultrasonically welded together.
59. A pressure-controlled drip irrigation emitter element according
to claim 58 and wherein said internal raised elongate portion has a
generally triangular cross section and said internal elongate
recess has a generally rectangular cross section.
60. A pressure-controlled drip irrigation emitter element according
to claim 55 and wherein said pressure reducing pathway maintains
its functionality even when sealing between inwardly facing sides
of said two mutually sealed portions is incomplete.
61. A pressure-controlled drip irrigation emitter element according
to claim 55 and wherein one of said first and second emitter
element portions includes a circumferential raised wall and an
internal raised wall, having a protrusion therebetween, said
protrusion being operative to at least partially prevent particular
matter from flowing into said pressure reducing pathway.
Description
REFERENCE TO RELATED APPLICATIONS
[0001] The present application is related to U.S. Provisional
Patent Application Ser. No. 60/732,611, filed Nov. 1, 2005 and
entitled DRIP IRRIGATION APPARATUS, the disclosure of which is
hereby incorporated by reference and priority of which is hereby
claimed pursuant to 37 CFR 1.78(a) (4) and (5)(i).
FIELD OF THE INVENTION
[0002] The present invention relates to drip irrigation apparatus
and methods of manufacture thereof.
BACKGROUND OF THE INVENTION
[0003] The following patent publications are believed to represent
the current state of the art:
[0004] U.S. Pat. Nos. 4,177,946; 4,285,472; 4,430,020; 4,473,191;
4,534,515; 4,874,132; 5,106,021; 5,615,838; 6,027,048; 6,206,305
and 6,382,530.
SUMMARY OF THE INVENTION
[0005] The present invention seeks to provide improved drip
irrigation apparatus and methods of manufacture thereof.
[0006] There is thus provided in accordance with a preferred
embodiment of the present invention drip irrigation apparatus
including a main water flow channel having associated therewith
along a length thereof a plurality of pressure-controlled drip
irrigation emitter units and at least one secondary water flow
channel extending generally parallel to the main water flow channel
and receiving water from at least one of the plurality of
pressure-controlled drip irrigation emitter units, the at least one
secondary water flow channel having water outlets disposed along
the length of the main water flow channel, intermediate the
plurality of pressure-controlled drip irrigation emitter units.
[0007] In accordance with a preferred embodiment of the present
invention the at least one secondary water flow channel includes at
least one of a weeping hose and a sweat irrigation hose.
Preferably, the at least one secondary water flow channel has
associated therewith at least one pressure reducing pathway, having
outlets which correspond to the water outlets.
[0008] There is also provided in accordance with another preferred
embodiment of the present invention drip irrigation apparatus
including a main water flow channel having associated therewith
along a length thereof a plurality of pressure-controlled drip
irrigation emitter units, at least one secondary water flow channel
extending generally parallel to the main water flow channel and
receiving water from at least one of the plurality of
pressure-controlled drip irrigation emitter units and at least one
pressure-reducing pathway associated with each of the at least one
secondary water flow channel and distributed therealong, the at
least one pressure-reducing pathway having outlets disposed along
the length of the main water flow channel, intermediate the
plurality of pressure-controlled drip irrigation emitter units.
[0009] In accordance with a preferred embodiment of the present
invention the outlets are defined by welding. Preferably, the at
least one pressure reducing pathway includes a series of discrete
labyrinths each having an inlet and an outlet. Additionally, the
discrete labyrinths are realized by embossing of the at least one
secondary water flow channel. Alternatively, the discrete
labyrinths are realized by attaching discrete labyrinth elements to
the at least one secondary water flow channel.
[0010] In accordance with another preferred embodiment of the
present invention the at least one pressure reducing pathway
includes a generally continuous series of non-mutually
communicating labyrinths, each having an inlet and an outlet.
Preferably, the non-mutually communicating labyrinths are realized
by embossing of the at least one secondary water flow channel.
Additionally or alternatively, the inlet faces the at least one
secondary water flow channel and the outlet faces away from the at
least one secondary water flow channel.
[0011] In accordance with yet another preferred embodiment of the
present invention the at least one pressure reducing pathway
includes a generally continuous labyrinth, having multiple inlets
and multiple outlets. Preferably, the multiple outlets are
generally evenly spaced on either side of each of the multiple
inlets. Additionally or alternatively, two of the multiple outlets
are provided for each of the multiple inlets. As a further addition
or alternative, the multiple inlets face the at least one secondary
water flow channel and the multiple outlets face away from the at
least one secondary water flow channel.
[0012] In accordance with still another preferred embodiment of the
present invention at least one of the plurality of
pressure-controlled drip irrigation emitter units includes a low
pressure leakage prevention feature. Preferably, at least one of
the plurality of pressure-controlled drip irrigation emitter units
includes an inlet aperture, a raised wall having a rim, the raised
wall and the rim surrounding the inlet aperture and an elastic
element operative to be displaced when water pressure in the main
water flow channel exceeds a predetermined threshold, and to be in
sealed engagement with the rim of the raised wall when water
pressure in the main water flow channel does not exceed the
predetermined threshold. Additionally or alternatively, at least
one of the plurality of pressure-controlled drip irrigation emitter
units includes two mutually sealed portions.
[0013] In accordance with a further preferred embodiment of the
present invention a first one of the two mutually sealed portions
includes a circumferential raised elongate portion and an internal
raised elongate portion extending between two sections of the at
least one pressure-reducing pathway, and a second one of the two
mutually sealed portions includes a circumferential elongate recess
and an internal elongate recess, the two mutually sealed portions
being sealed by engagement of the raised elongate portions with the
elongate recesses. Preferably, the raised elongate portions have a
generally triangular cross section, and the elongate recesses have
a generally rectangular cross section. Additionally or
alternatively, the two mutually sealed portions are sealed
ultrasonically.
[0014] In accordance with a yet further preferred embodiment of the
present invention the two mutually sealed portions are sealed
ultrasonically along the raised elongate portions and the elongate
recesses. Preferably, at least one of the two mutually sealed
portions and the at least one pressure reducing pathway is not
deformed by ultrasonic sealing of the raised elongate portions and
the elongate recesses. Additionally or alternatively, dimensions of
at least one of the two mutually sealed portions and the at least
one pressure reducing pathway are not changed by ultrasonic sealing
of the raised elongate portions and the elongate recesses.
[0015] In accordance with a still further preferred embodiment of
the present invention the at least one pressure reducing pathway
maintains its functionality even when sealing between inwardly
facing sides of the two mutually sealed portions is incomplete.
Preferably, the first one of the two mutually sealed portions
includes a circumferential raised wall and an internal raised wall
having a protrusion therebetween, the protrusion being operative to
at least partially prevent particular matter from flowing into the
at least one pressure reducing pathway.
[0016] In accordance with an additional preferred embodiment of the
present invention the raised wall includes a non-circular wall, and
the rim is configured such that at a predetermined threshold
pressure across the elastic element, the elastic element
transitions from generally complete circumferential disengagement
with the rim to generally complete circumferential engagement with
the rim. Preferably, the rim is configured such that at a second
predetermined threshold pressure across the elastic element, the
elastic element transitions from generally complete circumferential
engagement with the rim to generally complete circumferential
disengagement with the rim. Additionally or alternatively the rim
of the non-circular wall is non-planar.
[0017] In accordance with another preferred embodiment of the
present invention the main water flow channel is defined by welding
of one elongate edge of a sheet to an interior location therealong.
Preferably, the at least one secondary water flow channel is
defined by welding of another elongate edge of the sheet to a
labyrinth defining strip which is welded to the sheet at an
exterior location therealong.
[0018] In accordance with yet another preferred embodiment of the
present invention the main water flow channel is defined by welding
of first and second elongate edges of a first sheet at a seam
location. Preferably, the at least one secondary water flow channel
is defined by welding of a first elongate edge of a second sheet to
the first elongate edge of the first sheet at the seam location and
by welding a second elongate edge of the second sheet to a
labyrinth defining strip which is welded to the first sheet at an
exterior location therealong.
[0019] In accordance with still another preferred embodiment of the
present invention the main water flow channel is defined by an
elongate tube. Preferably, the at least one secondary water flow
channel is defined by welding of a first elongate edge of a sheet
to the elongate tube at a first exterior location therealong and by
welding of a second elongate edge of the sheet to a labyrinth
defining strip which is welded to the elongate tube at a second
exterior location therealong. Alternatively, the at least one
secondary water flow channel is defined by welding of a first
elongate edge of a sheet to the elongate tube at a first exterior
location therealong and by welding of a second elongate edge of the
sheet to the elongate tube at a second exterior location
therealong, the sheet having a labyrinth defining strip welded at a
surface thereof which faces an exterior-surface of the elongate
tube.
[0020] As a further alternative, the at least one secondary flow
channel is defined by a second elongate tube surrounding the
elongate tube, the second elongate tube having welded at a first
location of an interior surface thereof a labyrinth defining strip
and being welded at a second location of the interior surface
thereof to an outer surface of the elongate tube.
[0021] In accordance with a further preferred embodiment of the
present invention the main water flow channel has welded at an
interior location therealong at least one of the plurality of
pressure-controlled drip irrigation emitter unit. Preferably, the
at least one secondary water flow channel includes material having
at least one of weeping hose functionality and sweat irrigation
functionality.
[0022] There is further provided in accordance with a further
preferred embodiment of the present invention a pressure-controlled
drip irrigation emitter element including a water inlet, an inlet
control chamber receiving water from the water inlet via an inlet
aperture, a pressure reducing pathway receiving water from the
inlet control chamber, an outlet control chamber receiving water
from the pressure reducing pathway, an elastic element separating
the inlet control chamber and the outlet control chamber and a
non-circular wall surrounding the inlet aperture and having a rim,
the rim being configured such that at a predetermined threshold
pressure across the elastic element, the elastic element
transitions from generally complete circumferential disengagement
with the rim to generally complete circumferential engagement with
the rim.
[0023] There is additionally provided in accordance with an
additional preferred embodiment of the present invention a
pressure-controlled drip irrigation emitter element including a
water inlet, an inlet control chamber receiving water from the
water inlet via an inlet aperture, a pressure reducing pathway
receiving water from the inlet control chamber, an outlet control
chamber receiving water from the pressure reducing pathway and an
elastic element separating the inlet control chamber and the outlet
control chamber, the inlet control chamber, the outlet control
chamber and the pressure reducing pathway being defined by
ultrasonic sealing of first and second emitter element portions in
a manner such that the dimensions of the pressure reducing pathway
are not affected.
[0024] In accordance with a preferred embodiment of the present
invention the inlet aperture is surrounded by a non-circular wall
having a rim, the rim being configured such that at a predetermined
threshold pressure across the elastic element, the elastic element
transitions from generally complete circumferential disengagement
with the rim to generally complete circumferential engagement with
the rim. Preferably, the rim is configured such that at a second
predetermined threshold pressure across the elastic element, the
elastic element transitions from generally complete circumferential
engagement with the rim to generally complete circumferential
disengagement with the rim.
[0025] In accordance with another preferred embodiment of the
present invention the rim of the non-circular wall is non-planar.
Preferably, one of the first and second emitter element portions
includes a raised elongate portion and another of the first and
second emitter element portions includes a corresponding elongate
recess, the raised elongate portion and the elongate recess being
ultrasonically welded together. Additionally or alternatively, the
raised elongate portion has a generally triangular cross section
and the elongate recess has a generally rectangular cross
section.
[0026] In accordance with still another preferred embodiment of the
present invention the one of the first and second emitter element
portions also includes an internal raised elongate portion
extending between two sections of the pressure-reducing pathway,
and the another of the first and second emitter element portions
also includes a corresponding internal elongate recess, the
internal raised elongate portion and the internal elongate recess
being ultrasonically welded together. Preferably, the internal
raised elongate portion has a generally triangular cross section
and the internal elongate recess has a generally rectangular cross
section.
[0027] In accordance with yet another preferred embodiment of the
present invention the pressure reducing pathway maintains its
functionality even when sealing between inwardly facing sides of
the two mutually sealed portions is incomplete. Preferably, one of
the first and second emitter element portions includes a
circumferential raised wall and an internal raised wall having a
protrusion therebetween, the protrusion being operative to at least
partially prevent particular matter from flowing into the pressure
reducing pathway.
[0028] There is also provided in accordance with another preferred
embodiment of the present invention a pressure-controlled deep
irrigation emitter element disposed along an interior wall of a
water supply tube including a water inlet coupled to the interior
wall of the water supply tube, an inlet control chamber receiving
water from the water inlet via an inlet aperture, a pressure
reducing pathway receiving water from the inlet control chamber,
the pressure reducing pathway being separated from the interior
wall of the water supply tube, an outlet control chamber receiving
water from the pressure reducing pathway via a pressure reducing
pathway outlet passage and an elastic element separating the inlet
control chamber and the outlet control chamber, the pressure
reducing pathway outlet passage extending from the pressure
reducing pathway, along a pathway extending between the emitter
element and the interior wall of the water supply tube, and to the
outlet control chamber.
[0029] In accordance with a preferred embodiment of the present
invention the inlet aperture is surrounded by a non-circular wall
having a rim, the rim being configured such that at a predetermined
threshold pressure across the elastic element, the elastic element
transitions from generally complete circumferential disengagement
with the rim to generally complete circumferential engagement with
the rim. Preferably, the rim is configured such that at a second
predetermined threshold pressure across the elastic element, the
elastic element transitions from generally complete circumferential
engagement with the rim to generally complete circumferential
disengagement with the rim.
[0030] In accordance with another preferred embodiment of the
present invention the rim of the non-circular wall is non-planar.
Preferably, the inlet control chamber, the outlet control chamber
and the pressure reducing pathway are defined by ultrasonic sealing
of first and second emitter element portions in a manner such that
the dimensions of the pressure reducing pathway are not affected.
Additionally or alternatively, the first and second emitter element
portions includes a raised elongate portion and another of the
first and second emitter element portions includes a corresponding
elongate recess, the raised elongate portion and the elongate
recess being ultrasonically welded together.
[0031] In accordance with yet another preferred embodiment of the
present invention the raised elongate portion has a generally
triangular cross section and the elongate recess has a generally
rectangular cross section. Preferably, the one of the first and
second emitter element portions also includes an internal raised
elongate portion extending between two sections of the
pressure-reducing pathway, and the another of the first and second
emitter element portions also includes a corresponding internal
elongate recess, the internal raised elongate portion and the
internal elongate recess being ultrasonically welded together.
Additionally or alternatively, the internal raised elongate portion
has a generally triangular cross section and the internal elongate
recess has a generally rectangular cross section.
[0032] In accordance with a further preferred embodiment of the
present invention the pressure reducing pathway maintains its
functionality even when sealing between inwardly facing sides of
the two mutually sealed portions is incomplete. Preferably, one of
the first and second emitter element portions includes a
circumferential raised wall and an internal raised wall, having a
protrusion therebetween, the protrusion being operative to at least
partially prevent particular matter from flowing into the pressure
reducing pathway.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The present invention will be understood and appreciated
more fully from the following detailed description, taken in
conjunction with the drawings in which:
[0034] FIG. 1 is a simplified, general schematic illustration of
drip irrigation apparatus constructed and operative in accordance
with a preferred embodiment of the present invention;
[0035] FIGS. 2A and 2B are simplified pictorial illustrations of
first and second sides of a first portion of a drip irrigation
emitter element useful in the drip irrigation apparatus of FIG.
1;
[0036] FIGS. 3A and 3B are simplified pictorial illustrations of
first and second sides of a second portion of the drip irrigation
emitter element useful in the drip irrigation apparatus of FIG.
1;
[0037] FIG. 4 is a first simplified exploded view illustration of
the drip irrigation emitter element of FIGS. 2A-3B;
[0038] FIG. 5 is a first simplified assembled view illustration of
the drip irrigation emitter element of FIG. 4;
[0039] FIG. 6 is a second simplified exploded view illustration of
the drip irrigation emitter element of FIGS. 2A-5;
[0040] FIG. 7 is a second simplified assembled view illustration of
the drip irrigation emitter element of FIG. 6;
[0041] FIG. 8 is a simplified sectional illustration of the drip
irrigation emitter element of FIGS. 2A-7, taken along section lines
VIII-VIII in FIG. 5, the drip irrigation emitter element being
placed inside a drip irrigation line of the general type shown in
FIG. 1;
[0042] FIG. 9 is a simplified sectional illustration of the drip
irrigation emitter element of FIGS. 2A-7, taken along section lines
IX-IX in FIG. 5, the drip irrigation emitter element being placed
inside a drip irrigation line of the general type shown in FIG.
1;
[0043] FIG. 10 is a simplified sectional illustration of the drip
irrigation emitter element of FIGS. 2A-7, taken along section lines
X-X in FIG. 5, the drip irrigation emitter element being placed
inside a drip irrigation line of the general type shown in FIG.
1;
[0044] FIGS. 11A, 11B, 11C and 11D are simplified illustrations of
a problem in the operation of prior art pressure-controlled
anti-leakage drip irrigation emitters, FIG. 11A being a simplified
not-to-scale pictorial illustration, FIGS. 11B and 11C being
sectional illustrations taken along respective section lines
XIB-XIB and XIC-XIC in FIG. 11A, and FIG. 11D being a superposition
of portions of FIGS. 11B and 11C;
[0045] FIGS. 12A, 12B, 12C and 12D are simplified illustrations of
a solution to the problem in the operation of prior art
pressure-controlled anti-leakage drip irrigation emitters as shown
in FIGS. 11A-11D, FIG. 12A being a simplified not-to-scale
pictorial illustration, FIGS. 12B and 12C being sectional
illustrations taken along respective section lines XIIB-XIIB and
XIIC-XIIC in FIG. 12A, and FIG. 12D being a superposition of
portions of FIGS. 12B and 12C;
[0046] FIGS. 13A, 13B, 13C and 13D are generally to-scale
simplified illustrations which correspond to FIGS. 12B and 12C in
the context of the drip irrigation emitter element of FIGS. 2A-10,
FIGS. 13A and 13B showing a first operative orientation of the drip
irrigation emitter element and FIGS. 13C and 13D showing a second
operative orientation of the drip irrigation emitter element;
[0047] FIGS. 14A, 14B, 14C and 14D are simplified illustrations of
another solution to the problem in the operation of prior art
pressure-controlled anti-leakage drip irrigation emitters as shown
in FIGS. 11A-11D, FIG. 14A being a simplified not-to-scale
pictorial illustration, FIGS. 14B and 14C being sectional
illustrations taken along respective section lines XIVB-XIVB and
XIVC-XIVC in FIG. 14A, and FIG. 14D being a superposition of
portions of FIGS. 14B and 14C;
[0048] FIGS. 15A, 15B, 15C and 15D are generally to-scale
simplified illustrations which correspond to FIGS. 14B and 14C in
the context of the drip irrigation emitter element of FIGS. 2A-10,
FIGS. 15A and 15B showing a first operative orientation of the drip
irrigation emitter element and FIGS. 15C and 15D showing a second
operative orientation of the drip irrigation emitter element;
[0049] FIGS. 16A, 16B, 16C and 16D are simplified sectional
illustrations of drip irrigation apparatus constructed and
operative in accordance with a preferred embodiment of the present
invention, taken at locations indicated by respective arrows A, B,
C and D in the general schematic illustration of FIG. 1;
[0050] FIGS. 17A, 17B, 17C and 17D are simplified sectional
illustrations of drip irrigation apparatus constructed and
operative in accordance with another preferred embodiment of the
present invention, taken at locations indicated by respective
arrows A, B, C and D in the general schematic illustration of FIG.
1;
[0051] FIGS. 18A, 18B, 18C and 18D are simplified sectional
illustrations of drip irrigation apparatus constructed and
operative in accordance with yet another preferred embodiment of
the present invention, taken at locations indicated by respective
arrows A, B, C and D in the general schematic illustration of FIG.
1;
[0052] FIGS. 19A, 19B, 19C and 19D are simplified sectional
illustrations of drip irrigation apparatus constructed and
operative in accordance with still another preferred embodiment of
the present invention, taken at locations indicated by respective
arrows A, B, C and D in the general schematic illustration of FIG.
1; and
[0053] FIGS. 20A, 20B, 20C and 20D are simplified sectional
illustrations of drip irrigation apparatus constructed and
operative in accordance with a further preferred embodiment of the
present invention, taken at locations indicated by respective
arrows A, B, C and D in the general schematic illustration of FIG.
1.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0054] Reference is now made to FIG. 1, which is a simplified,
general schematic illustration of drip irrigation apparatus
constructed and operative in accordance with a preferred embodiment
of the present invention. FIG. 1 shows a main water flow channel
100 having disposed at longitudinally spaced locations therealong,
typically separated from each other by approximately one meter, a
plurality of pressure-controlled drip irrigation emitter elements
102, which preferably include a low pressure leakage prevention
feature. Each drip irrigation emitter element 102 provides a
pressure-compensated liquid flow output to a secondary water flow
channel 104, which extends generally parallel to main water flow
channel 100, via a pressure-compensated emitter element output
aperture 106 formed in a common wall 108, joining main water flow
channel 100 and secondary water flow channel 104.
[0055] At least one longitudinally spaced secondary water flow
channel labyrinth 110 communicates with secondary water flow
channel 104 and provides a reduced pressure output at multiple
water outlets 112 which communicate with the outside of the
secondary water flow channel 104. Preferably a plurality of inlets
114 are provided to the at least one longitudinally spaced
secondary water flow channel labyrinth 110 along the length
thereof. Outlets 112 and inlets 114 are typically defined by
welding or by other manufacturing techniques. Typically water
outlets 112 are separated from each other by 10 cm. Alternatively,
secondary water flow channel 104 may be a weeping hose, such as a
weeping hose of the type described in U.S. Pat. No. 5,299,885, the
content of which is incorporated herein by reference, or such as an
Aquapore weeping hose commercially available from Aquapore Moisture
Systems, Inc. of Phoenix, Ariz. Alternatively, secondary water flow
channel 104 may be any type of hose suitable for sweat
irrigation.
[0056] FIG. 1 includes five enlargements showing five alternative
labyrinth structures. An enlargement designated by Roman numeral I
shows the at least one longitudinally spaced secondary water flow
channel labyrinth 110 implemented as a series of discrete
labyrinths 116, each having an inlet 118 and an outlet 120. The
discrete labyrinths 116 may be realized by embossing of the
secondary water flow channel 104 or alternatively by attaching
discrete labyrinth elements to the secondary water flow channel
104.
[0057] An enlargement designated by Roman numeral II shows the at
least one longitudinally spaced secondary water flow channel
labyrinth 110 implemented as a generally continuous series of
non-mutually communicating labyrinths 122, each having an inlet 124
and an outlet 126. The generally continuous series of non-mutually
communicating labyrinths 122 may be realized by embossing of the
secondary water flow channel 104.
[0058] An enlargement designated by Roman numeral III shows the at
least one longitudinally spaced secondary water flow channel
labyrinth 110 implemented as a generally continuous labyrinth 128,
having multiple inlets 130 and outlets 132. Preferably, the outlets
132 are generally evenly spaced on either side of each inlet 130.
Typically two outlets 132 are provided for each inlet 130.
[0059] An enlargement designated by Roman numeral IV shows the at
least one longitudinally spaced secondary water flow channel
labyrinth 110 implemented as a generally continuous series of
non-mutually communicating labyrinths 142, each having an inlet 144
facing the secondary water flow channel 104 and an outlet 146
facing in an opposite direction, away from the secondary water flow
channel 104. The generally continuous series of non-mutually
communicating labyrinths 142 may be realized by embossing of the
secondary water flow channel 104.
[0060] An enlargement designated by Roman numeral V shows the at
least one longitudinally spaced secondary water flow channel
labyrinth 110 implemented as a generally continuous labyrinth 148,
having multiple inlets 150 facing the secondary water flow channel
104 and multiple outlets 152 facing in an opposite direction, away
from the secondary water flow channel 104. Preferably, the outlets
152 are generally evenly spaced on either side of each inlet 150.
Typically two outlets 152 are provided for each inlet 150.
[0061] Reference is now made to FIGS. 2A and 2B, which are
simplified pictorial illustrations of first and second sides of a
first portion of a drip irrigation emitter element useful in the
drip irrigation apparatus of FIG. 1, to FIGS. 3A and 3B, which are
simplified pictorial illustrations of first and second sides of a
second portion of the drip irrigation emitter element useful in the
drip irrigation apparatus of FIG. 1, to FIG. 4, which is a first
simplified exploded view illustration of the drip irrigation
emitter element of FIGS. 2A-3B, to FIG. 5, which is a first
simplified assembled view illustration of the drip irrigation
emitter element of FIG. 4, to FIG. 6, which is a second simplified
exploded view illustration of the drip irrigation emitter element
of FIGS. 2A-5, to FIG. 7, which is a second simplified assembled
view illustration of the drip irrigation emitter element of FIG. 6,
and to FIGS. 8, 9 and 10, which are simplified sectional
illustrations of the drip irrigation emitter element of FIGS. 2A-7
when placed inside a drip irrigation line of the general type shown
in FIG. 1.
[0062] Turning initially to FIGS. 4-7, water from main water flow
channel 100 (FIG. 1) passes a water filtering grid 200, as
indicated by an arrow 201, and through an inlet aperture 202, which
aperture is surrounded by a raised wall 204. When the pressure of
the water in main water flow channel 100 exceeds a predetermined
threshold, preferably 0.5 Atmospheres, the water displaces a
generally rectangular planar elastic element 206, which, in the
absence of such pressure, lies in sealed engagement with a rim 208
of raised wall 204.
[0063] An inlet control chamber 209 is defined by rim 208, a
surface 210 and generally rectangular planar elastic element 206.
Displacement of generally rectangular planar elastic element 206
from sealed engagement with rim 208 allows water to flow through
aperture 202 into inlet control chamber 209, as described further
hereinbelow with reference to FIGS. 13A-13D, along surface 210, as
indicated by arrows 211, and via a longitudinal recess 212 formed
in surface 210 to an inlet 214 of a labyrinthine passageway 216.
The structure of the labyrinthine passageway 216 is seen from
additional consideration of FIGS. 2A and 3B which illustrate
facing, mutually sealed sides 220 and 222 of respective portions
224 and 226 of a drip irrigation emitter element 230, useful as the
drip irrigation emitter element 102 (FIG. 1).
[0064] Portions 224 and 226 of drip irrigation emitter element 230
are sealed together at a circumferential raised elongate portion
232 to which is connected an internal raised elongate portion 234,
which extends between two sections 236 and 238 of pressure-reducing
labyrinthine passageway 216. Elongate portions 232 and 234 extend
from side 222 of portion 226 and sealingly engage correspondingly
located elongate recesses 242 and 244 formed on side 220 of portion
224. Preferably, elongate portions 232 and 234 have a generally
triangular cross section as seen in the enlarged portion of FIG. 6,
and recesses 242 and 244 have a generally rectangular cross section
as seen in the enlarged portion of FIG. 4.
[0065] The labyrinthine passageway 216 is defined by a series of
tooth-like protrusions 250 which extend from a surface 251 and have
a top surface 252. In the assembled drip irrigation emitter element
230, when elongate portions 232 and 234 are sealed to respective
elongate recesses 242 and 244, surfaces 210 and 252 lie in mutually
touching, preferably sealed engagement. Preferably, the sealing is
effected ultrasonically and the dimensions of the circumferential
raised elongate portion 232, the internal raised elongate portion
234 and corresponding recesses 242 and 244 are such that ultrasonic
sealing thereof does not deform or affect the dimensions or mutual
engagement of surfaces 210 and 252 and particularly does not affect
the dimensions of the labyrinthine passageway 216.
[0066] It is appreciated that sealing between internal elongate
portion 234 and corresponding elongate recess 244 is provided such
that in the event of incomplete sealing between surfaces 210 and
252, water will not bypass much of the labyrinthine passageway 216
from section 236 to section 238 and from the region lying between
surface 210 and elastic element 206 to section 238.
[0067] The water flows through the labyrinthine pathway 216 to a
labyrinthine pathway outlet 260 and the water pressure is
correspondingly reduced by about 0.4 Atmospheres, typically from a
line pressure of 0.5 to 4 Atmospheres.
[0068] Reference is now made additionally to FIGS. 8-10, which
illustrate a side 270, shown with particular clarity in FIG. 3A, of
portion 226 of element 230, being sealed to an interior wall
surface 272 of a water supply pipe 274, useful as main water flow
channel 100 (FIG. 1).
[0069] As seen in FIGS. 3A, 4 and 5, a circumferential raised wall
280 and an internal raised wall 282 define respective rims 284 and
286 which are heat welded to interior wall surface 272 (FIG.
8).
[0070] Water passes through labyrinthine pathway outlet 260 and
enters a chamber 290, from which it exits via an outlet 292 and
enters an outlet control chamber 294, formed at side 222 of portion
226 and sealed by generally rectangular planar elastic element 206.
Elastic element 206 is supported by a surface 296 which surrounds
outlet control chamber 294.
[0071] As seen particularly in FIGS. 8-10, generally rectangular
planar elastic element 206 governs water flow through an outlet 300
of outlet control chamber 294, as a function of the line pressure
applied to generally rectangular planar elastic element 206 at a
surface 302 thereof, which surface engages rim 208. Outlet 300 is
typically in the form of a circular hole. Preferably, a shallow
slot 304, which is seen with particular clarity in FIGS. 3B and 6,
is provided in communication with the outlet 300, to assist in
providing efficient pressure responsive flow control of water
passing through the outlet 300.
[0072] Water passing through outlet 300 enters a volume 310,
defined between a surface 312 of side 270 and surface 272 of water
supply pipe 274, and then passes to a volume 314, defined between a
surface 316 of side 270 and surface 272 of water supply pipe 274,
via a partial obstruction 320. The partial obstruction 320 is
provided for helping to prevent particulate matter from passing
back from volume 314 into volume 310.
[0073] Water leaves volume 314 via an opening 322 formed in water
supply pipe 274, which opening corresponds to pressure-compensated
emitter element output aperture 106 (FIG. 1).
[0074] Reference is now made to FIGS. 11A, 11B, 11C and 11D, which
are illustrations of a problem in the operation of prior art
pressure-controlled anti-leakage drip irrigation emitters, FIG. 11A
being a simplified not-to-scale pictorial illustration, FIGS. 11B
and 11C being sectional illustrations taken along respective
section lines XIB-XIB and XIC-XIC in FIG. 11A, and FIG. 11D being a
superposition of portions of FIGS. 11B and 11C.
[0075] Reference is made to prior art pressure-controlled
anti-leakage drip irrigation emitters which employ a non-square,
rectangular elastic element 380 which is secured along its
non-square, rectangular periphery and a circular raised wall 382
surrounding an inlet aperture 384. When the liquid pressure
underlying the rectangular elastic element 380 is such that an
underside surface 386 of the elastic element 380 barely touches
portions 388 of the top surface 390 of wall 382, which lie closest
to an edge of the elastic element 380, the underside surface 386
does not touch portions 392 of the top surface 390 which lie
further from an edge of the elastic element 380. This can be seen
with particular clarity in FIGS. 11B and 11C as well as in the
superposition of FIG. 11D.
[0076] The present inventors have understood that this constitutes
a problem in pressure-controlled anti-leakage drip irrigation
emitters, since there exists a range of pressures at which the
inlet aperture is not fully open or fully closed by the elastic
element 380, resulting in a leakage situation. Furthermore, the
circumferentially incomplete contact between the elastic element
380 and top surface 390 of wall 382 surrounding the inlet aperture
384 inhibits sealing of the inlet aperture at even lower pressures,
inasmuch as any contact between the elastic element 380 and any
location on top surface 390 increases the amount of force required
to establish further and full contact. Accordingly, the level of
fluid pressure underlying the elastic element 380 required to
achieve sealing of the inlet aperture is much lower than would
otherwise be required to seal the inlet aperture, and undesired
leakage occurs following termination of water supply to the drip
irrigation line and following initial supply of water to the drip
irrigation line.
[0077] Reference is now made to FIGS. 12A, 12B, 12C and 12D, which
are illustrations of a solution to the problem in the operation of
prior art pressure-controlled anti-leakage drip irrigation emitters
as shown in FIGS. 11A-11D and discussed hereinabove, FIG. 12A being
a simplified not-to-scale pictorial illustration, FIGS. 12B and 12C
being sectional illustrations taken along respective section lines
XIIB-XIIB and XIIC-XIIC in FIG. 12A, and FIG. 12D being a
superposition of portions of FIGS. 12B and 12C.
[0078] As seen in FIGS. 12A-12D, a non-circular raised wall 400
surrounds an inlet aperture 402. In this case, in accordance with a
preferred embodiment of the present invention, when the liquid
pressure underlying a rectangular elastic element 406 is such that
an underside surface 408 of the elastic element 406 barely touches
portions 410 of the top surface 412 of wall 400, which lie closest
to an edge of the elastic element 406, the underside surface 408
simultaneously or nearly simultaneously also barely touches
portions 414 of the top surface 412 which lie further from an edge
of the elastic element. This can be seen with particular clarity in
FIGS. 12B and 12C as well as in the superposition of FIG. 12D.
[0079] The present inventors have understood that this solves the
problem in prior art pressure-controlled anti-leakage drip
irrigation emitters which was discussed above with reference to
FIGS. 11A -11D, by greatly reducing or eliminating the range of
pressures at which the inlet aperture is not fully open or fully
closed by the elastic element 380, resulting in a leakage
situation. Furthermore, the circumferentially complete contact
between the elastic element 406 and top surface 412 of wall 400
surrounding the inlet aperture 402 enhances sealing of the inlet
aperture. Accordingly, the level of fluid pressure underlying the
elastic element 406 required to achieve sealing of the inlet
aperture can be higher than would otherwise be required to seal the
inlet aperture in the prior art. Thus, scaling takes place
following termination of water supply to the drip irrigation line
at a higher line pressure and thus enables efficient use of the
drip irrigation line over a greater range of variation of height
than was possible in the prior art. Any leakage that occurs, takes
place over a substantially shorter period following termination of
water supply to the drip irrigation line, and over a shorter period
following initial supply of water to the drip irrigation line, than
in the prior art.
[0080] Reference is now made to FIGS. 13A, 13B, 13C and 13D, which
are generally to-scale simplified illustrations which correspond to
FIGS. 12B and 12C in the context of the drip irrigation emitter
element of FIGS. 2A-10, FIGS. 13A and 13B showing a first operative
orientation of the drip irrigation emitter element and FIGS. 13C
and 13D showing a second operative orientation of the drip
irrigation emitter element.
[0081] FIGS. 13A and 13B are generally to-scale simplified
illustrations which correspond to FIGS. 12B and 12C in the context
of the drip irrigation emitter element of FIGS. 2A-10. The
non-circular configuration of the inlet aperture 402 (FIGS.
12A-12D) can be seen by considering the separations between
portions of the rim 208 in respective FIGS. 13A (410 in FIG. 12B)
and 13B (414 in FIG. 12C), which represent mutually perpendicular
cross-sections of the drip irrigation emitter element. The
indicated angles illustrate the angular engagement between the
elastic element 206 and rim 208 of the wall 204 of the inlet
aperture 202.
[0082] FIGS. 13A and 13B show the drip irrigation emitter element
in a closed operative orientation in which surface 302 of elastic
element 206 lies in sealed engagement with rim 208, thereby
preventing the flow of water from inlet aperture 202 into inlet
control chamber 209. FIGS. 13C and 13D show the drip irrigation
emitter element in an open operative orientation in which surface
302 of elastic element 206 is displaced from sealed engagement with
rim 208, thereby allowing the flow of water from inlet aperture 202
into inlet control chamber 209.
[0083] Transition of the drip irrigation emitter element from the
closed operative orientation of FIGS. 13A and 13B to the open
operative orientation of FIGS. 13C and 13D occurs when the water
pressure in main water flow channel 100 (FIG. 1) exceeds a
predetermined threshold preferably of 0.5 Atmospheres. Transition
of the drip irrigation emitter element from the open operative
orientation of FIGS. 13C and 13D to the closed operative
orientation of FIGS. 13A and 13B occurs when the water pressure in
main water flow channel 100 (FIG. 1) drops below a predetermined
threshold preferably of 0.2 Atmospheres.
[0084] Reference is now made to FIGS. 14A, 14B, 14C and 14D, which
are simplified illustrations of another solution to the problem in
the operation of prior art pressure-controlled anti-leakage drip
irrigation emitters as shown in FIGS. 11A -11D, FIG. 14A being a
simplified not-to-scale pictorial illustration, FIGS. 14B and 14C
being sectional illustrations taken along respective section lines
XIVB-XIVB and XIVC-XIVC in FIG. 14A, and FIG. 14D being a
superposition of portions of FIGS. 14B and 14C.
[0085] As seen in FIGS. 14A-14D, a non-circular raised wall 460
having a non-uniform wall height, surrounds an inlet aperture 462.
It is appreciated that the inlet aperture 462 is typically of
somewhat smaller dimensions than that of FIGS. 2A-10 and 12A -13B.
The wall 460 is configured to be lowest at portions 464 of a top
surface 466 of wall 460, which lie closest to an edge of an elastic
element 470 and highest at portions 472 of the top surface 466 of
wall 460, which lie furthest from an edge of the elastic element
470.
[0086] In this case, in accordance with another preferred
embodiment of the present invention, when the liquid pressure
underlying the rectangular elastic element 470 is such that an
underside surface 474 of the elastic element 470 barely touches
portions 464 of the top surface 466 of wall 460, the underside
surface 474 simultaneously or nearly simultaneously also barely
touches portions 472 of the top surface 466. This can be seen with
particular clarity in FIGS. 14B and 14C as well as in the
superposition of FIG. 14D.
[0087] The present inventors have understood that this embodiment
also solves the problem in prior art pressure-controlled
anti-leakage drip irrigation emitters which was discussed above
with reference to FIGS. 11A-11D, by greatly reducing or eliminating
the range of pressures at which the inlet aperture is not fully
open or fully closed by the elastic element 380 (FIGS. 11A &
11B), resulting in a leakage situation. Furthermore, the
circumferentially complete contact between the elastic element 470
and top surface 466 of wall 460 surrounding the inlet aperture 462
enhances sealing of the inlet aperture. Accordingly, the level of
fluid pressure underlying the elastic element 470 required to
achieve sealing of the inlet aperture can be higher than would
otherwise be required to seal the inlet aperture in the prior art,
and any leakage that occurs takes place over a substantially
shorter period following termination of water supply to the drip
irrigation line and over a shorter period following initial supply
of water to the drip irrigation line than in the prior art. This
enables efficient use of the drip irrigation line over a greater
range of variation of height than was possible in the prior
art.
[0088] Reference is now made to FIGS. 15A, 15B, 15C and 15D which
are generally to-scale simplified illustrations which correspond to
FIGS. 14B and 14C in the general context of the drip irrigation
emitter element of FIGS. 2A-10, but having a somewhat smaller inlet
aperture 202. The non-circular configuration of the inlet aperture
202 and its non-uniform wall height (FIGS. 14A-14D) can be seen by
considering the separations between and variations in height of
portions of the rim 208 in FIGS. 15A and 15C (464 in FIG. 14B) and
in FIGS. 15B and 15D (472 in FIG. 14C), which represent mutually
perpendicular cross-sections of the drip irrigation emitter
element. The indicated angles in FIGS. 15A and 15B illustrate the
angular engagement between the elastic element 206 and rim 208 of
the wall 204 of the inlet aperture 202.
[0089] FIGS. 15A and 15B show the drip irrigation emitter element
in a closed operative orientation in which surface 302 of elastic
element 206 lies in sealed engagement with rim 208, thereby
preventing the flow of water from inlet aperture 202 into inlet
control chamber 209. FIGS. 15C and 15D show the drip irrigation
emitter element in an open operative orientation in which surface
302 of elastic element 206 is displaced from sealed engagement with
rim 208, thereby allowing the flow of water from inlet aperture 202
into inlet control chamber 209.
[0090] Transition of the drip irrigation emitter element from the
closed operative orientation of FIGS. 15A and 15B to the open
operative orientation of FIGS. 15C and 15D occurs when the water
pressure in main water flow channel 100 (FIG. 1) exceeds a
predetermined threshold of preferably 0.5 Atmospheres. Transition
of the drip irrigation emitter element from the open operative
orientation of FIGS. 15C and 15D to the closed operative
orientation of FIGS. 15A and 15B occurs when the water pressure in
main water flow channel 100 (FIG. 1) drops below a predetermined
threshold of preferably 0.2 Atmospheres.
[0091] Reference is now made to FIGS. 16A, 16B, 16C and 16D, which
are simplified sectional illustrations of drip irrigation apparatus
constructed and operative in accordance with a preferred embodiment
of the present invention, taken at locations indicated by
respective arrows A, B, C and D in the general schematic
illustration of FIG. 1.
[0092] FIGS. 16A-16D show drip irrigation apparatus of the general
type shown in FIG. 1, and more particularly of the type shown in
enlargements II and III in FIG. 1. FIGS. 16A-16D show drip
irrigation apparatus of the type shown in enlargement II of FIG. 1,
formed of an elongate sheet of plastic 500 to which drip irrigation
emitter elements 502, preferably of the type described hereinabove
with reference to FIGS. 2A-10, are welded.
[0093] One elongate edge of sheet 500, designated by reference
numeral 504, is welded to an interior location of the sheet 500,
which is designated by reference numeral 506, thereby to define a
main water flow channel 508 which corresponds to main water flow
channel 100 (FIG. 1).
[0094] An opposite elongate edge of sheet 500, designated by
reference numeral 510 is welded at an exterior location of sheet
500, which is designated by reference numeral 512, to a secondary
water flow channel labyrinth-defining strip 514, which is also
welded to sheet 500, so as to define a secondary water flow channel
516, and a secondary water flow channel labyrinth 518.
[0095] Alternatively, strip 514 may have weeping hose functionality
and/or sweat irrigation functionality, and in such a case, need not
define a labyrinth.
[0096] FIG. 16A is a partially sectional, partially pictorial
illustration, taken at arrows A-A in the general schematic
illustration of FIG. 1 and along the section lines A-A in
enlargement II of FIG. 1, which section lines pass through a water
inlet 520 of the drip irrigation emitter element 502, which allows
water to flow from main water flow channel 508.
[0097] FIG. 16B is a partially sectional, partially pictorial
illustration, taken at arrows B-B in the general schematic
illustration of FIG. 1 and along the section lines B-B in
enlargement II of FIG. 1, which section lines pass through a water
outlet 522 of the drip irrigation emitter element 502, which allows
water to flow into the secondary water flow channel 516.
[0098] FIG. 16C is a partially sectional, partially pictorial
illustration, taken at arrows C-C in the general schematic
illustration of FIG. 1 and along the section lines C-C in
enlargement II of FIG. 1, which section lines pass through a water
inlet 524 of the secondary water flow channel labyrinth 518, which
allows water to flow from the secondary water flow channel 516 into
the secondary water flow channel labyrinth 518.
[0099] FIG. 16D is a partially sectional, partially pictorial
illustration, taken at arrows D-D in the general schematic
illustration of FIG. 1 and along the section lines D-D in
enlargement II of FIG. 1, which section lines pass through a water
outlet 526 of the secondary water flow channel labyrinth 518 which
allows water to flow from the secondary water flow channel
labyrinth 518 to the atmosphere.
[0100] Reference is now made to FIGS. 17A, 17B, 17C and 17D, which
are simplified sectional illustrations of drip irrigation apparatus
constructed and operative in accordance with another preferred
embodiment of the present invention, taken at locations indicated
by respective arrows A, B, C and D in the general schematic
illustration of FIG. 1.
[0101] FIGS. 17A-17D show drip irrigation apparatus of the general
type shown in FIG. 1, and more particularly of the type shown in
enlargements II and III in FIG. 1. FIGS. 17A-17D show drip
irrigation apparatus of the type shown in enlargement II of FIG. 1,
formed of an elongate sheet of plastic 530 to which drip irrigation
emitter elements 532, preferably of the type described hereinabove
with reference to FIGS. 2A-10, are welded.
[0102] The elongate edges of sheet 530, designated by reference
numerals 534 and 536, are welded together at a seam 538, thereby to
define a main water flow channel 540 which corresponds to main
water flow channel 100 (FIG. 1).
[0103] An elongate edge 542 of an additional elongate sheet of
plastic 544 is welded at seam 538 to edge 534 of sheet 530.
Alternatively, elongate sheet 544 may incorporate material having
weeping hose functionality and/or sweat irrigation functionality.
An opposite elongate edge 546 of sheet 544 is welded at an exterior
location of sheet 530, which is designated by reference numeral
548, to a secondary water flow channel labyrinth-defining strip
550, which is also welded to sheet 530, so as to define a secondary
water flow channel 552, and a secondary water flow channel
labyrinth 554. Alternatively, strip 550 may have weeping hose
functionality and/or sweat irrigation functionality, and in such a
case, need not define a labyrinth.
[0104] FIG. 17A is a partially sectional, partially pictorial
illustration, taken at arrows A-A in the general schematic
illustration of FIG. 1 and along the section lines A--A in
enlargement II of FIG. 1, which section lines pass through a water
inlet 556 of the drip irrigation emitter element 532, which allows
water to flow from main water flow channel 540.
[0105] FIG. 17B is a partially sectional, partially pictorial
illustration, taken at arrows B-B in the general schematic
illustration of FIG. 1 and along the section lines B-B in
enlargement II of FIG. 1, which section lines pass through a water
outlet 558 of the drip irrigation emitter element 532, which allows
water to flow into the secondary water flow channel 552.
[0106] FIG. 17C is a partially sectional, partially pictorial
illustration, taken at arrows C-C in the general schematic
illustration of FIG. 1 and along the section lines C-C in
enlargement II of FIG. 1, which section lines pass through a water
inlet 560 of the secondary water flow channel labyrinth 554, which
allows water to flow from the secondary water flow channel 552 into
the secondary water flow channel labyrinth 554.
[0107] FIG. 17D is a partially sectional, partially pictorial
illustration, taken at arrows D-D in the general schematic
illustration of FIG. 1 and along the section lines D-D in
enlargement II of FIG. 1, which section lines pass through a water
outlet 562 of the secondary water flow channel labyrinth 554 which
allows water to flow from the secondary water flow channel
labyrinth 554 to the atmosphere.
[0108] Reference is now made to FIGS. 18A, 18B, 18C and 18D, which
are simplified sectional illustrations of drip irrigation apparatus
constructed and operative in accordance with yet another preferred
embodiment of the present invention, taken at locations indicated
by respective arrows A, B, C and D in the general schematic
illustration of FIG. 1.
[0109] FIGS. 18A -18D show drip irrigation apparatus of the general
type shown in FIG. 1, and more particularly of the type shown in
enlargements II and III in FIG. 1. FIGS. 18A-18D show drip
irrigation apparatus of the type shown in enlargement II of FIG. 1,
formed of an elongate tube of plastic 570, to an interior wall of
which are welded drip irrigation emitter elements 572, preferably
of the type described hereinabove with reference to FIGS. 2A-10.
The plastic tube 570 defines a main water flow channel 574 which
corresponds to main water flow channel 100 (FIG. 1).
[0110] An elongate edge 576 of an elongate sheet of plastic 578 is
welded to tube 570 at an exterior location therealong, designated
by reference numeral 580. An opposite elongate edge 582 of sheet
578 is welded to a secondary water flow channel labyrinth-defining
strip 584, which is welded to tube 570 at an exterior location
therealong, designated by reference numeral 586, so as to define a
secondary water flow channel 588, and a secondary water flow
channel labyrinth 590.
Elongate sheet 578 may alternatively incorporate material having
weeping hose functionality and/or sweat irrigation functionality.
Strip 584 may alternatively have weeping hose functionality and/or
sweat irrigation functionality and in such a case, need not define
a labyrinth. FIG. 18A is a partially sectional, partially pictorial
illustration, taken at arrows A-A in the general schematic
illustration of FIG. 1 and along the section lines A-A in
enlargement II of FIG. 1, which section lines pass through a water
inlet 592 of the drip irrigation emitter element 572, which allows
water to flow from main water flow channel 574.
[0111] FIG. 18B is a partially sectional, partially pictorial
illustration, taken at arrows B-B in the general schematic
illustration of FIG. 1 and along the section lines B-B in
enlargement II of FIG. 1, which section lines pass through a water
outlet 594 of the drip irrigation emitter element 572, which allows
water to flow into the secondary water flow channel 588.
[0112] FIG. 18C is a partially sectional, partially pictorial
illustration, taken at arrows C-C in the general schematic
illustration of FIG. 1 and along the section lines C-C in
enlargement II of FIG. 1, which section lines pass through a water
inlet 596 of the secondary water flow channel labyrinth 590, which
allows water to flow from the secondary water flow channel 588 to
the secondary water flow channel labyrinth 590.
[0113] FIG. 18D is a partially sectional, partially pictorial
illustration, taken at arrows D-D in the general schematic
illustration of FIG. 1 and along the section lines D-D in
enlargement II of FIG. 1, which section lines pass through a water
outlet 598 of the secondary water flow channel labyrinth 590, which
allows water to flow from the secondary water flow channel
labyrinth 590 to the atmosphere.
[0114] Reference is now made to FIGS. 19A, 19B, 19C and 19D, which
are simplified sectional illustrations of drip irrigation apparatus
constructed and operative in accordance with still another
preferred embodiment of the present invention, taken at locations
indicated by respective arrows A, B, C and D in the general
schematic illustration of FIG. 1.
[0115] FIGS. 19A-19D show drip irrigation apparatus of the general
type shown in FIG. 1, and more particularly of the type shown in
enlargements IV and V in FIG. 1. FIGS. 19A-19D show drip irrigation
apparatus of the type shown in enlargement IV of FIG. 1, formed of
an elongate tube of plastic 600, to an interior wall of which are
welded drip irrigation emitter elements 602, preferably of the type
described hereinabove with reference to FIGS. 2A-10. The plastic
tube 600 defines a main water flow channel 604 which corresponds to
main water flow channel 100 (FIG. 1).
[0116] An elongate edge 606 of an elongate sheet of plastic 608 is
welded to tube 600 at an exterior location therealong, which is
designated by reference numeral 610. An opposite elongate edge 612
of sheet 608 is welded to tube 600 at another exterior location
therealong, designated by reference numeral 614, thereby defining a
secondary water flow channel 616. Welded to an interior facing
surface of sheet 608 is a secondary water flow channel
labyrinth-defining element 618, which defines a secondary water
flow channel labyrinth 620.
[0117] Elongate sheet 608 may alternatively incorporate material
having weeping hose functionality and/or sweat irrigation
functionality, and in such a case, element 618 may be omitted.
[0118] FIG. 19A is a partially sectional, partially pictorial
illustration, taken at arrows A-A in the general schematic
illustration of FIG. 1 and along the section lines A-A in
enlargement IV of FIG. 1, which section lines pass through a water
inlet 622 of the drip irrigation emitter element 602, which allows
water to flow from main water flow channel 604.
[0119] FIG. 19B is a partially sectional, partially pictorial
illustration, taken at arrows B-B in the corresponding schematic
illustration of FIG. 1 and along the section lines B -B in
enlargement IV of FIG. 1, which section lines pass through a water
outlet 624 of the drip irrigation emitter element 602, which allows
water to flow into the secondary water flow channel 616.
[0120] FIG. 19C is a partially sectional, partially pictorial
illustration, taken at arrows C-C in the general schematic
illustration of FIG. 1 and along the section lines C-C in
enlargement IV of FIG. 1, which section lines pass through a water
inlet 626 of the secondary water flow channel labyrinth 620, which
allows water to flow from the secondary water flow channel 616 to
the secondary water flow channel labyrinth 620.
[0121] FIG. 19D is a partially sectional, partially pictorial
illustration, taken at arrows D-D in the general schematic
illustration of FIG. 1 and along the section lines D-D in
enlargement IV of FIG. 1, which section lines pass through a water
outlet 628 of the secondary water flow channel labyrinth 620, which
allows water to flow from the secondary water flow channel
labyrinth 620 to the atmosphere.
[0122] Reference is now made to FIGS. 20A, 20B, 20C and 20D, which
are simplified sectional illustrations of drip irrigation apparatus
constructed and operative in accordance with a further preferred
embodiment of the present invention, taken at locations indicated
by respective arrows A, B, C and D in the general schematic
illustration of FIG. 1.
[0123] FIGS. 20A-20D show drip irrigation apparatus of the general
type shown in FIG. 1, and more particularly of the type shown in
enlargements IV and V in FIG. 1. FIGS. 20A-20D show drip irrigation
apparatus of the type shown in enlargement IV of FIG. 1, formed of
an inner elongate tube of plastic 650, to an interior wall of which
are welded drip irrigation emitter elements 652, preferably of the
type described hereinabove with reference to FIGS. 2A-10. The
plastic tube 650 defines a main water flow channel 654 which
corresponds to main water flow channel 100 (FIG. 1).
[0124] An outer elongate plastic tube 656, which may be extruded
over inner elongate tube 650, defines with an outer surface of
inner elongate tube 650 a secondary water flow channel 658. Tube
656 may or may not be joined to tube 650.
[0125] Welded to an interior facing surface of tube 656 is a
secondary water flow channel labyrinth-defining element 660, which
defines a secondary water flow channel labyrinth 662. Tube 656 may
alternatively incorporate material having weeping hose
functionality and/or sweat irrigation functionality, and in such a
case, element 660 may be omitted.
[0126] FIG. 20A is a partially sectional, partially pictorial
illustration, taken at arrows A-A in the general schematic
illustration of FIG. 1 and along the section lines A-A in
enlargement IV of FIG. 1, which section lines pass through a water
inlet 664 of the drip irrigation emitter element 652, which allows
water to flow from main water flow channel 654.
[0127] FIG. 20B is a partially sectional, partially pictorial
illustration, taken at arrows B-B in the general schematic
illustration of FIG. 1 and along the section lines B-B in
enlargement IV of FIG. 1, which section lines pass through a water
outlet 666 of the drip irrigation emitter element 652, which allow
water to flow into the secondary water flow channel 658.
[0128] FIG. 20C is a partially sectional, partially pictorial
illustration, taken at arrows C-C in the general schematic
illustration of FIG. 1 and along the section lines C-C in
enlargement IV of FIG. 1, which section lines pass through a water
inlet 668 of the secondary water flow channel labyrinth 662, which
allows water to flow from the secondary water now channel 658 to
the secondary water flow channel labyrinth 662.
[0129] FIG. 20D is a partially sectional, partially pictorial
illustration, taken at arrows D-D in the general schematic
illustration of FIG. 1 and along the section lines D-D in
enlargement IV of FIG. 1, which section lines pass through a water
outlet 670 of the secondary water flow channel labyrinth 662, which
allows water to flow from the secondary water flow channel
labyrinth 662 to the atmosphere.
[0130] It is appreciated by persons skilled in the art that the
present invention is not limited by what has been particularly
shown and described hereinabove. Rather the scope of the present
invention includes both combinations and subcombinations of various
features described hereinabove as well as variations and
modifications thereto which would occur to a person of skill in the
art upon reading the above description and which are not in the
prior art.
* * * * *