U.S. patent number 3,791,587 [Application Number 05/341,713] was granted by the patent office on 1974-02-12 for flow-reducing device particularly useful for trickle irrigation.
Invention is credited to Mordeki Drori.
United States Patent |
3,791,587 |
Drori |
February 12, 1974 |
FLOW-REDUCING DEVICE PARTICULARLY USEFUL FOR TRICKLE IRRIGATION
Abstract
A flow-reducing device is described particularly useful for
trickle irrigation. The device includes a flow-retarding member
formed with a plurality of holes extending therethrough from one
face to the opposite face. The member is further formed on both
faces with a plurality of recesses, each recess bridging a pair of
holes. The recesses on one face overlap those on the opposite face,
such that the pair of holes bridged by a recess on one face lead to
separate recesses on the opposite face. The water is thus caused to
flow through the holes and recesses in succession, passing back and
forth from one to the other face of the member and finally exiting
in a slow trickle.
Inventors: |
Drori; Mordeki (Kiron,
IL) |
Family
ID: |
26320470 |
Appl.
No.: |
05/341,713 |
Filed: |
March 15, 1973 |
Foreign Application Priority Data
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Mar 17, 1972 [IL] |
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39007 |
May 23, 1972 [IL] |
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39511 |
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Current U.S.
Class: |
239/267; 239/553;
239/542; 239/551 |
Current CPC
Class: |
A01G
25/023 (20130101); A01G 2025/006 (20130101) |
Current International
Class: |
A01G
25/02 (20060101); A01G 25/00 (20060101); B05b
001/20 () |
Field of
Search: |
;239/542,550,551,553,267,266,268,269 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1,513,948 |
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Jan 1968 |
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FR |
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2,011,961 |
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Sep 1971 |
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DT |
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Primary Examiner: Ward, Jr.; Robert S.
Attorney, Agent or Firm: Barish; Benjamin J.
Claims
What is claimed is:
1. A flow-reducing device particularly for trickle irrigation,
comprising, a housing, a flow-retarding member disposed therein,
said member being formed with a large number of holes extending
therethrough from one face to the opposite face thereof, said
housing including an inlet communicating with one of said holes,
constituting the inlet hole of the member, and hole-bridging means
providing flow paths between the holes at both faces of said member
to direct the fluid entering through the inlet hole to flow through
said holes in succession, passing back and forth from the one to
the opposite face of the member, and then to exit through an outlet
hole in the member.
2. A device according to claim 1, wherein said hole-bridging means
comprises a plurality of recesses formed on both faces of the
flow-retarding member, each recess bridging a pair of the holes,
the pair of holes bridged on one face by one recess leading to
separate recesses on the opposite face, and walls in contact with
both said faces of the flow-retarding member to direct the fluid to
flow through said recesses.
3. A device according to claim 2, wherein said flow-retarding
member is relatively thin having a thickness which is a small
fraction of its length.
4. A device according to claim 2, wherein there are a plurality of
said flow-retarding members, and a separator member between each
pair, said separator member being formed with a hole providing
communication between the outlet hole of one of the respective pair
of flow-retarding members and the inlet hole of the other
flow-retarding member of the pair.
5. A device according to claim 4, wherein each of said
flow-retarding and separator members is in the form of an annular
disc.
6. A device according to claim 1, wherein said housing includes an
inner sleeve, and an outer sleeve, and said flow-retarding member
is in the form of a strip helically wound around the inner sleeve
and enclosed by the outer sleeve.
7. A device according to claim 1, wherein said flow-retarding
member is in the form of a removable insert, and said housing
defines a compartment for said insert, said compartment being open
at least at one end to permit removal and insertion of the
flow-retarding member insert.
8. A device according to claim 7, wherein said compartment is
curved, and said flow-retarding member insert is of flat flexible
material flexed to assume the curvature of the compartment.
9. A device according to claim 7, for applying to a fluid supply
pipe having an opening in a wall thereof, wherein said housing
includes curved flexible inner and outer walls defining said
compartment and clampable onto the supply pipe, and an inlet stem
carried by said inner wall for passing through the pipe wall
opening, the flow-retarding member insert being disposed in the
compartment between the outer and inner housing walls and being
removable from the open end thereof, said inlet stem including a
passageway communicating with the inlet opening of the
flow-retarding member insert.
10. A trickle device including an inlet and an outlet for
application to a water supply pipe to provide a slow water trickle
therefrom, said device comprising: a housing having an outer wall
and a spaced inner wall; mean carried by said inner wall for
attaching the housing to a water supply pipe to extend laterally of
and parallel to the axis of the water supply pipe when applied
thereto; said outer and inner walls defining an axially extending
compartment of rectangular section and open at at least one end;
the inner wall of the compartment including said inlet, the latter
communicating with the water flowing through the water supply pipe;
and a flow-retarding insert in said compartment and removable from
said open end thereof, said insert being of rectangular section and
formed with a circuitous path for the water to travel from said
inlet to the outlet thereof.
11. A device according to claim 10, wherein said inner and outer
walls are of flexible material enabling same to be clamped onto the
water supply pipe and firmly holding the insert in the compartment;
and wherein said inlet is in the form a stem adapted to pass
through an opening in the water supply pipe when the device is
clamped thereto.
12. A device according to claim 10, wherein said flow-retarding
insert includes a member formed with a plurality of holes extending
therethrough from one face to the opposite face thereof, said
insert being further formed with a plurality of recesses on both
faces thereof, each recess bridging a pair of the holes, the pair
of holes bridged on one face by one recess leading to separate
recesses on the opposite face.
Description
BACKGROUND OF THE INVENTION
The present invention relates to flow-reducing devices, and
particularly to such devices useful for trickle irrigation.
Trickle irrigation is increasingly gaining wide-spread use as a
means for supplying water, and sometimes fertilizer and other soil
additives, to field crops and orchards.. In some known devices, the
trickle flow of the water is effected by small openings, but these
devices have the disadvantage that they easily clog. In other
devices, a long-circuitous path, sometimes called a labyrinth or
maze, is provided for the water so that it eventually discharges in
the form of a slow trickle. The known devices of this type,
however, are generally large, expensive, and/or difficult to clean
and maintain because of the long circuitous path that must be
provided.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a novel
flow-reducing device, particularly for trickle irrigation, the type
including a long circuitous path for the water, which device can be
built of small size and low cost when compared to the known trickle
devices.
Briefly, the novel device includes a flow-retarding member disposed
within a housing and formed with a large number of holes extending
completely through the member from one face to the opposite face,
and hole-bridging means providing flow paths between the holes at
both faces to direct the fluid entering through the inlet hole to
flow through the holes in succession, passing back and forth from
one to the opposite face of the member, before exiting from the
housing.
Conceivably, the hole-bridging means would be recesses formed in
the housing walls (or other members disposed within the housing)
which contact the two faces of the flow-retarding member.
Preferably, however, and in accordance with another feature of the
invention, the hole bridging means comprises a plurality of
recesses formed on both faces of the flow-retarding member, each
recess bridging a pair of holes, the pair of holes bridged on one
face by one recess leading to separate recesses on the opposite
face. The walls in contact with both faces of the member thus
direct the fluid to flow through these recesses when passing from
one hole to the next.
Such a construction produces a very large flow path in a very small
space. Moreover, the flow path produced has many sharp turns, wall
discontinuities, and alternations of narrow cross-sections (the
holes) with large cross-sections (the recesses). The velocity of
the fluid thus changes frequently and abruptly, the fluid moving
faster through the holes and slower through the recesses. The fluid
is thus subjected, in a relatively small space, to considerable
friction, eddying swirling, and turbulence, which thus reduces its
pressure until it exits at a very slow rate.
Another advantage of such a construction is that it can be produced
in volume at low cost.
The flow-retarding member may take many different forms, some of
which are described below. In general, it is relatively thin,
having a thickness which is a small fraction of its length.
According to a further feature of the invention, the flow retarding
member may be in the form of an insert which is removably applied
through one end of the housing. Such an arrangement simplifies the
manufacutre of the device, and particularly simplifies its
maintenance and repair, since the insert may be conveniently
removed, inspected, cleaned and replaced in the field.
Further features and advantages of the invention will be apparent
from the description below.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described herein, by way of example only, with
reference to the accompanying drawings, wherein:
FIG. 1 is a longitudinal sectional view of one form of trickle
irrigation device constructed in accordance with the invention,
FIGS. 1a and 1b illustrating the two faces of the flow-retarding
member used in the device;
FIG. 2 is a longitudinal sectional view of another trickle device
constructed in accordance with the invention, FIG. 2a illustrating
a modification thereof;
FIG. 3 is a view, partly in transverse section, illustrating a
further trickle device constructed in accordance with the
invention, FIG. 3a being an enlarged fragmentary view thereof, and
FIG. 3b illustrating one face of the flow-retarding member used
therein;
FIG. 4 is a transverse sectional view of a further trickle device
constructed in accordance with the invention, FIG. 4a illustrating
the flow-retarding member used therein, and FIG. 4b being a partial
sectional view along lines B--B of FIG. 4a;
FIG. 5 is a view, partly in transverse section, illustrating a
still further trickle device constructed in accordance with the
invention, FIG. 5a being a sectional view along lines A--A of FIG.
5, and FIG. 5b illustrating the flow-retarding member used in the
device of FIG. 5;
FIG. 6 is a longitudinal sectional view of a further trickle device
constructed in accordance with the invention, FIG. 6a being a
sectional view along lines A--A of FIG. 6, and 6b illustrating the
flow-retarding member used in the device of FIG. 6; and
FIG. 7 is an end elevational view illustrating a still further
trickle irrigation device constructed in accordance with the
invention, FIG. 7a being a sectional view along lines A--A of FIG.
7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The trickle irrigation device or nozzle illustrated in FIG. 1, 1a,
1b of the drawings is embodied in an in-line coupling, for coupling
two water supply pipes (not shown). The device comprises a housing,
generally designated 2, including two sections 4,6 each formed with
ribbed sleeve 8,10, for receiving the respective ends of the water
supply pipes. The two sections 4,6 are joined together by threads
as shown at 10, and each includes an annular wall 12,14 of
disc-shape. A radial opening 16 is formed in section 6, this
opening leading into the space between the two walls 12,14, and
serving as an inlet thereto for the water passing through the water
supply pipes.
A disc-shaped flow-retarding member 20 is disposed in the space
between the two walls 12,14 of the housing. Member 20 is formed
with a large number of holes 22 extending therethrough from one
face 24 (FIG. 1b) to the opposite face 26 (FIG. 1a) thereof. Each
face is also formed with a plurality of channels or recesses 28
each bridging a pair of holes 22. The recesses on one face (e.g.,
24) overlap those on the other face (e.g., 26) such that the pair
of holes bridged by a recess on one face lead to separate recesses
on the opposite face.
One hole 22' in member 20 communicates with inlet opening 16 of the
housing via a recess 28', this hole being called the inlet hole;
and another hole 22" serves as the outlet hole of the device, this
hole leading to the outside via recess 28 ".
In the assembled device, both faces 24, 26 of the flow-retarding
member 20 are firmly pressed against the flat faces of housing
walls 12,14 whereupon the recesses 20 provide flow-paths between
the holes 22 at both faces of the member. The water entering the
inlet hole 22' is thus directed by the recesses to flow through the
holes 22 successively to pass back and forth from one to the
opposite face of the member, and then to exit through outlet hole
22" and its recess 28".
Many arrangements may be used for the holes 22 and recesses 28. In
FIGS. 1a and 1b, the holes 22 are formed on concentric circles 30,
as also are the recesses 28, but the latter further include
radially extending recesses 29 to bridge the holes of adjacent
concentric circles.
It will thus be seen that the flow-retarding member 20, and the
faces of the walls 12,14 in contact therewith, force the water to
flow through a very long circuitous path back and forth from one
face of the member to the other until it exits through outlet
opening 22". It will also be seen that this flow path has many
sharp turns. Further, the cross-sectional area of this path
frequently and abruptly changes, relatively small cross-sectional
areas (the holes 22) alternating with relatively large
cross-sectional areas (the recesses 28). This produces frequent and
abrupt changes in the velocity of the flowing water, and also
discontinuities in the wall bounding the flow path. All these
factors increase the friction, eddying, swirling and turbulence of
the water as it moves through this path such that a very reduced
flow or trickle is produced at the outlet end.
Moreover, this slow trickle is produced by the use of a relatively
small device which can be inexpensively manufactured, and by the
use of relatively large holes which have less tendency to clog. As
one example, trickle irrigation nozzles can be produced according
to the designs of FIGS. 1, 1a and 1b having a flow-rate as low as 2
liters per hour using opening (22) as large as 1.5 mm, and even
larger.
The flow-rate can be even further reduced or even larger openings
can be used, by providing a plurality of flow-retarding members
producing a series path for the water from one member to the
next.
Such a trickle device is illustrated in FIG. 2, wherein two
flow-retarding members, 120a, 120b are interposed between the flat
walls 112,114 of the nozzle housing 102. Each member 120a, 120b is
of the same construction as the flow-retarding member 20 of FIG. 1,
except the outlet hole (22", FIG. 1) of the member communicates,
via an opening 130 in a separator member 132, with the inlet hole
of the second flow-retarding member 120b. Thus the water flowing
through inlet 116 of the trickle device passes successively through
the holes (22, in FIG. 1) in flow-retarding member 120a, back and
forth from one to the opposite face of the member, then through
opening 130 of separator 132, and then successively through the
holes of the second flow-retarding member 120b, finally exiting
through outlet 134.
The trickle device illustrated in FIG. 2a is the same as that of
FIG. 2, except that one of the walls, 114, of the housing is
provided with a shroud 136, which together with the other wall 112
of the housing, completely encloses the flow-retarding members
120a, 120b and the separator member 130.
FIGS. 3, 3a and 3b illustrate a trickle device having a large
number of flow-retarding members, each being in the form of a flat
ring 220a, 220b, etc. (FIG. 3a), each pair of rings being separated
by a separator ring 230. Thus, each flow-retarding ring 220 (see
FIG. 3b) includes the plurality of holes 222 and bridging recesses
228, but in this case there is only one (or a few) circular arrays
of such openings and recesses. In addition, as in the case of
separator member 130 in FIG. 2, each separator ring 230 in the
embodiment of FIG. 3 includes an opening 232 (FIG. 3a) providing
communication between the outlet hole of one ring 220 and the inlet
hole of the next ring 220.
The water thus flows back and forth from one face to the opposite
face of each ring 220, and then through opening 232 of the
separator 230, to the next flow-retarding ring, until it traverses
all the rings, and exits in the form of a slow trickle.
The flow-retarding member is illustrated in the above-described
trickle devices as being in the shape of a relatively thin flat
plate or disc having a thickness which is a small fraction of both
the length and width (i.e., the diameter, in the case of the
illustrated annular discs or rings) of the member. The member
however, may take other shapes.
FIGS. 4, 4a and 4b illustrate a trickle device wherein the
flow-retarding member is in the form of a strip 320 (i.e., its
thickness is a small fraction of its length) which is helically
wound within the housing. In this case the housing includes two
sleeves, namely an outer sleeve 312 and an inner sleeve 314, the
latter being formed with a helically-winding, upstanding wall 330.
The flow-retarding strip 320, e.g., of flexible plastic material,
is formed with the through-going holes 322, and with the bridging
recesses 328 on its opposite faces. The strip is wound onto the
inner sleever 314 between and against the helical wall 330, and
then the outer sleeve 312 is placed thereover.
It will be seen that the water entering the device through inlet
316 will flow back and forth from one to the opposite face of strip
320 while it progresses helically along the length of the device
until it exits from outlet 334.
FIGS. 5, 5a and 5b illustrate a still further variation. Here, the
flow-retarding member (shown as 420 in FIG. 5b) is of flat flexible
material, such as plastic. It is formed with the through-going
holes 422 and the bridging recesses 428 on both faces, as described
earlier. In addition, it is formed with a central aperture 424
which communicates with the inlet hole 422'. The holes and recesses
are arranged spirally around the central aperture 424, the outlet
hole 422" being formed in a corner (the upper right corner in FIG.
5b) of the member.
FIG. 5 illustrates the trickle device applied as a tap to a water
supply pipe, rather than as an in-line coupling between a pair of
water supply pipes as in the previously described embodiments. In
this case, a hole is formed in the wall of the water supply pipe
430, and an inlet stem 432 is inserted through the hole and through
the center aperture 424 of the flow-retarding member 420. The
latter is wrapped around the pipe 430 and is retained in place by a
sleeve 412, constituting a portion of the housing. A further sleeve
413 is inserted through the open end of sleeve 412, between the
latter and the flow-retarding member 420, and the open end is
closed by a collar 414 threaded onto sleeve 412. Sleeve 413 is
conical, and collar 414 abuts against the end of it, forcing same
to press tightly against the flow-retarding member 420.
It will be seen that the inlet to the trickle device of FIG. 5 is
through stem 432, the water flowing through inlet hole 422' of the
member, and then successively through the other holes 422, back and
forth from one to the other side of the member, and finally exits
through outlet hole 422" and the housing outlet 434.
FIGS. 6, 6a, and 6b illustrate a trickle device in which the
flow-retarding member is in the form of an insert which can be
readily inserted and removed from the housing. The insert,
identified as 520 and shown per se in FIG. 6b, is in the form of a
strip of flat material, preferably plastic of rectangular section.
The holes 522 and the recesses 528 are formed in zig-zag fashion
beginning with the lower end and proceeding to the upper end. Thus,
the inlet hole 522' is at a lower (right) corner of the strip, and
the outlet hole 522" is at an upper (left) corner.
FIGS. 6 and 6a illustrate the flow-retarding member 520 of FIG. 6b
used in an in-line coupling between a pair of water supply pipes.
The coupling includes a sleeve 512 adapted to receive a water
supply pipe at each end, and an outer sleeve 514 of rectangular
section joined to sleeve 512 along one side thereof. Outer sleeve
514, and the portion of sleeve 512 to which it is joined, together
form an axially-extending compartment 518 closed at one end 519 and
opened at its opposite end. The compartment is of similar
rectangular section as the flow retarding member 520, and the
latter is disposed within the compartment with the inlet hole 522'
of the member communicating with inlet opening 516 in sleeve
512.
It will be seen that the water entering inlet opening 516 will
travel through the holes and recesses of the flow-retarding member
520, back and forth from one face to the other, until it exits
through outlet hole 522" and housing outlet 534, as described
earlier with respect to the other embodiments.
The embodiment of FIGS. 6, 6a and 6b has the further advantage that
the flow-retarding member 520 can be easily inserted and removed
through the open end (left) of the compartment 518, for purposes of
inspection, cleaning, and replacement in the field. Also, if a
different flow-rate is desired, this can easily be accomplished by
merely substituting the insert designed for the desired flow
rate.
FIGS. 7 and 7a illustrate another embodiment of the invention,
wherein the trickle device is in the form of a tap which may be
clamped onto a water supply pipe to tap the water from an opening
formed in a wall of the pipe.
In this case, the housing of the trickle device also includes
spaced inner and outer axially-extending walls 612, 614 defining an
axially-extending compartment 618 therebetween for receiving the
flow-retarding member 620. Here, however, the walls are curved to
form a curved compartment and terminates in extensions 615 enabling
the housing to be clamped onto the water supply pipe 630. Further,
the housing contains a stem 632 formed with a bore 634 to provide
communication with the flow-retarding member 620 within
compartement 618. The flow-retarding member 620 is preferably also
of flat flexible plastic material of rectangular section, for
example as members 420 and 520 in the embodiments of FIGS. 5 and 6.
This member also includes the through-going holes and recesses on
both faces to cause the water to flow through the holes
successively and to pass from one face to the other, beginning with
the inlet hole communicating with stem 632.
To facilitate clamping the housing, constituting by sleeves 612 and
sleeve 614, onto the water supply pipe 630, the housing is made of
flexible material preferably plastic. The flow-retarding member 620
inserted within compartment 618 is tightly press-fitted into the
compartment. To remove this member, it is only necessary a to flex
the two ends 615 of the housing which releases the insert and
permits its removal. Thus, the compartment may be open at both ends
since the insert is firmly retained therein.
Many other variations, modifications and applications of the
illustrated embodiments will be apparent.
* * * * *