U.S. patent number RE29,022 [Application Number 05/534,745] was granted by the patent office on 1976-11-02 for self-flushing irrigation valve.
Invention is credited to Lloyd Spencer.
United States Patent |
RE29,022 |
Spencer |
November 2, 1976 |
Self-flushing irrigation valve
Abstract
A self-flushing irrigating valve formed, at least in part, of an
elastically deformable material which, when subjected to
differential pressures below a preselected value, occupies an open
position forming a passage for the flushing of water therethrough;
and when subjected to differential pressures above a preselected
value, forms a constricted passage for trickle flow of water
therethrough. The valve, when in its trickle flow condition, tends
to effect further constriction on further increase in differential
pressure thereby tending to produce a uniform flow rate through a
range of effective pressures.
Inventors: |
Spencer; Lloyd (Pasadena,
CA) |
Family
ID: |
26937146 |
Appl.
No.: |
05/534,745 |
Filed: |
December 20, 1974 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
245312 |
Apr 19, 1972 |
03767124 |
Oct 23, 1973 |
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Current U.S.
Class: |
239/542; 138/45;
239/547; 239/107 |
Current CPC
Class: |
A01G
25/023 (20130101); A01G 25/16 (20130101); B05B
15/50 (20180201) |
Current International
Class: |
A01G
25/16 (20060101); B05B 15/02 (20060101); A01G
25/02 (20060101); B05B 015/02 () |
Field of
Search: |
;239/106-111,542,547,569,570 ;138/44,45,46 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Love; John J.
Assistant Examiner: Mar; Michael
Claims
I claim:
1. A self-flushing valve for disposition in a chamber, the chamber
being subjected periodically to fluid under pressure whereby, on
initiation of a pressure period, the fluid pressure progressively
rises from a minimum pressure to a maximum pressure and, on
termination of the pressure period, the fluid pressure
progressively falls from its maximum pressure to the minimum
pressure, the self-flushing valve comprising:
a. means forming an exit port in the chamber and, on flow of fluid
therethrough, creating in its vicinity, a region of reduced
pressure;
.[.b. and valve means including at least one flexible wall formed
of elastomeric material having a first surface subjected to the
fluid pressure in the chamber as supplied thereto, and an opposing
surface exposed to the pressure as reduced in the vicinity of the
exit port;
c. the wall being yieldably biased, when the difference between the
chamber pressure and reduced pressure is below a predetermined
value to occupy a position permitting flushing flow of liquid
through the exit port and outlet;
d. the wall being movable, when the difference between said
pressures exceeds said predetermined value, to throttle the exit
port;
e. and the wall, when in its throttling position defining at least
in part, a trickle passage forming an entrance to the exit port..].
.Iadd.
b. and a tubular valve means including confronting wall elements
defining an exit end and an entrance end displaced axially from the
exit end, the interior of the valve means being exposed to said
region of reduced pressure and including opposed wall elements, at
least one of which is formed of elastomeric material adapted to
occupy a first position forming with the other wall elements, an
axially extending flush passage discharging through the chamber
exit port, and a second position collapsed toward the other wall
elements to form therewith a trickle passage of substantially
reduced cross-sectional area;
c. the flexible wall element being responsive to increase of the
pressure differential in the chamber and the flush passage above a
predetermined value to cause movement of the wall element from its
first position to its second position thereby converting the flush
passage to a trickle passage;
d. the flexible wall element exerting a counterforce, when in its
second position, tending to return the wall element to its first
position, and being movable from its second position to its first
position upon reduction of the pressure differential in the chamber
and trickle passage below said predetermined value. .Iaddend.
2. A self-flushing valve as defined in claim 1, wherein:
.[.a. the wall is part of a tubular member extending into the
chamber from the exit port and providing a plurality of said walls
forming, when in their biased condition, a flushing passage
preceding the exit port, and mutually collapsible to form said
trickle passage..]. .Iadd.
a. a plurality of flexible wall elements are provided and are
mutually collapsible to form said trickle passage. .Iaddend.
3. A self-flushing valve as defined in claim 1, wherein:
a. the valve means includes a rigid wall .Iadd.element
.Iaddend.confronting the flexible wall .Iadd.element,
.Iaddend..[.the.]. .Iadd.said .Iaddend.wall .Iadd.elements
.Iaddend..[.being complementary.]. .Iadd.complementing each other
.Iaddend.to form the flushing passage or the trickle passage. .[.4.
A self-flushing valve as defined in claim 1, wherein:
a. a valve seat surrounds the entrance end of the exit port;
b. the wall is a flap member biased to an angular position,
clearing the valve seat for flushing flow of fluid and yieldably
movable into engagement with the valve seat to throttle the exit
port;
c. and the trickle passage is a groove defined between the flap and
the
valve seat when the flap is in its throttling position..]. 5. A
self-flushing valve as defined in claim 1, wherein:
a. .[.portions of the.]. .Iadd.said flexible .Iaddend.wall element
.[.of the trickle passage are contrictable.]. .Iadd.is yieldable
.Iaddend.in .Iadd.direct .Iaddend.response to increasing pressure
in the chamber above said predetermined value .[.thereby tending.].
to maintain a .Iadd.substantially .Iaddend.constant rate of trickle
.Iadd.flow through the outlet over a relatively wide range of
pressure variations in the
chamber. .Iaddend. 6. A self-flushing valve for controlling flow
from a periodically pressurized fluid system wherein fluid pressure
progressively rises from a minimum pressure to a maximum pressure
on initiation of a pressure period and progressively falls from the
maximum pressure to the minimum pressure on termination of the
pressure period, the self-flushing valve comprising:
a. housing means defining a chamber having a major inlet
communicating with the fluid system and a minor outlet for the
discharge of fluid from the system;
b. and a tubular valve formed, at least in part, of elastomeric
material disposed in the chamber, one end thereof being in
communication with the outlet, and the other end thereof positioned
to receive fluid through the inlet for flow within the tubular
valve to the outlet;
c. at least portions of the walls of the .[.tube.]. .Iadd.tubular
valve .Iaddend.being in confronting relation and forming outer
surfaces exposed to pressure of the fluid in the chamber
surrounding the valve, and inner surfaces exposed to the reduced
pressure incidental to flow of fluid through the valve and
outlet;
d. said walls being biased, when the pressure differential across
the walls is below a preselected value, to maintain the tubular
valve in a condition for flushing said value, said walls being
collapsible toward each other to reduce the flow therethrough to a
trickle flow;
e. the tubular valve on reduction of pressure differential across
said walls, tending to return to a condition of flushing flow,
whereby the tubular valve assumes a flushing condition at the
beginning and end of
each pressure period. 7. A self-flushing valve as defined in claim
6, wherein:
a. the tubular valve is polygonal in cross section, each side
having obtusely related walls confronting like walls and defining,
when the valve is in its flushing flow condition, a central bore
with radiating channels, and defining, when the valve is in its
trickle flow condition, a minute
central passage. 8. A self-flushing valve as defined in claim 6,
wherein:
a. the tubular valve is formed by a pair of walls .[.joined at
their margins.]., the midportions of the walls being spaced from
each other when the valve is in its flushing flow condition, and in
mutual contact when the valve is in its trickle flow condition, at
least one of the walls having a minute flow channel forming with
the other wall, a passageway to
effect the trickle flow condition. 9. A self-flushing valve as
defined in claim 6, wherein:
a. the tubular valve is polygonal in cross section and at least one
trickle flow channel extends along at least one of the walls, the
inner surfaces of the walls being spaced from each other when the
valve is in its flushing flow condition, and being in mutual
contact when the valve is in its trickle flow condition except for
the trickle flow channel and
covering portion of a confronting wall. 10. A self-flushing valve
as defined in claim 6, wherein:
a. the chamber is annular and the housing means receives a
centrally disposed supply tube;
b. a set of tubular valves is joined to and extends axially from a
common
base ring surrounding the supply tube. 11. A self-flushing valve as
defined in claim 10, wherein:
a. each tubular valve includes a longitudinally faceted fixed wall
forming a circular wall of the chamber, and a pair of confronting
faceted yieldable walls defining with the fixed wall a generally
triangular flushing passage, the walls being mutually engageable
with each other and with the fixed wall to close the flushing
passage to a trickle passage.
A self-flushing valve as defined in claim 6, which further
includes:
a. an anti-syphon valve .Iadd.causing .Iaddend.admission of air
into the
chamber on generation of a negative pressure therein. 13. A
self-flushing valve as defined in claim 6, wherein:
a. said walls are further yieldable after forming the trickle
passage to cause shrinking of the trickle passage with increased
pressure differential thereby tending to produce constant trickle
flow with change
in supply pressure in the range above said preselected value. 14. A
self-flushing valve as defined in claim 6, wherein:
a. the housing means includes a pair of complementary cylindrical
housing members, one axial end thereof being adapted for connection
to a supply line and forming the inlet to the chamber, the opposite
axial end having .Iadd.a plurality of .Iaddend.said .[.outlet .].
.Iadd.outlets .Iaddend.;
b. and a .[.single.]. .Iadd.ring of .Iaddend.tubular valve means
is
disposed axially in the chamber. 15. A self-flushing valve as
defined in claim 6, wherein:
a. the housing means includes a pair of complementary cylindrical
housing members, one axial end thereof being adapted for connection
to a supply line and forming a centrally disposed inlet, the
chamber being annular and surrounding the inlet;
b. at least one axial end of the housing means having a ring of
said outlets;
c. a set of the tubular valves are arranged in a circle and are
joined to a common base ring having apertures communicating between
the valves and said outlets;
d. and a set of distributor tubes are secured in the housing means
outlets.
6. A self-flushing valve, comprising:
a. means defining an outlet port surrounded by a valve seat;
b. a flap valve element for the valve port formed of elastomeric
material;
c. means sealing clamping the flap valve by one margin at one side
of the valve seat;
d. the valve element forming adjacent the clamping means on
integral hinge element, the hinge element being yieldably biased to
hold the valve element on an angular relation to the port to permit
flushing flow of fluid between the valve element and valve seat and
out the port, the hinge element being yieldable and the valve
element being of sufficient area to cooperate with the valve seat
so as to create a predetermined pressure differential caused by
flushing flow through the port to close upon the valve seat;
e. the valve seat and flap valve element defining therebetween a
trickle flow passage operable upon closure of the flap valve
element upon the
valve seat element. 17. A self-flushing valve as defined in claim
16, wherein:
a. the valve element when closed relative to the other valve seat
to produce trickle flow is yieldable to pressure changes to effect
corresponding change in the area of the trickle flow passage,
thereby tending to produce constant trickle flow of fluid through a
range of fluid
pressures. 18. A self-flushing valve, comprising:
a. tubular member having an inlet at one end and an outlet at its
other end;
b. the tubular member including a plurality of side walls normally
disposed in angular relation and joined longitudinally to form
alternately, longitudinally extending acute apeces and obtuse
apeces and collectively defining an internal flushing passage for
fluid communicating between said inlet and outlet;
c. the side wall being resiliently yieldable in response to a
predetermined pressure differential between their outer surfaces
and inner surfaces to collapse inward into mutually sealing
relation;
d. and trickle passage means for fluid formed at their obtuse
apeces when the side walls are in their collapsed condition and
communicating between
said inlet and outlet. 19. A self-flushing valve as defined in
claim 18, wherein:
a. the trickle passage means being constrictible in response to
increased external pressure to maintain substantially constant flow
of fluid therethrough. .Iadd. 20. A self flushing valve for
disposition in a fluid passageway, the passageway being subjected
periodically to fluid under pressure whereby, on initiation of a
pressure period the fluid pressure progressively rises from a
minimum pressure to a maximum pressure, and on termination of the
pressure period, the fluid pressure progressively falls from its
maximum pressure to its minimum pressure, the self flushing valve
comprising:
a. valve means including a pair of mutually confronting wall
elements normally spaced to form a flush flow passage having a
major transverse dimension and a minor transverse dimension, the
flush flow passage having a first end forming an entrance end
communicating with the fluid passageway and a second end disposed
longitudinally therefrom forming an outlet end, the flush flow
passage creating on fluid flow therethrough a region or reduced
pressure;
b. at least one of the wall elements being formed of elastomeric
material having a first surface exposed to fluid pressure in the
fluid passageway and a second surface subjected to the region of
reduced pressure in the flush flow passage to cause collapse toward
the other wall element to close the flush flow passage upon
increase of fluid pressure above its minimum pressure;
c. the flexible wall element exerting a counterforce tending to
cause separation from the other wall element upon approach of the
fluid pressure towards its minimum pressure to cause a final flush
flow between the wall elements;
d. and the wall elements including confronting portions forming a
trickle passage therebetween upon closure of the flush flow passage
for trickle
flow from the fluid passageway to the outlet. .Iaddend. .Iadd. 21.
A self flushing valve comprising:
a. means forming a fluid passageway, the passageway being subjected
periodically to fluid under pressure whereby, on initiation of a
pressure period, the fluid pressure progressively rises from a
minimum pressure to a maximum pressure, and on termination of the
pressure period, the fluid pressure progressively falls from its
maximum pressure to its minimum pressure;
b. valve means including a pair of mutually confronting wall
elements normally spaced to form a flush flow passage having a
major transverse dimension and a minor transverse dimension, the
flush flow passage having a first end forming an entrance end
communicating with the fluid passageway and a second end disposed
longitudinally therefrom forming an outlet end, the flush flow
passage creating on fluid flow therethrough a region of reduced
pressure;
c. at least one of the wall elements being formed of elastomeric
material having a first surface exposed to fluid pressure in the
fluid passageway and a second surface subjected to the region of
reduced pressure in the flush flow passage to cause collapse toward
the other wall element to close the flush flow passage upon
increase of fluid pressure above its minimum pressure;
d. at least one of the wall elements having at least one groove of
preselected dimension forming, upon closure of the flush passage, a
trickle passage, the trickle passage undergoing constriction as the
fluid pressure increases thereby to produce an essentially constant
rate of trickle flow through a range of fluid pressure;
e. the flexible wall element exerting a counterforce tending to
cause separation from the other wall element upon approach of the
fluid pressure towards its minimum pressure to cause a final flush
flow between the wall
elements. .Iaddend..Iadd. 22. A self flushing valve, as defined in
claim 21, wherein:
a. both wall elements are flexible and mutually collapse toward
each other to close the flush passage and form the trickle passage.
.Iaddend..Iadd. 23. A self flushing valve, as defined in claim 21,
wherein:
a. upon collapse of the flush flow passage, the entrance end of the
trickle passage coincides with the entrance end of the flush flow
passage. .Iaddend.
Description
A rapidly developing form of irrigation is known as drip or trickle
irrigation. Its advantages are substantial and are noted as
follows:
1. It uses much less water than other irrigation systems.
2. There is a minimal waste of the water used.
3. The water is applied rather precisely in the area needed to
minimize weed growth and in amounts which avoid excessive wetting
of surrounding soil to permit machine cultivation without
compaction of wetted soil.
4. It permits efficient use of liquid pesticides, fumigants and
fertilizer in the system.
However, its disadvantages are also substantial and are noted as
follows:
1. The water must be supplied through a multitude of minute
openings of only a few thousandths of an inch in diameter, one or
more for each plant, which are easily clogged by equally minute
particles, either mineral or organic.
2. To reduce clogging problems, expensive filtering equipment is
required.
3. Low pressures are required across the openings to increase the
usable size and yet produce drip or trickle flow. This complicates
the problem of uniform distribution of water to the plants. Also,
low pressures and attendant non-turbulent flow tend to promote
growth of slime in the system which aggravates the clogging
problem.
4. Attempts have been made to provide a flushing cycle which will
clean the drip of trickle openings; however, because of the
enormous number of such openings to be flushed, this solution has,
heretofore, been excessively expensive.
SUMMARY OF THE INVENTION
The present invention is directed to an inexpensive, but effective,
self-flushing valve adapted to use in an irrigation system, and is
summarized as follows:
First, to provide a self-flushing irrigating valve which is so
inexpensive that one may be provided for each drip or trickle
opening.
Second, to provide a self-flushing valve which may be mounted in
any position and which, when subjected to differential pressures
below a preselected value, forms an open passage dimensioned to
permit flushing of particulate matter, or which, when subjected to
differential pressures above a preselected value, closes to form a
passage dimensioned to effect drip or trickle flow.
Third, to provide a self-flushing valve which, by choice of an
elastomeric or rubber-like material having preselected physical
properties and dimensions such as wall thickness the valve can be
designed to have a predetermined rate of drip or trickle flow; for
example, if desired, the rate of flow may be held to a gallon per
hour or less or arranged to flow at several gallons per hour.
Fourth, to provide a self-flushing valve, which may be so arranged
that, after assuming its drip or trickle flow state, tends to flow
at near a constant rate throughout a wide range of pressures.
Fifth, to provide a minimal cost a self-flushing valve which may be
arranged as a single piece multiple orifice valve element,
permanently connected housing members and small diameter
distributor tubes extending from the valve to points of
discharge.
Sixth, to provide a self-flushing valve as indicated in the
preceding object which, with a minimal number of parts, may be
arranged for mounting on a riser with distributor tubes extending
downwardly, then laterally from the riser; or may be arranged at an
end of a supply line for extension of the distributor tubes beyond
the line; or interposed in a supply line to extend different
distances along the line or laterally therefrom.
Seventh, to provide a self-flushing valve wherein several
embodiments thereof provide elastomeric tubes normally forming a
passage dimensioned to permit flushing flow of water, and capable
of constricting in response to a predetermined differential
pressure to collapse the passage to a few thousandths of an inch,
thereby to cause drip or trickle flow.
Eighth, to provide a self-flushing valve structure, an embodiment
of which a wall of the housing forms a series of fixed walls each
cooperating with complementary elastomeric walls to form a series
of self-flushing valves.
Ninth, to provide a self-flushing valve, an embodiment of which has
a ported valve face and a flap member normally clearing the valve
face for flush flow of water, the flap member being subject to
differential water pressure to close upon the disk and form
therewith a drip or trickle passage.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view showing an assembly of one
embodiment of the self-flushing irrigating valve.
FIG. 2 is an end view thereof with the distributor tubes
omitted.
FIG. 3 is a transverse sectional view thereof taken through 3--3 of
FIG. 1 with the self-flushing valves shown in end elevation.
FIG. 4 is an enlarged end view of one of the self-flushing valves
in its normal or flushing condition.
FIG. 5 is a longitudinal sectional view thereof taken through 5--5
of FIG. 4.
FIG. 6 is a longitudinal sectional view corresponding to FIG. 5
showing the valve in its collapsed or trickle condition.
FIG. 7 is a transverse sectional view taken through 7--7 of FIG. 6
also showing the trickle condition.
FIG. 8 is a further enlarged fragmentary sectional view taken
within circle 8 of FIG. 7 showing particularly the portions forming
the trickle bore.
FIG. 9 is a similar enlarged fragmentary sectional view taken
within circle 9 of FIG. 8.
FIG. 10 is an enlarged fragmentary end view showing a modified
embodiment of the self-flushing valve.
FIG. 11 is an enlarged end view showing another embodiment of the
self-flushing valve.
FIG. 12 is a fragmentary end view of a further embodiment of the
self-flushing valve shown in its flushing condition.
FIG. 13 is a similar fragmentary end view showing the valve in its
trickle condition.
FIG. 14 is an end view of a modified assembly of the self-flushing
irrigating valve with a portion in section.
FIG. 15 is a longitudinal sectional view thereof taken through
15--15 of FIG. 14 as it appears joined to the end of a riser.
FIG. 16 is a longitudinal view thereof modified to fit at the end
of a horizontal supply line for disposition of distributor tubes in
extended relation, and indicating by broken lines the manner in
which it may be installed intermediate the ends of a supply
line.
FIG. 17 is a longitudinal sectional view thereof also arranged for
installation intermediate the ends of a supply line wherein the
number of self-flushing valves are doubled.
FIG. 18 is a fragmentary side view of a supply line showing a
single self-flushing valve unit projecting therefrom.
FIG. 19 is a transverse sectional view thereof taken through 19--19
of FIG. 18.
FIG. 20 is a perspective view showing an embodiment of the
self-flushing valve formed as an extrusion.
FIG. 21 is a longitudinal sectional view of an extruded valve
fitted on a mounting pin.
FIG. 22 is a similar sectional view showing a molded valve having
an end sleeve and also fitted on a mounting pin.
FIG. 23 is an enlarged fragmentary transverse sectional view taken
through 23--23 of FIG. 25 of the type of valve assembly shown in
FIG. 14, but showing a modified embodiment of the self-flushing
valve elements in which a portion of a housing wall forms a part of
each valve unit, the valves being shown in their flushing
condition.
FIG. 24 is a fragmentary transverse sectional view thereof taken
through 24--24 of FIG. 25 showing the valves in their trickle
condition.
FIG. 25 is a fragmentary longitudinal sectional view thereof taken
through 25-25 of FIG. 23.
FIG. 26 is an enlarged fragmentary transverse sectional view taken
through 26--26 of FIG. 27, and showing a further modified
self-flushing valve assembly essentially the type shown in FIG.
14.
FIG. 27 is a fragmentary longitudinal sectional view thereof taken
through 27--27 of FIG. 26, showing a valve by solid lines in its
flushing flow condition, and by dotted lines in its trickle flow
condition.
FIG. 28 is a further enlarged fragmentary sectional view taken
within circle 28 of FIG. 27 and showing a valve in its trickle flow
condition.
FIG. 29 is a still further enlarged fragmentary sectional view
taken within circle 29 of FIG. 28 but offset rearwardly of the
plane represented by FIG. 28.
FIG. 30 is an enlarged fragmentary sectional view taken through
30--30 of FIG. 14 and illustrates an anti-syphon valve in its
closed condition.
FIG. 31 is a similar sectional view showing the anti-syphon valve
in its open position.
The term "trickle" used herein to describe flow from the
self-flushing valve is intended to include "drip"; that is, under
trickle flow condition the valve may be designed to discharge water
at a fraction of a gallon per hour, or may be designed to discharge
water at several gallons per hour.
Reference is first directed to the embodiment shown in FIGS. 1
through 8. Each self-flushing valve 1 herein illustrated is formed
of elastomeric material, the specifications of which may vary to
meet specific conditions of use. The self-flushing valve is tubular
and, in the construction illustrated, is essentially triangular in
cross section forming three side walls 2 which define obtuse V's 3
and are joined by acute apices which, externally, may be rounded as
indicated by 4, but internally, preferably form relatively sharp
apices 5. Also, internally the obtuse V's 3 are preferably sharp in
their normal condition as it seems this produces a lower trickle
flow rate, as will be described later.
A set, in this case six, self-flushing valves are molded in a ring
and extend in parallel relation from an integral, common disk 6.
The disk is provided with a set of outlet apertures 7 centered with
respect to each corresponding valve. While the angle defined by
each obtuse V 3 may vary, an included angle of 150.degree. seems
adequate. If the radius of each apex 5 is one-eighth inch, the
circular space defined by the apices 3 is approximately
one-sixteenth inch in diameter, quite adequate for self-flushing
operation.
Referring to FIGS. 1, 2 and 3, the set of self-flushing valves is
received in a cup shaped housing member 8 having a flat end wall 9
and a cylindrical side wall 10. The end wall is provided with a
ring of outlet apertures 11 which are aligned with the apertures 7
and are, preferably, the same diameter. Externally, the end wall is
provided with an extension 12 having sockets 13 of larger diameter
than the apertures 11 and registering therewith. The sockets
receive distributor tubes 14 which may be cemented therein.
Extruded plastic tubing about one-eighth inch in outside diameter
and providing a bore about one-sixteenth inch in diameter is
suitable.
The construction shown in FIGS. 1, 2 and 3 may be used at the end
of a garden hose. For this use a second housing member 15 is
provided having an internally screwthreaded end 16 to receive a
hose fitting and terminating at a partition 17 having a central
aperture 18 and supporting a washer 19. Beyond the partition, the
housing member 15 is reduced in diameter to fit within the wall 10
of the housing member 8 and engages the periphery of the disk 6.
The housing members are preferably formed of plastic material which
may be joined by cement. Should it be desired, however, the
housings may be joined by a screwthread connection. Also, in place
of the screwthreads 16, the housing member 15 may be arranged for
connection by an adhesive to a conventional plastic pipe.
Operation of the self-flushing irrigating valve is as follows:
When the water supply is shut off, the self-flushing valve assumes
the flushing condition shown in FIGS. 4 and 5. When the water is
first turned on, the valve remains in its flushing condition until
the water pressure reaches a preselected value whereupon the valve
suddenly collapses, as indicated in FIGS. 6 and 7, to form a
trickle passage 20 as indicated in FIGS. 7 and 8, in idealized
form. The walls of the trickle passage are formed in the region of
the apices 3; however, some stretching takes place in this region
obliterating the initial sharp edge.
The size of the trickle passage depends on several factors, such
as:
1. The physical properties of the elastomeric material comprising
the valve. Highly flexible soft material having low shore harness
will form a smaller passage than a material having greater shore
hardness. It is well known that rubber, synthetic rubber and
elastomeric plastic materials may be compounded to provide a wide
range of properties. For example, a soft material may produce a
trickle flow of a half gallon per hour; whereas a less soft
material may produce a trickle flow of several gallons per
hour.
2. The wall thickness of the valve.
3. The length of the valve. Longer valves do not collapse
throughout their length; that is, their outer ends may remain open
as indicated in FIG. 6. However, if the length is shortened so as
to terminate at line 21 or 22 in FIG. 6, the end itself will be in
a collapsed state.
Once the valve has collapsed to its trickle flow condition, some
further compression will occur depending on the pressure causing
the valve to take on the characteristics of a constant flow valve.
Stated otherwise, at any pressure above the critical pressure at
which the valve collapses to its trickle flow condition, the flow
tends to compensate for pressure change. The tendency is toward
increase in flow with decrease in pressure. However, by proper
choice of the physical properties of the material comprising the
valve, a virtually constant flow condition is feasible.
The embodiment of the irrigating assembly as shown in FIGS. 1, 2
and 3 is coupled to a hose and the distributor tubes, which may be
of different length, are placed so as to terminate adjacent
corresponding plants. If required, a pair or more of distributor
tubes may water a single plant. As the flow may be essentially
constant, the volume of the water received is proportional to the
length of time of the irrigating cycle irrespective of pressure,
thus eliminating the different flow rates due to difference in
elevation.
Reference is now directed to FIG. 9. To increase the rate of flow
under trickle conditions, appropriate portions of the mutually
engaging inner surfaces of the valve walls 2 may be provided with
one or more minute grooves 23. To aid in producing a constant flow
condition, the side margins of each groove may project from the
wall surface and thus tend to crush, as indicated by 24, reducing
the effective area of the groove as external pressure if increased.
If desired, the apices 5, which tend to become rounded when the
valve is in its drip or trickle condition, may have complementary
projections which fill the trickle passage 20, or nearly so, so
that the grooves 23 become the principal trickle passages.
Reference is now directed to FIG. 10. If for any given shore
hardness of the elastomeric material, a larger drip or trickle
passage is desired, each wall may be increased in thickness toward
its midline as indicated by 24. If the side margins or apices 3 are
not increased in thickness, this can be accomplished without
appreciable change in the critical pressure at which the valve
collapses to its trickle condition.
Reference is now directed to FIG. 11, which discloses a four-sided
self-flushing valve 25 which functions essentially the same as the
valve 1. While the number of sides could be further increased, the
area of each side is reduced for a given overall size tending to
reduce its sensitivity to pressure.
Reference is now directed to FIGS. 12 and 13, which disclose a
two-sided self-flushing valve 26. In this case, the walls are
normally convex and collapse to a mutually engaging flat condition.
In order to provide a trickle passage, one or both surfaces may be
provided with a channel 27. More than one channel may be provided
and have normally protruding marginal walls capable of being
resiliently compressed, as indicated in discussing FIG. 9, so as to
provide an essentially constant flow. A two-sided valve 26, made of
the same material as the valve 1, tends to close to drip or trickle
flow condition at a lower critical pressure. While the walls of the
valve 26 are shown as curved, they may comprise angularly related
flat portions in the manner of the walls 2.
Reference is now directed to FIGS. 14 and 15. If a greater number
of self-flushing valves 1, 24 or 26 is desired in an assembly, they
may extend from a ring 28 of the desired diameter and having
appropriately located apertures 7. For purposes of illustration, a
ring of sixteen valves is illustrated. The ring fits within an
annular housing 29 having an end wall 30, a radially inner wall 31
and a radially outer wall 32. As in the first described embodiment,
the end wall 30 is provided with a ring of outlet apertures 11.
Also, the end wall 30 includes an annular extension 12 having
sockets 13 of larger diameter than the apertures 11 so as to
receive distributor tubes, similar to the tubes 14.
The housing 29 receives a cover 33 having a cylindrical wall which
fits inside the outer wall 32 and is cemented thereto. Within the
inner wall 31 is fitted and cemented a plastic riser tube 34 for
connection to an irrigation system. In this case the distributor
tubes extend downwardly along the riser tube, then radially to the
desired points of discharge.
If it is desired to arranged distributor tubes so as to extend
beyond the supply tube, the cover 33 may be provided with a tubular
extension 35 into which a supply tube 36 may be cemented, as shown
in FIG. 16, and the inner wall 31 may be closed by a plug 37. If
the assembly is desired to be used intermediate the ends of a
supply line, a second tube 36 may be substituted for the plug 37 as
indicated by broken lines in FIG. 6. Still further, two housings 29
may be placed end-to-end and connected by a sleeve 38, as shown in
FIG. 17.
Reference is now directed to FIGS. 18 and 19. In some cases, a
single valve may be encased. This is accomplished by providing a
small circular base 39 for the valve 1 or its equivalent having a
single aperture. The base is received in a cylindrical outer shell
40 having an end closed except for a perforation 41 communicating
with a distributor line socket 42, if a distributor line is needed.
Cemented in the outer shell is an inner shell 43 which retains the
periphery of the base 39. The common ends of the shells have
confronting flanges 44 and 45.
One manner of use of the single valve assembly is to mount the
assembly in the wall of a plastic tube 46 which may be flexible or
rigid. Initially the tube is open and provided with a series of
perforations to receive a series of inner shells 43 over which the
outer shells 40 are fitted. The shells are cemented together and
the flanges 44 and 45 are cemented to the tube 46. The tube itself
may be closed in various manners; for example, the tube may be an
extrusion with interlocking margins 47 and 48 which are cemented or
heat fused together.
Reference is now directed to FIG. 20 which illustrates an extruded
valve 49 having a cross section similar to the valve 1. This
construction is intended to be fitted over a tubular mounting boss
50, shown in FIG. 21.
Reference is directed to FIG. 22 which illustrates a self-flushing
valve 51 which may take the form of the previously described valve,
but which is joined to a cylindrical base 52 so as to fit over a
cylindrical boss 53.
Reference is now directed to FIGS. 23, 24 and 25. The valve
assembly here shown is an alternative to the valve as shown in
FIGS. 14 through 17, and utilizes modifications of the housings 29
and 33. In this embodiment, the cylindrical wall of the cover
housing 33 forms a part of each self-flushing valve. More
particularly, the cover housing 33 is provided with a cylindrical
wall 51, the inner surface of which is provided with a plurality of
axially extending ribs 52 each defining an obtuse angle
corresponding to the angle 3 of the valve 1.
In place of the set of valves 1, a set of self-flushing valves 53
are formed in part by a single, essentially cylindrical wall 54 of
elastomeric material confronting the wall 51 and completed by the
ribs 52. More specifically, the wall 54 is provided with a radially
inwardly converging pair of wall strips 55 confronting each rib 52.
Each wall strip is formed of two obtusely related portions and thus
are similar to the walls 2 of the valve 1, including the obtuse
angles 3. Each pair of converging strips 55 also form a rounded
apex 4 and internal apex 5. Each pair of wall strips 55 and
corresponding rib 52 forms a flushing passage similar to that of a
valve 1 as shown in FIG. 23. The wall 54 is molded integrally with
a ring 56 similar to the ring 28. The ring is provided with exit
apertures 7 in alignment with the flushing passages.
The flushing valves 53 function the same as the valves 1; that is,
below a preselected critical pressure differential between the
pressure internally of the valves 53 and the surrounding chamber,
the valves remain in their flushing condition. At the critical
pressure they close as shown in FIG. 24 to form trickle passages 20
which, in this case, it will be noted are tangent to the radially
outer margins of the apertures 7.
Reference is now directed to FIGS. 26 through 29. The embodiment of
the valve assembly here illustrated is also related to the
construction shown in FIGS. 14 through 17. An annular housing 56 is
provided, corresponding to the housing 29. The housing 56 includes
an annular base wall forming in part an annular valve face 57
having a ring of valve ports 58 corresponding to the apertures 7.
At one radial side is a channel 59 which receives a rim 60 of
elastomeric material to which is integrally attached a set of
radially directed flap valves 61 which are molded to the rim in
such a manner as to be biased in an upwardly inclined position over
corresponding ports 58. The flap valves are quite close together so
that flushing flow through the valve ports will, when the pressure
differential overcomes the biasing force in the hinged connections
with the rim 60, snap the flap valves shut. Conversely, when the
pressure differential drops below a critical value, the flap valves
return to their flushing condition.
Formed in the valve face 57 are one or more trickle channels 62
which have, preferably, obtusely related walls so as to be
relatively broad with respect to their depth. This configuration
enables the flap valve to depress therein in proportion to line
pressure as indicated in FIG. 29 to effect a constant flow
condition. However, this same effect is accomplished to some degree
as the flap valves 61 are depressed into the valve ports 58, as
indicated in FIG. 28. Alternatively, the trickle passage or
passages may be formed in the flap valves and constant flow control
may be attained as discussed in connection with FIG. 9.
It should be noted that the representations in the drawings of the
trickle passages or channels need to be exaggerated in order to be
illustrated, as they represent passages which may have an effective
diameter as small as 0.005 inches for flow in the order of a gallon
per hour at a line pressure in the order of 50 pounds per square
inch, and range upward to 0.030 inches depending on the number of
gallons per hour desired.
Reference is now directed to FIGS. 30 and 31 which illustrates a
modification of FIG. 14 in which a ring of anti-syphon valve ports
63 are arranged in the base 30 under the base ring 28. The base
ring is yieldable to negative pressure in the valve to deflect
upwardly and open the anti-syphon valves. Thus, with minimal
increase in cost an anti-syphon effect may be attained, eliminating
the need for separate anti-syphon valves.
In a previous comment referring to the valve 1, it was noted a 1/16
inch flushing port is provided in a 11/4 inch valve. It should be
noted that the side walls 2 are, during low pressure flushing
periods, outwardly expandable to pass large particles. Thus, if the
apertures and distributor line passages downstream of the valve are
made, effectively, as large as the expanded valve tube, materially
larger particulate matter can be passed through the self-flushing
valve.
While particular embodiments of this invention have been shown and
described, it is not intended to limit the same to the details of
the constructions set forth, but instead, the invention embraces
such changes, modifications and equivalents of the various parts
and their relationships as come within the purview of the appended
claims.
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