Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
The present invention relates to a method of auto-
matically regulating irrigation apparatus connected to a water
pipe, and a device for carrying out the method.
Swedish Patent specification 353,210 discloses the
provision of irrigation apparatus connected to a water pipe with
an automatic regulating device by means of whieh irrigation is
coupled in for periods with adjustable length, broken by water-
less periods with a length dependent on the relative humidity of
the surrounding air. This device comprises a main valve with
a valve body formed as a differential piston, having a small-
bore central through duet to its major side, a duct from this
major 'side to a eontrol valve whieh is arranged to elose and
open the main valve when it closes and opens said duct,
as well as a pivoting means wi.th an open bowl, arranged to be
supplied with water from a drop means eontrolled by the
eontrol valve, and as soon as the supplied amount of water has
reaehed a limiting value to tip over and actuate the control
valve by means of a projecting portion sueh that it eloses the
main valve and the water flow to the clrop means, keeping them
elosed until suE:Eiei.ent wa~er has eval.)oratecl ~rom t,he bowl so that
the ti.ppi.nc3 means tlps hack agai.n, ~he ~ro-jec~inc3 porti.on dis-
en~aginc3 the control valve so ~llat tl-e ].atte.r rec)pens the mai.n
valve and the wate:r flow to the drop means. It has been found
desirable to arranc3e t:llat the irr:i,gation takes place substantial.ly
at night, and that the lc~ cJth oF the waterless periods wil.l also
be dependellt on rainfall.
According to the present invention there is provided
a method of automatically regulating an irrigation apparatus
connected to a water pipe in which a main valve with a valve
body in the form of a differential piston is controlled by a
control valve such that its movement between open and closed
' positiolls is provided by the water pressure in the pipe, the
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control valve being control.led by a tipping means which in a
first tipped position causes the control valve to assume a
position closing the main valve and in a second tipped position
releases the control valve so that the latter can assume a
position opening the main valve, the tipped position of the
tipping means being determined by the water level in an open
bowl on one side of said means said bowl being supplied with
water in the form of drops at an adjustable rate from a drop
means as long as the control valve is in an open position, while
the drops are interrupted when the tipping means is caused to
tip over towards the s:ide of the bowl by the increased water
level in the bowl and thereby close the control valve and there-
after lose water by evaporation until the reduced water level
allows the tipping means to tip back again to its opposite
position for opening the control val.ve, the pressure of air,
controlled by the difference between day ancl night temperatures,
which is enclosed .in an air chamber on the opposite side of the
tipping means causing the watcr at the bottom o~ the air chamber
to be forced out via a slit in an intermcdiate wall between said
bottom and the open bow]. into thc! open bowl during the day and
to be sucked into th~ bottom durir)c~ the night.
The present invention a:l.so provides an apparatus for
automatically re~u].ating an i.rric3ation apparatus connected t.o
a valve pipe which apparatus compri.ses a main valve with an
inlet, an outlet and a valve body includincJ a differential
piston, with a narrow central throuyh bore to a major side
thereof, a duct from said side to a control valve which is
arranged when it closes and opens the duct to close and open the
main valve, tipping means having an open bowl arranged to be
supplied with water from a drop means controlled by the control
valve and adapted when the amount of water Su~p]ied has reached
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a limitin~ value to ti.p over and thereby in cooperation with
a yrojection to act on the con-trol valve to close the main
valve and the water flow to the ~rop means and to keep them
closed until sufficient water has evaporated from the bowl when
the tipping means tips back again, whereby the projection re-
leases the control valve so that the latter reopens the main
valve and the water flow to the drop means, the tipping means,
control valve and main valve being enclosed in a casing with a
perforated bottom, said casing being providea above the open
bowl with a depression having perforations, the tipping means
having a closed air chamber extending upwards over the upper
edge of the open bowl and having in common with said bowl a
flat bottc~, and being connected with said bowl by means of a narrow
slit adjacent the bottom over a greater portion of the width
of the bowl.
In one embodiment of the present invention the air
chamber is also connected to the open bowl by at least onc duct
extending from an opening in the wall of the air chamber, facing
the open bowl and to the opposite end of said bowl, and said
duct is provided with a na~ ow sl.it ad-jacent the bottom of said
howl. and al.ong its whole lcngth.
Suitably a stepped block is provi.ded which is arranged
for displacement at r.ight angles to thc~ Earther c~nd o the air
chamber ancl its steps serve as stro~e-l.imiting and selecting
stops for the tipping means.
In a further embodiment o~ the present invention the control
valve has a spindle extending vertically upwards, about which a
float is attached, the projection being arranged to engage
against the upper end of said spindle and hold the control valve
closed, as long as the open bowl is filled with water.
~ uitably the float is surrounded by a bowl which is
circular upwardly, open and increasing upwardly in diameter
with a side opening ahove the ~rop means an~ an overflow, sald
bowl being covered by a lid with a central opening for the
spindle and a dependent rim fitting into the bowl, with a narrow
groove directly facing the side opening, said groove being suh-
stantially as wide as the side opening and the float is dimen-
sioned so that when the bowl is filled with water to the overflow,
it gives the spindle a substantially upwardly directed force.
The present invention will be further illustrated by
way of the accompanying drawings in which:
- Fig. 1 is a longitudinal section through an irrigation
device in accordance with the embodiment of the invention in a
position for irrigation;
Fig. 2 illustrates a detail of the embodiment of Fig.
1 in a closing position;
Fig. 3 is a section along the line III-III in Fig. l;
and
Fig. 4 is a section along the line IV-IV in Fig. 2.
A casing 11 enclosing the device is formed from two
parts which slide into each other with a substantially flat
bottom 21 having perforations 22 and a roof 33 provided with a
rainwater collecting depression 12, the substantially flat bottom
of which is provided with perforations 13.
~le bottom 21 carrics a ~in valve 1, with an inlet 2 extending
out of t~le casing 11 and a~apted for connection to a water pi~e, as well as
an outlet 3 adapted Eor connection to an irrigation apparatus (not shown).
~le main valve 1 ccmprises a valve bodv 4 in the form of a differential
piston with a narrow gauge central bore 5 to its major side, from which a duct
6 extends substantially vertically to a control valve 7 with a
vertical spindle 25 having a float 26 fastened thereto. The
float 26 is surrounded bv an upwardly open circular bowl 27 with
an overflow 8 and a side opening 29. The wall 34 of the bowl
27 diverges upwardly. A cover 30 with a central opening for the
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spi.n~le 25 is pLovide~i wi.th a clepelldent rim 32 rotatabl~ fittirly
in the bowl 27 and with a narrow ~Iroove 31 opposite the sicle open-
ing 29 of the bowl 27. The width of the groove 31 subs-tantially
corresponds to the side opening 29. 'I`ogether, they constitute a
throuyh passage to a drop means 9 having a nose or spout. The
siae opening 29, which is in the form of a slit, is thus connected
to the reservoir of water in the circular bowl 27 by means of the
narrow groove 31 and thus the discharge of water through the slit
29 is very slight such that it delivers the liquid dropwise. The
reservoir thus may contain more water and overflow the slit 29
and such overflow is accommodated by the overflow 28. The area
of the throu~h passage defined by the groove 31 and the sli.t 29
can be adjusted by rotating the cover 30 in the bowl 27 thus in-
creasing or decreasing the overlap between the slit 29 and the
groove 31 and thus the rate of passage of water through the slit
29 is adjustable and as such the rate of formation of drops or
the cirop means 9.
In the casing a pivoting means, consisting of two bowls
8, 14 with a common flat bottom 16 is provided on either side
of a piVOt.illg shaft 35. Of these ~owls, the bowl 8 i.s ul~wardly
open anci disposcd undcr the casing de~)ression 12 and under the
drop means 9. The otller bowl 14 has a c:Loscd air chamber 15, from
the roof of which a ~rojection 10 in the ~orm of an arm extends
in over the spi.ndle 25. Thc~ ai.r chamber 15 is connected to the
opell howl 8 by a narrow transverse slit 17 ~djacent the common
bottom 16, and by means of at least one duct 18 passing to the
opposite end of the open bowl 8 with a narrow length-wise slit
20 adjacent the bottom 16. The cross section of the duct 18 is
optional. All that is important is that the extending of the
roof increases continuously from being negligibly larger than
the width of the slit 20 at the furthermost end or the open bowl
8 to a maximum a-t its opening into the air chamber 15. The
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height of -the opening is determineci by the quantity of water de-
sired to be retained in the air chamber 15 and the air volume of
the latter. The opening height must be somewhat larger than the
~um of the width of the slits 17, 20 and the maximum difference
in the day and night levels of the water in the air chamber 15.
On the bottom 21 of the casing 11 there is disposed a
staircase shaped ~lock 23 beneath the air chamber end which can
be displaced with respect to the pivoting shaft 35.
The apparatus operates as follows:-
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seqinning with the situation in which the open bowl 8
is full of water and has caused the pivoting means to tip in
this direction, the projecting portion of arm 10 engages against
the spindle 25 so -that the spindle 25 presses the control valve
7 sealingly against its seating. In this manner, the pressure
against the major side 36 of the differential piston 4 will be
equal to the pressure in the water pipe and cause the main valve
1 to shut off the flow to the irrigation installation. The water
in the float bowl 27 has dropped down from the drop means 9 into
the open bowl 8, so that the float chamber 27 is emptv and the
weight of the float 26 coacts with the arm 10 to keep the
control valve 7 in a closed position.
If a period of fine weather now occurs, the water in
the open how] 8 will evaporate and exit through the perforations
13. The pressure of the arm 10 against the spindle 25 is thus
reduced, whi]e the water enclosed in the air chamber ~ will
remain substantially unaltered. E~or a given water level in the
open bowl 8, the water ~rcssure propac3atc!d via the through bore
5 in the differential piston ~, and khe duct 6 to the
cont~ol valve 7 will press ac3ainst the control valve 7 so that
it opens ~omewhat and lets water into the float bowl 27. The
10at 26 presses the s~indl.e 25 u~wards towards the arm 10 so
that this causes the tilting means to tip over ~owards the air
chamber side. Since the float bowl 27 is now filled to the
over10w 28, water will pass out through the groove 31 and side
opening 29 to the drop means 9, from which it drops down onto
the open bowl 8 at a rate which can be adjusted by turning the
lid or cover 30. When the weight of water in the open bowl 8 has
risen to a given value, it causes the tipping means to tip back
again to the starting position, and via the arm 10 press the con-
trol valve 7 and main valve 1 to a closed position. The water
in the float bowl 27 drops down into the open bowl so that the
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float 26 will coact with the arm 10 to keep the valves 1 and
7 in a closed position, whereafter the sequence described above
starts once again.
The temperature oE the air in the air chamber 15 na-
turally alters in accordance with that of the surroundings and
thereby also its volume. As a result a portion of the water in
the bottom basin of the air chamber 15 will be forced out into
the open bowl 8 via the transverse slit 17 during the day and
sucked back again during the night. In turn, this causes the
tipping means to be in an open position during irrigation times,
i.e. tipped towards the edge chamber side during the night and
in a closed position during the day. Irrigation thus always
takes place at night, which is best Eor plant growth and is pro-
vided by the air chamber 15.
If the slit 17 were the only connection between the
air chamber 15 and the open bowl 8,/there would be difficulties
in obtaining as much water in the air chamber 15 as required to
obtain sharp and distinct motion from the clos~d ~day-t~me) to the
oF~en(night-time) position. These difficulties arc overcome by
means of tlle duct 18, which allows wat~r to bc tak~n into the
air chamber 15 sucll that i~s sllr~ace coincides w;ith the top of
the duct opening wherl the tipping means is tipped maximally over
towards the air chamber si(1c.
To adjllst the ma~imum tipping of the tipping means
towards the air chamber side, which determines the lcngth of
the irrigation periods, the block 23 is displaceable such that
its steps 24 form stops limiting the tipping angle.
