IRRIGATION EMITTER
The invention relates to agricultural emitters that are used to provide and control
provision of water to plants.
BACKGROUND
Irrigation systems that deliver water, often containing plant nutrients, pesticides and/or
medications, to plants via networks of irrigation pipes are very well known. In many such
irrigation networks, water from an irrigation pipe is delivered to the plants by "emitters" or
"drippers", hereinafter generically referred to as emitters, which are connected to or installed
along the length of the pipe. Each emitter comprises at least one inlet or an array of inlets
through which water flowing in the pipe enters the emitter and an outlet through which water
that enters the emitter exits the emitter. The emitter diverts a relatively small portion of water
flowing in the pipe and discharges the diverted water to irrigate plants in a neighborhood of
the location of the emitter.
Generally, to control rate of water discharge by the emitter, the emitter comprises an
elastic diaphragm and/or a water flow and pressure reduction channel, a "labyrinth channel" or
"labyrinth" through which water that enters the emitter must flow to reach the emitter outlet.
The labyrinth channel is a high resistance flow channel along which pressure of water flowing
through the emitter drops relatively rapidly with distance along the labyrinth channel. The
pressure drop from a relatively high water pressure at the emitter inlet, to a relatively low
discharge pressure, generally a gauge pressure equal to about zero, substantially at or near the
emitter outlet. The labyrinth channel generally comprises a tortuous "obstacle" flow path that
generates turbulence in water flowing in the labyrinth to reduce water pressure and discharge
of water by the emitter. Usually, the obstacle path comprises a configuration of baffles that
impede and introduce turbulence into water flow.
. The elastic diaphragm operates to control liquid flow so that it is substantially
independent of inlet pressure for a range of pressures typically encountered in irrigation
applications and is equal to a flow rate between about 0.5 and 12 liters per hour (1/h). The
diaphragm is usually seated on a support shelf and is located between the inlet and the outlet
and constrains water that enters the emitter inlet to pass through the labyrinth to reach the
emitter outlet and flow out of the emitter. The diaphragm is responsive to pressure of the
entering water, and as pressure of the entering water increases, the diaphragm undergoes
increasing distortion. The distortion operates to increase resistance to liquid flow through the
dripper with increase in distortion. In some emitters, the distortion increases resistance to
water flow through the emitter with increase in inlet pressure by increasing a length of the

labyrinth through which liquid is constrained to flow to reach the outlet. Some emitters are
formed having an outlet reservoir into which water that flows through the labyrinth empties,
and from which water exits the emitter and additionally or alternatively, the increase in
resistance may be accomplished by changing a dimension of an outlet reservoir to increase
resistance of liquid in the outlet reservoir to exit the reservoir.
An emitter having a flow regulated so that it is substantially independent of inlet liquid
pressure is referred to as a regulated emitter.
Labyrinths and various other liquid flow channels in emitters have a tendency to
become blocked by particulate matter, such as dirt, debris or agglomerations of plant nutrients
that may be carried by liquid that flows through the emitter during plant irrigation from
irrigation pipes in which the emitters are mounted. In addition, emitter outlets and flow
channels have a tendency to get clogged with dirt and debris that are sucked back into the
emitters by water and/or air backflow. Water and/or air backflow typically occurs when supply
of water to irrigation pipes providing water to plants in a field or hothouse is turned off and
pressure in the pipes falls. For subsurface drip irrigation (SDI) pipes, which are buried in the
ground or a growing medium, particulate matter in the surrounding soil or growing medium
tends to be drawn into and clog emitters in the pipes when water pressure in the pipes falls.
For above surface drip irrigation, backflow tends to clog emitters by drawing into the emitters
particulate matter in mud and dust in environments in which the emitters often are located.
To reduce a probability of particulate matter carried by liquid flowing in irrigation
pipes from entering and clogging emitters mounted in the pipes, emitters are generally.
designed having various types of inlet filtering configurations. The inlet filters tend to prevent
particulate matter greater than a given size that may be carried by irrigation liquids in the pipes
from entering the emitters. Internal liquid flow channels of the emitters are formed sufficiently
large so that particulate characterized by a size less than the given size that are passed by the
filters do not clog the channels. To reduce a probability that dirt and debris is sucked back into
emitters when water pressure is reduced in the pipes emitters have been designed to seal
themselves against back flow when pressure in an irrigation pipe in which they are installed is
reduced. Such drippers, commonly referred to as "anti-siphon" or "non-return" emitters, are
usually configured having an elastic diaphragm that sets on and seals an inlet orifice of the
emitter.
US Patent 6,027,048, the disclosure of which is incorporated herein by reference,
describes a regulated non-return agricultural emitter comprising a filter configuration, a
labyrinth, and an elastic diaphragm that seals the emitter against "backflow". The inlet

configuration comprises two relatively long inlet channels that "are relatively larger in width
than those of conventional emitter units". Each inlet channel has an array of "filter baffles"
along its length and is "undercut" in an outside surface of the emitter so that it is partially
covered with a lip that runs along the length of the channel. The baffles and lip operate to
prevent particulate matter in liquid carried by an irrigation pipe in which the emitter is
installed and that might clog the emitter from entering the inlet channel. The two inlet
channels communicate via a coupling channel to a "single restricted inlet" through which
liquid from the irrigation pipe in the inlet channels enters the emitter. An elastic diaphragm
operates to regulate liquid flow through the emitter. To provide a non-return function, the
diaphragm seals the single restricted inlet when water pressure in the irrigation pipe is reduced
below a desired threshold pressure.
The patent notes that the use of "inflow paths which are relatively larger in width than
those of conventional emitter units" aids in "minimizing the dangers of blockage", and are "of
particular significance where, as in the emitter unit specifically described and illustrated, a
non-return valve construction is provided for. With such a construction, only a single restricted
inlet ... into the emitter unit is available, and such a restricted inlet could not accommodate
adequate filtering means."
US Patent 5,615,838, the disclosure of which is incorporated herein by reference,
describes integrated emitters, referred to as in-line emitters, that have a non-return feature and
optionally provides a regulated flow of water. In an embodiment of the invention, a flexible
membrane closes the emitter to flow into or out of the emitter when inlet pressure to the
emitter falls below a minimum pressure. The membrane optionally functions to control a
length of a labyrinth through which water flows responsive to inlet pressure to regulate flow of
water provided by the emitter.
SUMMARY
An aspect of some embodiments of the invention relates to providing a regulated non-
return emitter suitable for mounting inside an irrigation pipe and comprising a relatively
simple configuration.
An aspect of some embodiments of the invention, relates to providing the emitter with
a relatively simple filtering configuration.
In an embodiment of the invention, the emitter comprises a relatively long manifold
flow channel formed on an internal surface of the emitter. The manifold communicates with a
plurality of inlets through which liquid from an irrigation pipe comprising the emitter enters
into the manifold and the emitter.

An elastic diaphragm seats on the manifold channel and constrains liquid that enters
the manifold via the inlets to flow through a labyrinth before debauching into an outlet
reservoir from which the liquid exits the emitter.
According to an aspect of some embodiments of the invention, the manifold channel
comprises a raised rim on which the diaphragm seats to seal at least a portion of the channel
and constrain thereby the liquid to flow through the labyrinth.
According to an aspect of some embodiments of the invention, an array of
protuberances, hereinafter referred to as "registration buttons", on the internal emitter surface
on which the manifold channel is formed, position the diaphragm so that it seats on the
labyrinth and forms a wall of the labyrinth.
In an embodiment of the invention, the diaphragm deforms responsive to inlet pressure
of liquid that enters the inlets to regulate liquid flow through the emitter by changing
dimensions of the outlet reservoir.
There is therefore provided in accordance with an embodiment of the invention an
emitter comprising: a plurality of inlet apertures through which liquid enters the emitter; a
manifold flow channel into which liquid that passes through the apertures flow; an elastic
diaphragm that seats on the manifold flow channel; an outlet aperture through which liquid
that enters the emitter exits the emitter; wherein liquid that enters the inlet apertures displaces
only a portion of the diaphragm from the manifold channel so that the liquid can leave the
manifold channel and flow through the emitter to reach the outlet aperture.
Optionally, the emitter comprises a labyrinth that receives liquid that has flowed in the
manifold channel. Optionally, the emitter comprises a regulation reservoir that receives liquid
that flows through the labyrinth. Optionally, the emitter is configured so that displacement of
the diaphragm decreases volume of the regulation reservoir.
In some embodiments of the invention, the diaphragm seats on the labyrinth to
constrain liquid to flow through the labyrinth.
In some embodiments of the invention, the emitter comprises first and second parts
that sandwich the diaphragm between them. Optionally, the first part is formed having the
manifold channel. Optionally, the emitter has a feed flow channel formed in the first part that
receives liquid that exits the manifold channel and directs flow of the received liquid in a
direction to enter the labyrinth. Optionally, the diaphragm covers a first portion of the feed
flow channel leaving a second portion uncovered. Optionally, the received liquid exits the feed
flow channel via the second portion of the feed flow channel to enter the labyrinth. Optionally,

when the diaphragm is displaced from the manifold channel, it is displaced from at least a
portion of the first portion of the feed flow channel.
In some embodiments of the invention, the first part is formed having a plurality of
protuberances on which the diaphragm rests. Optionally, when the diaphragm is displaced
from the manifold channel some of the liquid that exits the manifold channel flows between
protuberances to reach the feed flow channel.
In some embodiments of the invention, the second part is formed having the labyrinth.
In some embodiments of the invention, the second part is formed having the reservoir
chamber.
There is further provided in accordance with an embodiment of the invention, an
emitter comprising: a first part having formed therein a manifold flow channel having first and
second regions; a second part having formed therein a labyrinth; and an elastic diaphragm
sandwiched between the first and second parts so that the diaphragm is maintained pressed by
the second part to the first region of the manifold flow channel. Optionally, liquid enters the
manifold flow channel via a plurality of apertures. Optionally, the second part is formed
having a regulation reservoir, and wherein the diaphragm is located between the reservoir and
the second region of the manifold flow channel.
BRIEF DESCRIPTION OF FIGURES
Non-limiting examples of embodiments of the present invention are described below
with reference to figures attached hereto. In the figures, identical structures, elements or parts
that appear in more than one figure are generally labeled with a same symbol in all the figures
in which they appear. Dimensions of components and features shown in the figures are chosen
for convenience and clarity of presentation and are not necessarily shown to scale. The figures
are listed below.
Fig. 1A shows a schematic exploded view of a regulated non-return emitter comprising
an emitter housing, an elastic diaphragm, and a housing insert (rotated out of position for
convenience of presentation), in accordance with an embodiment of the invention;
Fig. 1B, shows a schematic perspective view of the emitter housing shown in Fig. 1A
from a direction opposite that from which the housing is shown in Fig. 1 A., in accordance with
an embodiment of the invention;
Fig. 1C schematically shows the diaphragm shown in Fig. 1A seated in the emitter
housing, in accordance with an embodiment of the invention;

Fig. 1D schematically shows a perspective view of the emitter shown in Fig. 1A
completely assembled, in accordance with an embodiment of the invention;
Fig. 2A schematically shows the assembled emitter shown in Fig. 1D mounted in an
irrigation pipe in accordance with an embodiment of the invention;
Fig. 2B schematically shows a view of the emitter in Fig. 2A cutaway to show flow
patterns of liquid in the emitter, in accordance with an embodiment of the invention;
Fig. 2C schematically shows another view of the emitter in Fig. 2A cutaway to show
flow patterns of liquid in the emitter, in accordance with an embodiment of the invention;
Fig. 2D schematically shows the emitter housing shown in Fig. 1A and flow patterns of
liquid along a bottom surface of the emitter, in accordance with an embodiment of the
invention;
Fig. 2E schematically shows a view of the emitter cutaway to show flow of liquid
through a labyrinth of the emitter, in accordance with an embodiment of the invention; and
Fig. 2F schematically shows a view of the emitter cutaway to show the elastic
diaphragm shown in Fig. 1A sealing the emitter against backflow, in accordance with an
embodiment of the invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Fig. 1A shows a schematic, exploded, perspective view of an emitter 20 configured to
be inserted inside an irrigation pipe, divert liquid flowing in the pipe and emit the diverted
liquid from the pipe to irrigate plants, in accordance with an embodiment of the invention.
Emitter 20 optionally comprises a housing 22, an elastic diaphragm 50 and a housing insert 60.
In the perspective of Fig. 1, internal features and surfaces of housing 22 and housing insert 50
are shown.
Housing 22 is formed having an optionally rectangular diaphragm recess 23 defined by
a bottom internal surface 24, relatively long, optionally mirror image, edge surfaces 25, and
relatively short edge surfaces 26 and 27. Long edge surfaces 25 are surfaces of, optionally
mirror image, side support shelves 28. Short edge surfaces 26 and 27 are surfaces of end
support shelves 29 and 30 respectively.
Bottom internal surface 24 is formed having an optionally straight manifold flow
channel 32 that communicates with a linear array of inlet apertures 33 through which liquid
flowing in an irrigation pipe in which the emitter is mounted may enter the emitter. The
manifold channel is rimmed with a raised rim 34. Each inlet aperture 33 is characterized by a
size that tends to prevent particulate matter that may clog emitter flow channels from entering
the emitter. The inlet apertures are, optionally, formed by a plurality of parallel ribs 35 that are

optionally substantially perpendicular to the length of manifold flow channel 32 and separated
by, optionally equal width, spaces 43. The ribs depend towards manifold flow channel 32 from
an external surface 36 of housing 22 shown in a Fig. IB. Fig. IB, schematically shows a
perspective view of housing 22 from a direction opposite that from which housing 22 is shown
in Fig. 1A. Spaces 43 t between the ribs intersect manifold flow channel 32. The size of each
inlet aperture 33 is defined by a space 43 between ribs 35 and the width of manifold flow
channel 32, i.e. the inlet aperture size is substantially equal to a projection of the space
between two adjacent ribs 35 on a space defined by the width of the manifold flow channel. In
accordance with an embodiment of the invention, the width of manifold channel 32 is larger
than the width of each space 43 so that particulate matter that may pass through a space 43, in
general, would not clog the manifold flow channels.
Bottom surface 24 (Fig. 1A) is also optionally formed having a linear feed flow
channel 38 that is optionally parallel to manifold inlet channel 32. Feed flow channel 38
extends in a direction towards end shelf 30 from a region 41 alongside manifold channel 32 to
beyond the manifold channel 32 and into a cranny 39 formed in the end shelf. An array of
registration buttons 40 surrounds manifold and feed channels 32 and 38 in a portion of bottom
surface 24 near end shelf 30. Registration buttons 40 and manifold rim 34 rise above bottom
surface 24 to about a same height.
Elastic diaphragm 50 is shaped to seat in diaphragm recess 23 of housing 22 and has a
rectangular shape with long edges 52. When seated in the diaphragm recess, the diaphragm is
framed by long edge surfaces 25 and short edge surfaces 26, and 27. Fig. 1C schematically
shows diaphragm 50 seated in diaphragm recess 23 (Fig. 1 A).
It is noted that when diaphragm 50 is positioned in the diaphragm recess, the
diaphragm covers features on bottom surface 24 except for a portion 37 of feed flow channel
38 that is located in cranny 39. Portion 37 of the feed flow channel in the cranny is hereinafter
referred to as a feed channel outlet port 37.
Housing insert 60 has an inside surface 62 and is shaped to be inserted into housing 22
so that portions of the inside surface seat on support shelves 28, 29 and 30. Inside surface 62
of housing insert 60 is formed having a labyrinth 64 that empties into an internal "regulation
reservoir" 70 and is connected to a labyrinth inlet channel 65 having a labyrinth inlet port 66.
Labyrinth 64 may be any suitable labyrinth known in the art and is optionally a labyrinth
similar to a labyrinth described in PCT Patent Application IB2006/052473, the disclosure of
which is incorporated herein by reference. Regulation reservoir 70 is formed having a "trickle
channel" 72 and a regulation reservoir outlet channel 74 discussed below.

Housing insert 60 is flipped 180° about an axis 90 relative to its orientation in Fig. 1A
to be inserted into housing 22. When the housing insert 60 is properly inserted into housing
22, the insert is supported by support shelves 28, 29 and 30 and labyrinth inlet port 66 (Fig.
1A) of the insert is located over cranny 39 and feed channel outlet port 37 (Fig. 1A and Fig.
1C) of housing 22. To secure housing insert 60 in the housing, any of various methods and or
materials known in the art may be used. For example, insert 60 may be bonded in housing 22
by ultrasonic welding or by gluing.
With housing insert 60 securely in place in housing 22, diaphragm 50 is sandwiched
between the insert and the housing, pressing firmly on inside surface 62 of insert 60 and rim
34 and registration buttons 40 on bottom internal surface 24 of housing 22. By being pressed
snugly to inside surface 62 of insert 60 the diaphragm provides a top wall for labyrinth 64 that
substantially seals the labyrinth against leakage of liquid where the diaphragm covers the
labyrinth.
Fig. ID schematically shows a perspective view of emitter 20 completely assembled
with insert 60 flipped and seated in housing 22. In the perspective of Fig. ID, an outside top
surface 68 of housing insert 60 is shown. The top surface is optionally curved to match a
curvature of an irrigation pipe in which emitter 20 is intended to be installed so that it may be
bonded to an inside surface of the pipe. Top surface 68 is optionally formed having an outside
liquid reservoir 76 that communicates with regulation reservoir 70 (Fig. 1A) via regulation
reservoir outlet channel 74. Liquid exits an irrigation pipe in which emitter 20 is installed from
outside liquid reservoir 76.
Fig. 2A - 2E schematically illustrate operation of emitter 20 when mounted in an
irrigation pipe 100 in which liquid, indicated by a block arrow 102 for irrigating plants is
flowing, in accordance with an embodiment of the invention. Fig. 2A schematically shows the
irrigation pipe partially cutaway to show the emitter mounted therein.
In Fig. 2B emitter 20 is cutaway to show a cross section of the emitter in a plane AA
indicated in Fig. 2A. Plane AA bisects emitter 20 along the length of manifold flow channel
32. A portion, indicated by wavy arrows 104, of liquid 102 flowing in irrigation pipe 100 is
diverted into emitter 20 and flows into manifold flow channel 32 through spaces 43 between
ribs 35, which define inlet apertures 33 of the emitter. Liquid 104 that enters manifold flow
channel 32 is substantially prevented from exiting the manifold channel in a first region,
indicated by a bracket 106, of the channel opposite labyrinth 64 because in that first region
insert 60 presses diaphragm 50 snuggly onto rim 34 of the manifold channel thereby sealing
the channel in that region against egress of liquid.

However, in a second region, indicated by a bracket 110, of manifold channel 32,
opposite regulation reservoir 70, diaphragm 50 is not constrained to remain pressed against
rim 34. As a result, in second region 110 of manifold channel 32, when pressure of liquid 104
that enters the manifold channel exceeds a predetermined threshold pressure, the pressure
pushes diaphragm 50 off of rim 34 of the manifold channel. The threshold pressure is
determined, inter alia, by properties of material from which diaphragm 50 is produced,
dimensions of the diaphragm, dimensions of the rim 34 and dimension of regulation reservoir
70. Diaphragm 50 and regulation reservoir 70 may be configured using any of various
methods and materials known in the art to provide a desired threshold pressure. Optionally, the
threshold pressure is substantially zero.
As diaphragm 50 is lifted off rim 34, liquid 104 flows out of second region 110 of
channel 32 filling a space 112 that its pressure creates between the diaphragm and housing 22.
The flow of liquid out of the manifold channel 32 in second region 110 is schematically
represented in Fig. 2B by arrows 114 and generates a flow of liquid indicated by wavy arrows
115 in the manifold channel towards second region 110. Liquid 114 that flows out of manifold
channel 32 exits the manifold channel under diaphragm 50 to flow in substantially all
directions in space 112 between diaphragm 50 and bottom surface 24 of housing 22,
eventually to flow into feed flow channel 38. Optionally, space 112 overlies at least region 41
(Fig. 1A) of feed flow channel 38 as shown in a Fig. 2C.
Fig. 2C schematically shows a cross section of emitter 20 along a plane BB indicated
in Fig. 2A in which diaphragm 50 is lifted off rim 34 by pressure of liquid 104 (Fig. 2B)
flowing into emitter 20 and liquid flowing out of manifold channel 32 enters feed flow channel
38. In Fig. 2C, and in Fig. 2D that follows, liquid flowing towards feed flow channel 38 from
space 112 is schematically represented by block arrows 120. Fig. 2D schematically shows
housing 22 and bottom internal surface 24 of the housing, and in the figure, arrows 120
schematically indicate flow of liquid from manifold channel 32 to feed flow channel 38 by
various flow routes. As indicated in Fig. 2D, some of the flow routes to feed flow channel 38
pass around registration buttons 40.
Liquid that enters feed flow channel 38 flows along the feed flow channel to feed flow
outlet port 37 (Fig. 1A, IC, 2D) from where it exits the feed flow channel. The exiting fluid
flows upwards from the outlet port along cranny 39 (Fig. 1A, 1C, 2D) to flow into labyrinth
inlet channel 65 via labyrinth inlet port 66 (Fig. 1A, 2B) and therefrom into labyrinth 64. In
Fig. 2B fluid flowing upwards from outlet port 37 along cranny 39 and into inlet port 66 is
schematically represented by a block arrow 126. Liquid that flows into labyrinth 64 wends it

way through the labyrinth to enter regulation reservoir 70. Arrows 128 in Fig. 2B
schematically represent liquid flowing through the labyrinth and into regulation reservoir 70.
Details of liquid flow into and through labyrinth 64, in accordance with an
embodiment of the invention are shown in Fig. 2E. The figure schematically shows a cross
section of emitter 20 along a plane CC indicated in Fig. 2A showing labyrinth 64, labyrinth
inlet channel 65 and its inlet port 66. Liquid, indicated by arrows 130, from feed flow channel
38 (Fig. 2C, Fig. 2D) flows upwards along cranny 39 (Figs. 1 A, 1C) of housing 22 to labyrinth
inlet port 66 and enters labyrinth inlet channel 65. Liquid 130 then flows into labyrinth inlet
channel 64 and meanders its way through the labyrinth to debauch into regulation reservoir 70.
From the regulation reservoir the liquid flows into outlet reservoir 76 shown in Figs. 2A - 2C
and exits irrigation pipe 100 via orifice 101.
Resistance to flow of liquid into regulation reservoir 70 from the labyrinth and from
the regulation reservoir into outlet reservoir 76 is a function of displacement of diaphragm 50
away from bottom internal surface 24 of housing 22 and into the regulation reservoir and
increases with the displacement. The displacement in tum is a function of inlet pressure of
liquid entering emitter 20 that operates to lift the diaphragm off rim 34 and into the regulation
reservoir and increases with increasing pressure. By suitably determining dimensions of
regulation reservoir 70 and elasticity and thickness of diaphragm 50, resistance to liquid flow
through regulation reservoir 70 is determined, in accordance with an embodiment of the
invention, to increase substantially linearly with increase in inlet pressure. As a result, the
diaphragm operates to regulate flow of liquid from irrigation pipe 100 through emitter 20 and
flow rate of liquid from the irrigation pipe that passes through emitter 20 and exits the
irrigation pipe is substantially independent of inlet pressure. Trickle channel 72 (Fig. 1A)
functions to maintain liquid flow through emitter 20 for inlet pressures that are so large that
diaphragm 50 is pressed against reservoir outlet channel 74 and would in the absence of the
trickle chamber seal the outlet channel.
Diaphragm 50 also operates to seal emitter 20 against backflow of liquid into emitter
20 and when liquid pressure in irrigation pipe 100 drops below the threshold pressure the
diaphragm relaxes to seat on rim 34 and seal the emitter against backflow of and possible
concomitant suction of debris into the emitter (Fig. 2F).
In the description and claims of the present application, each of the verbs, "comprise"
"include" and "have", and conjugates thereof, are used to indicate that the object or objects of
the verb are not necessarily an exhaustive listing of members, components, elements or parts
of the subject or subjects of the verb.

The invention has been described with reference to embodiments thereof that are
provided by way of example and are not intended to limit the scope of the invention. The
described embodiments comprise different features, not all of which are required in all
embodiments of the invention. Some embodiments of the invention utilize only some of the
features or possible combinations of the features. Variations of embodiments of the described
invention and embodiments of the invention comprising different combinations of features
than those noted in the described embodiments will occur to persons of the art. For example,
the features of housing insert 60, may be formed in a housing for an emitter in accordance
with an embodiment of the invention and the features of housing 22 may be incorporated in an
insert. Manifold flow channel 32 and/or feed flow channel 38, which are shown as rectilinear
may be curved. The scope of the invention is limited only by the claims.

We Claim:
1. An emitter comprising:
a plurality of inlet apertures through which liquid enters the emitter;
a manifold flow channel into which liquid that passes through the apertures flow;
an elastic diaphragm that seats on the manifold flow channel;
an outlet aperture through which liquid that enters the emitter exits the emitter;
wherein liquid that enters the inlet apertures displaces only a portion of the diaphragm
from the manifold channel so that the liquid can leave the manifold channel and flow through
the emitter to reach the outlet aperture.
2. An emitter according to claim 1 and comprising a labyrinth that receives liquid that has
flowed in the manifold channel.
3. An emitter according to claim 2 and comprising a regulation reservoir that receives
liquid that flows through the labyrinth.
4. An emitter according to claim 3 configured so that displacement of the diaphragm
decreases volume of the regulation reservoir.
5. An emitter according to claim 2 wherein the diaphragm seats on the labyrinth to
constrain liquid to flow through the labyrinth.
6. An emitter according to claim I comprising first and second parts that sandwich the
diaphragm between them.
7. An emitter according to claim 6 wherein the first part is formed having the manifold
channel.
8. An emitter according to claim 7 and having a feed flow channel formed in the first part
that receives liquid that exits the manifold channel and directs flow of the received liquid in a
direction to enter the labyrinth.
9. An emitter according to claim 8 wherein the diaphragm covers a first portion of the
feed flow channel leaving a second portion uncovered.

10. An emitter according to claim 9 wherein the received liquid exits the feed flow channel
via the second portion of the feed flow channel to enter the labyrinth.
11. An emitter according to claim 10 wherein when the diaphragm is displaced from the
manifold channel, it is displaced from at least a portion of the first portion of the feed flow
channel.
12. An emitter according to claim 6 wherein the first part is formed having a plurality of
protuberances on which the diaphragm rests.
13. An emitter according to claim 12 wherein when the diaphragm is displaced from the
manifold channel some of the liquid that exits the manifold channel flows between
protuberances to reach the feed flow channel.
14. An emitter according to claim 6 wherein the second part is formed having the
labyrinth.
15. An emitter according to claim 6 wherein the second part is formed having the reservoir
chamber.
16. An emitter comprising:
a first part having formed therein a manifold flow channel having first and second
regions;
a second part having formed therein a labyrinth; and
an elastic diaphragm sandwiched between the first and second parts so that the
diaphragm is maintained pressed by the second part to the first region of the manifold flow
channel.
17. The emitter according to claim 16, wherein the second part is formed having a
regulation reservoir, and wherein the diaphragm is located between the reservoir and the
second region of the manifold flow channel.
18. The emitter according to claim 16, wherein liquid enters the manifold flow channel via a
plurality of apertures.

An emitter (20) comprising: a plurality of inlet apertures
through which liquid enters the emitter; a manifold flow channel
(32) into which liquid that passes through the apertures flow; an
elastic diaphragm (50) that seats on the manifold flow channel;
an outlet aperture through which liquid that enters the emitter
exits the emitter (20); wherein liquid that enters the inlet
apertures (33) displaces only a portion of the diaphragm (50)
from the manifold channel so that the liquid can leave the
manifold channel and flow through the emitter (20) to reach the
outlet aperture.