Drip Emitter

Field of the Invention

The invention, subject matter of this application, relates to the drip emitters field in general and to the field of drip emitters that comprises a pressure regulator mechanism in particular.

Background of the Invention

Preliminary Remark - the invention presented herein after would be described in terms of applications referring to agricultural irrigation with water. However, any professional in this field would understand that the invention is not restricted solely to this field, but rather the invention is also applicable to drip emitters that are employed in other uses, as for example wetting and flushing (rinsing) minerals with water or using various different liquids and not just water (for example, detergents or water containing fertilizing materials). As is well known from earlier instances, there exist drip emitters that are used in agricultural irrigation systems that incorporate in them a mechanism to regulate their throughput quantities (flow rate). The pressure of the water arriving at the drip emitters is not constant, but rather varies in accordance with the variations of the pressure in the deployed water supply conduits unto which they are connected. Such variations in water pressure occur, for example, due to pressure variations in the source supplying the water to the conduit, the relative locations of the drip emitters or the varying topography of the landscape upon which the irrigation system is deployed (e. g. mountains, slopes, hills, valleys and similar variables). A regulating mechanism based on an elastomer component enables to increase or decrease the water flow passage to the outlet (exit) opening from the drip emitter, exploiting the movements of the elastomer component in accordance with the water pressure prevailing in the conduit. In drip emitters, the differential regulation principle is implemented, wherein the elastomer component is exposed - on its one side, to the water pressure prevailing in the conduit and on its other side, to the reduced pressure of the water as it exits from the flow reducer

throttle means (herein after: throttle means) embedded in the drip emitter (for example, a flow passage means incorporating a labyrinth like construction). Thus, by integrating a regulating mechanism into the drip emitter, it is viable to maintain an essentially constant throughput (flow rate) level through the drip emitter, as required for optimal irrigation applications, independently of the water pressure variations that occur, as said, in the conduit.

Drip emitters that incorporate, as said, an elastomer component together with the throttle means, are installed in agricultural irrigation systems in a variety of modes - inside the water supply conduit and as an integral part thereof, or as discrete units located between conduit sectors along its length, or as separate units stuck or connected into it from the outside.

Recognized and known from before are drip emitters in which the throttle means (for example — a labyrinth resembling flow passage or a continuum of vortex cells), are integrally formed, already in the production stage, within an elastomer component. As separate units that are stuck or connected to the water supply conduit from the outside, such stick able drip emitters are described, for example, in the Irrifrance SA patent No. FR2468810 (see there, in figures No. 6 and No. 11) and in Tucker's patent US 4,553,083.

Also recognized and known to every professional in the field, there are drip emitters that can be stuck or connected to the water supply conduit from the outside, in which the elastomer component, in which there is formed, as said, a throttle means, was also exploited to be used as a flexible^endable membrane of the regulating mechanism (by allocating a specific portion of the elastomer component to this end). Forming the throttle means as an integral part as said, inside the same elastomer component proper of which a portion will be also used as the bendable membrane of the regulating mechanism, as different from forming the throttle in one or more components of the drip emitter's housing assembly, might result in various advantages. Thus for example - the elastomer component mandates high quality and strict (meticulous) design and manufacturing tolerances of the precise dimension values as is obviously needed for obtaining exact performance of the

movable membrane in a regulating mechanism. At the same time, also the throttle means mandates high quality and meticulous design and manufacturing process, and this due to the significant influence of the surface workmanship quality and the dimensions of the flow passage on the performance attributes of the throttle. Thus, unifying the efforts and the' means - the movable membrane component and the throttle means and their formation in one single component — in the elastomer component, might lead to substantial simplification of the process and to substantial reduction of the cost required for producing the injection molds and in the quality assurance efforts controlling the drip emitter's housing assembly elements.

This and more - it is a common practice to install drip emitters that are mounted inside the water supply conduit and to affix them to the inner wall of the conduit concurrently with the continuous production process of the conduit (for example in the extrusion process of the conduit as a tubular profile). It is an accepted technique to use heat welding in order to affix the drip emitters unto the inner wall of the conduit by exploiting the large internal heat amounts that prevail anyhow at the wall of the conduit when it exits the extruder. Under these circumstances, a throttle means that would be formed at the housing component of the drip emitter that is brought unto heat welding contact with the inner wall of the conduit, might suffer damage due to the influence of the thermal shock to which the component was exposed. In contrast to this potential harm, forming the throttle means as part of the elastomer component means that is not brought into direct contact with the hot wall of the conduit but rather is included within the drip emitter's body, thus shifting the throttle means away from the heat and protects it from the heat. Such a design, namely a design that does not call for heat welding of the component at which the throttle means is formed to the wall of the conduit (generally made of polyethylene), enables also to manufacture the throttle means from a thermosetting material, such as silicone or EPDM rubber, and by this imparting better endurance to the elastomer component, against the heat generated at the extruder.

At the same time, drip emitters that are stuck into or connected to the water supply conduit from the outside, and in them - as said, form the throttle means (for example a flow passage means resembling a labyrinth or a continuum of vortex cells) was formed integrally within that very same elastomer component that a portion thereof served in them as the bendable membrane of the regulating mechanism - they had problems in their sealing properties. The elastomer component was located within the housing assembly of the drip emitter, without being anchored along its circumference to the housing component. As the circumferential anchoring was missing, the bending stress to which a portion of the membrane was exposed (due to the water pressure) was expressed by a movement of the whole elastomer component away from the drip emitter's housing assembly walls, in a manner that induced an unwanted water passage there — rather than trough the throttle means.

In another and additional aspect, those existing drip emitters did not provide an answer to an additional challenge that is raised when irrigating with dripping systems, namely the capability to prevent spilled water and emptying the water supply conduit at the time irrigation is terminated (in a manner that would prevent wasting water and the need to build up the water pressure in the conduit at any time it is wished to renew the irrigation cycle), and also to prevent suction of contaminates into the drip emitter and the water supply conduit when the water pressure level in the conduit drops.

At the same time, there are other recognized and well known regulated drip emitters in which the elastic resistance to bending of the membrane in the regulating mechanism is exploited for providing a sealing effect at the water inlet opening to the drip emitter. The sealing materializes when the pressure of the water in the conduit drops below a pre set threshold value, or - in other words, exploiting the regulator's membrane to act also in forming a no drain valve. Such a drip emitter is described for example in Mehoudar's patent US 5,279,462. A drip emitter stick able from the outside, into the water supply conduit is described their wherein its throttle means is formed in the housing assembly and not in the elastomer component.

A no drain valve means is not found in drip emitters which are stuck into - or being connected to - the water supply conduit, in which, as said, the throttle means (for example - a labyrinth resembling flow passage means or a continuum of vortex cells), was formed integrally within that elastomer component proper that a portion of which does also serve as the bendable membrane of a regulating mechanism.

Summary of the Invention

The present invention enables to achieve the cost savings advantages as we have shown above, linked to drip emitters in which the throttle means is integrally formed within the same elastomer component that a portion thereof serves also as the membrane of the regulating mechanism, and this concurrently with imparting maximum sealing and preventing an unwanted water passage through venues that do not pass through the throttle means.

The present invention is given to implementation in all the types of drip emitters in which the throttle means is integrally formed within the same elastomer component proper, of which a portion of it serves also as the membrane of the regulating mechanism - including also drip emitters that are intended for installation inside the irrigation conduit while it is being manufactured (and such a drip emitter is described in the application, but as a preferred embodiment of the invention). Moreover, in another and additional preferred embodiment of this invention, a drip emitter in accordance with the invention, includes also a no drain valve.

In one aspect of the present invention, the invention constitutes a drip emitter. The drip emitter comprises components that were known in drip emitters long ago -such as a housing assembly that can be installed for flow passage into it from the water supply conduit. The housing assembly is formed with an internal space, a water inlet opening that connects to a flow passage into it from a water supply conduit to the internal space, and a circumferential bracket formed around the internal space. An emitter unit as per the invention includes in addition a cover component that is mountable unto the circumferential bracket of the housing assembly. The cover component is formed with a flow control opening and a water outlet opening that connects to a flow passage from the internal space of the housing assembly to the outer side of the cover component. A third component in the emitter unit as per the invention constitutes an elastomer component that is mountable inside the internal space of the housing assembly and is being located in the space opposite the cover component.

In a drip emitter as per the invention, the elastomer component is integrally formed (already during the manufacturing process) with a first embedded space on its one side, a second embedded space on its other side and a regulating membrane portion that separates between the two embedded spaces, the first one and the second one. Thus, upon installing the elastomer component and positioning it in the internal space of the housing assembly opposite the cover component, the first embedded space is connected to a flow passage leading to it from the water inlet opening and the second embedded space is located vis a vis the flow control opening and the water outlet from the cover. In addition, also integrally formed in the elastomer component, there resides a throttle means for decreasing the water pressure - that is connected to a flow passage into it from the first embedded space and to the exit of water from it after the pressure was decreased - to the second embedded space. Thus, the regulating membrane portion is movable towards the flow control and water outlet opening that is formed in the cover component and moving away from it, while conducting the regulating action by increasing or decreasing the dimensions of the flow passage from the throttle means towards the flow control and water outlet opening, and this in accordance with the differential water pressure that prevails in the embedded spaces - the first and the second ones. From the constructional aspect, an emitter unit as per the invention, is characterized by that the elastomer component in the drip emitter is anchored around its circumference to the housing assembly and to the cover assembly and insures maximal sealing and prevention of non desired water flow, during the regulating action, that is not through the throttle means. In a preferred embodiment of the invention, the elastomer component is also fastened at the major part of its surface area as a "sandwich" between the housing assembly and the cover component, in a manner that ensures stressing the membrane regulating portion that as said - is integrally formed in it, into a stretching that is essentially local during the period of the regulating action (in contra distinction to the regulated drippers as per prior knowledge, in which the

elastomer component was fully "floating" rather than being anchored around its circumference) .

In another preferred embodiment of a drip emitter in accordance with the invention, the elastomer component is integrally formed on its both sides with protruding projections around its circumference, the internal space of the housing assembly is formed with a matching embedded groove around its circumference and the cover component faces the internal space is also formed with a matching embedded groove around its circumference. Thus, upon installing the elastomer component within the internal space of the housing assembly and affixing the cover component unto the circumferential bracket of the housing assembly, the projections formed on the two sides of the elastomer component are contained within the embedded grooves that are formed in the internal space of the housing assembly and in the cover component, and anchored, as said, the elastomer component around its circumference to the housing assembly and the cover component.

In yet another additional aspect of the present invention, the water flow inlet opening of the drip emitter in accordance with the invention is formed with a circumferential shoulder that protrudes into the internal space of the housing assembly. Thus, upon installing the elastomer component within the internal space of the housing assembly and fixing the cover component unto the circumferential bracket of the housing assembly, the regulating membrane portion is biased against the circumferential shoulder of the water inlet opening in order to form a no drain valve induced by the elastic resisting force of the portion.

Brief Description of the Accompanying Figures

The present invention will be described herein under in conjunction with the accompanying figures. Identical components, wherein some of them are presented in the same figure - or in case that a same component appears in several figures, will carry an identical number.

Figure No. 1 constitutes an exploded view of the components of an example of a drip emitter in accordance with the present invention designed for being installed inside the water supply conduit during the process of its manufacturing.

Figure No. 2 constitutes an exploded view taken from another angle of the components of the same drip emitter that is illustrated in figure No. 1.

Figure No. 3 constitutes a perspective view of the cross section (enlarged) of the elastomer component of a drip emitter of which its components are illustrated in figures No. 1 and No. 2.

Figure No. 4 constitutes a perspective view of the drip emitter of which its components are illustrated in figures No. 1 to No. 3.

Figure No. 5 constitutes a perspective view from another angle of the drip emitter that is illustrated in figures No. 4. Figure No. 6 constitutes a cross section view of the drip emitter illustrated in figure No. 5, wherein it is installed flush to the inner wall of the water supply conduit.

Figure No. 7 constitutes a cross section view of the width of the drip emitter illustrated in figure No. 6 (the a-a cross section marked in figure No. 6).

Detailed Description of a preferred embodiment of the Invention

Referring to Figures No. 1 to 3. These figures constitute a presentation of exploded views - taken at different angles, of the components of a drip emitter,

5 for example of drip emitter 10 in accordance with the present invention. Drip emitter 10 is one of the kind that is intended for installation inside the water supply conduit while it is being manufactured (the conduit is not illustrated), while allowing formation of a gap to enable continuation of water passage along the conduit's length. Figure No. 3 constitutes a perspective view of the cross section

10 (enlarged) of the elastomer component 40 of drip emitter 10.

Drip emitter 10 is made up of only three parts - housing assembly 20, cover component 30 and elastomer component 40.

Housing assembly 20 is an essentially rectangular and flat unit. It can be manufactured by injecting a polymeric material into a mold. Housing assembly

15 20 is formed with an internal space 51 and water inlet opening 55 which connect for water passage into internal space 51. Circumferential bracket 59 is formed around internal space 51.

Cover component 30 is also an essentially rectangular and flat unit that can be manufactured by injecting polymeric material into a mold. From the point of 20 view of its dimensions it can be affixed unto circumferential bracket 59 (for example by ultra sonic soldering). Cover component 30 is formed with flow control and water outlet opening 63 that connects to a water passage from internal space 51 of housing assembly 20 to the outer side 67 of cover 30.

Elastomer component 40 is also formed as an essentially rectangular and 25 flat unit and can be manufactured from synthetic of natural rubber. From the point of view of its dimensions it can be located in internal space 51 of housing assembly 20, opposite the inner side 71 of the cover component 30.

Elastomer component 40 is integrally formed (during the manufacturing stage) with a first embedded space 75, whose shape is rectangular, on one side 79

30 of the component, and with a second embedded space 83, whose shape is also

rectangular, on the other side 85 of the component. The relatively thin wall 87 that remains between the first embedded space 75 to the second embedded space 83 constitutes the regulating mechanism's membrane portion that separates, as said, between the two embedded spaces — the first 75 and the second 83. Thus, upon installing of elastomer component 40 and locating it at internal space 51 of housing assembly 20 opposite to the cover component 30, the first embedded space 75 is connected to a flow passage into it from the water inlet opening 55 and the second embedded space 83 is located facing the flow control and water outlet opening 63. Any professional in this field would understand that the regulating membrane portion 87 might also be formed in a configuration that is not necessarily rectangular in its shape (for example - square or circular), as well as of different shapes or even a variable cross section (as far as these aspects influence as necessity on the geometry of the portion's motion when it is exposed to a stretching stress).

Moreover, an elastomer component 40 is integrally formed (as said - already during the manufacturing stages) with a throttle means 89 serving to reduce the water pressure. Throttle means 89 is connected unto a flow passage into it - from first embedded space 75, and to water exit from it, following reduction of the water pressure in it, into second embedded space 83. Thus, regulating membrane portion 87 is movable towards the flow control and water outlet opening 63 and to shifting away from it while performing a regulating operation by means of increasing or decreasing the flow passage dimensions from the throttle means towards the flow control and water outlet opening 63, and this, as said, in accordance with the differential pressure that prevails in the first and second embedded spaces - 75 and 83.

In the presented example of drip emitter 10, the flow control and water outlet opening 63 that is formed in cover component 30, is formed at its inner side

71 and around the circumference of opening 63 with a depression 88. The walls of depression 88 converge towards the flow control and water outlet opening 63.

The depression is essentially oval, wherein its length in the length dimension of

cover component 30 is larger than its width dimension (for example, say approximately by 40%). Any professional in this field would understand that in consideration of the elongated rectangular configuration of the regulating membrane portion 87 - such an oval dent would alleviate the task of the regulation operation and of adapting the stretching surface area of the membrane to the flow control and water outlet opening 63.

In another aspect of the features relating to the presented example of drip emitter 10 - throttle means 89 constitutes verily a flow passage 91 integrally formed as an embedded passage on the two sides of elastomer component 40. In accordance with the illustrated example, flow passage 91 includes first labyrinth means 93, that is formed on one side 79 of elastomer component 40, wherein at one end 95 it is connected to water flow into it from embedded space 75, and wherein it includes an array of baffles 97 protruding into flow passage 91. In addition, flow passage 91 includes a water passage opening 99 that is connected to a flow passage into it from other end 101 of first labyrinth means 93. Second labyrinth means 103 is formed at the second side 85 of elastomer component 40. Second labyrinth means 103 is connected on its one end 105 to a water flow passage into it from opening 99 and on its other end 107 to a flow passage from it to second embedded space 83. In the illustrated example, the second labyrinth means 103 also includes an array of baffles 109 that are protruding into flow passage 91.

In accordance with the illustrated example, flow passage 91 is characterized by that upon mounting of elastomer component within internal space 51 of housing assembly 20 and fixing cover component 30 to circumferential bracket 59 of the housing assembly, flow passage 91 is defined and bounded by internal space 51 and the lower surface area 71 of cover component 30.

Any professional in this field would understand that a drip emitter as said, might include a throttle means of different design or structure, which is not necessarily configured precisely so - as two labyrinth portions connected in series

(as described in the illustrated example), but, for example; might be configured as

a portion in the shape of a narrow channel, an additional portion configured as a continuum of vortex cells or any combination of portions as said. The dimensions of the flow passage at the different points along the throttle means might also vary. An emitter unit in accordance with the invention overcomes the difficulties and failures of the sealing entities, that as said, were detected in drippers that are within the domain of prior art as cited. The solution is achieved by anchoring the elastomer component (40 in the illustrated example) around its circumference to the housing assembly (20) and to the cover component (30). In other words, in accordance with the present invention, the regulating membrane portion of the elastomer component is not "floating" but rather harnessed around its circumference and its motion at the time of actually engaged in regulating operation is not dependent on a movement of the elastomer component away from the walls of the housing assembly. In the illustrated example, the anchoring or harnessing of elastomer component 40 is performed by integrally forming the component (at the time it is being manufactured) on its both sides - 79 and 85, with projections around its circumference - protrusion 111 on the 79 side and protrusion 113 on the 85 side. Internal space 51 of cover component 20 is formed with an embedded groove 115 around its circumference. Groove 115 matches in its dimensions circumferential protrusion 111 that is formed on the side 79 of the elastomer component. Cover component 30, on its inner side 71 - that upon affixing it unto circumferential bracket 59 on housing assembly 20 faces internal space 51, is also formed with an embedded groove 117 around its circumference. Embedded groove 117 matches in its dimensions, circumferential protrusion 113, the protrusion that is formed at side 85 of elastomer component 40.

Thus, in accordance with the illustrated example, upon installing of elastomer component 40 within internal space 51 of housing assembly 20 and affixing cover component 30 on circumferential bracket 59 of housing assembly 20, protrusions 111 and 113 (that are formed on the two sides of elastomer component 40) are contained within embedded grooves 115 and 117 that are

formed in the internal space of the housing assembly and the cover component, respectively.

Any professional in this field would understand that anchoring the elastomer component around its circumference and in a manner that ensures that the movement of the regulating membrane portion formed in it would not be linked to the motion of the component away from the walls of the house assembly, might be achieved also using other means - for example pressing the edges of the elastomer component as a "sandwich" in a pressure bracket around its circumference, between the housing assembly and the cover component.

In addition, in accordance with he illustrated example, on installing elastomer component 40 within internal space 51 of housing assembly 20 and affixing cover component 30 to the circumferential bracket 59 in housing assembly 20, the larger part of the surface area of the elastomer component are pressed as in a "sandwich" between the housing assembly to the cover component in a manner that insures that the membrane portion of the regulating mechanism would be stressed to exert an essentially local stretching, at the time of the regulating operation process.

Any professional in this field would understand that in the presented example of drip emitter 10, the elastomer component might be symmetric at its width dimension and hence might be mountable in any sense (direction) in this dimension - face up or face down. This is in contra distinction from its lengthwise dimension that mandates constructing the drip emitter in an exact orientation between the three components - the water inlet opening facing the regulating membrane, and the membrane, on its side to be opposite the flow control and water outlet opening.

Referring to figures No. 4 and 5. The figures constitute a perspective view (made at different angles) of the drip emitter 10 whose components are illustrated in figures No. 1 to No. 3. As said, drip emitter 10 is of the kind designed to be installed within the water supply conduit (that is not illustrated)

while leaving a gap to enable continuation of the water flow along the conduit. Drippers of this kind are well known from earlier instances, and are found in various forms and shapes, essentially as flat rectangles - that are affixed unto the inner wall of the conduit during the process of its manufacturing, on a partial sector of its circumference (for example on less than half of the circumference of the inside of the width cross section of the conduit), or as round drippers affixed to the conduit during the process of its manufacturing, on the larger part of the inside of the width cross section of the conduit while still allowing for a flow passage at their center (along the lengthwise axis). Drip emitter 10 that is described solely as an example, constitutes one of the first kind - but only as an example, noting that any professional in this field would understand that the present invention, might also be implemented in drip emitters of the second kind, as well as also in drip emitters that can be stuck and that are connected to the water supply conduit from the outside. Drip emitter 10 is illustrated in figures No. 4 and No. 5, showing it when it is assembles and before being inserted into the water supply conduit (that is not illustrated) while it is being manufactured. Cover component 30 is formed - on its external side 67, with a circumferential protruding bulge 403 that bounds sector 405 on the external side of the component. Flow control and water outlet opening 63 is formed within sector 405, and any professional in this field would understand that sector 405 constitutes the "outlet pool" of the water from the drip emitter (in a manner that enables piercing the wall of the water supply conduit, by a perforation or by a groove in order to connect the "pool" with the area intended to be irrigated). Protrusion bulge 403 is adapted to being affixed unto the inner wall of the water supply conduit at less than half of its circumference in the width cross section, wherein - in the illustrated example, the protrusion is formed with an arch like feature in a manner rendering it compatible - from the geometrical point of applicability - to being affixed flush upon the inner wall of the conduit.

Reverting once more to figures No. 1 and No. 2. In the illustrated example, housing assembly 20 is formed with openings 121 and 123 on its to sides and also an elastomer component 40 formed with protrusions 125 and 127 on its two sides.

These protrusion matches, the width of the openings' dimensions. Thus, and as might also be seen in figures No. 4 and No. 5, on installing elastomer component 40 within internal space 51 of housing assembly 20, protrusion 125 is included within opening 121 and protrusion 127 is included within opening 123. Any professional in this field would understand that combining the protrusions and the openings enables easy alignment in the length wise dimension of the components - the housing assembly and the elastomer component — one relatively to the other, in a manner that alleviates the implementation of mechanization and automation of the of the process of assembling the drip emitters (prior to inserting them into the water supply conduit while it is being manufactured). The protrusions and the openings enable proper and correct assembly of the elastomer component at its length dimension but simultaneously enable a degree of freedom in the manner of assembling the elastomer component in the rolling plane (because, as seen in the illustrated example, elastomer component 40 is symmetric as far as the shape and the dimensions of the spaces 75 and 83 formed in it are concerned, and hence it is amenable to being installed "face up" or "face down").

Any professional in this field would understand as well that a similar combination of protrusions and the openings, in order to alleviate the alignment of the components in the length wise dimension for the mechanized and automated process, might be implemented between cover component 30 and housing assembly 20.

This and even more - any professional in this field would understand that coupling of the protrusions and the openings enable visual inspection of the elastomer component even after the drip emitter has been assembled. Hence, by selecting an appropriate pigmentation during the process of manufacturing the elastomer component, it is possible to dedicate a specifically characterizing color to one elastomer component that is formed with a selected throttle means and a regulating membrane portion that are attuned to provide a given throughput (flow rate) while selecting a different pigmentation color to a unit with a different selected throughput (flow rate) and so on, wherein the cover components 30 and

the housing assemblies 20 remain identical (the identification of the drip emitter would be made by visually inspecting the color of the elastomer component which can be observed by verifying the color of the protrusions).

Another constructional characteristic of drip emitter 10, is the forming of water inlet opening 55 in housing assembly 20 with a filter means 407 (see figures No. 5 and 6). Filter means 407 filters the incoming water flow in order to prevent contaminations from penetrating into the drip emitter, for example contamination entities whose size is larger than the dimensions of the minimal flow passage path along the throttle means. Referring to figures No. 6 and 7. These figures constitute cross section views of drip emitter 10 illustrated in figures No. 4 and No. 5. In this figures, drip emitter 10 is illustrated wherein it is already affixed unto wall 603 of water supply conduit 605 (for example - by heat welding).

Drip emitter 10 includes a no-drain valve. As can be seen in figures No. 6, water inlet opening 55 is formed in a housing assembly 20, with a circumferential shoulder 607 protruding into internal space 51 of the housing assembly. The state of drip emitter 10 as shown in the figure illustrates its state upon and after the installation of elastomer component 40 within internal space 51 of housing assembly 20 and affixing cover component 30 unto circumferential bracket 59 of the housing assembly. This represents also the state of the drip emitter at the time that the water pressure prevailing in conduit 605 is lower than the pre-designed regulating pressure (for example — upon shutting off the water source). Under this condition, regulating membrane portion 87 is strained and biased against circumferential shoulder 607 of water inlet opening 55, thus forming a no drain valve resulting from the elastic resistance of the membrane portion.

In figure No. 6 one can discern additional structural aspects, some of them were referred to earlier, when referring to other figures. They are: an oval dent 88 unto which membrane portion 87 converges when it stretched, flow control and water outlet opening 63 that is connected to the flow passage from this opening to "outlet pool" 405 and from there - through groove 609 that has been formed at the wall of conduit 605 - unto the surface area intended to be irrigated, filter means

407 that filters the water entering the drip emitter through inlet opening 55, and the anchoring of elastomer component 40, in which the throttle means and the regulating membrane are formed, around the circumference of the component to cover component 30 and housing assembly 20. The circumferential anchoring prevents a shifting movement of the elastomer component from the walls of the housing assembly at the time the no drain valve is opened and the regulating action is in operation. Anchoring that in accordance with the illustrated example, is being executed by including protrusions 111 and 113 that are located on both sides of elastomer component 40, into the embedded grooves 115 and 117, and in the illustrated example, also by pressing the larger part of the surface area of the elastomer component as a "sandwich" between the housing assembly and the cover component in a manner that insures that the regulating membrane portion would be stresses to an essentially local stretching stress at the time of regulating.

The regulating action is carried out by drip emitter 10 (that is in accordance with the illustrated example) by means of stretching the regulating membrane portion towards the flow control and water outlet opening 63 that, in accordance with the illustrated example, is located opposite the center of the membrane, but any professional in this field would understand that also a drip emitter in which the flow control and water outlet opening is not located exactly and unconditionally facing the center of the membrane portion - a regulating action would anyhow be initiated (for example, locating the opening of the flow control and water outlet opening not facing the membrane portion but rather on the side if it).

To recapitulate - it was shown that a drip emitter in accordance with the present invention is relatively low priced for production (a natural derivative from the fact that it is assembled from only three parts), with concentrating the design and quality assurance in one component only — the elastomer component (wherein it is integrally formed with the throttle means as well). A drip emitter as per the invention prevents the passage of unwanted flow at the time the regulating action is active (as a consequence of the implementation of the circumferential anchoring of the elastomer component). The invention might be applied to drip emitters that

are intended for being installed inside a conduit undergoing an extrusion process while it is being extruded, while providing maximal protection to the delicate throttle means that is susceptible to the influence of the extrusion generated heat and imparting the capability to manufacture the elastomer component from materials that are relatively immune to heat damage (as a result from forming the throttle means as a part of the elastomer component which is not coming into direct contact with the extruded conduit).

A drip emitter in accordance with the invention might include also a no drain valve, as pointed out and cited above. It will be appreciated by persons who are skilled in the art, that the present invention is not limited by the drip emitter that has been particularly shown and described above. Rather, the scope of the present invention is only defined by the claims that follow.