WO2006030419A2

WO2006030419A2 - Dual component drip emitter and production means

Info

Publication number: WO2006030419A2
Application number: PCT/IL2005/000964
Authority: WO
Inventors: Zvika Einav
Original assignee: Plastro Irrigation Systems Ltd.
Priority date: 2004-09-13
Filing date: 2005-09-11
Publication date: 2006-03-23
Also published as: WO2006030419A3; IL164043A0; IL164043A

Abstract

The present invention relates to a dual component dripper that comprises an internal component that includes a labyrinth with a flow passage in it, and an external component that includes an exit pool formed at its outer wall surface, and wherein said dripper is characterized by said internal component is suited by its dimensions for being assembled into said external component, using a linear movement so that upon assembling said internal component inside said external component, said flow passage provided in said labyrinth will be connected and provide for a water flow passage leading into said exit pool.

Description

Dual Components Drip Emitter and its Production Means

Field of the Invention

This invention relates to the field of drip emitters in general, and in particular to the methods for manufacturing drip emitters suitable for being installed within a tube, while the tube is being manufactured, and the means used for manufacturing such drip emitters.

Background of the Invention

It is specifically noted that the present invention and its background are presented with reference to an application of agricultural irrigation using water, but any professional in the field would appreciate that the invention is not restricted solely to irrigation applications, and it can also be implemented in other applications, such as for example - for rinsing / flushing minerals, as well as for drip emitters that shed liquids that are not water.

Drip emitters for irrigation are in regular use and well known for agricultural irrigating by dripping water drops. A drip emitter might be described as a device that accepts water at a certain pressure. The dripper reduces the water pressure by passing the flow of the water through a mechanism that presents resistance to the flow, for example - driving the water flow through a flow passage formed with in labyrinth (maze) of sharpened barriers (herein after "baffles") positioned in the water flow path. The baffles' labyrinth interferes with the flow and reduces the water pressure. Thus, following the reduction of the pressure, the water exits the dripper in the form of drops.

An integral dripping tube is well known and recognized product in the field. We are talking about a tubular conduit into which - inline (during the process its manufacturing) - for example by an extruding process or as using a sheet and rolling it indo a tube, and into this tubular conduit, units of drip emitters are integrated - installed inside it along its length, at given distances one from the other. Dripper units might be cylindrical, and then they are secured to the inner wall of the tube along all their circumference area (see for example Eckstein's US

3,981,452 patent), or flat drippers in which case they are secured to the tube only along part of their circumference (as for example in Gorney et al's US 4,728,042 patent).

Accurate opening of the openings in the tube, exactly at the suitable positions - namely facing the outlets for the water formed at the drippers located along the length of the tube, completes the production of the integral tube. Thus, the water flowing in it is shed outwards at the suitable locations, providing the desired dripping droplets.

Processes and means for manufacturing integral drippers' tubes while extruding the tube, are also well known and recognized from days yore (see for example Mehoudar's US 5,022,940 patent). Naturally, the growing acceptance and widespread usage of the dripper's irrigation technology has led to strong competition between the diverse manufacturers that are forced to ensure high quality products at competitive prices.

Thus for example, quality wise, the drippers have to conform to severe standards regulating the uniformity of the water throughput exiting from them.

The drippers have to present high capability to withstand clogging that might be the result of various contamination items common in the water supply. In integral drippers' tube, the dripper body has to adhere strongly to the tubes inner surface.

In order to succeed in this competition and survive, manufacturers are forced to produce the drip emitters in essentially a fast and low priced process

(for example resorting to injecting the drippers bodies in multi cavity molds). The requirements for producing integral dripper tubes dictates fast in-line production of the tube simultaneously with installing the drippers' bodies while the tube undergoes its manufacturing process.

A model that was finalized by most manufacturers, implemented a manufacturing process by extruding the integral tube wherein the drippers installed into it are flat drippers. Each dripper is made of a single component, manufactured separately in an injection process, and formed with a labyrinth of sharpened (pointed) baffles. The drippers are installed one after the other inside the extruded tube during the run of the extruding process. In each of the dripper bodies, the baffle's labyrinth is led to direct flush contact with the inner wall of the tube, so that the inner surface of the tube is used for securing the labyrinth to it and forming a boundary encompassing the flow channel that is formed within the dripper.

In an integral dripping tube of this kind, securing the dripper body to the inner wall of the tube being extruded, is done by exerting force combined with exploiting the heat of the tube's extruded plastic material from which the tube is being manufactured, for heat welding the dripper - including the dripper's baffles labyrinth to the inner wall of the extruded tube, that - this is to be remembered, keeps moving all the time as part of its continuos production process.

An example for such integral dripping tubes can be found, for example, at the site of the applicant, at the address WWW.plastro .com (see there - for example, the product Hydrodrip Super).

A optimal design for reducing the water pressure, of the kind of a labyrinth of baffles planted in the flow path, dictates the forming of these barriers as narrow baffles, sharpened at their ends, a subterfuge that induces an increase of the water turbulence. Enhanced water turbulence prevents deposition of contamination particles hovering in the water, a deposition that might lead to clogging and blocking of the passages in the labyrinth. Creation of enhanced turbulence enables, in addition, to increase the dimensions of the flow passages in the labyrinth without suffering a reduction in the required throughput of the drippers. Verily, when the baffles of the labyrinth are thin and sharpened, it is very easy to attach them to the inner walls of the tube, due to the low heat capacity of the bonding area. On the other hand, excessive heat might immediately harm the thin pointed baffles of the labyrinth. Moreover, the integral dripping tubes production method based on attaching the pointed thin baffles labyrinth to the internal wall of the tube, has additional drawbacks, namely -

The thickness of the extruded tube influences the bonding process. The extruded tube might be of a very thin thickness (say 0.1 to 0.4 mm). When the wall of the extruded tube is very thin, a problem of lacking sufficient heat energy as required for achieving a good bond between the tube's material and the body of the dripper installed in it arises. The manufacture must then compensate for this heat deficiency by exerting increased pressure on the contact between the dripper's body and the wall of the continually moving wall of the tube. Excess pressure might result in a failure of the bonding. When the wall thickness of the extruded tube is relatively large, a problem of excess heat develops. Excess heat might lead to melting of the ends of the labyrinth's thin baffles.

Under these circumstances, due to the considerations of saving and lowering the production costs, the manufacturers do not design a specific dripper body to match a specific tube wall thickness, and as a inherent result - manufacturers market integral dripping tubes in accordance with the results actually obtained in the manufacturing process, due to the insertion of the same dripper body in different tubes of varying wall thickness. Thus, the same dripper body provides different throughputs when installed in tubes differing in their wall thickness.

Excess amounts of melted material might clog the flow passage in the labyrinth. The welding process of the drippers to the tube's wall is - as said - a process in which a combination of pressure and heat (whose source is the material of the tube being extruded) bonds the two together. The surface area of the dripper's body is brought to its melting point and fastened to the inner surface of the tube undergoing the extruding process's - that, as said, keeps advancing continually all the time. Naturally, such a process, that is based on the melting of materials, can not be considered as an accurate one nor given to exact calculations, and hence is prone to produce excess amounts of melted material. In a single component dripper formed with a pointed baffles labyrinth, it is the labyrinth that is brought to direct contact with the hot material of the tube that has just been extruded (and that moves all the time). This excess material slides into the designed flow passages between the baffles of the labyrinth. Accumulation of this excess material in the flow passage, reduces its dimensions and later might block contaminants found in the water, leading to their deposition on the labyrinth and clog the dripper entirely.

The need for expertise and experience in the integral-dripping tubes' production line is thus evident. As said, the manufacturers cope with the quality requirement specifying that the bodies of the drippers have to adhere strongly to the inner wall surface of the tube. Optimal welding of the dripper's body to the inner surface of the extruded tube would be the outcome of weighing a large number of variables - the thickness of the tube wall, the actual melting temperature, the length of the cooling bath (into which the tube is drawn after it was extruded), water temperature of this cooling bath, types of materials from which the dripper's body on the one hand and tube on the other hand were manufactured, the shape of the drippers' body, the pressure exerted for fastening the drippers to the tube inner surface, etc.

The proliferation of variables dictates the need for the production line workers to acquire experience and expertise, and limits the efficiency - it is not enough just to purchase a line ready for manufacturing integral dripping tube, rather - the line workers must be trained and acquire the needed high level expertise. Summary of the invention

According to one aspect, the present invention constitutes a dual component dripper, one that is suitable to function in an integral dripping tube. The dripper, a subject matter of the present invention, is suitable for being installed within a tube while it is being manufactured and features low sensitivity to the tube's production conditions. The dripper is suitable for mounting into tubes of different wall thickness, without its throughput being impaired. Integrating these drippers into the tube, does not require marked expertise nor experience. A dripper in accordance with the present invention comprises an internal component that includes a labyrinth with its flow passage in it and an external component that includes an exit pool formed at its outer wall. A dripper in accordance with the present invention is characterized by having its internal component adjusted through its dimension to be installed by a linear motion into its external component, so that when the internal component is coupled into (within) the external component, the flow passage in the labyrinth would be connected to a flow passage to the exit pool.

According to a second aspect, the present invention constitutes an integral dripping tube in which dual component drippers as defined above are installed. According to a third aspect, the present invention constitutes means for manufacturing the dual component dripper as cited earlier. The manufacturing means enables the assembly of the drippers already within the injection mold in which their components are produced side by side (hereinafter - "in tandem"), so that no extra costs results due to the dripper being a double components device (which might have required an advance assembly operation).

The means for manufacturing the drippers comprises an injection mold formed with at least one cavity meant for production by injection of the dripper two components in tandem (side by side). The mold includes, in addition, means for assembling the dripper two components one into the other by a linear movement whose direction is essentially perpendicular to that of the opening of the mold while the two components are still located in the cavity. In addition the mold includes means for extracting the already assembled dripper from the cavity.

According to a fourth aspect, the present invention constitutes a method for manufacturing dual component drippers as cited earlier, that includes the stages of forming the dripper's two components in tandem (side by side), by injecting the plastic into only one injection mold and assembling the two components of the dripper one unto the other, in a linear movement carried out in a direction that is essentially perpendicular to the direction of opening the injection mold while the two components are in the injection mold and finally - extracting the already assembled dripper from within the injection mold.

Brief Description of the Drawings

The present invention will be better understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings, in which:

Drawing No. 1 presents an exploded view of an example of a preferred embodiment of a dual component dripper in accordance with the invention.

Drawing No. 2 constitutes a perspective view of the example dual component dripper whose components are illustrated in drawing No. 1, in the assembled state. Drawing No. 3 constitutes a cross section perspective view of the example dual component dripper whose components are illustrated in drawing No. 2.

Drawing No. 4 constitutes a cross section perspective view of an integral dripping tube in which dual component drippers of the type illustrated in drawings No. 1 to 3 were installed. Drawings No. 5 constitutes a schematic illustration of an injection mold suitable for manufacturing the dual component dripper illustrated in drawings No. l to 3.

Drawing numbers No. 6 to 13 constitute schematic illustrations of the different manufacturing stages of the dripper components illustrated in drawings No. 1 to 3 - their assembly one to another, wherein all is accomplished in a mold of the type illustrated in drawing No. 5, and finally the extraction of the already assembled dual component emitter from within the mold. Detailed Description of Preferred Embodiment

Let's refer to drawings No. 1 to 3. The drawings depict first an exploded view of an example of a dual component dripper 10 in accordance with the invention, a perspective view of an assembled dual component dripper 10 and a cross section perspective view of an assembled dual component dripper 10.

Dual component dripper (herein after "dripper") 10 is assembled from two components - an internal component 20 and an external component 30. Internal component 20 is formed in the shape of a semi rectangular surface. Two water inlets 41 and 42 are formed on the component. Each of these inlets includes an input filters 43 and 44, respectively. Each of these water inlets (41, 42) enables passage of water through it into passage 45. Passage 45 is formed inside baffles labyrinth 47. Passage 45 leads to transit pool 49. External component 30 is formed as a semi hollow profile whose cross section is rectangular. On the external wall surface 52 of external component 30 and nearly along the entire length dimension of the component, an exit pool 54 is formed. A thin protruding shoulder 56 binds it. The dimensions of internal component 20 are adapted for assembly in a linear motion in the direction of arrow 60 to the inside (within) external component 30.

Dual component dripper 10 that is illustrated as an example in drawings No. 1 to 3, is formed - as said, with an internal component 20 whose shape is like a semi rectangular surface, while external component 30 is formed as a rectangular hollow profile. However, Any professional in this field would understand that it is possible to design a similar dual component dripper whose shape of the components is different. For example, one in which the cross section of the external component is not rectangular (and hence also the cross section of the internal component which would be inserted and included in it), or formed in the shape of a hollow profile that is not closed at its bottom. Referring to drawings No. 2 and No. 3 - On assembling internal component 20 to within external component 30, opening 62 that is formed in external component 30 is located above transit pool 49 which is formed as said in internal component 20. In other words, on assembling the internal component 20 inside external component 30, the flow passage 45 existing in the pointed baffles labyrinth 47 is linked to the water flow passage of the exit pool 54 formed in external component 30.

External component 30 of dripper 10 is formed with an internal wall 70 (see drawing No. 3), so that upon assembling internal component 20 inside external component 30, inner wall surface 70 of external component 30 bounds the flow passage 45 located in labyrinth 47. In other words, the pointed baffles labyrinth 47 is actually in direct contact with the inner wall 70 of external component 30. Any professional in this field would understand that upon assembling dripper 10, passage 45 constitutes the damping mechanism of dripper 10 whose function is to reduce the water pressure.

Referring to No. 4, Drawing No. 4 constitutes a cross section view of a typical portion of an integral dripping tube 410. The dripping tube includes a tubular conduit 412 in which dual component drippers 10 were installed (two of them are shown in the drawing and designated 10' and 10", respectively). The drippers are located along the length of tubular conduit 412 wherein they are fastened flush in part of their circumference to its inner wall surface 414.

Any professional experienced in this field would understand that drawing

No. 4 constitutes, as said, just a typical section of an integral dripping tube. An integral dripping tube comprises many drippers that are installed in it at the time the tube is being manufactured - "in line" -located at a selected distance one from each other.

The installation ("planting") of drippers 10 inside tubular conduit 412 and the operation of fastening them unto its internal wall surfaces 414, might be executed in a continuous process in the course of manufacturing the tubular conduit 412 (e.g. - manufacturing the conduit by extrusion). For example - while applying common and known methods and means already in use for manufacturing integral dripping tubes (see for example - Mehoudar's US 5,022,940 patent). In an integral dripping tube, in which the drippers are integrated in the course of its manufacturing using the extruding technique, dripper 10 is led to contact with the inner wall surface 414 of the tube, wherein protruding shoulder 56 formed in external component 30 of the dripper is the one fastened to the internal wall surface of the tube. Any professional in this field would understand that in order to facilitate the geometrical match between the body of dripper 10 to the profile of the tubular conduit 412, it is possible to form protruding shoulder 56 with an arched cross section configuration in a manner that it would suit - considering the geometrical aspect — to the cross section profile of tubular conduit 412. During operation, water under pressure driven to flow through tubular conduit 412, enters dripper 10 via two water inlets 41 and 42 (see drawings numbered 1 to 3). The water flow is directed into water passage 45 formed in the dripper's pointed baffles labyrinth 47. Passage 45 constitutes the damping mechanism of dripper 10 and reduces the pressure of the water flowing through it. The water, whose pressure diminished as said in its passage between the baffles of the labyrinth, continues towards passage pool 49 and from there, via opening 62, to exit pool 54. Fastening the body of dripper 10 to the inner wall surface 414 of tubular conduit 412 bounded the exit pool 54 producing a closed cavity 416. From exit pool 54, water - whose pressure was reduced as said, is shed outwards, via an elongated slit 418 that was formed in the wall of tubular conduit 412 - opposite exit pool 54.

Any professional in this field will appreciate that in distinction from the model that was materialized by the majority of manufacturers, and to which we pointed in the "Background of the Invention" section above, in an integral dripping tube as in accordance with the present invention, the pointed baffles labyrinth is not led to direct contact with the heated material of the tube, and hence the inner surface areas of the tube are not exploited for securing the labyrinth to the wall nor for bounding the flow channel within the dripper.

As explained above when referring to drawings No. 1 to No. 3, internal wall 70 (see drawing 3) of external component 30 is the one that defined flow passage 45 of labyrinth 47, and thus the dripper's pointed baffles labyrinth 47 is not fastened to the flow of the hot material from which tubular conduit 412 is formed.

An additional characteristic of an integral dripping tube in accordance with the invention is - that for the length dimension of the tube, high accuracy is not required when forming the openings in the tube to be opposite the water exits from the drippers. As was explained earlier, when referring to drawings No. 1 to No. 3, exit pool 54 (formed on the external wall 52 of external component 30), extends nearly along the entire length of the component's length dimension, a factor that facilitates the opening of the water exit opening from the tube (for example, see the configuration of the elongated slit 418 in drawing No. 4), and this, as said - without being compelled to provide special accuracy.

Professional experienced in this field would rightly appreciate the advantages embodied by these characteristics of the invention, namely - that the baffles of the labyrinth do not have to be driven to direct contact with the flow of the hot material from which the extruded tube is made, and the essentially large area that the body of the dripper presents from the aspect of accuracy requirements regarding the forming of outlet openings in the tube.

Clearly, not having to expose the labyrinth's baffles to direct contact with the flow of the tube being extruded, reduces the production problems pointed by us in the 'Background of the Invention' section above. The size of the exit pool enables to alleviate the accuracy requirements for the formation of the outlet holes in the tube along the length dimension, as well as - enables implementation of an exit opening in an elongated slit configuration (one or more), as is recommended, e. g., for the application of using integral dripping tubes when intended to be buried in the ground.

A dual element component dripper 10 - being by definition a bi- component device, requires preliminary assembling operation of the internal component 20 into the inside of external component 30. In order to cut the costs that - obviously, are linked to the necessary task of assembling the drippers before ""planting" (inserting) them in the tube, the present invention includes also means for manufacturing the dual component drippers referred to in the application. This means enables automatic assembly of the drippers, already when they are still inside the mold at which their components are manufactured. Drawing No. 5 constitutes a schematic illustration of an injection mold 510 suitable for manufacturing the dual component dripper 10, illustrated in drawings No. l to 3.

Injection mold 510 comprises, as normally accepted, two assemblies - 520 and 530, that might be brought together one to the other and separated one from the other in the directions of arrow 540 (see drawing No. 5). Any professional in this field would understand that the directions of coupling (closing) and opening (de-coupling) of the injection mold (as illustrated by arrow 540) is essentially perpendicular to the contact surface areas of the two assemblies.

Assembly 520, which is the moveble side of the injection mold, is formed with a cavity 550 for manufacturing by injection the two components of dripper

10 - internal component 20 and external component 30 in tandem (side by side), in a manner that will be elaborated upon below - when referring to the drawings numbered 6 to 13. Accordingly, assembly 530, which is the static side of the injection mold, is formed with the suitable designating protruding entities 562 and 564 for forming the surface contours of internal component 20 (see for example drawings numbered 1 to 3 - the configuration of the pointed baffles labyrinth 47 and transit pool 49), as well as the surface areas of the external component 30 (for example see there - opening 62, exit pool 54).

Injection mold 510 includes, in addition, assembling means 570 for assembling - one into the other - the two components of the dripper 10, namely 20 and 30 (internal and external, respectively, the components are not illustrated). The discussion explaining the structure and the operation mode of assembling means 570 would be presented in detail later, when referring to drawings number 6 to 13. Injection mold 510 includes in addition means 580 (it is veiled in the drawing, hence presented by a broken line) for extracting the assembled dripper 10 from within cavity 550.

At this stage it will be sufficient to indicate that in the illustrated example, assembling of the two dripper components 20 and 30 one into the other, is accomplished by a linear movement of the internal component 20 in the direction of arrow 575 - into the external component 30 that remains at its position. The direction is essentially perpendicular to that of the direction of opening mold 510 as shown by arrow 540. An additional feature is that the assembly of the two components one into the other, is accomplished while the two components are still in cavity 550.

Any professional in this field would understand that a mold as the shown mold 510, might include a large number of cavities (i. e., it might be a multi cavity mold). Accordingly, the mold would also include a suitable number of means for assembling drippers in each of the cavities and for extracting the assembled ones from every one of them. Subject to this aspect it is to be stressed that injection mold 510 is only illustrated schematically in drawing No. 5, being solely an example presented for providing a principled explanation of the mode of operation of the means for manufacturing the dual component dripper.

In addition, any professional in this field would understand that in another configuration yet still being in accordance with the present invention, assembling the two dripper's components 20 and 30 one inside the other, might as well be accomplished by a linear movements of both components together. A dynamic movement in which both external component 30 and internal component 20 will participate in moving one towards the other, or using a different mold configuration which continues to be in accordance with the invention - by a linear movement of external component 30 (in a direction opposed to that of arrow 575) towards internal component 20 that would be held fixed at its position.

Any professional experienced in this field would also understand that mold

510 comprises means (that are not illustrated) for directing and driving the raw material injected into cavity 550 as common in injection molds techniques. For example, a "hot runner" for transporting molten raw material under pressure through a "gate" -one or more, into the cavity.

Similarly, and aided by several means for "piloting" (directing) raw material as stated above, wherein in each one of them a different kind of raw material flows, injection mold 510 might serve for manufacturing the internal and external components of the dripper, from raw materials that are different one from the other. For example, the raw material used to manufacture the internal component might be of the polypropylene type, whereas the raw material used to manufacture the external component would be of the polyethylene type - similar to the raw material commonly used for extruding the tubular conduit in which the drippers are installed (in a manner that facilitates the task of bonding the drippers' body to the internal tube wall, because the materials in contact are identical).

Let's refer to drawings numbers 6 to 13. These drawings constitute schematic illustrations of the manufacturing stages of the components of dripper 10, the one illustrated in drawings No. 1 to 3 - their assembly one to another, wherein all is accomplished within mold 510 of the type illustrated in drawing No. 5, and finally the extraction of the already assembled dripper 10 from within mold 510.

The moveble assembly 520 of mold 510 is illustrated in drawing No. 6. The illustration presents the state immediately following the injection of the drippers components 20 and 30 in tandem. The assembling means 570 serves to assemble the two dripper's components one unto the other, including Plunger 610 movable in the direction of arrow 620. Plunger's assembly 610 is formed with pin 630. Pin 630 is in contact with one end 640 of internal component 20 (that has just been formed by injection). Assembling means 570 includes in addition, a support means 650 that is movable in the direction of arrow 670 (the directions of arrows 620, 670 and arrow 575 depicted in drawing No. 5 are all in the same direction, and it is essentially perpendicular to the direction of opening injection mold 510). Support assembly 650 is formed with pin 660. Around pin 660 an external component 30 was injected. Pin 660 is in contact with a second end 680 of internal component 20.

Drawing No. 7 depicts extractor means 580 for removing dripper 10 from within cavity 550 immediately after its assembly (in a manner to be elaborated upon when referring to drawings number 8 to number 13). In the illustrated example - reference is made to 4 mobile pins, numbered 710, 720, 730 and 740, respectively.

Drawing No. 8 illustrates assembling means 570. Assembling means 570 serves to assemble the two dripper's components, 20 and 30, together (one to the other) during the process of inserting internal component 20 into external component 30.

The insertion of internal component 20 into external component 30, as it happens immediately following the forming of the components by injection, might require some support means for internal component 20, to avoid its collapse or deformation. Hence, in the illustrated example - Plunger assembly 610 pushes - by pin 630, the internal component 20 into the external component 30 (in the direction of arrow 620). Simultaneously, support means 650 withdraws (in the direction of arrow 670), while it supports (by pin 660) during the entire retreating action, internal component 20 at its end 680 - see drawing No. 6. End 680 is the end that leads the linear movement of internal component 20 into the space within external component 30. This being performed wherein the velocity at which pin 660 retreats essentially equals that of the advancing pin 630. Thus, internal component 20 is pushed at the end of one side and supported at its other end during all the process of being inserted in external component 30.

Any professional in this field would understand that simultaneously, care has to be taken to ensure that external component 30 would not shift from its location (for example, preventing its movement with a stop in the direction of the internal component's movement, aided by an under cut formation formed in the intended direction of extracting the dripper following its assembly).

In drawings No. 9 and No. 10, an additional and different preferred configuration of means for assembling the dripper's two components one into the other is illustrated. In this configuration, and similarly to the previous presented one, the internal component 20 of the dripper is pushed at one end, but - and this is in difference from the previous one, simultaneously, the inner component of the dripper is being pulled at its other end (and not only supported as in the previous configuration), during the entire duration of the operation while being inserted into the external component.

In drawing No. 9 the illustration depicts assembling means 910 immediately after the termination of the injection of the two components in tandem. The external component of the dripper is identical to the external component 30 of dripper 10 as it was described when referring to previous drawings. However, the internal component 920 of the dripper illustrated in drawings No. 9 and No. 10 is different from internal component 20 by being formed with an end that will be leading, later, its linear movement into external component 30, with an addition of bracket means 930. Applying supporting assembly 940, bracket means 930 enables to pull internal component 920 into external component 30. Pin 950 of supporting assembly 940 is formed at its end with anchoring means 960 that is connected to bracket 930 in such a manner that enables to pull internal component 920.

Drawing No. 10 constitutes a close up view of the method of performing the connection between bracket means 930 and anchoring means 940. In the illustrated example, bracket means 930 is formed by injection in the shape of a trapezoidal end 970, while anchoring means 940 is formed at the end of pin 950, as two teeth 980 and 990 respectively, that encircle the trapezoidal end 970.

In this variant configuration, inserting internal component 920 into external component 30 is performed when - similarly to the former configuration, the plunger assembly 610 pushes with a pin the internal component 920 into external component 30. Simultaneously, support assembly 940 retreats, while it pulls internal component 920 (not only supports it) at a velocity that is essentially equal to that of the pushing action and in the direction of the push. At the termination of the insertion of internal component 920 into external component 30, the addition that characterizes the configuration of internal component 920, namely - bracket means 930, protrudes outwards from external component 30. Thus, a separation of the assembled dripper from anchoring means 960 is enabled. This is accomplished by removing the dripper by an extracting movement in a direction essentially perpendicular to the pulling direction, using the extracting means made to extract the already assembled dripper from the mold cavity. The operation of the extracting means would be described in detail when referring to drawings No. 11 to No. 13. Any professional in this field would understand that the specific configurations of the bracket means and the anchoring means that were described above (trapezoidal end that is encircled by two teeth), are merely an example, and it is possible to form such means that would enable to pull the internal component into the external component, also in many different shapes.

Drawings No. 11 to 13 show the extraction of the already assembled dripper 10 from within cavity 550. At this stage, the pushing of internal component 20 into the inside of external component 30 by plunger assembly 610 while aided by supporting the internal component 20 with support assembly 650, was terminated. Now, extracting means 580 for removing dripper 10 from within cavity 550 enters into operation, and - in the illustrated example, four mobile pins

- 710, 7120, 730 and 740, respectfully, extract the assembled dripper from the cavity. Any professional in this field would appreciate that in the method of manufacturing and assembling dripper 10 as described above, there is actually embodied an innovative general method for manufacturing of a dual component dripper (such as dripper 10 or a similar one).

This general method includes the stages of - forming the two dripper components in tandem by injecting plastic material into a single injection mold, assembling the two components of the dripper - one into the other, by a linear movement in a direction essentially perpendicular to the direction of opening of the injection mold and while the two components are still in the mold, and finally

- extracting the already assembled dripper from the cavity. It will be appreciated by persons who are skilled in the art, that the present invention is not limited by what has been particularly shown and described above. Rather, the scope of the present invention is only defined by the claims which follow.

Claims

1. A dual component dripper that comprises - an internal component that includes a labyrinth with a flow passage in it, and an external component that includes an exit pool formed at its outer wall surface, and wherein said dripper is characterized by -

said internal component is suited by its dimensions for being assembled into said external component, using a linear movement so that upon assembling said internal component inside said external component, said flow passage provided in said labyrinth will be connected and provide for a water flow passage leading into said exit pool.

2. A dual component dripper in accordance with claim No. 1, wherein - said internal component is formed essentially as a rectangular surface, and said external component is formed essentially as a hollow rectangular profile, with an internal wall surface, such that - on assembling said internal component inside said external component, said internal wall surface of said external component bounds said flow passage within said labyrinth situated in said internal component.

3. A dual component dripper in accordance with claim No. 2, wherein - said external wall surface of said external component in which said exit pool is formed, is adapted by its design to be fastened to an inner surface area of a tubular conduit, in a manner such that opening a passage in the wall of said tubular conduit will connect said exit pool to a flow passage leading to the outside of said tubular conduit.

4. A dual component dripper in accordance with claim No. 2, wherein - said internal component comprises in addition - at least one water inlet formed at one end of its surface and is connected to a water flow passage from it to a water flow passage in said labyrinth, and a transit pool connected to water passage into it from said flow passage formed in said labyrinth, and when - upon assembling said internal component within said external component, said exit pool in said external component is connected to a water flow passage leading to it from said transit pool formed in said internal component.

5. A dual component dripper in accordance with claim No. 2, wherein - said internal component, at its one end that leads its linear motion into said external component, is formed in addition with - a bracket means that is amenable to be anchored to an anchoring means that enables to pull said internal component, and wherein upon assembling said internal component inside said external component, said bracket component protrudes from said external component.

6. A dual component in accordance with claim No. 5, wherein - said bracket means is formed in the shape of a trapezoidal end.

7. An integral dripping tube that comprises - a tubular conduit formed with internal surface area, and plurality of dual component drippers of the type defined in claim No. 1 are located along the length of said tubular conduit, wherein they are fastened flush to said inner surfaces of said tubular conduit, at least in parts of their circumference.

8. Means for manufacturing a dual component dripper of the type defined in claim No. 1, that comprises - an injection mold that comprises - at least one cavity intended for manufacturing by injection said two components of the dripper in tandem, and

assembling means for assembling said two dripper's components one to the other, by a linear motion which is essentially perpendicular to the direction of opening of said mold and at the time said two components are still in said cavity, and

extracting means for extracting said assembled dripper from within said cavity.

9. Means for manufacturing a dual component dripper in accordance with claim No. 8, wherein - said mold includes in addition - means for directing (leading) raw materials for manufacturing said internal and external components of said dripper.

10. Means for manufacturing a dual component dripper in accordance with claim No. 9, wherein - said raw materials serving for manufacturing said internal and external components of said dripper are different one from the other.

11. Means for manufacturing a dual component dripper in accordance with claim No. 10, wherein -

polypropylene is a raw material used for manufacturing said internal component.

12. Means for manufacturing a dual component dripper in accordance with claim No. 10, wherein - polyethylene is a raw material used for manufacturing said internal component.

13. Means for manufacturing a dual component dripper in accordance with claim No. 8, wherein - by said linear motion, said means for assembling said two dripper components one to the other inserts said dripper's internal component into said dipper's external component.

14. Means for manufacturing a dual component dripper in accordance with claim No. 13, wherein - said means for assembling said two dripper's component one to the other, includes - a plunger assembly for pushing said dripper's internal component into said dripper's external component, and support assembly for supporting said dripper's internal component at one of its ends, that leads its linear motion into said external component, simultaneously with it being pushed at its other end by said plunger assembly, at a velocity that is essentially equal to said pushing velocity and in said pushing direction.

15. Means for manufacturing a dual component dripper in accordance with claim No. 14, wherein - said support assembly also pulls said dripper's internal component into said dripper's external component, simultaneously with pushing it by said plunger assembly, at a velocity that is essentially equal to said pushing velocity and in said pushing direction.

16. Means for manufacturing a dual component dripper in accordance with claim No. 15, wherein - said support assembly includes - anchoring means anchorable to bracket means formed at an end of said dripper's internal component, for pulling said dripper's internal component into said dripper's external component.

17. Means for manufacturing a dual component dripper in accordance with claim No. 16, wherein - said anchoring means includes at least one tooth formed in a manner that enables extracting the assembled dripper in a direction essentially perpendicular to its pulling direction.

18. A method for manufacturing a dual component dripper of the type defined in claim No. 1, that includes the steps of - forming the two dripper's components in tandem, by injecting plastic material into a single injection mold, and assembling said two dripper's components one to the other, by a linear movement whose direction is essentially perpendicular to that of said mold's opening and while the two components are still found in the mold, and extracting the assembled dripper from within said injection mold.