IL119447A - Regulated flow restrictor device particularly useful as a drip irrigation emitter - Google Patents

Description

ηΊοοοϋ ηκ νί d*it ΪΙ Ϊ Ά ntm REGULATED FLOW RESTRICTOR DEVICE PARTICULARLY USEFUL AS A DRIP IRRIGATION EMITTER REGULATED FLOW RESTRICTOR DEVICE PARTICULARLY USEFUL AS A DRIP IRRIGATION EMITTER The present application is a division of Israel Patent Application No. 110062 filed June 20, 1994.

Israel Application 110062 filed June 20, 1994 describes a number of regulated flow restrictor devices particularly useful as drip irrigation emitters. The regulated flow restrictor devices described in that Patent Application include a flow-regulating passageway defined by first and second opposed walls having an inlet end connectable to a source of pressurized fluid, an outlet end for outletting the fluid, and a plurality of baffles extending transversly of, and longitudinally spaced between, the first and second passageway walls to define a labyrinth imposing a resistance to the flow of the fluid through the passageway in order to restrict the flow therethrough from the inlet end to the outlet end; one of the passageway walls being exposed to the pressure of the source of pressurized fluid and being displaceable, in response thereto, towards and away from the other passageway wall; the baffles defining, with the passageway walls, clearances which, by the displacement of the displaceable passageway wall, are sequentially closed with increasing pressure at the passageway inlet end to maintain a substantially uniform flow to and through the passageway outlet end despite variations in the pressure of the source of pressurized fluid.

According to the invention of this divisional application, there is provided a regulated flow restrictor device for assembly in a water conducting tube to be used as a drip irrigation emitter, comprising: a cylindrical housing to be secured within the tube; and an elastomeric membrane secured to a face of the cylindrical housing such as to define with the face a flow control passageway having an inlet to communicate with the interior of the tube, and an outlet to communicate with an outlet opening through the tube, with the opposite face of the elastomeric membrane subject to the water pressure within the tube such that the membrane is deflected towards and away from the face of the cylindrical housing to vary the flow control passageway in response to variations in the water pressure within the tube; characterized in that the elastomeric membrane is secured to the outer face of the cylindrical housing to define the flow control passageway therewith.

According to further features in the described preferred embodiments, the cylindrical housing is formed with a plurality of narrow slits therethrough for conducting the water to the flow control passageway.

Further features of the invention in this divisional application will be apparent from the description below.

The invention of the present application is herein described, by way of example only, with reference to the accompanying drawings, wherein: Fig. 1 is a longitudinal sectional view illustrating another drip irrigation emitter, corresponding to Fig. 14 of Parent Application 110062, and constructed in accordance with the invention of this divisional application; Figs. 1a and 1b are sectional views along lines 1a and 1b of Fig. 1 ; Fig. 2 is a sectional view illustrating a still further form of drip irrigation emitter, corresponding to Fig. 23 of Parent Application 110062, and constructed in accordance with the invention of this divisional application; Figs. 3, 4 and 5 are plan views, at three different 90° positions, illustrating only the emitter housing in the emitter unit of Fig. 2; Figs. 4a, 4b and 4c are sectional views along lines 4a, 4b and 4c of Fig. 4, respectively; Figs. 6a, 6b and 6c are sectional views illustrating- a -reverse/clearance arrangement of the regulating baffles under no-pressure, low-pressure and high-pressure conditions, respectively; Figs. 7, 8 and 9 are plan views at three different 90° positions, illustrating only, the emitter housing in an emitter unit including the reverse arrangement of baffles of Figs. 6a-6c; and Figs. 8a, 8b and 8c are sectional views along lines 8a—8a, 8b—8b and 8c--8c in Fig. 8.

Fig. 1 illustrates a construction similar to that of Figs. 10-13 of Parent Application 110062, except that the emitter unit ©at, housing 320 is made of rigid material and cooperates with an elastomeric membrane 331 to define the labyrinth between the inlet opening 323 communicating with the inlet pressure, and the outlet/ includes a diametrically-extending tube 324a and an annular chamber 324b communicating with two outlet openings 322 in the water supply tube 321. In the construction illustrated in Fig. 1, the baffles 328 are of equal ·¾Κ3.οκηοαβ. to define a labyrinth 333 of fixed resistance to flow, whereas the baffles 329 are of decreasing usmui is to form the clearances 335 of increasing heights in the direction of the outlet 324, and thereby to define a labyrinth 334 having a pressure-variable resistance to flow. The arrangement is such that an increase in the inlet pressure, which is applied to the outer surface of the rubber membrane 331 , deflects that membrane to successively close these -clearances, and thereby- to — successively cause the baffles 329 to change the resistance to flow through labyrinth 334 in the same manner as described above.

In the emitter unit illustrated -in Figs. 2-5, the outer surface of the cylindrical housing/ is formed with both groups of baffles, therein designated 728 (Fig. 3) and 729 (Fig. 4), respectively. Baffles 729 are covered by the elastomeric membrane 731 which is secured in place by an external cap 732. The cylindrical further formed with a large number of narrow slits 734 which conduct the water from the interior of the housing to its external surface and then to the non-regulating baffles 728. From there, the water flows via a throughgoing hole 723 to the flow-regulating baffles 729 and the inner surface of membrane 731. The water then flows through an outlet opening 724 back to the outer surface of housing 720 to annular recesses 724a, 724b on opposite sides of the housing in alignment with outlet openings 722 formed in the tube 721.

Figs. 6a-6c are views corresponding to Fig. 2, and Figs. 7, 8 and 9 are views corresponding to Figs. 3, 4 and 5, respectively, illustrating a further variation wherein the clearances, therein designated 835, defined by the Flow-regulating baffles 829 and membrane 831 , are reversely arranged; that is, they are of increasing height in the direction from the housing inlet opening 823 towards the -housing-outlet opening-824 (opposite to the arrangement-of— Figs. 2-5). Baffles 829 are of the same thipknc-sG-, but are formed in a slanted surface of the emitter unit and thereby produce, with membrane 831, the clearances of increasing height. These clearances are also sequentially closed with increasing pressure of the water within maintain a substantially uniform flow to and through the housing outlet opening 824.

Fig. 6a illustrates the position of the membrane 831 when the water within the housing is not pressurized, wherein it will be seen that the clearances 835 between baffles 829 and membrane *831 are of the largest height adjacent to the inlet 823 to this labyrinth and decrease in height towards the outlet 824. Fig. 6b illustrates the condition where the water within the housing 820 is under low pressure, whereupon it will be seen that the clearances adjacent the outlet 824 begin to close; and Fig. 6c illustrates the condition where the water within the housing is under high pressure, wherein it will be seen that the membrane 831 sequentially closes more of these clearances from the housing outlet towards the housing inlet.

The arrangements illustrated in Figs. 2-9 produce a number of important advantages .

Thus, providing thr mrmhrnnn RT1 , nnrl the flow-regulating labyrinth defined by baffles 729, 829, and the membrane 731, 831, on the outer surface of the housing 720, 820, enables a larger surface area of the housing to: be used "for the slits"~(734~ 834) "and" the fixed labyrinth - 828. In addition, this arrangement more securely holds the membrane 731, 831 in place over the flow-regulating baffles 729, 829. Further, the reverse arrangement of clearances illustrated in Figs. 6a-6c defined by. the flow-regulating baffles 829 also enables the emitter to be used under lower line pressures, produces a self-regulation in response to variations in the water pressure, and also produces a better cleaning action in the event of clogging. When this reverse-clearance arrangement is used, the flow rate may be reset to a new value by changing the fixed resistance provided by the non-regulating baffles (828), and the flow rate will remain relatively constant even with variations in the line pressure.

- While the invention has been described with respect to preferred embodiments, it will be appreciated that these are set forth merely for purposes of example, and that many other variations, modifications and applications of the invention may be made.

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Claims (10)

1. A regulated flow restrictor device for assembly in a water conducting tube to be used as a drip irrigation emitter, comprising: 3>2 a cylindrical housing to be secured within said and an elastomeric membrane secured to a face of with said face a communicate with communicate with an outlet opening through the tube, with the opposite face of the elastomeric membrane subject to the water pressure within the tube such that the membrane is deflected towards and away from said face of the cylindrical housing to vary the flow control passageway in response to variations in the water pressure within the tube; characterized in that said elastomeric membrane is secured to the outer face of said cylindrical housing to define said flow control passageway therewith.

2. The device according to Claim 34, wherein said cylindrical housing is formed with a plurality of narrow slits therethrough for conducting the water to said flow control passageway.

3. The device according to either of Claims 1 or 2, wherein said flow control passageway includes a plurality of baffles formed on the outer face of the cylindrical housing and defining, with the elastomeric membrane, a plurality of clearances which vary the resistance of the flow of the water through said passageway in response to variations in the pressure of the water within the tube; said clearances being sequentially closed with increasing pressure at the housing inlet to maintain a substantially uniform flow to and through the housing outlet in response to variations in the pressure of the water within said tube".

4. The device according to Claim 3, wherein said clearances are of increasing height in the direction from said housing inlet towards said housing outlet.

5. The device according to Claim 5, wherein said clearances are of increasing height in the direction from said housing outlet towards said housing inlet.

6. - 6. A drip irrigation emitter, comprising: a cylindrical tube for conducting water therethrough ; a plurality of cylindrical housings secured within the tube at longitudinally-spaced locations thereof; and an elastomeric membrane secured to a face of each cylindrical housing such as to define with said face a flow control passageway having an inlet communicating with the interior of the tube, and an outlet communicating with an outlet opening through the tube, the opposite face of the elastomeric membrane being subject to the water pressure within the tube whereby the membrane is deflected towards and away from said face of the cylindrical housing to vary the flow control passageway in response to variations in the water pressure within the tube; characterized in that each of said elastomeric membranes is secured to the outer face of its respective cylindrical housing to define said flow control passageway therewith.

7. The emitter according to Claim 6, wherein said cylindrical housing is formed with a plurality of narrow slits therethrough for conducting the water to said flow control passageway.

8. The emitter according to either of Claims 6 or 7, wherein said flow control passageway includes a plurality of baffles formed on the outer face of the cylindrical housing and defining, with the inner face of the elastomeric membrane, a plurality of clearances which vary the resistance of the flow of the water through said passageway in response to variations in the pressure of the water within the tube; said clearances being sequentially closed with increasing pressure at the housing inlet to maintain a substantially uniform flow to and through the housing outlet in response to variations in the pressure of the water- within said tube ; -;—

9. The emitter according to Claim 8, wherein said clearances are of increasing height in the direction from said housing inlet towards said housing outlet.

10. The emitter according to Claim 8, wherein said clearances are of increasing height in the direction from said housing outlet towards said housing inlet. y Tel-Aviv 61 230