DRIP IRRIGATION DEVICE

Description

Patent Consulting Studio srl Giuseppe Bianchetti and others 4017 M Description of the industrial invention entitled: FM / rt “DRIP IRRIGATION DEVICE in the name of: NAAN IRRIGATION SYSTEMS MI 93 A / 00367 February 5, 1993 The present invention relates to drip irrigation emitters. There are several types of drip irrigation emitters known. The following list of the applicant's patents is an example of the development of drip irrigation technology: U.S. Patent 4,423,838; U.S. Patent 4,519,546; U.S. Patent 4,540,125; U.S. Patent 4,655,397; U.S. Patent 4,728,042; U.S. Patent 4,687,143. Recently, pressure compensated drip irrigation emitters have become widely used because they allow generally uniform irrigation outputs despite certain variations in inlet pressure Ί and thus expand the variety of applications of such emitters. Conventional pressure-compensated drip irrigation emitters are capable of providing acceptable output uniformity over a limited range of inlet pressures. This limitation greatly limits the application possibilities available for these emitters. The present invention provides an improved emitter for pressure compensated drip irrigation. - 3 - Patent Consulting Studio srl Giuseppe Bianchetti and others The present invention provides a pressure compensated dripper capable of providing an output quantity that has acceptable uniformity over a significantly greater range of inlet pressures than prior art pressure compensated drippers. There is therefore provided in accordance with a preferred embodiment of the present invention a drip irrigation device which includes a housing, a water inlet and a water outlet and a water flow path extending therebetween which is defined in the housing, and a pressure-sensitive membrane disposed within the housing and arranged to regulate the flow of water and wherein the orientation of the pressure-sensitive membrane is responsive to the pressure of water pressing on the membrane at a plurality of different mutually spaced points on the membrane. Furthermore, in accordance with a preferred embodiment of the invention, at the plurality of different mutually spaced points on the membrane, water communicates with different mutually spaced points along the water flow path and is at different pressures. According to a further preferred embodiment of the invention, the membrane has two main positions, a first position in which the membrane seals the ingress of water and a second position in which the membrane modulates the amount of water flowing through the water flow path. Patent Consulting Studio srl Giuseppe Bianchetti and others Still in accordance with a preferred embodiment of the invention, when the membrane is in its second position, i.e. during the normal dripping function, the precise orientation of the membrane and thus its modulation of the amount of water flowing is effected by the buoyancy of the water on the membrane at at least two different mutually spaced points on the membrane. In accordance with a preferred embodiment of the invention, the drip irrigation device is capable of providing flow uniformity of approximately 10% over a pressure range of 1-8 atmospheres. The present invention will be more fully described by the following detailed description with reference to the drawings in which: Figures 1A and 1B are exploded side and sectional views, respectively, of a drip irrigation emitter constructed and operating in accordance with a preferred embodiment of the invention; Figure 1C is an illustration of part of the dispenser of Figure 1A, rotated 180° about its general axis of symmetry; Figures 2A and 2B are side and sectional views, respectively, of the drip irrigation emitter of Figures LA - 1C; Figures 2C and 2D are partial sectional views of the drip irrigation emitter of Figures 1A - 2B in orientations rotated relative to each other by 180° about the general axis of symmetry of the emitter; Figure 2E is a partial cross-sectional view of part of the dispenser- 5 - Studio Consulenza Brevettuale srl Bianchetti Giuseppe and others tore of Figures 1A - 2D in the orientation illustrated in Figure 2D; Figures 3A, 3B, 3C, and 3D are views of four operating arrangements of the drip irrigation emitter of Figures 1A - 2B; Figures 4A and 4B are sectional views indicating the position of the membrane against a curved support in the orientation of Figure 3D. Reference is now made to Figures 1 - 4B, which illustrate a pressure-compensated drip irrigation emitter device constructed and functional in accordance with a preferred embodiment of the invention. The emitter comprises a housing that preferably includes a base member 10 defining a drip irrigation outlet 12 and a cover member 14 that is intended to fit interlockingly with the base member 10 via an engaging edge 16. The emitter also includes a membrane 18 that is mounted between the interior of the base member 10 and the cover member 14. In accordance with a preferred form of the present invention, the membrane 18 has two primary positions, a first position, in which the membrane seals a water inlet and a second position, in which the membrane modulates the amount of water flowing through a water flow path. The cover member 14 defines a water inlet 20 which may be configured as illustrated to fit into an opening in a water supply line. Generally, upon initial pressurization of the dispenser, pressurized water from the water supply line passes through the inlet 20 and forces the mem - 6 - Patent Consulting Studio srl Bianchetti Giuseppe et al. brana 18 from its position when not pressurized, as illustrated in Figure 3A, to an intermediate position, illustrated in Figure 3B. When the membrane 18 is in the position illustrated in Figure 3B, water from the inlet 20 passes through the membrane and the inner inlet wall into a volume 24 above the membrane and thence through a passage 26, which communicates with the volume 24 via a pressure reducing conduit 28, which may be of any suitable configuration, such as a configuration described in any of the applicant's patents cited above, the disclosure of which is incorporated herein by reference. Conduit 28 terminates in a passage 30 extending generally radially inwardly of base member 10 that communicates with a first side of an internal pressure control volume 32, which is partially and symmetrically bifurcated by a curved membrane engagement wall 34 having a membrane engagement surface 36, as described in detail in Figures 4A and 4B. Water passing from the first side of volume 32 past wall 34 to the second side enters a conduit 38 which communicates with a volume 40 surrounding the membrane 18 at the lower side of an intermediate portion thereof. From volume 40, the water flows through a passage 42 into a second pressure-reducing passage 44, which empties into passage 46, which communicates with outlet 12. The operation of the drip irrigation emitter described will now be summarized. As noted above, with reference to Figure 3B, the water from the inlet 20 passes through the membrane 18 and the - 7 - Patent Consulting Studio srl Bianchetti Giuseppe et al wall 22 in volume 24. This flow causes membrane 18 to rapidly move from an upper central-type position, represented by Figures 3A and 3B to a lower central-type position, represented by Figures 3C and 3D. By considering Figures 3C and 3D, it can be understood that the engagement between the membrane 18 and the engagement surface 36 provides regulation of the flow of water through the dispenser. It will also be understood that the arrangement of the membrane 18 at the volume 40, and the resulting configuration of the membrane 18, provides further regulation of the flow of water through the dispenser. It will also be understood that the inward movement of the membrane 18, from its orientation in Figure 3C to its orientation in Figure 3D, causes the membrane to be pushed closer toward the engagement surface 36. It is a particular feature of the present invention that advantageous engagement of the water with the membrane is provided at a later stage of water flow through the dispenser than in the prior art, thereby providing more sensitive pressure compensation than in the prior art and consequently, allowing the dispenser to provide appropriately pressure compensated outlet velocities over a significantly greater range of inlet pressures. It should be understood that the present invention is not limited by what has been particularly illustrated and described above. The scope of the present invention is defined solely by the following claims.

Claims

- Studio Consulenza Brevettuale srl Bianchetti Giuseppe et al. CLAIMS 1. A drip irrigation device comprising: a housing comprising a water inlet, a water outlet, and a water flow path extending therebetween; and a pressure-sensitive membrane disposed within the housing and capable of regulating the flow of water, and wherein the orientation of the pressure-sensitive membrane is responsive to the pressure of water impinging on the membrane at a plurality of different, mutually spaced points on the membrane.

2. A drip irrigation device according to claim 1 wherein at the plurality of several mutually spaced points on the membrane, water communicates with several mutually spaced points along the water flow path and is at different pressures.

3. A drip irrigation device comprising: a housing including a water inlet, a water outlet, and a water flow path extending therebetween; and a pressure-sensitive membrane disposed within the housing and provided to regulate the water flow, wherein the pressure-sensitive membrane pushes on the water flow to restrict the flow at a plurality of different mutually spaced points along the water flow path.

4. A drip irrigation device as claimed in claim 1, wherein said membrane has two main positions, a first position in which the membrane seals the water inlet, and a second position in which the membrane modulates the amount of water flowing through the water flow path.

5. A drip irrigation device according to claim 2, wherein said membrane has two main positions, a first position, wherein the membrane seals the water inlet and a second position, wherein the membrane modulates the amount of water flowing through the water flow path.

6. A drip irrigation device according to claim 3, wherein said membrane has two main positions, a first position, wherein the membrane seals the water inlet and a second position, wherein the membrane modulates the amount of water flowing through the water flow path.

7. A drip irrigation device according to claim 4, wherein when the membrane is in its second position, the precise orientation of the membrane and therefore its modulation of the amount of water flowing is effected by the pushing of water onto the membrane at at least two different mutually spaced points on the membrane.

8. A drip irrigation device according to claim 1, which is intended to provide flow uniformity of 10% over an inlet pressure range of 1-8 atmospheres.

9. A drip irrigation device according to claim 2, which is intended to provide flow uniformity of 10% over an inlet pressure range of 1-8 atmospheres.

10. A drip irrigation device according to claim 3, which is intended to provide flow uniformity of 10% over an inlet pressure range of 1-8 atmospheres.

11. A drip irrigation device according to claim 4, which is intended to provide 10% flow uniformity over an inlet pressure range of 1-8 atmospheres.

12. A drip irrigation device comprising: a housing comprising a water inlet, a water outlet, and a water flow path extending therebetween; and a pressure-sensitive membrane disposed within the housing and intended to regulate the water flow, being intended to provide flow uniformity of 10% over an inlet pressure range of 1 to 8 atmospheres. Milan, February 25, 1993. Attorney (Giuseppe Bianchetti) of Studio Consulenza Brevettuale srl