IMPROVEMENTS RELATING TO DRIP IRRIGATION

Abstract: A drip irrigation arrangement including a supply conduit (1) has embossed thereinto channel shapes (2) forming thereby a resistance conduit by having a covering (3) surrounding the channel shape (2) with an entry from the supply conduit into the resistance conduit at (5) the channel shape being of tortuous pathway and having an outlet to atmosphere at (12).

Description: IMPROVEMENTS RELATING TO DRIP IRRIGATION This invention relates to drip irrigation and in particular to a drip irrigation arrangement and to a method of manufacture of a drip irrigation arrangement. It is at the present time, conventional to use a technique commonly known as "Drip Irrigation" which comprises supplying water through a supply conduit to reach a number of watering locations, and then having at each of the locations a separate device which is adapted to take water at pressure within the supply conduit, reduce the pressure as the water passes through the device and allow the water thereafter to "Drip" from an outlet. With a very large number of individual separate devices, each of these hitherto have had to be manufactured separately and then installed usually at a site where the arrangement is to be installed so that at each dripper location an appropriate device often called "an emitter" must be interconnected with the supply conduit and set to whatever is the appropriate dripping rate required and also adjusted with respect to an expected supply water pressure at the specific location which will of course vary along the length of the supply conduit. The cost of such emitters and the installation can be expensive and time consuming and it is an object of this invention to propose at least an arrangement and method which can reduce such problems. Accordingly the invention can be said to reside in-a drip irrigation arrangement including a supply conduit with a covering secured against an outer face of the conduit wall, a resistance conduit for liquid extending between the said covering and the said outer face of the conduit wall, an inlet into the resistance conduit from the supply conduit through the supply conduit wall, and a drip outlet from the resistance conduit distal from the inlet location. The invention can also be said to reside in a method of effecting a drip irrigation arrangement which includes the steps of effecting from a supply conduit, a resistance conduit defined between an outer face of the supply conduit wall and a covering secured against the outer face of the supply conduit wall, effecting an inlet into the resistance conduit through the wall of the supply conduit, and effecting an outlet from the resistance conduit distal from the inlet location. In preference, the resistance conduit is effected, at least in main, by a channel within the outer face of the supply conduit wall, the resistance conduit " being defined by sides and bottom of the channel and the covering over the channel. In preference, a channel is first impressed into the outer face of the supply conduit wall then this is covered with the covering whereby the resistance conduit is thereby defined. It will now be understood that the concept of this invention is to incorporate a resistance conduit by using at least in the main the material of the supply conduit itself. A significant advantage of this arrangement is cost in that such a shaping can be effected during the course of manufacture of the supply conduit and the quantity of materials necessary in addition to the materials necessary for the supply conduit, are small. In preference, the resistance conduit is defined by a covering over a channel which channel follows a zig zag path which follows in a first instance in a direction substantially aligned parallel to the elongate direction of the supply conduit thereby providing a first channel portion, at an end of the said first channel portion an interconnecting channel to a second channel portion providing for a zig zag path this following, in the main, a direction parallel to the elongate direction of the supply conduit, at an end thereof connected through an interconnecting channel at least eventually to a drip outlet. The invention will now be described with reference to a preferred embodiment which shall be described with the assistance of drawings in which, Fig.l is a perspective view of a supply conduit (part cut away) with a covering over channels impressed -within the supply conduit in accord with an arrangement according to the embodiment, Fig.2 is an illustration of the channel pattern as incorporated for one segment in Fig. 1 once again with cover removed, Fig.3 is an illustration of the channel pattern at the entry segment, Fig.4 is an illustration of the channel pattern at the exit segment, Fig.5 is a cross sectional view with cover included of the embodiment as in Fig.l, Fig.6 is a plan view of the suppy conduit, cover removed, Fig.7 is a cross section of the embodiment as in Fig.l. Referring to the embodiment drawings, the supply conduit 1 is comprised of a black pipe having a 19 mm outside diameter and comprised of polyethelene plastics material. The supply conduit 1 has embossed thereinto channel shapes shown typically at 2. The sleeve 3 which is comprised of a polyethelene plastics material is secured so as to fully encompass the supply conduit 1 and to hold sufficiently tightly around this so as to provide a reasonable sealing effect for liquid at modest pressure to be contained thereby between the outer face 4 of the conduit 1 and the sleeve 3. In the embodiment, the sleeve comprises a material having a shrink capacity which is therefore first secured fully around the pipe having overlapping faces adhered together using heat sealing. With such closely wrapped surrounding sleeve, the sleeve is then subjected to further heating so as to induce the shrinking effect, the characteristic of the material used being selected so as to contract the sleeve to have very tight pressure around the conduit 1. Impressed into the outer surface of the conduit 1 are a series of channels and in particular as shown in Fig. 3 there is a channel portion having a cross shaped aperture of 1 mm in width at 5 passing fully through the wall of the conduit 1. The channel portion in this vicinity at 6 allows for water from within the conduit 1 to pass through the aperture 5 and then commence a passage through a first tortuous pathway providing a zig zag path extending broadly in a direction parallel to the direction of the elongation of the conduit 1. To achieve this zig zag tortuous pathway, there is provided a channel having approximately a width of 1.24 mm and a depth of 1.24 mm and, as is shown in the drawing which is drawn only to approximate scale, water will then pass through the tortuous pathway to a first end where there is a further pathway which directs the water back, once again tortuously but nontheless in the general direction of alignment parallel to the direction of elongation of the conduit 1. In the arrangement of the embodiment, there are twelve such portions six of these arranged to direct the water in one direction along the elongate direction of the conduit 1 and the remaining six alternatively are arranged by a channel connection as is shown to provide for passage of water back through the other tortuous pathway. The channel as shown is covered by cover 3 and by providing such a pathway having a relatively large cross sectional area that is of approximately 1.24 by 1.24 square millimetres in area, the resistance conduit thus formed can nonetheless because of its available length provide adequate resistance to water coming at pressure through the entry aperture at 5 but not being particularly vulnerable to blockage by smaller particles. Such a longer conduit can be economically achieved because the material costs in providing the pathway are only in the main those that are available in the supply conduit 1. An exit end of the twelfth channel portion at 8 extends into channel portion 9 and then through into channel portion 10 which, as will be seen in Fig. 4 is between a raised portion of the wall 11 blocking the position of the cover 3 at 12 so that channel 10 is an outlet providing thereby a drip exit for water having passed through the resistance conduit. In the forming of the respective channel portions, according to this embodiment there are provided six separate impressions which have an interconnecting channel portion at 13 and at 14 typically. A die impression is achieved with such heat and to such an extent that the channel shaped can be retained within the wall for the reasonable life of the supply conduit 1. The resistance conduit in each case is then defined by sides 15 and 16 and bottom 17 of the channel and the cover 3.

Claims: 1. A drip irrigation arrangement including a supply conduit with a covering secured against an outer face of the conduit wall, a resistance conduit for liquid extending between the said covering and the said outer face of the conduit wall, an inlet into the resistance conduit from the supply conduit through the supply conduit wall, and a drip outlet from the resistance conduit distal from the inlet location. 2. A drip irrigation arrangement as in claim 1 further characterised in that the resistance conduit is effected at least in the main, by a channel within the outer face of the supply conduit wall the resistance conduit being defined by sides and bottom of the channel and the covering. 3. A drip irrigation arrangement as in either of the preceding claims 1 or 2 further characterised in that the covering is in the form of a sleeve extending around the conduit. 4. A drip irrigation arrangement as in any one of preceding claims 2 or 3 further characterised in that the drip outlet is effected by the channel shape within the conduit wall extending beyond an edge of the covering. 5. A drip irrigation arrangement as in any one of preceding claims 3,4 or 5 further characterised in that the resistance conduit is comprised of a channel following at least in the main, along a direction of elongation of the supply conduit. 6. A drip irrigation arrangement as in any one of preceding claims 3,4 or 5 further characterised in that the supply conduit is comprised of at least in the main, the plastics material polyethelene. 7. A drip irrigation arrangement as in any one of preceding claims 2,3,4, 5 or 6 further characterised in that the covering is a sleeve comprised of at least in the main the plastics material polyethelene. 8. A method of effecting a drip irrigation arrange¬ ment from a supply conduit which includes the steps of effecting a resistance conduit deformed between an outer face of the supply conduit wall and a covering occured against the outer face of the supply conduit wall, effecting an Inlet into the resistance conduit through the wall of the supply conduit, and effecting an outlet from the resistance conduit distal from the inlet location. 9. A method of effecting a drip irrigation arrange¬ ment as in Claim 8 in which the method further includes the step of impressing a channel shape into the outer face of the supply conduit, then covering across the top of the channel shape with the covering whereby to define the resistance conduit. 10. A drip irrigation arrangement substantially as described in the specification with reference to and is illustrated by the accompanying drawings.

Inventors: SNELLING PETER JOHN, SNELLING, PETER, JOHN
Applicants: SNELLING PETER JOHN, SNELLING, PETER, JOHN
Application year: 1985
Main classification: A01G25
IPC codes: A01G25