Patent Description:
Irrigation systems deliver liquid comprising water, often containing plant nutrients, pesticides and/or medications, to plants via networks of irrigation pipes.

Relative thin walled irrigation pipes, sometimes called tapes, may be used for irrigation, for example when the irrigation pipes are used for short durations of time, such as a single season and then possibly disposed.

During installment or use, the irrigation pipes may be exposed to wear and tear that may cause damage to the pipes in particular in cases where the irrigation pipe has a relative thin wall.

Irrigation pipes may deliver liquid to plants via emitters or drippers that are installed on or integrated inside the irrigation pipes. Such emitters may be heat bonded to the pipe to form a so-called drip irrigation pipe or dripper pipe. In some cases such dripper pipes may be susceptible to damage at the areas of bonding and/or areas of connection to the drip emitter. <CIT> describes an elongated irrigation tube having a plastic or polymer peripheral wall in which there are a series of dispensing holes leading from the interior of said tubing to the exterior of said tubing. The tubing is constructed to include at least one of all of said holes having a cross-sectional shape along a section taken perpendicular to the length of said holes such that the ratio of the length of the perimeter of the interior of the wall of each hole to the cross-sectional area of the hole is greater than that of a circle; that said wall includes a body of a plastic material containing an effective amount of a root inhibitor to preclude root growth within said holes and adjacent to said holes at the exterior of said wall; and that said wall consisting of an even number of elongated panels and line like areas of reduced thickness which are more flexible than said panels joining said panels, said areas permitting said tubing to automatically fold flat when coiled. <CIT> describes a drip irrigation system comprises a hose with a flexible wall circumscribing and bounding a main flow-path for carrying irrigation fluid, and pressure-compensated emitters spaced along the length of the hose and providing a communicating channel between the main flow-path and a region at lower pressure outside the main flow-path, such as the region outside the hose, the pressure-compensating function of the emitters producing a flow-rate through the emitters that is weakly dependent on the pressure differential across the emitters. <CIT> describes integral conduits to disburse fluids along their length, fabricated out of two materials, and a method for manufacturing such structures with permeable wall parts; characterized by extruding a profile of thermoplastic material with a lengthwise extended slitted wall, and where this longitudinal slit is being outfitted with a permeable material consisting of one or more layers of fabric; the sides of the fabric strips being imbedded and sandwiched in the thermoplastic wall of the conduit, lengthwise along both sides of the slit. <CIT> describes irrigation pipes and processes and devices for making them. Pipes for irrigating plants, especially their roots, with a substantially circular cross-section and apertures covered by a filter material applied to the outside of the pipe, in which the pipe has longitudinal lips whose opposite longitudinal sides form an intermediate space within which the apertures lie and in which a filter strip, for example of woven or mineral fibres or the like, is surrounded or held by the lips or the apertures are recessed in relation to the outer surface of the pipe and are each covered by a piece of filter material.

The subject-matter of the present invention is defined by the features of independent claim <NUM>. The following examples and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope.

In an embodiment there is provided a thin walled irrigating pipe having a tensile layer formed as a continuous strip upon an outer side of the pipe for increasing tensile strength of the pipe, wherein the tensile layer comprising a higher tensile strength than material of the remainder of the pipe outside of the tensile layer. The tensile layer comprising a higher tensile strength than the material of the remainder of the pipe outside of the tensile layer. The pipe comprises axially spaced apart apertures for communicating liquid out of the pipe and the apertures being formed also through the tensile layer. Moreover, in a cross section orthogonal to the pipe axis and taken along any location along the pipe's axis, the tensile layer extends only along a portion of the pipe's periphery.

In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed descriptions.

It is intended that the embodiments and figures disclosed herein are to be considered illustrative, rather than restrictive. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying figures, in which:.

Further, where considered appropriate, reference numerals may be repeated within the figures to indicate like elements.

Attention is first drawn to <FIG> illustrating an irrigation pipe <NUM> in accordance with at least certain embodiments of the invention. The irrigation pipe has a pipe wall <NUM> formed about a longitudinal axis X of the pipe forming an internal through going lumen <NUM> serving as a main passageway of the pipe for axially channeling liquid through the pipe.

The pipe includes in addition openings <NUM> formed axially along the pipe's wall <NUM> serving as passageways through which liquid flowing through lumen <NUM> can exit the pipe. The openings <NUM> may take form of apertures drilled or punched through the pipe wall.

In an embodiment of the invention, the irrigation pipe may include an operative layer <NUM> formed along the pipe's wall possibly as here illustrated along areas of the wall including the openings <NUM>. The operative layer, in various embodiments of the invention may serve as a tensile layer for increasing tensile strength of the pipe so as to increase the maximal stress that the pipe can withstand while e.g. being stretched or pulled.

In various embodiments, provision of such tensile layer may be especially useful in so called thin-walled pipes sometimes called 'tapes'. Such a thin walled pipe structure may be characterized by a wall thickness that may range from about <NUM> (<NUM> mil) to about <NUM> millimeter (<NUM> mil) (measured in a radial direction on a pipe held in a cylindrical state). Such relative thin wall thickness may render the pipes relative weak, inter alia, when exposed to tensile stresses, such as when laid or retrieved from a field. In the example exhibited in <FIG> and <FIG>, tensile layer <NUM> is illustrated formed at least along an outer side of wall <NUM>.

Attention is drawn to <FIG> schematically illustrating a cross section of an embodiment of pipe <NUM> taken along a plane generally orthogonal to axis X of the pipe, such as plane II-II marked in <FIG>. In this embodiment, operative layer <NUM> is illustrated formed along an outer side of the pipe's wall <NUM> with the openings <NUM> penetrating through layer <NUM> and wall <NUM> into lumen <NUM> of the pipe.

Attention is drawn to <FIG> schematically illustrating a cross of an embodiment of pipe <NUM> generally similar to that seen in <FIG>, however in this example including an irrigation emitter <NUM> attached here to an inner side of the pipe's wall. A plurality of emitters such as emitter <NUM> may be axially attached along the pipe's wall, with each emitter being located adjacent a respective opening formed through the pipe to serve as passageways through which liquid flowing in the pipe can be directed out of the pipe for irrigation.

In an embodiment of the invention, operative layer in a tensile layer formation <NUM> may be arranged to be formed from materials with a strength-to-density ratio that is higher than a comparative strength-to-density ratio in the remainder material of the pipe.

In a non-binding example, tensile layer <NUM> in a formation having a relative high strength-to-density ratio, may be made of materials such as: COC, PP or the like.

In certain cases, materials suitable for forming tensile layer <NUM> may be defined as having a relative high secant-modulus (where secant-modulus when referred to herein being defined according to ASTM D638-<NUM> - see section <NUM>). For example, tensile layer <NUM> in one example may be chosen to be from Polypropylene having a secant-modulus of about <NUM> MPa and density of about <NUM> gr/cm^<NUM>, while the material of the remainder of the pipe may be formed from Polyethylene having a secant-modulus of about <NUM> MPa and density of about <NUM> gr/cm^<NUM>.

In certain embodiments, filler materials may be added to tensile layer <NUM> e.g. to increase the layer's secant-modulus. In some cases, the filler materials may act as a "reinforcing" filler.

In yet further embodiments, tensile layer <NUM> may be defined as a layer having a relative high tensile-strength in relation to tensile strength of material forming the remainder of the pipe wall (where tensile strength possibly being defined acc. to ASTM D638-<NUM>).

Possibly, such tensile layer may be formed from a material having a '<NUM>% Tension secant Modulus' that may be higher than similar modulus existing in the remainder of the pipe. For example, the '<NUM>% Tension secant Modulus' of tensile layer <NUM> may be greater than about <NUM> MPa.

Alternatively, or in addition - increased resistance to tension of tensile layer <NUM> may be defined by an increased Elastic Modulus of layer <NUM> in relation to same modulus as present in the remainder material of the pipe.

In some embodiments, such tensile layer <NUM> may in addition or alternatively include Nano-fillers such as Nano-Graphene, Nano carbon tubes, Nano-clays, Nano-Cellulous (or the like), where such Nano-fillers being designed to form up to about <NUM>% in wt% from the matrix forming tensile layer <NUM> in a final extruded pipe.

In certain cases, tensile layer may in addition or alternatively be made from PP or PE materials including glass fibers. Such glass fibers may be noncontinuous Fibers (short or long) and/or possibly such glass fibers forming between about <NUM>% to about <NUM>% and preferably between about <NUM>% to about <NUM>% in wt% of polyolefin material forming layer <NUM>. In some examples, tensile layer <NUM> may be formed from COC (Cyclic Olefin Copolymer) material - while in some cases prestretched continuous fiber(s) (possibly fiber bundles) (coated or not coated) may be embedded within layer <NUM> for increasing its tensile strength.

In one example, determination of relative tensile strength properties of a pipe including tensile layer <NUM> may be defined according to ASTM D638-<NUM>. Four sectors may first be marked on a circumference of a drip irrigation pipe in a section of the pipe not including a dripper or tape. Then, five dumbbell shape samples (according to ASTM D638-<NUM>) may be cut from each one of the four sectors - resulting in a total of twenty such samples.

In a subsequent step, each one of the samples may then be stretched in a Tensile test machine (according ASTM D638-<NUM>, speed <NUM>/min), while recording the yield force and maximum force (In Newtons) obtained for each sample. Then the five samples relating to each sector may be averaged to record an average value for each sector - and existence of material forming a tensile layer <NUM> according to the various embodiments of the invention, may be identified by a sector having an average result that is higher by about <NUM>% or more than results present in the other tested sectors of the pipe.

In at least certain embodiments, operative layer <NUM> (in addition or in alternative to forming a tensile) may be arranged to include materials suitable for at least partially limiting formation of biological matter and/or entry of plant roots into passageways of the pipe, such as openings <NUM>.

Operative layer <NUM> may include operative-material(s) in the form of metallic materials, e.g. copper preferably copper oxide. In addition, operative layer <NUM> preferably includes such operative-material(s) mixed within polymeric material to consequently form a meltable polymeric substance that can be e.g. extruded and/or co-extruded during manufacturing of the pipe in order to integrally form at least part of the pipe's wall <NUM>.

In the description and claims of the present application, each of the verbs, "comprise" "include" and "have", and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements or parts of the subject or subjects of the verb.

Further more, while the present application or technology has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and non-restrictive; the technology is thus not limited to the disclosed embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art and practicing the claimed technology, from a study of the drawings, the technology, and the appended claims.

The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures can not be used to advantage.

The present technology is also understood to encompass the exact terms, features, numerical values or ranges etc., if in here such terms, features, numerical values or ranges etc. are referred to in connection with terms such as "about, ca. , substantially, generally, at least" etc. In other words, "about <NUM>" shall also comprise "<NUM>" or "substantially perpendicular" shall also comprise "perpendicular". Any reference signs in the claims should not be considered as limiting the scope.

Claim 1:
A thin walled irrigating pipe (<NUM>) having a tensile layer (<NUM>) formed as a continuous strip upon an outer side of the pipe (<NUM>) with increased tensile strength, wherein the pipe (<NUM>) comprises axially spaced apart apertures for communicating liquid out of the pipe (<NUM>) and the apertures being formed also through the tensile layer (<NUM>), wherein the tensile layer (<NUM>) comprising a higher tensile strength than material of the remainder of the pipe (<NUM>) outside of the tensile layer (<NUM>), characterized in that
the tensile layer (<NUM>) comprising a secant-modulus higher than a comparative secant-modulus in the remainder material of the pipe (<NUM>) outside of the tensile layer, and in that
in a cross section orthogonal to the pipe axis and taken along any location along the pipe's axis, the tensile layer (<NUM>) extends only along a portion of the pipe's periphery.