DE20114122U1 - Flexible hose for irrigation - Google Patents

Description

GKS & S MAXIMILIANSTRASSE 58 D-80538 MUNICH GERMANY

LAWYERS

MUNICH

DR. HELMUT EICHMANN

GERHARD BARTH

DR. ULRICH BLUMENRÖDER, LLM.

CHRISTA NIKUS-FALTER

DR. MAXIMILIAN KINKELDEY, LL. M.

SONJA SCHAEFFLER

DR. KARSTEN BRANDT

ANJA FRANKE, LL.M.

UTE STEPHANI

DR. BERND ALLEKOTTE, LL.M.

DR. ELVIRA PFRANG, LLM.

PATENT ATTORNEYS EUROPEAN PATENT ATTORNEYS

MUNICH

DR. HERMANN KINKELDEY PETER H. JAKOB WOLFHARD MEISTER HANS HILGERS DR. HENNING MEYER-PLATH ANNELIE EHNOLD THOMAS SCHUSTER DR. KLARA GOLDBACH MARTIN AUFENANGER GOnFRIED KLITZSCH DR. HEIKE VOGELSANG-WENKE REINHARD KNAUER DIETMAR KUHL DR. FRANZ-JOSEF ZIMMER BETTINA K. REICHELT DR. ANTON K. PFAU DR. UDO WEIGELT RAINER BERTRAM JENS KOCH, M. S. (U of PA) M. S.

BERND ROTHAEMEL DR. DANIELA KINKELDEY DR. MARIA ROSARIO VEGA LASO THOMAS W. LAUBENTHAL

PATENT ATTORNEYS

EUROPEAN PATENT ATTORNEYS

BERLIN

PROF. DR. MANFRED BÖNING DR. PATRICK ERK, M.S. (MIT)· ■PATENT ATTORNEY

COLOGNE

DR. MARTIN DROPMANN

CHEMNITZ MANFRED SCHNEIDER

OF COUNSEL PATENT ATTORNEYS

AUGUST GRUNECKER DR. GUNTER BEZOLD DR. WALTER LANGHOFF

DR. WILFRIED STOCKMAIR (■1996)

YOUR REF.

OUR REF.

DATE

G4601-80/g

27.08.01

UNIFLEC UTILTIME S.p.A.

Via deirindustriea

33086 Montereale Valcellina

Pordenone

ITALY

Flexible hose for irrigation

GRÜNECKER KINKELDEY STOCKMAIR & SCHWANHÄUSSEfi. MAXIMIUANSTR. 58 D-80538 MUNICH GERMANY

;TEt. · +49 89^*23 50; '*W< ((!HS) +49*39 22 02 87·· · FAX (GR 4) +49 89 21 86 92 93

http://www.grunecker.de
e-mail: postmaster@grunecker.de

DEUTSCHE BANK MUNICH TTo' 17 51734 BLZ 700 700 SWIFT: DEUT DE MM

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Description

of the utility model with the designation: “FLEXIBLE HOSE FOR IRRIGATION”

The present invention relates to a flexible hose made of an elastomer reinforced with fabric layers, which serves to distribute liquids under pressure and is used in particular in irrigation systems.

Generally, different types of hoses are used for irrigation, such as, for example, rigid polyvinyl chloride hoses with different diameters and thicknesses depending on the pressure exerted; polyethylene hoses; polypropylene hoses; ester rubber pipes; PVC or polypropylene pipes coated with ester rubber and, finally, hoses made of an elastomer and reinforced by the superposition of different layers of fabric.

The most commonly used hoses, and the ones that offer the best quality, are those reinforced with fabric. This type of hose must meet a wide range of requirements: it must be more resistant to the internal pressure exerted by the fluid, it must have a reduced thickness of the hose walls, it must be sufficiently flexible to be rolled up on special reels and, above all, it must be able to withstand the twisting effect caused by the spiral path of the fabric weft.

Some of these technical issues have been addressed and resolved in various ways.

The patent DE 197 27 142, for example, shows a hose for irrigation consisting of a tubular layer of

plasticized PVC around which is wound a reinforcement layer of braided polyester yarn, which in turn is coated with a microlayer of plasticized PVC, onto which is applied a reinforcement fabric woven from polyester yarn and finally covered with an external cylindrical layer of PVC. This solution to the problem is a hose which, although it has better anti-torsion properties than the previous solutions, has the disadvantage of unacceptable rigidity, since the large number of fabric layers and the PVC used means that the thickness of the hose walls and therefore the size of the hose diameter takes on considerable proportions.

The Italian patent application PN2000A000030 of the same applicant provides for the insertion of two knitted fabric layers (called "tricotage") in the body of the hose, with the stitch pattern of one layer being opposite to that of the second. This solution to the problem further improves the anti-torsion behavior of the hose, but at the same time reduces its strength, making it unsuitable for some applications. The fabric tends to give way due to the internal pressure of the liquid and the hose tends to swell.

The aim of the present invention is to find a good compromise for the manufacture of a type of hose capable of meeting the various conflicting requirements posed by the different conditions of use. This aim is achieved by a hose made of an elastomer and comprising two layers of fabric for reinforcement, the inner layer of fabric being knitted as a tricot, as explained in more detail in the claims which conclude the present patent application.

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The characteristics and advantages of the present invention will become clear from the following description, given as a non-limiting example, with reference to the accompanying drawings, in which:

- Figure 1 shows a partial perspective view of a hose section according to the invention;

- Figure 2 shows the cross-section through the hose of Figure 1. With reference to the figures, schematically, in perspective

and shown as a cross-section a hose section consisting of an inner tubular layer 11 and an outer tubular layer 12, both made of an elastomer-containing material, preferably PVC.

According to the invention, a first fabric layer 13 made of a warp-knitted fabric (so-called tricot) is wound spirally around the inner tubular layer 11 for reinforcement. This reinforcement layer has warp-knitted rows inclined towards the tube axis and weft rows running substantially parallel to the tube axis, thereby contributing to a certain elasticity of the tube wall.

A second reinforcing fabric layer 14 is wound spirally around the first reinforcing fabric layer. This second reinforcing fabric layer 14 is made of threads braided in a net-like manner. The reinforcing layer 14 makes it possible to counteract the tendency of the hose to twist when a liquid under pressure flows through it. Preferably, the two reinforcing fabric layers 13 and 14 are separated by a thin layer of material 15, which is also made of an elastomer and preferably of PVC.

This solution has been shown in tests to be the most suitable solution to meet the different requirements of the various operating conditions to which this type of hose is exposed. .: j . ·: .··..". : : .;

In fact, by placing the warp-knitted reinforcement layer 13 further inside the hose than the braided reinforcement layer 14, a hose is obtained which, in use, absorbs well the internal pressure of the fluid flowing through it due to the elasticity of the stretchable warp-knitted layer 13. However, the expansion of the layer 13 is limited and kept under control by the presence of the outermost fabric layer 14 which, being made of braided material, cannot expand.

Therefore, a hose according to the invention is sufficiently flexible and at the same time very resistant to the shocks and tensile stresses to which the hose is subjected in use. Such a hose also has a lower specific weight, while offering the same performance, compared to similar hoses having other fabric reinforcements or fabric reinforcements arranged differently in the hose body. The specific arrangement of the fabric reinforcements makes it possible to eliminate the need for an additional intermediate elastomer layer, albeit of a small thickness, or to reduce the thickness of the inner and outer elastomer layers.

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Claims (3)

1. Flexible hose, in particular for irrigation systems, which has an inner tubular layer ( 11 ) and an outer tubular layer ( 12 ) made of an elastomer-containing material, preferably PVC, two layers of reinforcing fabric being provided between the two layers, and which is characterized in that the innermost fabric layer ( 13 ) is woven as a warp knit or tricot. 2. Flexible hose as in claim 1, characterized in that the outermost fabric layer ( 14 ) consists of net-like braided threads. 3. Flexible hose as in claim 1, characterized in that between the two fabric layers ( 13 , 14 ) serving for reinforcement there is provided a further concentric layer of a thin-walled hose ( 15 ) which consists of elastomer-containing material, preferably of PVC.