IL195397A

IL195397A - Drip irrigation pipe

Info

Publication number: IL195397A
Application number: IL195397A
Authority: IL
Inventors: Gilad Narkis; Ido Gilat; Moshe Raanan
Original assignee: Gilad Narkis; Netafim Ltd; Ido Gilat; Moshe Raanan
Priority date: 2007-11-21
Filing date: 2008-11-20
Publication date: 2013-03-24
Also published as: IL195397A0

Description

DRIP IRRIGATION PIPE Neiafim Ltd.

The inventors: : DWilO0ri Gilad Narkis Ido Gilat Moshe Raanan DRIP IRRIGATION PIPE BACKGROUND

[0001] The present disclosure relates to a drip irrigation pipe and to a production method of the drip irrigation pipe.

[0002] In such a pipe, fluid passing via a flow path is discharged from the pipe via an exit in the pipe wall. European Patent No. 1369028, the disclosure of which is incorporated herein by reference, describes a drip irrigation pipe with flaps that are cut out from the wall of the pipe. These flaps are pushed open to form an exit from the pipe when an irrigation procedure is activated and are withdrawn back to lock the exit when the irrigation procedure is terminated or interrupted. In an embodiment of the patent, the walls of the pipe are cut in a cone shape to fonn the flaps by a laser arrangement that includes a laser beam that is directed by a lens system to cut the wall. Such a laser arrangement is referred to by the patent as being described in European Patent No. 715926. This European Patent has a counterpart US Patent No. 5,744,779.

[0003] US Patent No. 5,744,779, the disclosure of which is incorporated herein by reference, mentions that drilling is a complicated and costly solution for performing exists in a drip irrigation pipe wall and in addition notes that a polymer and more precisely polyethylene that is used in such pipes is difficult to drill. The patent therefore goes on to describe a device comprising a laser which is used to volatilize the material of the pipe wall and thereby form an exit in the pipe wall.

[0004] US Patent Application No. 2006186228, the disclosure of which is incorporated herein by reference, describes a dripper which when bonded to a pipe wall may form a raised portion in the wall. In an embodiment of the application, a fixed blade, either rotating or motionless, is disposed at an angle in relation to the pipe to form a slit in the wall of the pipe in the form of a flap.

SUMMARY

[0005] The following embodiment 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.

[0006] In an embodiment, a drip irrigation pipe that extends along a longitudinal pipe axis, the pipe comprises a pipe wall and a drip emitter, the pipe wall comprises a flap being defined by a cut in the pipe wall, the flap remaining connected to the pipe wall at a bridge, the flap comprising a lid face at the cut and the pipe wall comprising a ground face at the cut, the drip emitter being bonded to the pipe wall adjacent the flap so that water passing through the emitter is able to exit the pipe via the flap, wherein at least a portion of the lid face or ground face, or both, is located about a tool axis that forms an acute angle a with a radius of the pipe as measured at least when the pipe is under internal working fluid pressure.

[0007] In an embodiment, the cut is formed by a rotating cutting tool that rotates about the tool axis.

[0008] In an embodiment, the cutting tool comprises a cutting edge adapted to perform a circular cut about the tool axis.

[0009] In an embodiment, at least a portion of the lid overlies the ground.

[0010] In some embodiments, at least a portion of the ground adjacent the bridge may overly the lid. [001 1] In an embodiment is also provided a method of producing a drip irrigation pipe comprising the steps of: providing a pipe having a longitudinal pipe axis and comprising drip emitters bonded at longitudinally spaced apart locations to a wall of the pipe, at least one of the drip emitters comprising a chamber having a chamber axis, advancing the pipe axially at an axial pipe velocity Px through a cutting station, providing at the cutting station a cutting tool having a cutting edge adapted to cut about a tool axis, advancing the cutting tool towards the pipe to perform a cut in the pipe wall that defines a flap and retreating the cutting tool away from the pipe, the tool axis forming an acute angle with the chamber axis at least when performing the cut and the flap remaining connected to the wall at a bridge.

[0012] In an embodiment, the cutting tool is a rotary cutting tool that is adapted to rotate about the tool axis.

[0013] In an embodiment, at each instance of advancement into the pipe wall or retreat out of the pipe wall, the cutting tool has a velocity that comprises a tool velocity Cx along a direction parallel to the pipe axis. [001 ] In an embodiment, Cx and Px are in the same direction.

[0015] In addition to the exemplary aspects and embodiment described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed descriptions.

BRIEF DESCRIPTION OF THE FIGURES

[0016] Exemplary embodiments are illustrated in referenced figures. It is intended that the embodiments and figures disclosed herein are to be considered illustrative, rather than restrictive. The disclosure, 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:

[0017] Fig. 1 shows a drip irrigation pipe in accordance with the present disclosure;

[0018] Fig. 2 shows a partial cross sectional view of the pipe taken in the plane II-II shown in Fig. 1 ;

[0019] Fig. 3 shows a schematic view of a part of a drip irrigation pipe production installation in accordance with the present disclosure;

[0020] Fig. 4 shows optional orientations of a cutting tool in the part of the production installation in accordance with the present disclosure;

[0021] Fig. 5 shows a top view of a flap carved into the drip irrigation pipe in accordance with the present disclosure;

[0022] Fig. 6 shows a cross sectional view taken along the lines VI- VI in Fig. 5; and

[0023] Fig. 7 shows a cross sectional view taken along the lines VII- VII in Fig. 5.

[0024] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated within the figures to indicate like elements.

DETAILED DESCRIPTION

[0025] Attention is first drawn to Figs 1 and 2 showing a drip irrigation pipe 10 with drip irrigation emitters 12 that are bonded to an inner surface of a wall 14 of the pipe 10. The pipe 10 extends along a longitudinal pipe axis X and has flaps 16 that are located at longitudinally spaced apart locations of the pipe 10 adjacent each emitter 12.

[0026] It should be noted that directional terms appearing throughout the specification and claims, e.g. "forward", "rear", "up", "down" etc., (and derivatives thereof) are for illustrative purposes only, and are not intended to limit the scope of the appended claims.

[0027] The drip emitter 12 has a pressure reduction passage (not shown) and a chamber 18 that are formed therein. The passage is in the form of a labyrinth for controlling the rate of fluid being discharged by the emitter 12. The chamber 18 is in the form of a recess that extends into the emitter 12 along a chamber axis Y and opens out about the axis Y to an outer face 20 of the emitter 12 that is bonded to the wall 14 of the pipe 10. At least when the pipe 10 has, under internal working fluid pressure, a generally cylindrical shape the chamber axis Y extends radially. The emitter 12 has a border surface 22 that faces into the chamber 18 and a base 24 of the border surface 22 faces the wall 14 of the pipe 10. An imaginary plane P which includes the pipe axis X is perpendicular to the chamber axis Y.

[0028] Each flap 16 is defined by a cut 26 that is carved into the wall 14 of the pipe 10 and has a bridge 28 where it remains integrally connected to the wall 14 of the pipe 10. The flap 16 has a lid face 30 at the cut 26 and the wall 14 has a ground face 32 at the cut 26. A head 34 of the cut 26 is defined as a region of the cut 26 most distant of the bridge 28 and a flap axis S of each flap 16 extends from the head 34 through a center of the bridge 28. As seen in Fig. 2, at least a portion of the lid face 30 and/or the ground face 32 forms an acute angle a with a normal 50 to the pipe wall 14, the normal 50 extending along a radius of the pipe 10 at least when the pipe is under internal working fluid pressure.

[0029] At the head 34 of the cut 26 (Fig. 2), the ground face 32 of the wall 14 generally faces out of the pipe 10 along a path that diverges away from the plane P and the lid face 30 of the flap 16 generally faces into the pipe 10 along a path that converges towards the plane P. Therefore, at the head 34 of the cut 26, the lid 30 overlies the ground 32. Attention is additionally drawn to Figs. 5 to 7. In a cross section perpendicular to the flap axis S taken along portions of the cut 26 away from the head 34 (Fig. 6) the lid 30 overlies the ground 32. In some embodiments, at cross sections perpendicular to the flap axis S taken along portions of the cut 26 adjacent the bridge 28 (Fig. 7) the ground 32 overlies the lid 30.

[0030] During irrigation, fluid flowing through the pipe 10 may flow through the passage of each emitter 12 onwards and into the chamber 18. Optionally, the fluid enters the chamber 18 via an aperture (not shown) in the base 24. The fluid flowing into the chamber 18 biases the flap 16 to resiliently bend about the bridge 28 to form an exit through which fluid may exit the pipe 10. As irrigation is stopped, fluid pressure in the chamber 18 falls and the flap 16 is drawn back to substantially close the exit. It is noted that as the flap 16 is drawn back, it may reach a position wherein its lid 30 lies upon and at least partially abuts the ground 32 which thereby stops the flap 16 from being sucked into the chamber 18. In addition it is noted that in the embodiments where the ground 32 overlies the lid 30 adjacent the bridge 28, the ground 32 may at least partially abut and bear against the lid 30 as the flap 16 opens and bends about the bridge 28 to thereby restrain the resiliency of the flap 16.

[0031] Attention is now drawn to Fig. 3. The production of the flap 16 in the drip irrigation pipe 10 may be performed as follows. A pipe 10 with drip emitters 12 is continuously advanced along its longitudinal axis X in a production line at a velocity Px in a forward direction F towards a cutting station 36 of the line. At the cutting station 36 is located a cutting tool 38 having a longitudinal tool axis T and a cutting head 40. It is noted that at least at the cutting station 36 the pipe 10 may have a flattened shape (not shown).

[0032] The cutting head 40 has an axially extending lumen (not shown) that opens out at a rim 42 to an axial end of the head 40 that faces the pipe 10. A cutting edge 44 of the cutting head 40 is located at the rim 42 and is adapted perform a cutting action about the tool axis T having a shape of a circle. This cutting action forms the cut 26 in the wall 14 as the cutting head 40 is advanced into the wall 14. Therefore optionally, at least part of the cut 26 may be cylindrically shaped. The tool axis T of the cutting tool 38 forms an acute angle a with the chamber axis Y. Optionally 60° > a > 10°; preferably 45° > a > 15° and more preferably a is substantially 30°.

[0033] It is noted that the circle formed by the cutting edge 44 during the cutting action has a proximal area 45 which is closest to the pipe 10 and a distal area 47 which is farthest from the pipe 10. The cutting edge 44 adjacent the proximal area 45 forms the portions of the cut 26 where the lid 30 overlies the ground 32 (Fig. 6). The cutting edge 44 adjacent the distal area 47 may form the portions of the cut 26 where the ground 32 overlies the lid 30 (Fig. 7) if indeed the cutting edge 44 adjacent the distal area 47 reaches a position where it cuts into the wall 14.

[0034] In addition it is noted that since the tool axis T is at an angle relative to the advancing pipe, the circular cut of the cutting edge 44 that makes the cut 26 forms a slotted shape of an oval or a part-oval in an outer surface of the wall 14 of the pipe 10, as seen in Fig. 5. The oval or part-oval shape extends continuously from the head 34 of the cut 26 towards the bridge 28 and subtends an angle β, relative to a center O of the oval contour of the oval or part-oval shape. The angle β should be sufficiently large so that the flap 16 permits irrigation fluid to pass. In one embodiment, the subtended angle ji is optionally 120° < β≤ 360°, preferably 180° < β < 360° and more preferably 240° < β < 360°. It is noted that a flap 16, in accordance with the present disclosure, with an angle β equal to 360° may still be connected to the wall 14 of the pipe 10 at a bridge 28 that lies below the slotted oval shape.

[0035] The cutting tool 38 is coupled to a drive (not shown) of the cutting station 36 that is adapted to perform a cutting sequence that includes, inter alia, advancement and retreat the cutting tool 38 towards the pipe 10 and away from the pipe 10. At each instance of advancement or retreat, the cutting tool 38 has, inter alia, a tool velocity Cx in the forward direction F. This tool velocity Cx may vary from one instance to the other.

[0036] As each drip emitter 12 reaches a given position in the production line, a detector (not shown) detects the location of the emitter 12 and sends a signal for the drive to start the cutting sequence. The cutting tool 38 is advanced towards the pipe 10, carves Ihe cut 26 in the wall 1 of the pipe 10 that defines the flap 16 and retreats away from the pipe 10.

[0037] Optionally, in an embodiment of the disclosure the cutting tool 38 is a punch and the cutting edge 44 is located substantially along the full circumference of the rim 42. In this embodiment, as the signal from the detector is received the cutting tool 38 is urged towards the pipe 10 to pierce the wall 14 of the pipe 10 and form the cut 26 that defines the flap 16. Piercing involves a certain degree of deformation that is imposed upon the wall 14 of the pipe 10 therefore to ensure that the cut 26 is formed the punch must advance into the chamber 18 of the emitter 12 a distance that takes account of such deformation.

[0038] In some cases during punching, the cutting edge 44 of the cutting tool 38 may meet and slightly carve the border surface 22 that surrounds the chamber 18 as or after it pierces the wall 14 of the pipe 10. Although slightly damaging the surface hit, in most cases this does not affect the performance of the emitter 12. However this may cause a problem, for example, in cases where the emitter is of the type where fluid enters the chamber 18 via an aperture in the base 24 and wherein the base 24 is carved by the punch.

[0039] To reduce the extent to which the cutting tool 38 may be required to enter the chamber 18 to form the cut 26, and thereby the extent of damage that may be imposed upon the border surface 22, the cutting tool 38 is preferably a rotary cutting tool that is adapted to rotate about the tool axis T during the cutting sequence. In such a rotary cutting tool 38, the cutting edge 44 may be located along the full circumference of the rim 42 or may alternatively occupy only a portion of the rim 42.

[0040] The inventors performed studies to determine relations between the tool velocity Cx and the pipe velocity Px that may be used in the production of a drip irrigation pipe 10 in accordance with the present disclosure. The studies indicate that Cx and Px should satisfy a relationship of optionally 1.5Px > Cx > 0.5Px, preferably 1.25Px > Cx > 0.75Px and more preferably 1 lPx > Cx > 0.9Px.

[0041] Attention is now drawn to Fig. 4 to show optional orientations the cutting tool 38 may have in relation to the pipe 10 at the cutting station 36. In orientations A and B, the tool axis T of the cutting tool 38 lies in a plane that includes the pipe and the chamber axes X, Y. In orientation A the tool axis T diverges away from the pipe axis X in the forward direction F and in orientation B the tool axis T converges towards the pipe axis X in the forward direction F. In orientations C and D, the tool axis T of the cutting tool 38 and the chamber axis Y lie in a plane that is perpendicular to the pipe axis X. It is noted that any intermediate orientation located between the aforementioned orientations A, B, C and D is optional for the present disclosure. Preferably, the cutting tool 38 is at orientation A or B in relation to the pipe 10 at the cutting station 36.

[0042] 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.

[0043] Although the present embodiment has been described to a certain degree of particularity, it should be understood that various alterations and modifications could be made without departing from the scope of the disclosure as hereinafter claimed.

ABSTRACT A drip irrigation pipe includes a pipe wall and a drip emitter. The pipe wall has a flap defined by a cut in the pipe wall that remains connected to the pipe wall at a bridge At least a portion of the cut is located about a tool axis that forms an acute angle a with radius of the pipe. 13

Claims

Nov/ 08 18:18 RfcD-Netaf im 972-4-G287446 What is claimed is:

1. A drip irrigation pipe extending along a longitudinal pipe axis, the pipe comprising a pipe wall and a drip emitter, the pipe wall comprising a flap being defined by a cut in the pipe wall, the flap remaining connected to the pipe wall at a bridge, the flap comprising a lid face at the cut and the pipe wall comprising a ground face at the cut, the drip emitter being bonded to the pipe wall adjacent the flap so that water passing through the emitter is able to exit the pipe via the flap, wherein at least a portion of the lid face or ground face, or both, is located about a tool axis that forms an acute angle a with a radius of the pipe as measured at least when the pipe is under internal working fluid pressure.

2. The drip irrigation pipe according to claim 1, wherein the cut is formed by a cutting tool that rotates about the tool axis.

3. The drip irrigation pipe according to claim 2, wherein the cutting tool comprises a cutting edge adapted to perform a circular cut about the tool axis.

4. The drip irrigation pipe according to claim 1, wherein at least a portion of the lid overlies the ground.

5. The drip irrigation pipe according to claim 1, wherein at least a portion of the ground adjacent the bridge overlies the lid. 9 v 08 1 8 R 8. D - fS e t a f i m p . 1 5

6. The drip irrigation pipe according to claim 1, wherein the angle a is greater than or equal to 10 degrees and smaller than or equal to 60 degrees.

7. The drip irrigation pipe according to claim 1, wherein the angle a is greater than or equal to 15 degrees and smaller than or equal to 45 degrees.

8. The drip irrigation pipe according to claim 1, wherein the angle a is substantially 30 degrees.

9. The drip irrigation pipe according to claim 1, wherein: the cut has an oval or part-oval shape in an outer surface of the pipe that extends continuously from a head of the cut towards the bridge; the oval or part-oval shape subtends an angle p, relative to a center of an oval contour to which the oval or part-oval shape belongs, 120° < β < 360°.

10. A method of producing a drip irrigation pipe comprising the steps of: providing a pipe having a longitudinal pipe axis and comprising drip emitters bonded at longitudinally spaced apart locations to a wall of the pipe, at least one of the drip emitters comprising a chamber having a chamber axis. advancing the pipe axially at an axial pipe velocity Px through a cutting station, providing at the cutting station a cutting tool having a catting edge adapted to cut about a tool axis, advancing the cutting tool towards the pipe to perform a cut in the pipe wall that defines a flap and retreating the cutting tool away from the pipe, the tool axis forming an acute angle with the chamber axis at least when performing the cut and the flap remaining connected to the wall at a bridge.

11. The method according to claim 10, wherein the cutting tool is adapted to rotate about the tool axis. 10 ϋ Nov 08 18:19 RiD-Netaf im 972-4-6287446 p.16

12. The method according to claim 10, wherein at each instance of advancement into the pipe wall or retreat out of the pipe wall, the cutting tool has a velocity that comprises a tool velocity Cx along a direction parallel to the pipe axis.

13. The method according to claim 12, wherein Cx and Px are in the same direction.

14. The method according to claim 13, wherein 1.5Px > Cx > 0.5Px.

15. The method according to claim 13, wherein 1.25Px > Cx > 0.75Px.

16. The method according to claim 13, wherein 1. lPx > Cx > 0.9Px.

17. The method according to claim 10, wherein: the cutting edge of the cutting tool has a circular shape; and said step of advancing the cutting tool towards the pipe to perform a cut in the pipe wall creates a cut with a shape of an oval or part oval in an outer surface of the pipe that: extends continuously from a head of the cut towards the bridge; and subtends an angle p, relative to a center O of an oval contour to which the oval or part-oval shape belongs, 120° < p < 360°.

18. A drip irrigation pipe extending along a longitudinal pipe axis and comprising: a pipe wall having a flap defined by a cut in the pipe wall, the flap remaining connected to the pipe wall at a bridge, the flap comprising a lid face at the cut and the pipe wall comprising a ground face at the cut; and a drip emitter bonded to the pipe wall adjacent the flap so that an irrigation fluid passing through the emitter is able to exit the pipe via the flap; wherein: 11 v Οθ 18:19 RID-Netafim 972-4-6287446 p .17 at least a portion of the lid face or ground face, or both, forms an acute angle a with a normal to the pipe wall; the cut has a shape of an oval or part-oval in an outer surface of the pipe that extends continuously from a head of the cut towards the bridge; the shape subtends an angle β, relative to a center O of an oval contour to which the shape belongs, 120° < β < 360°.

19. A method of producing a drip irrigation pipe comprising the steps of: providing a pipe having a longitudinal pipe axis and comprising drip emitters bonded at longitudinally spaced apart locations to a wall of the pipe, at least one of the drip emitters comprising a chamber having a chamber axis; advancing the pipe axially at an axial pipe velocity Px through a cutting station; providing at the cutting station a cutting tool having a cutting edge adapted to cut about a tool axis; advancing the cutting tool towards the pipe with the tool axis forming an acute angle with the chamber axis, such that: the cutting tool forms a cut in the pipe wall to thereby define a flap connected by a bridge to the pipe wall, the cut having a shape of an oval or part- oval in an outer surface of the pipe, the shape extending continuously from a head of the cut towards the bridge, the shape subtending an angle β, relative to a center O of an oval contour to which the oval or part-oval shape belongs, 120° < β < 360°; and retreating the cutting tool away from the pipe. 12