FIELD OF THE INVENTION
This invention relates to an irrigation pipe with plurality of connectors.
BACKGROUND OF THE INVENTION
Modern irrigation typically employs large pipe networks, for example in drip irrigation systems or in flood systems. An irrigation network includes main water supply pipes and irrigation branches deployed and assembled on the field.
The assembly of branches is made usually by specially designed lateral connectors and involves considerable labor costs but does not always prevent leakages.
For example, publications WO 02/066881 and JP08318177 disclose connectors for mounting lateral outlets of small diameter to the wall of a flexible, reliable and collapsible pipe of large diameter. These connectors comprise a tubular member with flaring end and external thread, and a matching nut. The pipe wall is punched in the field, in desired locations on its wall. The flaring end of the connector is then inserted in a wall opening which expands elastically and grips the connector above the flaring end. The connector is secured to the pipe by tightening the nut against the flaring end.
In this application, the term'Yollable pipe" means a pipe that is flexible enough to be rolled in a reel for any purpose, e. g. packaging, transportation, storage, sale, etc. The term" collapsible pipe" means a pipe which tends to collapse when left empty, for example lay-flat pipe. A rollable pipe may be or may not be collapsible.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, there is provided
an irrigation pipe with a plurality of connector elements for attachment of lateral
branches thereto after its manufacture, wherein the connector elements are
integrally fitted to the wall of the pipe during the manufacture. The pipe may be
rigid, Tollable, and collapsible (lay-flat pipe). Preferably, the pipe is adapted for
being cut into a plurality of .sections each having a plurality of the connector
elements. During the manufacture, each of the connector elements may be fitted
open and be adapted for closing after manufacture if not intended for use, or may
be fitted closed and be adapted for opening after manufacture to enable the
attachment. A connector element may be as well fitted open without being
adapted for closing.
In one embodiment, the walls of the pipe are punched during the
manufacture, and open connector elements are fitted on the holes.
In another embodiment, the connector elements are fitted closed by an
enclosure adapted to preserve pipe's fluid tightness under operative pressure. The
enclosure may be, for example, a portion of the wall of the pipe, and/or a portion
of the connector element, and/or a separate body fitted to the connector element,
or may be of other appropriate design. The enclosure may have an annular notch
facilitating the opening.
The connector elements may be fitted for example in the following
positions:
- adjacent the internal surface of said pipe;
- adjacent the external surface of said pipe;
- embracing portions of the internal and the external surface of said pipe;
- embedded between the internal and the external surface of said wall.
The connector elements may be formed from material of the pipe.
Alternatively, the connector element may be a pad fitted closed to the wall
and adapted for boring an opening therethrough in the field, thereby enabling the
attachment.
Examples of means for attachment of the connector elements to the lateral
branches may be: internal or external thread; bayonet lock; a bore with taper
adapted for holding a counterpart element of the lateral branch by friction; a bore
and usage of material adapted for assembly with a self-tapping counterpart
element of the lateral branch, or the like.
In accordance with another aspect of the present invention, there is
provided an irrigation pipe with an extended connector element for attachment of
lateral branches thereto after manufacture, for example in the field, wherein the
extended connector element is integrally fitted to the pipe's wall during
manufacture thereof and is adapted for boring through openings in desired
locations thereof, such that two or more lateral branches can be attached to these
locations.
The extended connector element may be for example an elongated strip
extending parallel to the axis of the pipe, or an annulus (ring) or part thereof, or
an elongated strip disposed along a helical line, or just any pad large enough to
accommodate two or more branch connectors. Preferably, the extended connector
element is made of suitable material, such that counterpart elements of the lateral
branches may be held in the openings by friction or by self-tapping.
In a pipe manufactured from a flat sheet by joining edges thereof in a
seam, the extended connector element may be fitted into the seam.
In accordance with both aspects of the present invention, the pipe may be
produced as high or low pressure resistant hose made of polymer materials
strengthened by bonded layer or layers such as textile, knitted woven or nonwoven
fabric, bi-oriented polymer, high stiffness polymer, etc. Polymer materials
such as PE, PP, PVC, TPE, elastomers and others may be used.
The pipe may be manufactured by any appropriate process, e.g. extrusion,
casting, blowing, welding or bonding of sheet material, etc. In particular, the
integral connector elements may be fitted into the pipe during manufacture by
extrusion by the method for fitting in-line drip emitters, as for example disclosed
in US 5,324,371.
In accordance with yet another aspect of the present invention, there is
provided a method for production of a semi-finished pipe, including: providing a
plurality of irrigation elements; providing strips of flexible weldable or bondable
material, such as polymer sheet; and fitting integrally the connector elements to
predetermined locations on the strip. The irrigation elements may be connector
elements for assembly of lateral branches to said pipe, drip emitters or sprinklers,
etc. The irrigation elements may be fitted, for example, by welding or bonding,
preferably by ultrasonic welding.
The irrigation pipe may be finished on the same or another production line
by bending or twisting the strip so as to juxtapose or overlap its lateral edges, and
welding or bonding integrally the edges so as to obtain a closed pipe section. The
method may include punching holes in the predetermined places.
The bending or twisting may be performed such that the connectors
remain either inside the pipe or outside the pipe.
The edges of the strip may be connected in a straight seam or in a spiral
seam.
In accordance with a further aspect of the present invention, there is
provided a method for production of an irrigation pipe which includes:
- providing a strip of flexible weldable or bondable material;
- bending or twisting the strip so as to overlap lateral margins thereof;
- welding or bonding integrally the margins so as tq obtain a seam and a
closed pipe section; and
- application and welding or bonding an additional tape over the seam, at
the internal and/or external side of the pipe, so as to seal the seam and/or the
edges.
Preferably, the additional tape is welded or bonded to the lateral margins
of the strip before obtaining a closed pipe section.
Preferably, the additional tape is welded by hot air welding.
The integral connectors offer rapid and easy assembly of branching pipes.
The integral connectors are reliably fitted during manufacture, yet the user is able
to choose the locations of the branches in the field. The non-used connector
elements can be easily closed or just may be left unopened. Due to the low
profile of the connector elements, the pipe may be rolled in rather tight reels
suitable for packaging, transportation, storage and sale, etc. The pipe can be
retrieved at the end of the irrigation season. The pipe is cheap, low-weight and
low-volume, and allows easy surface and subsurface installation.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to understand the invention and to see how it may be carried out
in practice, a number of embodiments will now be described, by way of nonlimiting
examples only, with reference to the accompanying drawings, in which:
Fig. 1 is a perspective view of an irrigation pipe of the present invention,
with integral connector elements and branch connectors;
Fig. 2 is an illustration of a collapsible irrigation pipe with integral
connectors rolled on a reel;
Fig. 3 is a sectional view of an internally fitted threaded connector
element in an irrigation pipe, and a lateral branch connector;
Fig. 4A is a sectional view of an externally fitted threaded connector
element;
Fig. 4B is a sectional view of a connector element fitting the irrigation
pipe from both sides;
Fig. 4C is a sectional view of a threaded connector element with threaded
enclosure;
Fig. 4D is a sectional view of a threaded connector element formed from
the material of the irrigation pipe wall;
Fig. 5 is a sectional view of a connector element with external thread and
a matching lateral connector with internal thread;
Fig. 6 is a sectional view of a connector element fitted to an irrigation pipe
and adapted for assembly with a self-tapping lateral connector;
Fig. 7 is a sectional view of a connector element with tapering (cone) bore
adapted for friction assembly with a matching tapered lateral connector;
Fig. 8 is a sectional view of an integral connector element and a lateral
connector constituting a bayonet lock;
Fig. 9 is a sectional view of an internally fitted connector element initially
closed by the pipe wall and a lateral connector with cutting teeth;
Fig. 10 is a sectional view of a connector element fitted between two
layers of an irrigation pipe;
Fig. 11 is a sectional view of a connector element initially closed by an
integral notched lid;
Fig. 12 is a sectional perspective view of an irrigation pipe of the present
invention, with integral connector elements of a second type, prepared for boring;
Fig. 13 is a sectional perspective view of an integral connector element of
the second type fitted in a longitudinal overlap seam of an irrigation pipe;
Fig. 14 is a perspective view of a spiral-welded irrigation pipe with a
connector element of the second type fitted in a spiral seam;
Fig. 15 shows a production scheme of a reliable pipe with integral
connectors; and
Figs. 16A, 16B and 16C show a process of reliable pipe welding with
protective tapes according to the invention.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
With reference to Figs. 1, 2 and 3, an irrigation pipe 10 of the present
invention comprises a pipe 12 and integral pipe connectors 14 fitted to the wall of
the pipe during the manufacture. The pipe connectors 14 are adapted for
assembly with lateral connectors 16 for branching pipes 18. The pipe 10 may be
rolled on a reel 20, as in the example of a collapsible pipe (lay-flat pipe) shown
in Fig. 2.
Figs. 3, 4A, 4B and 10 show integral connectors fitted in the following
positions:
- adjacent to the internal surface of the pipe 12, connector 14 in Fig. 3;
- adjacent to the external surface of the pipe 12, connector 22 in Fig. 4A;
- embracing portions of the internal and the external surface of the pipe
12, connector 24 in Fig. 4B; and
- embedded in the wall of a pipe 28, between two layers 30 and 32
forming the pipe wall - connector 26 in Fig. 10.
As shown in Fig. 4D; an integral connector 36 may be formed from
material of the pipe wall 38.
As seen in Figs. 3 to 8, the walls of the irrigation pipe 12 may be punched
during the manufacture and left open, so that the pipe connectors are fitted open
and ready for assembly with the lateral connectors. In this case, the pipe
connectors 14, 22, 24, 36 may be provided with caps 40 for closing connectors
that will not be used in the field. The caps preserve pipe's fluid tightness under
operative pressure.
Alternatively, as shown in Figs. 9, 10 and 11, pipe connectors may have
integral enclosures preserving pipe's fluid tightness under the operative pressure.
Such pipe connectors can be used for assembly after removal of the enclosure
which may be material of the wall, of the connector, or both.
In particular, Figs. 9 and 10 show integral pipe connectors 42 and 26
respectively, closed by a portion 44 of the pipe wall 12. The portion 44 may be
cut out before assembly by means of a suitable tool (see, for example, Fig. 12,
where such tool is used with connectors of another kind). Alternatively, a lateral
connector 46 may be formed with cutting teeth 48. In the latter case, the pipe
connector 42 may need higher profile to accommodate safely the teeth 48 after
the assembly.
Fig. 11 shows an integral pipe connector 50 made of a single piece of
material with enclosure 52. The enclosure 52 may be made formed with means
for facilitating its removal, for example, an annular notch 54 and a guiding recess
56 for supporting the tip of a rotary cutting tool.
Figs. 3 and 5 to 8 illustrate a few possible means for assembly of the
integral pipe connectors to lateral connectors. Fig. 3 shows the pipe connector 14
with internal thread 58 and a lateral connector 16 with matching external thread
60. As shown in Fig. 5, a pipe connector 62 may be made with external thread 64
while a lateral connector 66 may have an internal thread 68. Fig. 6 shows a pipe
connector 70 with smooth bore 72 made of relatively soft material while a lateral
connector 74 is made with threaded nozzle 76 of relatively hard material such
that the nozzle 76 can be self-tapped into the bore 72. Fig. 7 shows a pipe
connector 78 with a tapered (conical) bore 80 and a matching lateral connector
82 with tapered nozzle 84. The angle of taper and the materials of the connectors
are selected so as to provide reliable grip by friction after assembly. Fig. 8 shows
an integral pipe connector 86 and a lateral connector 88 formed as matching parts
of a bayonet lock with lugs 90 and L-shaped channels 92.
In accordance with another aspect of the present invention illustrated in
Figs. 12 to 14, an irrigation pipe 100 comprises a flexible pipe 102 and an
extended connector element 104 which is integrally fitted to the pipe's wall
during manufacture. The extended connector element 104 has sufficient size,
such that a plurality of bores 106 can be made and lateral connectors can be
attached in desired locations after the manufacture. As seen in Fig. 13, a band
108 of suitable material can be fitted along the irrigation pipe 100 as a continuous
integral pipe connector. Such band is especially suitable for fitting in an
overlapping seam, for example in a spiral-welded pipe 110 as shown in Fig. 14,
or in the straight-seam pipe 100 of Fig. 13
The integral connector element 104 or 108 may be bored by a rotary tool,
such as the tool 112 in Fig. 12, for assembly with a self-tapping lateral connector
such as 74 in Fig. 6, or with a tapered lateral connector held by friction, such as
82 in Fig. 7.
With reference to Fig. 15, there is shown an exemplary production scheme
of a reliable polymer pipe 10 with integral connectors 14, according to yet
another aspect of the present invention. The production is performed on a
conveyor line 111 including: feeding reel 113 for feeding raw strip'material 114,
strip accumulator 116, connectors fitting section 120, piping apparatus 121,
puller 122, printing and monitoring station 124, pipe accumulator 126, and a
receiving reel 20 for the pipe 10.
The connectors fitting section 120 includes connectors stock feeder 130, a
drum magazine 132, a feeding plunger 134, a chute 136, welding equipment units
138 , a pulling unit 140, and an optional punching device 142.
In the operation of the conveyor, the raw polymer sheet material is first
cut into strips 114 of predetermined width, and is wound on feeding reels 113
(this process is done before the reel 113 is loaded to the line 111). The strip 114
is fed to the accumulator 116 and further to the connector fitting section 120.
In the connector fitting section 120, the connectors feeder 130 loads the
drum magazine 132 with pipe connectors 14 arranging them in predetermined
orientation. The drum magazine 132 rotates in steps, at predetermined intervals
of time, and the feeding plunger 134 periodically pushes a connector 14 down the
chute 136. The connector is directed to the welding units 138.
The raw strip 114 is also directed to the welding units 138, the connector
14 is positioned on the flat strip 114 and ultrasonic welding or RF (microwave)
welding is performed. The strip 114 is pulled by the puller unit 140. The strip
114 may be optionally punched at the openings of the connectors in the punching
device 142, before or after the welding, in dependence, for example, on the
configuration of the connector.
The strip 114 with welded connectors 14 is then fed to the piping
apparatus 121. There, the strip is bent (twisted) into a sleeve with juxtaposed
edges or overlapping margins, and the edges or margins are welded by a
watertight seam into a pipe with closed section. The connectors may remain
either at the outer side of the pipe, or at the inside, as desired. The pipe 10 may
be welded by the same method as the connectors, or by a different one.
The ready pipe 10 is pulled by the puller 122, checked and stamped in the
printing and monitoring station 124 and, via the accumulator 126, is wound on
the receiving reel 20.
With reference to Figs. 16A, 16B and 16C there is shown a process of
Tollable or collapsible pipe production with protective tapes, according to the
present invention. Before feeding the polymer strip 114 (the same strip as above)
into the piping apparatus 121, two narrow protective tapes 132 and 134 are
welded to the margins of the strip (shown in cross section in Fig. 16A, welding
zone 136 between either tape and the strip being exaggerated). In the piping
apparatus 121, the strip is bent (twisted) into a sleeve with overlapping margins,
as seen in Fig. 16B, and the sleeve is welded into a pipe (overlapping welding
zone 140 also shown exaggerated). A tight seam 142 is formed, as shown in
Fig. 16C, where cut edges 138 are tightly covered by the protective tapes 132 and
134.
The polymer strip 114 for making a pipe usually has layered structure,
including polymer film or fabric and various laminating and coating layers. The
function of the protective tapes is to prevent the irrigation water from penetrating
between these layers from the cut edge 138, and weakening the pipe. The
protective tapes are preferably thin polymer tapes.
The welding of the tapes and the strip edges is done preferably by hot air,
without using additional adhesives. It would be appreciated that the welding or
bonding may be done by other known technologies like using adhesives, RF
welding and others. As it is more important to protect the inner edge, the outer
tape 132 may be omitted.
Although a description of specific embodiments and methods has been
presented, it is contemplated that various changes could be made without deviating
from the scope of the present invention. For example, the integral connectors may
be arranged in two rows along the pipe, or may be fitted with tearable caps similar
to ones in liquid bags. The fitting of the integral connectors may be performed by
pressing, press-heating or other methods. The pipe may be punched before fitting
the connectors, etc. The method of fitting to the strip before forming a closed pipe
may be used for attaching other irrigation elements such as drip emitters or
sprinklers (nozzles). The production scheme may include rolling of the strip with
fitted irrigation elements into a reel on one production line (e.g. after the elements
welding) as semi-finished product, and forming of the pipe in a piping apparatus on
another production line.

CLAIMS:
1. An irrigation pipe (10) with a plurality of connector elements (14) adapted for attachment of lateral branches thereto after the manufacture thereof, wherein said connector elements are integrally fitted to said pipe's wall during said manufacture, characterized in that at least one of said connector elements is formed with internal or external thread or is formed as a member of a bayonet lock, thereby enabling said attachment, and the connector elements have a low profile so that the pipe is rollable on a reel.
2. A pipe as claimed in Claim 1, wherein said pipe (10) is adapted for being cut into a plurality of sections each having a plurality of said connector elements.
3. A pipe as claimed in Claim 1, wherein, during said manufacture, each of said connector elements (14) is either fitted open and is adapted for closing after manufacture if not intended for use, or is fitted closed and is adapted for opening after manufacture to enable said attachment.
4. A pipe as claimed in Claim 3, wherein said pipe (10) is rollable on a reel.
5. A pipe as claimed in Claim 4, wherein said pipe (10) is collapsible.
6. A pipe as claimed in Claim 3, wherein at least one of said connector elements (14) is open and is fitted on a hole punched in said wall during said manufacture.
7. A pipe as claimed in Claim 3, wherein at least one of said connector elements (14) is fitted closed by an enclosure which is one or more of the following:

- a portion (44) of the wall of said pipe;
- a portion (52) of said connector element;
- a separate body (40) fitted to said connector element.
8. A pipe as claimed in Claim 7, wherein said enclosure (52) has an annular
notch (54) facilitating said opening.
9. A pipe as claimed in Claim 1, wherein at least one of said connector elements is formed from material of said pipe.
10. A pipe as claimed in Claim 1, wherein at least one of said connector elements (78) is formed with a bore and is adapted for holding a counterpart element of the lateral branch in said bore by friction or by self-tapping of said counterpart element.
11. A pipe as claimed in Claim 11, wherein said bore is tapered.
12. A pipe as claimed in Claim 1, wherein at least one of said connector elements is formed with a through bore and said pipe wall has a corresponding hole made during manufacture.
13. A pipe as claimed in Claim 3, wherein at least one of said connector
elements is a pad (104) fitted closed and adapted for boring an opening
therethrough in the field, thereby enabling said attachment.