The present invention concerns a pipe suitable for use in drip irrigation with integrally built-in dripper units, a method of manufacture of such a pipe and a machine for producing such a pipe.
The invention concerns particularly an irrigation pipe with a ~ripper unit of the kind comprising a cylinder provided with a continuous groove on its peripher~l surfaces and being tightly surrounded by a sleeve, the groove having an integral inlet in the cylinder while an outlet therefrom is provided in the sleeve. The groove may be a continuous spiral, may have a labyrinth path or may be of any of the Xnown shapes, which reduce the pressure of the water from the ~upply pipe, so that it leaves the dripper unit in a trickle.
Such a dripper unit will hereinafter be referred to a~ "a dripper unit of the kind defined~.
A dripper unit of the kind defined has up to now been manufactured with screw threads at both ends or with any other suitable means, so that it could be connected to an irrigation pipe adapted for this purpose.
It is an object of the present invention to provide an irrigation pipe with a dripper unit of the kind defined in which the dripper units cons~itute an integral part of the pipe without the necessity of assembling them at the irriga-tion site. It is obvious that because of such a pipe much labour and time is saved when laying the pipe for irrigation, since the units do not have to be attached at the required ~paces.
According to one aspect of the present invention
- 2 _ 10537Z6 there is provided a pipe ~uitable for use in drip irrigation which pipe comprises piping and dripper units of the kind defined at predetermined intervals along the length thereof, the piping constituting outer sleeves of the dripper units.
According to a second aspect of the present invention there is provided a method of producing by extru-sion a pipe suitable for use in drip irrigation, which method comprises feeding dripper units, during the extrusion of piping into an extruder at predetermined intervals, extruding the piping around the dripper units and making at least one aperture in the piping aligned with each of the dripper units.
According to a third aspect of the present invention there is provided a machine for producing a pipe suitable for use in drip irrigation, which machine comprises an extrusion means having an extruder nozzle for extruding piping, a storage unit for dripper units and a means for feeding the dripper units to the extruder nozzle so as to enable production of piping having dripper units at prede-termined intervals along the length thereof.
Preferably, the pipe is a continuous irrigation pipe.
For a better understanding of the present invention and to show how the same may be put into effect, reference will now be made, by way of example, to the accompanying drawings, in which:
Fig. 1 shows a longitudinal section of an irrigation pipe according to the invention, containing a dripper unit as hereinbefore defined.
Fig. 2 shows a schematic elevational view of a machine for manufacturing a pipe for drip irrigation according 1~537~'., to the invention, and Fig. 3 shows a side elevation illustrating the dripper feed mechanism.
Referring to the drawings, Figure 1 shows an extruded irrigation pipe 1 which serves as a sleeve of a dripper unit having a cylindrical part 2 and being provided with a peripheral helicoidal groove 3, it being understood that the groove may have a labyrinth path or be of any other shape which is adapted to reduce the pressure of the flow.
An inlet 4 made in the cylindrical part 2 leads from the interior of pipe 1 into groove 3 while an outlet 5 from the groove i8 provided in the pipe.
As can be seen in Fig. 1J pipe 1 is stretched somewhat over the cylinder 2, that is the pipe is of larger diameter in the region of cylinder 2. However, the internal dlameter of pipe 1 and cylinder 2 are egual, so that free flow of that part of the water which does not enter grooves
3 is permitted throu~h part 2.
The pipe of Fig. 1 is produced as can be seen in Fig. 2 in anfextruder 6 having a head 7 at an angle to the extension of the ~crew (not shown). This type of head 7 is known for producing cove~ed cables or sheathed wires.
If desired, a regular ~traight-line extruder head may be used which i8 adapted to feed the dripper unit to the nozzle at predetermined interval~.
Behind said head a dripper unit feed mechanism generally indicated by 8 is provided. This mechanism comprises a storage unit 9 in which a plurality of inner dripper parts 2 are disposed. These cylindrical parts 2 are fed into a position coaxial with the extruder nozzle 10 by a piston-~0~37Z~;
operated feed device 11 which may be actuated by hydraulic,pneumatic or other means.
At predetermined time periods,or~ i desired, at predetermined distances, i.e. after a predetermined length of pipe has been extruded, a dripper part 2 is fed into the extruder head 7 by means of a pu her mechanism 12, which may be operated by pneumatic, hydraulic or other means. When such a part 2 is inserted into the extruder head 7, the pipe is extruded around it through nozzle 10.
A sensing mechanism in combination with a drill, knife point or the like indicated generally at 13 is provided near the extrusion nozzle at a distance to permit the cooling of the pipe after its extrusion. This drill 13 makes an outlet 5 in the pipe of the wall in the required position.
If desired, two such mechanisms may be provided in diametrically opposite positions to make two apertures 5 in pipe 1 as shown in Fig. 1.
The control of the feed mechanism, push mechanism 12 and drilling mechanism 13 can be effected in any suitable manner, either by electrical, electronic, mechanical or the like control means.
It is, of course, understood, that the pipe together with its dripper unit constitutes pressure reducing means, which may be used where required for purposes other than irrigation.