US3896999A

US3896999A - Anti-clogging drip irrigation valve

Info

Publication number: US3896999A
Application number: US508631A
Authority: US
Inventors: Jaime Sahagun Barragan
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-09-28
Filing date: 1974-09-23
Publication date: 1975-07-29
Anticipated expiration: 1992-07-29

Abstract

An anti-clogging drip irrigation valve or dropper which can be unclogged without the need of disassemblage, comprises a flat relatively thick elongated assembly having a flexible film cover member, a relatively thick highly flexible member laminated to said cover member, at least one elongated channel means opening towards one of the faces of said highly flexible member opposite to the face laminated to said cover member, a plurality of partition means integrally formed with said highly flexible member and located within said elongated channel means in order to form labyrinth conduit means with a first cavity means formed at one of the ends of said elongated channel means and a second cavity means formed at the opposite end of said elongated channel means; and complementary cover means attached to said opposite face of said highly flexible member and to said partition means at their free ends, so as to complete a labyrinth passage means with said labyrinth conduit means and a first and a second respective chamber means with said first and second cavity means; fluid entrance means at one of said chamber means; and fluid outlet means at the other of said chamber means. The highly flexible nature of said relatively thick elongated assembly provides for the capability of said assembly to be squeezed and deformed to release all the obstructions or clogs which might have been deposited by the flowing fluid, in order to prevent clogging of said labyrinth passage means. The flat relatively thick elongated assembly can be directly attached to a complementary cover means consisting of a drip irrigation pipe having a hole in a position matching one of said chamber means to act as the fluid entrance means, or can be permanently adhered to a complementary cover means comprising a film member to form a disposable valve unit having connecting fluid entrance means at one of said chamber means to be inserted into a drip irrigation pipe.

Description

United States Patent [191 Barragzin [451 July 29,1975

1 1 ANTI-CLOGGING DRIP IRRIGATION VALVE [76] Inventor: Jaime Sahagun Barragn, Calle del Teco 287, Michoacan, Mexico [22] Filed: Sept. 23, I974 211 Appl. No.: 508,631

[30] Foreign Application Priority Data [56] References Cited UNITED STATES PATENTS 3,080,124 3/1963 Rathmann 239/542 X 3,578,020 5/1971 Rochte et a1. 137/525 X Hayner et a1. 138/42 Spencer 239/542 Primary Examiner-Robert S. Ward, Jr. A Attorney, Agent, or Firm-Imirie, Smiley & Linn Y 57] ABSTRACT .An' anti-clogging drip irrigation valve or dropper which can be unclogged without the need of disassemblageQcompris'es a flat relativelythick elongated assembly having a flexible film cover member, .a relatively'thick highly flexible member laminated to said cover member, at least one elongated channel means opening towards one of the faces of said highly flexible member opposite to the face laminated to said cover member, a plurality of partition means integrally formed with said highly flexible member and located within said elongated channel means in order to form labyrinth conduit means with a first cavity means formed at one of the ends of said elongated channel means and a second cavity means formed at the opposite end of said elongated channel means; and complementary cover means attached to said opposite face of said highly flexible member and to said partition means at their free ends, so as to complete a labyrinth passage means with said labyrinth conduit means and a first and a second-respective chamber means with said first and second cavity means; fluid entrance means at one of said chamber means; and fluid outlet means at the other of said chamber means. The highly flexible nature of said relatively thick elongated assembly provides for the capability of said assembly to be squeezed and deformed to release all the obstructions or clogs which might have been deposited by the flowing fluid, in order to prevent clogging of said labyrinth passage means.

The flat relatively thick elongated assembly can be directly attached to a complementary cover means consisting of a drip irrigation pipe having a hole in a position matching one of said chamber means to act as the fluid entrance means, or can be permanently adhered to a complementary cover means comprising a film member to form a disposable valve unit having connecting fluid entrance means at one of said chamber means to be inserted into a drip irrigation pipe.

10 Claims, 17 Drawing Figures PATENTEI] JUL 2 91975 SHEET PATENTED JUL 2 9 I975 SHEET SHEET PATENTEU JUL 2 9 I975 rlllil I. Illi- ANTI-CLOGGING DRIP IRRIGATION VALVE BACKGROUND OF THE INVENTION The present invention refers to an anti-clogging drip irrigation valve or dropper which can be attached to a drip irrigation pipe or which can serve as a separate disposable element to be connected thereto and, more particularly, it is related to an anti-clogging drip irrigation valve which is formed by a labyrinth passage provided in a highly flexible assembly in order to provide for its deformation by squeezing so as to release any obstruction or clog which might have been introduced in the passage.

As is well known, the drip irrigation method comprises applying irrigation fluid in a perfectly controlled manner to the neighborhood of the plants in order to keep a proportion of moisture necessary to provide for its growth with a minimum consumption of liquid. The drip irrigation systems require pipes which are installed along the rows of plants and include bores to which special droppers or valves are adapted, said valves being coupled to the pipes at points suitable to control the outlet of liquid. The valves which have been used in accordance with the prior art for the purpose of controlling the outlet of the liquid from the drip irrigation piping, can be generally embodied into two different types, namely, drop'pers acting by obstruction and droppers acting by friction.

The first type of droppers or valves includes a large multiplicity of different types of drip irrigation devices having a member capable of gradually'closing and opening the bore of the valve in order to provide for the dropwise emission of the liquid, such as is necessary for this type of systems. The droppers or valves working by friction, on the other hand, are provided with a very long and narrow passage in order to force the irrigation liquid to flow throughout the length of said passage, whereby a pressure drop by friction is produced sufficient to obtain the dropwise emission of the liquid at the outlet end of the passage.

A variant developed in the last years in connection with this type of drip irrigation devices comprises a valve having a relatively long and narrow passage to cause high friction losses, by the incorporation of baffies or the like causing sharp changes of direction in the path of the fluid flow, so as to cause impacts and turbulences to produce a higher friction loss in each change of direction, thereby enabling decrease in the lengths and increase in the cross sections of the prior art passages.

The valve systems operating by obstruction, however, have left much to desire, inasmuch as, regardless of the fact that they are capable of preventing clogging in view of their characteristics of comprising a movable member which can be removed to clean the valve, they are nevertheless very difficultly controllable and very easily disadjustable. Also, when there is a large amount of said valves in an irrigated land, the control of each of the valves is very troublesome, whereby these systems have been falling in disuse, by virtue of the very high labor costs for maintenance and control thereof. In effect, very frequently some of the droppers or valves emit excessive amounts of irrigation liquid while others are clogged and do not permit flow of liquid, whereby there is a high disuniformity in the irrigation rate, which is detrimental to the growth of the plants being served thereby.

On the other hand, the drip irrigation systems having valves systems working by friction loss have been built in accordance with the prior art as members containing a spiralling passage, with or without changes of direction, said passage being excessively narrow and, therefore, highly susceptible to be very frequently clogged by foreign matter or by the deposition of salts, particularly so in those places which are in the proximities of the liquid outlet, where the solar or ambient heat evaporates the liquid and gradually deposits salts which eventually completely obstruct said passage.

In United States copending patent application Ser. No. 288,629 filed by the same applicant on Sept. 13, 1972, there is disclosed and claimed a one-piece drip irrigation device which causes a pressure drop in the liquid from the irrigation pipe by the provision of a passage operating mainly by very frequent and sharp changes of direction of the flow and by impact of the liquid on a plurality of partitions or baffles, and which also partially solves the above mentioned problem of clogging of the passage, in view of the fact that said passage can be of a relatively large cross section, whereby clogging of the same is minimized. Also, in the CIP United States copending patent application Ser. No. 443,660 filed on Feb. 19, 197-4 by the same applicant, there is shown and described a modified drip irrigation device which operates under the same above mentioned principles but which can be manufactured in the form of a continuous strip or ribbon having spaced labyrinth passages formed therein, said ribbon being attached to a drip irrigation pipe having bores matching one of the ends of said passages and the liquid being emitted through suitable slits or bores placed at the opposite end of said passages. While the devices described and claimed in the above mentioned copending United States patent applications partially solve the problems of clogging, the fact still remains that, if said drip irrigation devices are clogged by the deposition of salts at the places near the liquid outlets by evaporation of the liquid, or by the entrance of foreign matter into some of the chambers formed in the labyrinth, thereby obstructing the same, it will be impossible to remove the clogs unless the devices are completely disassembled from the drip irrigation pipes forcleaning purposes. In other words, as the passages through which the liquid flows in this type of devices are generally integrally adhered to the outer walls of the drip irrigation pipes, it is not possible to unclog said devices, which therefore greatly precludes the functionality thereof.

BRIEF SUMMARY OF THE INVENTION Having in mind the defects of the prior art drip irrigation valves, it is an object of the present invention to provide an anti-clogging drip irrigation valve of the labyrinth type, which will solve all the problems of the prior art devices and will be of a very simple and economic construction.

It is another object of the present invention to provide an anti-clogging drip irrigation valve of the above mentioned character, which can be used directly attached to a drip irrigation pipe or as a separate unit engageable to a drip irrigation pipe to serve as a disposable dropper.

It is a more particular object of the present invention to provide an anti-clogging labyrinth type drip irrigation valve of the above mentioned character, which will provide for the removal of any clog which might be accidentally introduced within the labyrinth passage thereof.

One more object of the present invention is to provide an anti-clogging drip irrigation valve of the above mentioned characteristics, which will be highly economical both as to its fabrication and as to its use and which will not require of any type of control to effectively work.

Still one more object of the present invention is to provide an anti-clogging drip irrigation valve of the above mentioned character, which can be manufactured in the form of a flexible continuousribbon or in the form of separate short elements, both suitable to act in combination with a drip irrigation pipe having suitable bores.

BRIEF DESCRIPTION OF THE DRAWINGS The novelfeatures that are considered characteristic of the present invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the-following description of specific embodiments when read in connection with the accompanying drawings,.in which:

FIG. 1 is a top plan view of a first embodiment of a drip irrigation valve built in accordance with the present invention, showing the face having formed therein a labyrinth shaped channel and reception and emission cavities, with its complementary cover member removed to show inner details;

FIG. 2 is an elevational cross sectional view taken along lines 22 of FIG. 1 and looking in the direction of the arrows, showing the laminated structure of the valve in accordance with the present invention, as well as a complementary cover member attached thereto;

FIG. 3 is a cross sectional view taken along lines 3-3 of FIG. 1 and looking in the direction of: the arrows, also showing the said complementary cover member;

FIG. 4 is a side elevational view, partly broken away to show inner details, of the device built in accordance with the first embodiment of the present invention, together with a fluid supply pipe to which it is associated;

FIG. 5 is a cross sectional view taken along lines 5-5 of FIG. 4 and looking in the direction of the arrows;

FIG. 6 is a view similar to FIG. 4, showing a second embodiment of a drip irrigation valve built in accordance with the present invention,'in the form of a continuous ribbon having separate labyrinth passages associated to respective bores of the complementary pipe, and partly broken away to show inner details thereof;

'FIG. 7 is a bottom plan cross sectional view taken along lines 77 of FIG. 6 and looking in the direction of the arrows;

FIG. 8 is a view similar to FIG. 7, partly broken away to show inner details thereof, and showing still another embodiment of a drip irrigation valve built in accordance with the present invention;

F IG. 9 is a cross sectional elevational view of a drip irrigation valve built in accordance with the present invention, adhered to a pipe formed by a pair of flexible sheets sealed together at their edges;

FIG. 10 is a view similar to FIG. 9 but showing the drip irrigation valve of the present invention adhered to the inner wall of the pipe;

FIG. 11 is a view similar to FIG. 9 showing a drip irrigation valve built in accordance with the present invention, as adhered to a pipe formed by a flexible sheet sealed at the free edges thereof;

FIG. 12 is an elevational cross sectional view of the device shown in FIGS. 9 and 11, but showing the pipe already expanded by the passage of liquid therethrough;

FIG. 13 is a fragmentary cross sectional perspective view showing an embodiment of the drip irrigation valve in accordance with the present invention, in combination with a pipe formed by an overlapped sealed flexible sheet;

FIG. 14 is a cross sectional elevational view of a particularly preferred embodiment of a drip irrigation valve built in accordance with another embodiment of the present invention, in the form of a disposable dropper or valve unit connected to a drip irrigation pipe;

FIG. 15 is a cross sectional view taken along lines 15-15 of FIG. 14 and looking in the direction of the arrows;

FIG. 16 is a fragmentary cross sectional elevational view of an additional embodiment of a disposable dropper or valve built in accordance with the present invention, as connected at its upper end to a bore provided at the lowermost portion of the associated pipe; and

FIG. 17 is a fragmentary cross sectional elevational view of still another embodiment of a disposable dropper or valve as connected to a flexible tube which in turn can be connected at its free end to a suitable fluid supply pipe.

DETAILED DESCRIPTION Having now more particular reference to the drawings and more specifically to FIGS. 1 to 5 thereof, there is shown a drip irrigation valve built in accordance with a first embodiment of the present invention, which is generally illustrated in said figures by reference character 11, and comprises an elongated rectangular relatively thick flat plate 14 of a highly flexible material, preferably a plastic foam material having closed or isolated cells, provided that it has compressible characteristics for a purpose which will be more clearly apparent in the following description. The plate 14 of flexible material can have flanges 15 at all its four edges, for suitable engagement to a counterpart or complementary member 12 (not shown in FIG. 1) and is covered at its outer face by means of a laminated flexible film 13, in order to suitably protect said plate against external agents, as well as to reinforce the assembly to support fluid pressure.

At the opposite face, that is, at the face that will be attached to the above mentioned counterpart 12, plate 14 of element 11 built in accordance with the first embodiment, of the present invention is provided with a channel made in the form of a labyrinth by the provision of a plurality of walls or upstanding partitions 20, placed symmetrically and alternately within a cavity as clearly shown in FIG. 1 of the drawings, to provide a fluid passage 21, a reception chamber 18 at one end of said passage and an emission chamber 19 at the other end of said passage for a purpose which will be described in full detail hereinbefore. Passage 21 produces, as indicated by the arrows shown in FIG. 1, a large number of sharp changes of direction in the flow of the irrigation fluid, whereby said fluid will suffer considerable pressure drop from the reception chamher 18 to the emission chamber 19, in order to provide a flow from the emission chamber 19 which will be very slow and practically dropwise, such as is necessary in the drip irrigation systems to which this invention refers.

The flexible nature of the material of plate 14, including the partitions 20 forming the labyrinth passage 21 clearly illustrated in FIG. 1 of the drawings, as well as the flexible nature of the cover film 13, enable the device built in accordance with this first embodiment of the invention to be squeezed either manually or by means of a roller or the like, such that, if the labyrinth 21 be obstructed, either by the deposition of salts from evaporated liquid or by the introduction of debris therein, said obstruction can be removed by squeezing said drip irrigation device, either periodically in a maintenance-like manner or through specific needs of removing clogging therefrom.

The device built in accordance with the illustrative embodiment presently described, can be directly adhered to a rigid drip irrigation pipe 12, such that a bore 17 provided in the wall thereof will match the reception chamber 18 of the valve 11, to receive the irrigation fluid which flows through the pipe 12 at a predetermined pressure and to convey it through passage 21 formed between the partitions 20 and the wall of pipe 12, in order to reduce the pressure thereof to a predetermined value such that, at the emission chamber 19, said liquid will have a highly reduced pressure which will force it to flow very slowly, that is, in a dropwise manner, through suitable outlet means such as a slit or an orifice. In the particularly preferred embodiment of the present invention said outlet means comprises a loose tongue section 115 of flange corresponding to the extremity of the emission chamber 19, such that a check valve 22 is formed, as illustrated in FIG. 4 of the drawings. As long as there is pressure within the emission chamber 19, said check valve 22 will be opened by the flowing liquid in order to permit the dropwise emission thereof. However, when the flow of liquid through the pipe 12 ceases and certain vacuum is applied to the emission chamber 19, the loose tongue 115 is forced to bear against the wall of pipe 12, thereby closing the check valve 22 in order to prevent the back entrance of ambient debris. The provision of this type of check valve 22 at the emission chamber 19 of the valve 11 built in accordance with this embodiment of the invention, which is rendered possible by the flexibility of the material of plate 14, avoids the possibility of clogging of passage 21 by the entrance of dirt or debris from the surroundings when the flow of the irrigation fluid through the pipe 12 ceases and a partial vacuum is applied to the emission chamber 19 thereby otherwise enabling the sucking in of such dirt from the environment. By the provision of the flexible loose tongue 115 adjacent the wall of the pipe 12 in accordance with the above, said tongue 115 will act to provide a check valve 22, thus permitting the emission of liquid from the emission chamber 19 but preventing the entrance of foreign matter through said check valve 22, when cer tain suction is applied to the chamber 19, inasmuch as, under these conditions, the loose tongue 115 will be forced against the wall of the pipe 12 and will completely close the check valve 22.

If in spite of the above, some dirt builds up in any portion of passage 21 or in any of

chambers

18 and 19 of the dropper or valve 11, then the flexibility of plate 14 provides the additional possibility of squeezing the whole of the assembly 11 by means of the fingers or by means of a roller or the like, to substantially alter the shape of the valve 11, whereby the accumulated dirt will be released and thrown out of the system through the check valve 22 in a suitable manner.

Such as will be clearly apparent to any one skilled in the art, the valve or dropper device 11 built in accordance with the present invention can adopt a diversity of shapes other than that particularly and illustratively described in connection with FIG. 1 to 5 of the drawings. Therefore, in FIGS. 6 and 7 of the drawings there is illustrated a valve 11 built in accordance with the present invention, comprising a plate of highly flexible material 14 and a flexible cover film 13, but this illustrative embodiment of the invention having the shape of a ribbon or continuous strip with labyrinths 21 distributed throughout its length, with respective reception and

emission chambers

18 and 19, said labyrinths being spaced from each other by solid intermediate blocks 24, and said ribbon-like plurality of valves 11 being built by means of a pair of side vertical walls 23 and a plurality of partitions 20 which force the fluid to change direction in its flow through the passage 21 such as it can be clearly seen in FIGS. 6 and 7 of the drawings. In the particular case of a multiple dropper or valve device 11 having the shape ofa continuous ribbon built in accordance with the presently described embodiment, high reductions in labor cost can be achieved in view of the fact that this device can be previously attached to a pipe 1.2, previously providing bores 17 suitably distributed throughout the length of said pipe, matching the respective reception chambers 18 of each labyrinth 21 and leaving a section of the wall of pipe 12 loosely attached to a tongue section of the side wall portions 23, to form the check valve also designated by reference character 22 in FIGS. 6 and 7 of the drawings, so that the emission chambers 19 will discharge through said sidewardly provided check valve 22, such as previously described in connection with FIGS. 1 to 5 0f the drawings. The performance of the continuous ribbon-like dropper or valve 11 is exactly the same as that described for the individual valve elements 11 illustrated in FIGS. 1 to 5 of the drawings, whereby it is considered unnecessary to go into any further detail in connection therewith.

As it will be obvious to any one skilled in the art, the dropper or valve device 11 of the present invention, either built in the form of separate elements or patches such as those of FIGS. 1 to 5, or in the form of a continuous ribbon-like multiple element such as that of FIGS. 6 and 7, can be provided with passages 21 in the form of labyrinths having different designs, such as more particularly illustrated in FIG. 8 of the drawings. In said figure it can be seen that in accordance with a third embodiment of the present invention, a continuous ribbon-like element is provided, for instance, comprising a pair of side walls 23 and dropper-spacing blocks 24 along the length of the ribbon, and reception and

emission chambers

18 and 19 both located at the central portion of said dropper or valve 11, the latter being attached to pipe 12 such that the bores 17 provided in the said pipe, will match corresponding reception chambers 18.

The labyrinth passage 21 is formed between said side walls 23 and a longitudinal central baffle 25 provided with a plurality of transverse partitions 26 staggered with a corresponding plurality of partitions 20 projecting from each one of said side walls 23. An emission chamber 19 is provided at the end of the path of the above mentioned labyrinth, a portion of the side wall 23 bounding said chamber 19 being loosely engaged to the wall of pipe 12, such as illustrated at 22, in order to form the above described check valve which permits the dropwise discharge of the fluid but prevents the backflow of debris into the device.

In the particular case of the embodiment of FIG. 8, the irrigation liquid enters through opening 17 of the pipe, passes to the central reception chamber 18 of the dropper or valve 11, flows towards the left as illustrated in FIG. 8 along one side of the central baffle 25, then back towards the right along the opposite side of baffle 25 and then again back towards the left along the one side of said baffle 25 to the central portion of the dropper 11 to be discharged through the emission chamber 19 which is adjacent the reception chamber 18.

It will also be obvious to any one skilled in the art that great variations of the structures and designs of the labyrinths formed within the droppers or valves 11 built in accordance with the present invention are possible, but all such modifications must be construed as embodied within the true scope and spirit of the present invention, inasmuch as the manner of building such labyrinths is irrelevant as long as the material forming the plate 14 with its partitions be highly flexible to enable full squeezing thereof to release clogs from passage 21, and as long as the outlet means for the liquid from the emission chamber be preferably provided by a check valve formed by the loose portion of the side wall of said chamber, which permits opening of said portion when there is pressure within the emission chamber but prevents the entrance of foreign matter when a certain vacuum is applied thereto.

FIGS. 9 and 10 of the drawings illustrate a dropper or valve device 11 in accordance with any embodiment of the present invention, in combination with a pair of flexible sheets 27 sealed at their edges as shown at 28, in order to form a pipe which, once inflated by the passage of the fluid, would remain approximately in the disposition shown in FIG. 12 of the drawings. The arrangement of the openings 17 in one of the flexible sheets 27 of the pipe 12 will be such that they match the reception chambers of the labyrinths 21 of the valves 11. Also, the valve 11 can be arranged either inside (FIG. 10) or outside (FIG. 9) of the pipe, indistinctly. When inside, the fluid entrance means 22 will be provided by a bore as shown in FIG. 10.

The valve 11 of the present invention can also be applied to a pipe made of a single flexible sheet 27 such as illustrated in FIG. 11 of the drawings, the side edges of said sheet being sealed together as shown at 28, the dropper 11 working in combination with the thus formed pipe 12, once the latter has been inflated by the fluid, such that it will be arranged as shown in FIG. 12 of the drawings.

Still another embodiment of the association of a dropper or valve 11 and liquid supply pipe 12 in accordance with the present invention is illustrated in FIG. 13 of the drawings, wherein the valve 11 is attached on the outside or on the inside of a pipe 12 formed by a single plastic sheet sealed at its ends such that said ends are overlapped as illustrated at 29.

It will thus be seen that the dropper or valve device 11 in accordance with the embodiments shown in FIGS. 9 to 13 of the drawings, as provided either on the inside or on the outside of at least one flexible sheet which will thereafter form the pipe 12, enables plant production of a complete prefabricated drip irrigation unit having a pipe and a plurality of droppers, ready to be used in the field and easily transportable while in a folded condition. The deformable characteristics of both the flexible sheet forming the pipe 12 in accordance with FIGS. 9 to 13 of the drawings and of the plate 14 of the droppers or valves 1 1, besides providing fully foldable and easily handled units, also fully provide for removal of clogs from the droppers, in order to provide a controlled, continuous and efficient performance thereof.

The valve or dropper device in accordance with the present invention can adopt a highly preferred form which will be described hereinafter in connection with the embodiments shown in FIGS. 14 to 17 of the accompanying drawings, in which said dropper or valve is illustrated as an independent disposable unit 10. The unit dropper or valve 10 comprises a relatively thick plate 14 built with a highly flexible material such as a plastic foam having separate or closed cells, said plate being provided with side flanges 15, if desired and having laminated thereto a flexible cover sheet 13, on one of its faces, the channel 21 in the form of a labyrinth being provided, as previously described, by the projecting partitions 20. The valve or dropper 10 according to the particularly preferred embodiment of this invention is completed by attaching to the opposite face of plate 14, an additional flexible sheet 30, thereby forming a closed structure having a labyrinth passage 21, a reception chamber 18 and an emission chamber 19 with the tongue at the end of sheet 30 to provide the check valve 22 as shown in FIG. 14.

The disposable unit valve 10 can be used in a diversity of manners and thus, as clearly illustrated in FIG. 14 of the drawings, said disposable unit can be provided with a short tubular connector 31 which has supporting flanges 33 provided within the reception chamber 18 of the valve 10, and flanges 32 provided at the opposite end of the connector 31 to be introduced with pressure fit through the corresponding opening 17 of the drip irrigation pipe 12 so as to seal such connector 31 in a fluid tight manner to the opening 17 sidewardly provided in pipe 12.

The unit valve 10 in accordance with FIG. 14 can be used as an underground device, with part thereof buried, inasmuch as the provision of the check valve 22 will prevent any backflow into chamber 19, thereby also avoiding the introduction of debris and the like into the passage 21.

When the efficiency of the drip irrigation valve of the invention is reduced by prolongued use or by mistreatment, then said valve may be easily replaced, inasmuch as the valve 10 built in accordance with this embodiment of the invention is a very low cost disposable unit.

As a slightly modified embodiment of the disposable valve 10 illustrated in FIGS. 14 and 15, the reception chamber 18 of said valve can be provided, at its upper end, with an integral connector 31 sealed to the end wall of the reception chamber 18 as illustrated in FIG. 16 of the drawings, said connector 31 having a flange 32 to be inserted with a pressure fit through an opening 17 of a drip irrigation pipe 12, thereby providing a fluid tight joint between the disposable valve 10 and the opening 17 of the drip irrigation pipe. In this particular case, the valve 10 will be connected to bores provided at the lowermost section of the pipe 12.

As an additional embodiment of the disposable dropper or valve 10, said valve can be provided with an opening 35 at its upper end corresponding to the reception,chamber 18, within which a flexible tube 34 is engaged with a pressure fit, said flexible tube being connected to a distribution manifold as commonly used in connection with drip irrigation piping systems.

From the above it can be seen that there has been provided a dropper or valve device for drip irrigation systems which is highly versatile inasmuch as it can be attached to any type of complementary surfaces. For instance, it can be directly attached to a drip irrigation rigid pipe by the provision of opening in said pipe matching the reception chambers of each dropper or valve. The above mentioned dropper or valve can be built as separate elements or patches which can be attached to the pipe either colinearly or in circumferentially spaced positions in order to longitudinally overlap the same to shorten the distances between the openings of the pipe. The valves can also be built in the form of a continuous ribbon having a plurality of valves, which is attached along the rigid piping. The device of the present invention can also be attached either on the inside or on the outside of at least one flexible pipeforming film which edges are sealed together in any known manner in order to form a flexible drip irrigation pipe which will integrally contain a plurality of droppers or valves evenly distributed along the same. Finally, the dropper or valve in accordance with the present invention can constitute a separate disposable self-controllable drip irrigation valve unit, which can be connected by means of suitable connectors either to a drip irrigation pipe or to a flexible distribution pipe corresponding to a fluid distribution manifold.

Although certain specific embodiments of the pres ent invention have been shown and described, it is to be understood that many modifications thereof are possible. The present invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

What is claimed is:

1. An anti-clogging drip irrigation valve which comprises a flat relatively thick elongated assembly having a flexible film cover member, a relatively thick highly flexible member laminated to said cover member, at least one elongated channel means opening towards one of the faces of said highly flexible member opposite to the face laminated to said cover member, a plurality of partition means integrally formed with said highly flexible member and located within said elongated channel means in order to form labyrinth conduit means with a first cavity means formed at one of the ends of said elongated channel means and a second cavity means formed at the opposite end of said elongated channel means; complementary cover means attached to said opposite face of said highly flexible member and to said partition means at their free ends, so as to form a labyrinth passage means from said labyrinth conduit means and a first and a second respective chamber means from said first and second cavity means; fluid entrance means at one of said chamber means; and fluid outlet means at the other of said chamber means.

2. An anti-clogging drip irrigation valve according to claim 1 wherein said flat relatively thick elongated assembly is a highly flexible continuous ribbon-like member containing a plurality of said elongated channel means and partition means separated by block mans integrally formed in said relatively thick highly flexible member.

3. An anti-clogging drip irrigation valve according to claim 1 wherein said flexible film cover member is a thin thermoplastic film laminated to said relatively thick highly flexible member.

4. An anti-clogging drip irrigation valve according to claim ll wherein said relatively thick highly flexible member comprises a plastic foam material having closed or separate cells.

5. An anti-clogging drip irrigation valve according to claim 1 wherein said complementary cover means is a pipe of a drip irrigation system, said fluid entrance means comprising openings in said pipe matching each one of said one chamber means which therefore will constitute fluid reception chamber means for the drip irrigation valve.

6. An anti-clogging drip irrigation valve according to claim 5 wherein said fluid outlet means comprises a check valve formed by a loose section provided at said other of said chamber means so as to form an opening between said highly flexible member and said pipe, whereby said other chamber means will constitute fluid emission chamber means for the drip irrigation valve.

7. An anti-clogging drip irrigation valve according to claim 5 wherein said fluid outlet means comprises an opening provided through said highly flexible member and communicating said other of said chamber means to the environment.

8. An anit-clogging drip irrigation valve according to claim 1 wherein said complementary cover means is a flexible film having a form complementary to the face of said relatively thick highly flexible member, connector means being provided at one of the, ends of said highly flexible member to removably engage the thus formed valve unit to a hole of a drip irrigation pipe.

9. An anti-clogging drip irrigation valve according to claim 8 wherein said connector means comprises an element selected from the group consisting of a flanged nipple and a flexible tube.

10. An anti-clogging drip irrigation valve according to claim 8 wherein said fluid outlet means comprises a check valve formed by a loose section provided at the other end of said highly flexible member so as to form an opening between said highly flexible member and said complementary flexible film, which opening will remain opened as long as there is pressure in said elongated channel means but will be closed if a relative vacuum is applied to said elongated channel means.

Claims

4. An anti-clogging drip irrigation valve according to claim 1 wherein said relatively thick highly flexible member comprises a plastic foam material having closed or separate cells.

8. An anit-clogging drip irrigation valve according to claim 1 wherein said complementary cover means is a flexible film having a form complementary to the face of said relatively thick highly flexible member, connector means being provided at one of the ends of said highly flexible member to removably engage the thus formed valve unit to a hole of a drip irrigation pipe.