Patent Abstract:
An irrigation valve has a liquid passage, a sealing diaphragm and a control port that can receive control signals. The sealing diaphragm is held in the valve in a non clamped manner and is adapted to seal the passage. Upon receipt of a control signal the sealing diaphragm bends and opens a path for liquid around the sealing diaphragm that can exit the valve.

Full Description:
RELATED APPLICATIONS 
     This is a 35 USC 371 U.S. National Phase of International Application No. PCT/IB2012/050874, filed 26 Feb. 2012 and published in English as WO 2012/131503A1 on 4, Oct. 2012, which claims priority to U.S. Provisional application No. 61/469,110, filed 30 Mar. 2011. The contents of the aforementioned applications are incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     Embodiments of the present invention relate to irrigation valves and in particular to irrigation valves that are controlled by an external signal. 
     BACKGROUND 
     In such valves the external signal may be fluid pressure and the fluid pressure may control the opening and/or closing of the valve. 
     U.S. Pat. No. 5,829,473 describes a hydraulic or a pneumatic control signal that is introduced into a hydraulic valve by way of hydraulic or pneumatic pressure. This pressure applies a force on a diaphragm thus causing the diaphragm to move to a position in which it closes the valve for passage of fluid therethrough. 
     SUMMARY 
     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. 
     In an embodiment of the present invention there is provided an irrigation valve comprising a liquid passage extending therethrough at least in part along an axis, a sealing diaphragm operatively coupled to the passage and a control port for receiving a control signal, the sealing diaphragm being held in the valve in a non clamped manner and being adapted to seal the passage, wherein upon receipt of a control signal the sealing diaphragm is urged to elastically bend to thereby open a path for liquid around the sealing diaphragm that flows downstream to exit the valve. 
     Optionally, the sealing diaphragm comprises opposing up and down surfaces and a peripheral side surface therebetween, the up and down surfaces respectively face upstream and downstream and at least a portion of the path for liquid around the sealing diaphragm flows in contact with the diaphragm along an imaginary route extending first upon the up surface then upon the side surface and then upon the down surface. 
     If desired, the control signal is in the form of liquid pressure flowing inwards into the valve. 
     Typically, the irrigation valve comprises an elastic control diaphragm located inward of the control port, the control diaphragm adapted to bend under the pressure of the control signal to thereby transfer a signal inwardly that causes the bending of the sealing diaphragm that forms the path around the sealing diaphragm. 
     Optionally, the control diaphragm when bended substantially seals the valve to inward flow of the control signal passed the control diaphragm. 
     Typically, the sealing diaphragm is adapted to be biased axially upstream and axially downstream and at least when biased upstream is adapted to bear against a support of the valve and at least when biased downstream is adapted to bear against a rim of the valve, wherein the non clamped manner that the sealing diaphragm is held in the valve is characterized by the support not axially overlapping the rim. 
     Preferably, the sealing diaphragm when bearing against the rim seals the passage for liquid flow. 
     In an embodiment there is also provided an irrigation pipe comprising an irrigation valve in accordance with the present invention. 
     Optionally, the irrigation valve is coupled to an end of the pipe and the opening of the path through the valve is adapted to flush liquid out of the pipe. 
     Further optionally, the irrigation valve is coupled to a beginning of the pipe and the opening of the path through the valve is adapted to allow liquid to flow downstream into the pipe. 
     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 
       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 invention, 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: 
         FIG. 1  shows a perspective top view of an irrigation valve in accordance with an embodiment of the present invention; 
         FIG. 2  shows an exploded view of the valve shown in  FIG. 1 ; 
         FIG. 3  shows a perspective top view of a base of the valve; 
         FIG. 4A  shows a top view of the base of the valve; 
         FIG. 4B  shows a top view of the base and a sealing diaphragm of the valve being supported by the base; 
         FIG. 5  shows a perspective top view of a partition of the valve; 
         FIG. 6  shows a perspective bottom view of the partition of the valve; 
         FIG. 7A  shows a cross sectional view of the valve in a closed state; 
         FIG. 7B  shows a cross sectional view of the valve in an open state; and 
         FIG. 8  shows a perspective view of a portion of an irrigation system incorporating a valve in accordance with an embodiment of the present invention. 
     
    
    
     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 
     Attention is first drawn to  FIGS. 1 and 2 . An irrigation valve  10  in accordance with an embodiment of the present invention may have a base  12 , a sealing diaphragm  14 , a partition  16 , a piston  18 , a control diaphragm  20  and a casing  22 . The valve  10  has an inlet  24  that is formed at an upstream side of the valve  10  in the base  12 . An outlet  26  of the valve  10 , in an optional form of several apertures, is optionally formed at a downstream side of the valve  10  in the casing  22 , and the valve  10  has in addition a control port  28  that is optionally formed in the casing  22  for receiving external control signals for controlling the operation of the valve  10 . 
     The valve  10  extends along an axis X and has a liquid passage that is formed therein and provides liquid communication between the inlet  24  and the outlet  26 . An upstream portion of the passage is in the form of an axially extending lumen  30  (best seen in  FIGS. 7A and 7B ) that is formed in the base  12  and opens out of the base  12  at the inlet  24 . It should be noted that directional terms appearing throughout the specification and claims, e.g. “inner”, “outer”, “up”, “down”, “upstream”, “downstream”, etc., (and derivatives thereof) are for illustrative purposes only, and are not intended to limit the scope of the appended claims and that the directional terms “down”, “below” and “lower” (and derivatives thereof) define identical directions. 
     In addition it is noted that the directional terms “up” and “down” (and derivatives thereof) refer to opposing directions extending along the axis X which may coincide respectively with the downstream and upstream flow directions where the flow through the valve  10  extends along the axis X such as optionally in the lumen  30 . Finally it is noted that each part of the valve  10  even when shown by itself will be described herein as in its respective orientation in the assembled valve  10  and therefore in relation to the axis X and to the up, down, downstream and upstream directions. 
     Attention is drawn to  FIGS. 3 and 4A . A recess  32  of the base  12  that constitutes a part of the passage is formed at a downstream side of the base  12  and the lumen  30  opens downstream into the recess  32 . The recess  32  is partially bound by an upwardly facing floor  34  of the base  12  and a raised wall  36  of the base  12  that is formed about a perimeter of the floor  34  and projects axially downstream above the floor  34 . A support  38  of the base  12  that optionally includes a plurality of bulges  40  is formed in the recess  32 . The bulges  40  are located upon the floor  34  of the base  12  in an optional symmetrical pattern about the axis X with each bulge  40  projecting downstream above the floor  34  and being separated from an adjacent bulge  40  by a gap  42 . 
     Each bulge  40  has an upwardly facing seat  44  that has an inner end  46  proximal to the axis X and an outer end  48  distal to the axis X; and a protrusion  50  of each bulge  40  that is outward in relation to the seat  44  protrudes up above the seat  44  from adjacent the outer end  48  of the seat  44 . An optional effective supporting region of the support  38  is defined by an imaginary flat ring R that extends about the axis X and passes through each seat  44  between its inner and outer ends  46 ,  48 . An inner periphery of the ring R that defines an inner diameter D of the ring R extends through the inner ends  46  of the seats  44 . 
     Attention is drawn to  FIG. 4B . The sealing diaphragm  14  is optionally disc shaped and has a top surface  52  facing downstream, a bottom surface  54  (seen in  FIGS. 7A and 7B ) facing upstream and a peripheral side surface  56  that connects the top and bottom surfaces  52 ,  54 . In the valve  10 , the sealing diaphragm  14  is located in the recess  32  of the base  12  with its bottom surface  54  at a peripheral region thereof overlying the seats  44  of the support  38 . In this position, the sealing diaphragm  14  is snuggly received in the support  38  optionally resting upon the seats  44  and peripherally bounded at spaced apart locations by the protrusions  50  of the bulges  40 . 
     Attention is drawn to  FIGS. 5 and 6 . The partition  16  has a lower cavity  58  and an upper cavity  60  that extend axially one after the other in the partition. The lower cavity  58  is partially bound by a downwardly facing roof  62  of the partition  16  and a shroud  64  of the partition  16  that is formed about a perimeter of the roof  62  and projects axially upstream below the roof  62 . The upper cavity  60  opens out of the partition  16  at its upper side at an aperture  64  and opens down into the lower cavity  58  at a raised rim  66  that protrudes down beyond the roof  62  into the lower cavity  58 . The raised rim  66  is optionally circularly formed about the axis X and has a diameter d. The partition  16  has in addition two key ways  68  that extend sideways out of the partition  16  and away from the axis X to provide communication between the upper cavity  60  and the environment surrounding the partition  16 . 
     Attention is drawn to  FIGS. 2 to 6 . In the valve  10 , the partition  16  is received on the base  12  with its shroud  64  being snugly surrounded by the wall  36  of the base  12  and its lower cavity  58  being joined with the recess  32  of the base  12  to define a chamber  70  of the valve  10  (chamber  70  can be seen in  FIGS. 7A and 7B ). The sealing diaphragm  14  is kept confined in the chamber  70  between the base  12  and the partition  16  such that movement of the sealing diaphragm  14  downwards (upstream) will cause the sealing diaphragm  14  to bear against the support  38  at the seats  44  and movement of the sealing diaphragm  14  upwards (downstream) will cause the sealing diaphragm  14  to bear against the rim  66 . 
     Attention is drawn to  FIGS. 7A and 7B . In the valve  10  the control diaphragm  20  is placed adjacent the aperture  64  of the partition  16  between the control port  28  and an upper side of the piston  18 . Control diaphragm  20  has a width W 1  measured along the axis X that is optionally smaller than the axial distance C 1  between portions of the valve  10  that axially confine the control diaphragm  20  so that control diaphragm  20  is axially confined in the valve  10  in a “floating” “non clamped” manner. The control diaphragm  20  is adapted to transfer control signals received at the control port  28  into the valve  10  towards the piston  18  and the piston  18  is slidably received in the upper cavity  60  of the partition  16  and is adapted to be urged downwards (upstream) to protrude at a lower side thereof via the rim  66  into the chamber  70  of the valve  10 . The base  12  of the valve  10  is adapted to attach to an upstream fluid source (not shown) by optional threads that are formed on an outer face thereof. Optionally, other means may be provided at the base  12  for attachment to the fluid source such as for example a barb member (not shown) or any other connector or attachment means that may be suitable in the application in which the valve  10  is used. 
     In a closed state of the valve  10  ( FIG. 7A ), fluid under pressure that entered the valve  10  via the inlet  24 , occupies the lumen  30  of the valve  10  and bears against the sealing diaphragm  14  to urge the sealing diaphragm  14  to abut and/or bear against the rim  66  and seal the passage of fluid through the valve  10 . To form an open state in the valve  10  ( FIG. 7B ), a control signal in an optional form of fluid is urged into the valve  10  via the control port  28  to bear against the control diaphragm  20 . Above an optional threshold pressure of the fluid at the control port  28 , the fluid pressing against the control diaphragm  20  flexes the control diaphragm  20  and urges the piston  18  inwardly into the valve  10  until the lower side of the piston  18  protrudes into the chamber  70  of the valve  10  via the rim  66  and thereby flexes the sealing diaphragm  14  off the rim  66 . 
     In accordance with some of the embodiments of the present invention, the sealing diaphragm  14  has a width W 2  measured along the axis X that is optionally smaller than the axial distance C 2  between the rim  66  and the seats  44  of the support  38  that axially confine the sealing diaphragm  14  in the chamber  70  so that the sealing diaphragm  14  is axially confined in the chamber  70  of the valve  10  in a “floating” “non clamped” manner between the rim  66  and the support  38 . In some embodiments however the sealing diaphragm  14  may be axially confined in the chamber  70  in a “non-floating” manner that is characterized by width W 2  being slightly larger than axial distance C 2 . This may increase the threshold pressure that is required in order to open the valve  10  as now also the pressure of the diaphragm  14  that is pressed against the rim  66  has to be overcome for the valve  10  to assume its open state. 
     In accordance with some of the embodiments of the present invention the diameter d of the rim  66  (d is indicated in  FIG. 6 ) is optionally smaller than the diameter D of the effective supporting region of the support  38  (D is indicated in  FIG. 4A ) and thereby the rim  66  and the effective supporting region of the support  38  do not axially overlap or overlie each other. Therefore in such embodiments the sealing diaphragm  14  may be defined as being kept axially confined in a “non clamped” manner between portions of the valve  10  (e.g. rim  66  and seats  44 ) that do not axially overlap or overlie each other. 
     The optional “non clamped” and/or “floating” manners in which the diaphragms  14 ,  20  are confined in the valve  10  may assist to prolong the effective period of time that they may effectively function in the valve  10 . Stress that may have been present in the diaphragms  14 ,  20  if they were clamped in the valve, could shorten the effective period of time that they may function. Such stress that may have been formed for example between clamped portions of the diaphragms that are kept substantially fixed in place and portions of the diaphragms that are urged to flex, is substantially avoided when the diaphragms are held in a “non clamped” and/or “floating” manner in the valve  10 . Diaphragms  14 ,  20  when urged to flex are adapted to slightly slide upon the surfaces of the valve  10  that they bear against which results in the effect that they substantially only bend and only exhibit stress due to bending and substantially avoid any additional stress that may have been present if they were clamped in the valve  10 . 
     Attention is drawn to  FIG. 7B . In the open state of the valve  10 , the lifting of the sealing diaphragm  14  off the rim  66  forms a space between the top surface  52  of the sealing diaphragm  14  and the rim  66  that allows for a fluid flow indicated by dashed arrows to be formed through the valve  10 . Fluid upstream of the valve  10  may now flow downstream via inlet  24  into the lumen  30  of the valve  10  to bypasses the sealing diaphragm  14 . The fluid flows via the gaps  42  of the support  38  and then over the top surface  52  of the sealing diaphragm  14  and through the space between surface  52  and rim  66  into the upper cavity  60  of the partition  16 . From there, the fluid flows laterally away from the axis X via the key ways  68  of the partition  16  to the environment that is seized between the casing  22  and the partition  16  and from there the fluid flows out of the valve  10  through the outlets  26  in the casing  22  to the outside environment outside of the valve. 
     Attention is now drawn to  FIG. 8 . In an embodiment of the present invention, the valve  10  is adapted to be used in a drip irrigation system  74  that includes a plurality of drip irrigation lines  76  that are laid in a field for irrigating the field. Optionally, an end of each drip irrigation line  76  is coupled to a given valve  10  and a control tube  78  that is laid in the field provides fluid communication to the control ports  28  of the valves  10 . 
     During irrigation, matter such as grit, dirt or the like that exists in the liquid used for irrigation may accumulate over time and substantially block at least some of the irrigation being performed by the drip irrigation lines  76 . In some cases periodic flushing of the drip irrigation lines  76  may assist to remove such matter from the lines  76  and thereby improve the ability of the irrigation system  74  to properly function. 
     In an embodiment of the present invention, the periodic flushing of the drip irrigation lines  76  is performed by providing a control signal to the valves  10  that triggers the valves to assume their open states and allow liquid flowing through the drip irrigation lines  76  to be flushed out of the lines to thereby remove such matter that may have accumulated in the lines  76 . 
     In an embodiment, the control tube  78  is coupled to a fluid source (not shown) such as the source providing liquid to the irrigation system  74  and upon demand liquid from the source may be allowed to flow through the control tube  78  to enter the valves  10  at their control ports  28  and urge the valves  10  to assume their open states and allow the drip irrigation lines  76  that are coupled to the control tube  78  to be flushed. 
     In a non binding example, the control tube  78  is operatively coupled to a fluid source such as a manually operated pump and upon operation of the pump fluid such as air is urged to flow through the control tube  78  to enter the valves  10  at their control ports  28  and urge the valves  10  to assume their open states and allow the drip irrigation lines  76  that are coupled to the control tube  78  to be flushed. 
     In another embodiment, the valve  10  may fitted to a beginning of an irrigation line  76  (not shown) in order to control entry of liquid downstream into the line. 
     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. 
     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 invention as hereinafter claimed.

Technology Classification (CPC): 5