Abstract:
A dripline with outlet tubes for drip emitters is provided to direct water flow discharging from the dripline to aid in even water distribution to surrounding soil and plants. The outlet tubes extend away from the dripline and may be preassembled with the dripline during manufacture to facilitate ease of installation.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This patent application claims benefit to U.S. Provisional Application No. 61/662,272, entitled “Drip Emitter with Outlet Tube” and filed on Jun. 20, 2012, the content of which is incorporated herein by reference in its entirety. 
     
    
     FIELD 
       [0002]    This invention relates to the design of a dripline and, more particularly, to an improved outlet for drip irrigation emitters to increase dripline effectiveness. 
       BACKGROUND 
       [0003]    Drip irrigation is commonly used to supply irrigation to landscaping and crops. Drip irrigation emitters are generally known in the art for use in delivering irrigation water to a certain area at a predetermined and relatively low flow rate, thereby conserving water. The drip emitter taps a portion of the relatively high pressure irrigation water from a supply tube, such as a dripline, for flow through a typically long tortuous flow duct path to achieve a desired pressure drop prior to discharge at a target trickle or drip flow rate. 
         [0004]    In a conventional system, a large number of drip emitters are mounted at selected positions along the length of the irrigation supply tube to deliver the irrigation water to a large number of specific points, such as directly to a desired spacing for effective coverage or to a plurality of individual plants. More specifically, a number of drip emitters are fitted into a conduit and spaced apart at appropriate distances depending on the desired irrigation output. Each emitter includes an inlet to receive water flowing through the conduit, an outlet to emit water from the conduit at a specific, controlled rate for irrigation, and a body member intermediate the inlet and the outlet that defines the flow duct path. 
         [0005]    The controlled flow rate is important to insure that water is evenly distributed to the desired area and plants. However, experience has shown that when the dripline conduit is on an incline, for example with vineyard applications, the water discharging from the dripline tends to cling to the outside of dripline rather than flow away from the emitter and dripline to the surrounding area and plants. The water sticks to the dripline since the water molecules are more attracted to the surface of the dripline than they are to each other due to the covalent nature of water. This is undesirable because as the water flows along the outer surface of the dripline, the plants farther from the dripline outlet and farther down the incline in general will tend to receive more water than those towards the top of the incline. 
         [0006]    A known attempt to counteract the tendency of the water to flow along the outer surface of the dripline is to attach a collar around the dripline after every emitter opening or at least those on the inclined terrain. The collar would interrupt any water flowing along the dripline and deflect it away from the dripline. This forces the water to flow onto the surrounding area and plants rather than allowing it to travel down the dripline for a while before flowing onto the ground. While this solution accomplishes redirecting the water flow, it is expensive and labor intensive to implement. For instance, each collar must be manually fit onto a dripline after each emitter, and given a large installation, this generates a significant amount of additional labor and material costs. Thus, there is a desire for an improved emitter that improves the effectiveness of a dripline and reduces the costs and labor required for an installation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a perspective view of a dripline with an outlet tube; 
           [0008]      FIG. 2  is an end view of the dripline of  FIG. 1 ; 
           [0009]      FIG. 3  is a cross-sectional view of the dripline of  FIG. 2  taken along line A-A of  FIG. 2 ; 
           [0010]      FIG. 3A  is a cross-sectional view of the dripline of  FIG. 2  taken along line A-A of  FIG. 2  showing an alternative outlet tube; 
           [0011]      FIG. 3B  is a cross-sectional view of the dripline of  FIG. 2  taken along line A-A of  FIG. 2  showing another alternative outlet tube; 
           [0012]      FIG. 4  is an exploded top perspective view of the drip emitter of  FIG. 1 ; 
           [0013]      FIG. 5  is a perspective view of an alternative embodiment of the drip emitter of  FIG. 1  with a barbed outlet tube; 
           [0014]      FIGS. 6A ,  6 B, and  6 C are a cutaway views of alternative outlet tube configurations; and 
           [0015]      FIG. 7  is a perspective view of an alternative single-piece emitter. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0016]    Referring to  FIGS. 1-4 , an irrigation dripline  10  is shown with an emitter outlet tube  12  extending outward. The outlet tube  12  terminates with an outlet  14  spaced from the dripline  10 . The outlet tube  12  carries water away from the dripline  10  so that the water discharging from the outlet  14  will not cling to the dripline  10  and flow along the dripline  10  away from the area and plants that it is supposed to irrigate. The dripline  10  is preferably preassembled with the outlet tube  12 , which drastically reduces the material costs and amount of labor required to install a dripline system because additional fittings, such as collars, do not have to be installed to deflect the water. 
         [0017]    The outlet tube  12  is illustrated with a cylindrical shape with a circular cross-section. Other shapes and cross-sections, such as conical, square, rectangular, triangular etc., are contemplated. The length of the outlet tube  12  is long enough to space the outlet  14  from the dripline  10  such that the discharged water will not be in a position to cling to the dripline  10 . It also may be long enough to attach a lateral line. For example, it may be appropriate for the outlet tube  12  to be 0.125 to 0.5 inches long. The outlet tube also may have an outer diameter suitable for attachment of a lateral line. For example, it may have an outer diameter in the range of 0.125 to 0.25 inches. The inner diameter may be around 0.05 to 0.20 inches. The outlet tube  10  receives water from a drip emitter located inside the dripline  10 . The drip emitter reduces the pressure in the dripline so that a low volume or drip is discharged from the outlet tube  10 . The drip emitter can also be either a non-pressure compensating or a pressure-compensating drip emitter. 
         [0018]    More specifically, a series of drip emitters are affixed inside the dripline  10  to a wall  16  of the dripline  10  to discharge water at desired locations. The spacing between the emitters may depend on the desired application for the dripline  10 . A typical spacing is about  36  inches between adjacent emitters. One type of drip emitter suitable for use with the outlet tube  12  is illustrated in  FIGS. 2 ,  3  and  4  as emitter  18 . Emitter  18  is shown mounted to an inside surface  20  of the wall  16  of the dripline  10 . 
         [0019]    The emitter  18  has a generally rectangular body and includes a housing  22  and a cover  24 . The housing  22 , the cover  24  and outlet tube may be plastic molded components and may be molded from polyethylene. Alternatively, the components may be made of an elastomeric material, such as a thermoplastic or thermosetting elastomeric material like materials that use ethylene, propylene, styrene, PVC, nitrile, natural rubber, silicone, etc., to form a polymer or copolymer. In a preferred form, the elastomeric material may be made from thermoplastic polyolefin (TPO) and silicone rubber. 
         [0020]    The housing  22  and the cover  24  are adapted for easy assembly and define a substantially enclosed housing interior. A diaphragm  26  is disposed in the interior of the housing  22  interior between the housing  22  and the cover  24 . The housing  22  and the cover  24  may be secured together by gluing, welding and/or a mechanical interconnection, such a snap fit. 
         [0021]    The emitter  18  includes an inlet  28  to receive water from the dripline  10  and an outlet  30  to discharge water from the emitter  18 . The inlet  28  may consist of a number of ports sized to provide the appropriate intake of water collectively but small enough individually to prevent foreign debris from entering the emitter  18 . The outlet  30  discharges water into an outlet bath  32  formed between the housing  22  and the inside surface  20  of the wall  16  of the dripline  10 . The outlet tube  12  receives water from the outlet bath  32 . Alternatively, the outlet  30  could discharge directly to the outlet tube  12 , as illustrated in  FIG. 3B . This would avoid the use of the outlet bath  32 . 
         [0022]    A pressure reducing path connects the inlet  28  and the outlet  30 . More specifically, the pressure reducing path includes a tortuous path  34  and a metering chamber  36  defined by the housing  22  and the diaphragm  26 . The diaphragm  26  is preferably an elongated strip dimensioned to overlap and seal against the tortuous path  34  and the metering area  36  and is preferably a silicone or rubber material. 
         [0023]    The tortuous path  34  includes two series of opposing baffles  38  that form the tortuous path  34  with a zigzagging configuration. The metering chamber  36  includes a metering surface  40  that defines a metering groove  42 . 
         [0024]    Water entering from the dripline  10  through the inlet  28  first flows through the tortuous path  34  and then into the metering chamber  36 . Once in the metering chamber  36 , the water then flows through the groove  42  defined by the water metering surface  40  on the bottom of the watering meter chamber  36  to the emitter outlet  30 . Water flowing through this flow path experiences a pressure drop. 
         [0025]    The diaphragm  26  overlays the tortuous path  34  and the metering chamber  36  and alters the size of tortuous path  34  and the metering chamber  36  to compensate for change in water pressure in the dripline  10 . More specifically, in addition to flowing into the tortuous path  34 , water from the inlet  28  also flows into a pressure regulating chamber  44  formed in the cover  24  on the side of the diaphragm  26  opposite of the tortuous path  34  and the metering chamber  36 . So, when then the water pressure increases, water flowing from the inlet  28  into the pressure regulating chamber  44  causes the diaphragm  26  to deflect into the tortuous path  34  and the metering chamber  36  to further constrict the tortuous path  34  and the metering chamber  36  to cause a further reduction in pressure across the emitter  18 . 
         [0026]    The outlet  30  of the emitter  18  discharges into the outlet bath  32  formed between the housing  22  and the inside surface  20  of the wall  16  forming the dripline  10 . More specifically, the housing  22  defines the outlet  30 , which is located at the opposite end of the emitter  18  as the inlet  28 . The housing  22  also preferably includes a raised rim  46  extending about its perimeter. The raised rim  46  is used to mount the emitter  18  to the inside surface  20  of the dripline  10  by acting as an attachment zone. During assembly, the raised rim  46  is pressed into sealing engagement with the inside surface  20  of the dripline  10 , as shown in  FIG. 3 , as the dripline  10  is being formed around the inserted emitter  18 . The raised rim  46  forms a gap between a surface  47  of the housing  22  inside the raised rim  46  and the inside surface  20  of the wall  16  of the dripline  10 . The gap forms the outlet bath  32  for the discharge of water from the outlet  30  of the emitter  18 . 
         [0027]    The outlet tube  12  extends from the outlet bath  32  through the wall  16  to the outside of the dripline  10 . The outlet tube  12  includes a base  48  defining one or more inlet ports  50  to the outlet tube  12 . The inlet ports  50  may be circular and sized large enough to permit any grit or other foreign debris that passes into the outlet bath  32  to be discharged from the emitter  18 . The outlet tube  12  may be molded as a single piece with the housing  22  or may be molded separately and welded or glued to the housing  22 . Alternatively, the outlet tube  12  could be attached to the housing  22  directly over outlet  30 , as illustrated in  FIG. 3B . In such a configuration, inlet ports  50  would not be required. 
         [0028]    In another embodiment, the outlet tube  12  could be mechanically attached and/or welded or glued to the dripline  10 . In  FIG. 3A , one end of the outlet tube is configured with an annular groove  33  that receives the side wall of the dripline  10 . 
         [0029]    In an alternative embodiment shown in  FIG. 5 , the outlet tube  12  could have one or more barbs  52 ,  53  as the case requires. The primary barb  52  is sized to provide grip on an attached lateral line, such as a ¼″ transfer tube, and strengthen the transfer tube&#39;s connection to the emitter  18 . The secondary barb  53  may be smaller than the primary barb  52  and provides additional connection strength. Alternative configurations of the outlet tube  12  to provide grip on a dripline are shown in  FIGS. 6A ,  6 B, and  6 C.  FIG. 6A  shows the before mentioned configuration utilizing the primary  52  and the secondary barb  53 .  FIG. 6B  shows the tube  12  with ribbing  54  to provide grip on a transfer tube.  FIG. 6C  shows the tube  12  with protrusions  56  to provide a textured grip on a transfer tube. 
         [0030]    The emitter  18  is preferably inserted into the dripline  10  during the extrusion process for the dripline  10 . If the outlet tube  12  is attached to the housing  22 , it would create a bulge during the extrusion process, and a cutter may be used to cut off the tip of the outlet tube  12  in a manner that maintains the desired length. The cutting of the tip creates the opening  14  and allows the wall  16  of the dripline  10  to constrict back toward the base of the outlet tube  12  and around the outlet tube  12  to seal against it. Alternatively, the outlet tube  12  may be added after the emitter  18  is installed in the dripline  10 . For example, the dripline  10  may be drilled at the outlet bath  32  and the outlet tube  12  may be inserted and mechanically attached and or glued or welded to the dripline  10 . 
         [0031]    Additional description of the emitter  18  is in U.S. application Ser. No. 11/394,755, filed on Mar. 31, 2006 and published as U.S. Patent Application Publication No. 2006/0237561 on Oct. 26, 2006, both of which are hereby incorporated by reference. Many different emitter designs could include the outlet tube. For instance, other examples of emitters that can adopt the outlet tube are disclosed in U.S. application Ser. No. 13/430,308 filed on Mar. 26, 2012, U.S. application Ser. No. 12/436,394 filed on May 6, 2009 and published as U.S. Patent Application Publication No. 2010/0282873 on Oct. Nov. 11, 2009, and U.S. Pat. No. 7,648,085 issued on Jan. 19, 2010, all of which are hereby incorporated by reference. 
         [0032]    Another example of a pressure compensating emitter is the single piece emitter illustrated in  FIG. 7 . In this embodiment, an emitter  100  includes an integral body  120  which defines an inlet  130  connectible to a source of pressurized fluid, an outlet  140  with an exit tube  180  for discharging the fluid from the emitter body  120 , and a pressure reducing flow channel or passage  150  between the inlet  130  and outlet area  140  for reducing the flow of fluid discharged through the outlet  16 . In addition, the emitter body  120  defines a pressure compensating member  160  for reducing a cross-section of the flow channel in response to an increase in pressure of the pressurized supply line fluid. 
         [0033]    In the form illustrated, the emitter body  120  is made of an elastomeric material, such as a thermoplastic or thermosetting elastomeric material like materials that use ethylene, propylene, styrene, PVC, nitrile, natural rubber, silicone, etc., to form a polymer or copolymer. In a preferred form, the elastomeric material is made of thermoplastic polyolefin (TPO) and silicone rubber. This combination helps create an emitter and dripline that is capable of withstanding the high temperatures and harsh chemicals the emitter may be subjected to while in use. In addition, the emitter is made of a singular or unitary construction rather than having a multi-part construction and/or requiring the assembly of housing parts, diaphragms, etc. 
         [0034]    Fluid passes through the inlet opening  130  and enters a pressure-reducing flow channel  150  that produces a significant reduction in pressure between the fluid flowing in a primary lumen of the supply conduit or a dripline  170  and the fluid emptying into and present in the emitter outlet area  140 . From the outlet area  140 , the fluid enters an outlet tube  180  and flows out of the emitter  100 . 
         [0035]    In the form illustrated, the emitter body  120  defines opposed baffle walls to create the pressure-reducing flow channel and, in a preferred form, has an inner baffle wall  151  that is surrounded by an outer baffle wall  152  which extends about the inner baffle wall  151  in a generally U-shaped manner to form a flow passageway that generally directs the water in a U-shaped direction of travel. More particularly, the inner and outer baffle walls  151 ,  152  have alternating projections and recesses that form a tortuous passage and cause the fluid flowing therethrough to zigzag back and forth, reducing pressure with each turn the fluid makes. The outer baffle wall  152  is defined by an outer rim or peripheral wall of the emitter body  120  and the inner baffle wall  151  extends from a portion of the outer rim or peripheral wall and into to the middle of the emitter body  120  to form a peninsula about which the fluid flows from inlet  130  to outlet  140 . The upper surfaces of the emitter body preferably have a radius of curvature that tracks the radius of curvature of the tube  170  so that the emitter body  120  can be bonded securely to the inner wall of the tube  170  and create an enclosed pressure reduction passage from inlet  130  to outlet  140 . In the form illustrated, the tortuous passage is formed via alternating teeth extending from opposing surfaces of the inner and outer baffle walls  151 ,  152  and has a cross-section that is generally rectangular in shape when the emitter body  120  is bonded to the inner surface of the extruded dripline  170  (keeping in mind that the radius of curvature of the tube  170  will likely make the upper portion of the cross-section slightly curved and the side walls to be slightly wider at their top than at their bottom). 
         [0036]    It should be understood, however, that in alternate embodiments the pressure-reducing flow channel  150  may be made in a variety of different shapes and sizes. For example instead of having projections with pointed teeth, the baffles could be made with blunt or truncated teeth, with teeth that are angled or tapered, with curved or squared projections instead of triangular shaped teeth, with projections of other geometrical shapes or geometries, symmetric or asymmetric, etc. 
         [0037]    In addition to the pressure-reducing flow path  150 , the emitter  10  further includes a pressure compensating feature  160  which further allows the emitter  10  to compensate for increases in fluid pressure in the primary lumen of the tube  170 . More particularly, pressure compensating feature  160  allows the emitter  10  to maintain relatively constant outlet fluid flow and pressure even though the inlet fluid pressure may fluctuate from time-to-time. In the form illustrated, the pressure compensating feature  160  is a two part pressure compensation mechanism that comprises an elastomeric portion  161  capable of deflecting under pressure to reduce the cross-section of the pressure-reducing flow channel  150  and regulate fluid flow through the emitter, and a movable baffle portion  162  capable of changing the length of the flow channel to compensate for changes in supply line  170  fluid pressure. 
         [0038]    The elastomeric portion  161  being a deflectable portion of the emitter body  120  that is moveable between a first position wherein at least a portion of the pressure-reducing flow channel  150  is of a first cross-section and a second position wherein the at least a portion of the pressure-reducing flow channel  150  is of a second cross-section, smaller than the first cross-section to regulate fluid flow through the emitter. In the form illustrated, the floor  161  of the flow channel  150  forms an elastomeric portion and raises and lowers in response to increases and decreases in supply line  170  fluid pressure, respectively. Thus, when fluid pressure increases in the supply line  170 , the floor  161  of the flow channel  150  is pressed-up or deflected up into the flow channel  150  thereby reducing the cross-section of the flow channel to regulate the flow of fluid through the emitter  10 . Conversely, when fluid pressure in the supply line  170  reduces, the floor of the flow channel  150  retreats from the flow channel back to a normal position wherein the floor is not deflected up into the flow channel thereby increasing the cross-section of the flow channel to allow fluid to flow more freely through the flow channel  150 . 
         [0039]    The second part of the pressure compensation mechanism  160  comprises a movable structure, such as movable baffle portion  162 , which is capable of moving between a first low pressure position wherein the length of the flow channel  150  is of a first distance and a second high pressure position wherein the length of the flow channel  150  is of a second distance wherein the length of the flow channel is longer than the first distance to compensate for increase pressure in the supply line  170 . More particularly, in the form illustrated, the movable baffle portion  162  deflects up and down with the floor of the flow channel  150  to sealingly engage and disengage the movable baffle portion  162  with the inner wall of the supply line  170 , respectively, and thereby lengthen or shorten the extent of the flow channel for at least some fluid flowing therethrough to compensate for changes in supply line fluid pressure. 
         [0040]    The movable baffle portion  162  comprises a tapered portion of the central or inner baffle wall  151  that tapers down away from the inner surface of supply line  170  so that at lower fluid pressures in supply line  170 , fluid flows through the inlet  130  and first section (or upstream section) of flow channel  150  and then over the top of the tapered baffle section  162 , through the second section (or downstream section) of the flow channel  150  and then into the outlet pool  140 . Fluid may flow through the remaining portion of the flow channel  150  including intermediate bath  153  (located between the upstream and downstream sections of the flow channel  150 ), but it does not have to nor does all of the fluid flow through these portions of the flow channel  150  due to the gap between the upper surface of the tapered inner baffle wall section  152  and the inner surface of tube  170 . As fluid pressure increases in the fluid supply line  170 , the floor of the flow channel  150  starts to deflect upwards and into the flow channel  150  moving the tapered baffle section  162  toward the inner surface of tube  170  thereby reducing the gap between these two until the upper surface of the tapered baffle section  162  sealingly engages the inner wall of the tube  170  thereby preventing fluid from flowing over the top of the tapered baffle section  162  and lengthening the amount of the flow channel  150  through which all of the fluid must flow and reducing fluid pressure and flow due to same. 
         [0041]    Since the emitter  100  is made of an integral body  120 , the outlet area  140  is provided with obstructions or stops, such as posts or nubs  141 , that prevent the outlet are  140  from collapsing when the fluid pressure of supply line  170  raises to a level sufficient for deflecting the floor of the flow channel  150  into the flow channel  150  to reduce the cross-section of same and regulate fluid flow through the flow channel. The outlet tube  180  is centered between the posts  141 . The fluid enters the outlet area  140  and flows into the tube  180  through one or more inlets  181 . The fluid travels through the tube  180  and exits through an opening  182  of the tube outside the dripline. Alternatively, the exit tube  180  could be added after the emitter is installed in the dripline  170 . For example, the dripline  170  could be drilled over the outlet bath  140 , and the exit tube  180  could be inserted and mechanically attached and or welded or glued to the dripline  170 , such as that shown in  FIG. 3A . In another alternative embodiment, the outlet tube  180  could be positioned over the outlet of the tortuous path  150 , such as that shown in  FIG. 3B . 
         [0042]    Further disclosure of this embodiment as well as other drip emitter embodiments that may be used with the outlet tube  12  are disclosed in U.S. application Ser. No. 13/430,249, which is incorporated by reference herein. 
         [0043]    Alternatively, the emitter just described could be made of a rigid material. In this case, the emitter would not be pressure compensating, and there may not be a tapered portion of the baffles. It also may not need the posts  141  in the outlet area  140 . Otherwise, the emitter would generally be the same. 
         [0044]    While the foregoing description is with respect to specific examples, those skilled in the art will appreciate that there are numerous variations of the above that fall within the scope of the concepts described herein and the appended claims.