Abstract:
A subsurface emitter includes a piston valve both preventing water from draining from the system, and blocking the entry of roots and soil into the emitter body. A nozzle is present at one or both ends of a vertical tube. A piston is held in a normally closed position by a spring in the absence of water pressure, covering ports in the nozzle. When sufficient water pressure in provided, the spring is compressed and the nozzle uncovers the port providing a subsurface spray of water. The spray of water is sufficient to clear mineral deposits which otherwise may accumulate and block the port.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a Continuation In Part of U.S. patent application Ser. No. 14/295,863 filed Jun. 4, 2014, which application is incorporated in its entirety herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to subsurface watering and in particular to an improved subsurface emitter. 
         [0003]    The advantages of subsurface watering, especially in dry climates, has long been recognized. Conventional watering using sprinklers is often less than 50 percent efficiency due to evaporation. Watering using sprinklers further germinates seeds from weeds resulting in undesirable growth in garden areas. Use of weed killer after the growth of weeds begins often accumulates chemicals in the soil preventing later grow of decorative plants. Releasing water under a ground surface prevents the evaporation of water potentially raising efficiency to close to 100 percent and leave the surface dry to reduce or prevent weeds. 
       BRIEF SUMMARY OF THE INVENTION 
       [0004]    The present invention addresses the above and other needs by providing a subsurface emitter which includes a valve both preventing water from draining from the system, and blocking the entry of roots and soil into the emitter body. A nozzle is present at one or both ends of a vertical tube. A piston is held in a normally closed position by a spring in the absence of water pressure, covering ports in the nozzle. When sufficient water pressure in provided, the spring is compressed and the nozzle uncovers the port providing a subsurface spray of water. The spray of water is sufficient to clear mineral deposits which otherwise may accumulate and block the port. 
         [0005]    In accordance with one aspect of the invention, there is provided a subsurface emitter including a water pressure actuated valve which covers the port in the nozzle. Known subsurface emitters have quickly failed because plant roots follow the water back to the source and into the nozzle. Because the piston blocks the port when the watering system is off, the roots cannot enter and block the port. 
         [0006]    In accordance with another aspect of the invention, there is provided a subsurface emitter including a small port producing a high water velocity. The water velocity is sufficient to prevent an accumulation of minerals which otherwise may block the port. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0007]    The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein: 
           [0008]      FIG. 1A  is a side view of a subsurface emitter according to the present invention. 
           [0009]      FIG. 1B  is a top view of the subsurface emitter according to the present invention. 
           [0010]      FIG. 2  is an exploded side view of the subsurface emitter according to the present invention. 
           [0011]      FIG. 3A  is a cross-sectional view of the subsurface emitter according to the present invention in a closed position taken along line  3 - 3  of  FIG. 1B . 
           [0012]      FIG. 3B  is a cross-sectional view of the subsurface emitter according to the present invention in an open position taken along line  3 - 3  of  FIG. 1B . 
           [0013]      FIG. 4  is a detailed side view of a piston valve of the subsurface emitter according to the present invention. 
           [0014]      FIG. 4A  is a detailed side view of a second piston valve and spring of the subsurface emitter according to the present invention. 
           [0015]      FIGS. 5A and 5B  show a first embodiment of spray patterns of the subsurface emitter according to the present invention. 
           [0016]      FIGS. 6A and 6B  show a second embodiment of spray patterns of the subsurface emitter according to the present invention. 
           [0017]      FIGS. 7A and 7B  show a third embodiment of spray patterns of the subsurface emitter according to the present invention. 
           [0018]      FIG. 8  shows a layout of the subsurface emitter according to the present invention. 
       
    
    
       [0019]    Corresponding reference characters indicate corresponding components throughout the several views of the drawings. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing one or more preferred embodiments of the invention. The scope of the invention should be determined with reference to the claims. 
         [0021]    A side view of a subsurface emitter  10  according to the present invention is shown in  FIG. 1  and a top view of the subsurface emitter  10  is shown in  FIG. 1B . The emitter  10  includes a body  11 , at least one nozzle and preferably two nozzles  12  attached to opposite ends of the body  11 , and an inlet  18   a  and an outlet  18   b  on opposite sides of the body  11 . The nozzles  12  include at least one port (or orifice)  14  for spraying water from the emitter  10 . The inlet  18   a  may be offset to create turbulence inside the body to release dissolved air in the water. The emitter  10  resides in a subsurface area  40 . 
         [0022]    An exploded side view of the subsurface emitter  10  is shown in  FIG. 2 . A piston  20  resides in the nozzle  12  and is inserted into an end  11   a  of the body  11  which preferably provides a seat feature for the piston  20 . The piston  20  is preferably stepped and cylindrical, and a smaller diameter portion  20   a  enters the end  11   a  of the body  11  and a larger diameter portion  20   b  defining a circumferential surface  20   b′  (see  FIG. 4 ). A downward facing piston seat  21  is defined by the step in the piston  20 . A spring  22  resides in the nozzle  12  pushing the piston  20  against and into the end  11   a  of the body  11 . The spring  22  and piston  20 , and seat feature of the body  11 , create a valve between an interior  13  of the emitter  10  and ceiling  12   a  of the nozzle  12 . 
         [0023]    Those skilled in the art will recognize that the seat feature of the body  11  may be the end  11   a  of the body  11 , or a separate seat formed proximal to the end  11   a  of the body  11 , and any seat formed on or attached to the body  11  for sealing cooperation with the piston  20  is intended to come within the scope of the present invention. 
         [0024]    A cross-sectional view of the subsurface emitter  10  in a closed position taken along line  3 - 3  of  FIG. 1B  is shown in  FIG. 3A . The body  11  has a center line CL. The piston  20  is shown pushed against the end  11   a  (see  FIG. 2 ) of the body  11  preventing a backflow of water from the emitter  10  into a watering system  30 . In the closed position, a surface portion the piston  20  further resides over the port  14  preventing roots from growing into the port  14  and blocking the spray of water  15  (see  FIG. 3B ) from the port  14 . 
         [0025]    A cross-sectional view of the subsurface emitter  10  in an open position taken along line  3 - 3  of  FIG. 1B  is shown in  FIG. 3B . A flow of water  32   a  under pressure is provided to an interior  13  of the emitter  10  producing flows  34  to the nozzles  12  and  32   b  leaving the emitter  10 . The flows  34  push the pistons  20  to an open position exposing the ports  14  to the flows  34  creating a spray  15  from the emitter  10 . 
         [0026]    The port  14  is generally perpendicular to the centerline CL and may have various shapes but preferably has about the same height and width, and more preferably has a round cross-section. The area of the port  14  is selected to provide a high velocity spray into the surrounding subsurface area  40  to dig through the soil to provide wide coverage. The ports  14  are preferably between 0.023 and 0.04 inches in diameter for general use and preferably between 0.035 and 0.04 inches in diameter for clay soil. The ports  14  are not necessarily round and may be a elliptical or polygonal with an equivalent cross-sectional area. 
         [0027]      FIG. 4  shows a detailed view of a piston  20  of the subsurface emitter  10 . The smaller diameter portion  20   a  had a diameter D 3  and the larger diameter portion  20   b  has a diameter D 4 . The diameter D 3  is smaller than the inside diameter D 1  of the body  11  (see  FIG. 3A ) to allow water to flow between the piston  20  and the body end  11   a  when the piston is open and the diameter D 4  is only slightly smaller than the inside diameter D 2  of the nozzle  12 . The diameter D 1  is preferably about 0.8 inches and the diameter D 3  is preferably about 0.7 inches, and more preferably, the diameter D 3  is at least 0.1 inches less than the diameter D 1  to allow a flow of water from the body interior into a nozzle interior  12   c,  and most preferably, the diameter D 3  is at about 0.1 inches less than the diameter D 1  to allow a flow of water from the body interior into the nozzle interior. The diameter D 2  is preferably about 0.92 inches and the diameter D 4  is preferably about 0.91 inches around the circumferential surface  20   b′.    
         [0028]      FIG. 4A  shows a second embodiment of a piston  20 ′ and spring  22 ′. The spring  22 ′ resides partially inside a lengthened smaller diameter portion  20   a  of the piston  20 ′, the smaller diameter portion  20   a  having a length L 3  of about 0.46 inches. The larger diameter portion  20   b  includes a step reducing the diameter from a diameter D 5  of preferably about 0.91 inches and length L 1  of preferable about 0.08 inches to a diameter D 6  of about 0.8 inches and length L 2  of preferably about 0.08 inches. The reduced diameter D 6  allows a better flow of water to the ports  14  when the piston  20 ′ only moves slightly. 
         [0029]      FIGS. 5A and 5B  show a first embodiment of spray patterns of the subsurface emitter  10 . The combined top and bottom nozzles  12  provide eight sprays of water  15  generally evenly angularly spaced, i.e., spaced 45 degrees apart for general use in an open area. 
         [0030]      FIGS. 6A and 6B  show a second embodiment of spray patterns of the subsurface emitter  10  suitable for a side spray pattern. 
         [0031]      FIGS. 6A and 6B  show a third embodiment of spray patterns of the subsurface emitter  10  suitable for a narrow pattern. 
         [0032]      FIG. 8  shows a layout of the emitters  10  for watering a row of trees. The emitters  10  are fed by, for example, a two inch main water line, and groups of three or four emitters  10  surround each tree  50 , and up to six or eight emitters  10  for larger trees, and are fed in series by a half inch water line. Operating pressure is preferably between 20 and 80 Pounds per Square Inch (PSI) and more preferably 40 PSI. The emitters  10  are preferably five to eight feet from the tree and the top of the emitters  10  are preferably eight to twelve inches deep, and as much as 24 inches deep for some mature trees. 
         [0033]    The body and nozzle are preferably made from plastic and the piston is made from flexible PVC or vinyl. 
         [0034]    While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.