Abstract:
Improved sprinkler apparatus for distributing water from a pressurized water supply line via a sprinkler case connected to the pressurized water supply line, the apparatus includes a spray head and nozzle pivotably mounted in the sprinkler case for distributing water in a vertical plane, and a hydraulic motor disposed within the sprinkler case for causing the spray head to oscillate in the vertical plane.

Description:
[0001]    The present invention generally relates to irrigation systems and is more particularly directed to an improved irrigation sprinkler with uniform water distribution and coverage. 
         [0002]    Prior art sprinklers, including rotary pop-up sprinklers have many disadvantages. One of the disadvantages includes the lack of uniform disbursement of water regardless of the radial length of the area being sprinkled at any given instant by the nozzle. 
         [0003]    Current pop-up sprinkler design incorporate a water turbine to rotatably drive a sprinkler head mechanism with many of these designs also incorporating a means of adjusting the horizontal spray angle of the head. Such current designs also provide for a range of water spraying between 12 to 15 feet or 19 to 32 feet, or a similar range. 
         [0004]    The present invention includes a sprinkler design which improves water distribution and coverage by providing a vertical oscillation feature. This feature allows water distribution very similar to hand watering motion. In fact, it can be shown that in particular installations, this vertical motion also allows for nearly complete coverage by a single sprinkler head within a given lawn area and thus largely avoids the need for overlapping sprinkler head installation. This, of course, provides for reduce costs in both installation and operation of an irrigation system. 
       SUMMARY OF THE INVENTION 
       [0005]    Improved sprinkler apparatus, in accordance with the present invention, for distributing water from a pressurized water supply generally includes a spray head which is pivotably mounted in a sprinkler case for distributing water in a vertical plane along with a hydraulic motor disposed within the sprinkler case for causing the spray head to oscillate in a vertical plane. More particularly, the spray head may be movable within the sprinkler case between a retracted position and an extended position. 
         [0006]    The hydraulic motor may comprise a gear reduction mechanism to drive a low-speed cam system and connecting rod for causing vertical oscillation of the spray nozzle. In one configuration, the hydraulic motor is configured for oscillating the spray head through an angle of about 60°. A pop-up riser may be utilized for enabling movement of the spray head between a retracted (inoperative) position and an extended (popped-up) position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The advantages and features of the present invention will be better understood by the following description when considered in conjunction with the accompanying drawings, in which: 
           [0008]      FIG. 1  is a perspective view of sprinkler apparatus in accordance with the present invention as it may be attached to an underground water supply line for distributing water in a vertical plane; 
           [0009]      FIG. 2  is a cross sectional view of the apparatus shown in  FIG. 1  generally showing a spray head, riser and riser case along with a hydraulic motor for causing the spray head to oscillate in a vertical plane; 
           [0010]      FIG. 3  is a cross sectional view of an upper portion of the assembly shown in  FIG. 2  illustrating a cam plate, cam track, and connecting rod for causing oscillation of the spray head in the vertical plane; and 
           [0011]      FIGS. 4-9  illustrate calculations for the design of a cam track for providing vertical oscillation of the spray head in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    With reference to  FIGS. 1 and 2 , there is shown improved sprinkler apparatus  10  as it may be connected to a water supply  14  by way of a T coupling  18  and stub  22  in a conventional manner. The apparatus  10  includes a pop-up riser  26  slidably disposed within a riser case  30 , see also  FIG. 2 . 
         [0013]    In operation, water passes through a filter screen  34  and past a turbine wheel  38  in order to provide high speed rotation thereof. A hydraulic motor  40  causes a spray head  54  to oscillate in a vertical plane as herewith described and calculated. 
         [0014]    A gear set  42  provides for slower rotation of a earn plate  46 . A spray head  54 , when disposed in an extended position as shown in  FIG. 1  enables the distribution of water through the spray head  54  and nozzle  55  in a vertical plane through an angle of approximately 60 degrees, as illustrated by dashed lines  58  shown in  FIG. 1 . 
         [0015]    With reference again to  FIGS. 2 and 3 , the cam plate  46  includes a cam track  62  which engages a connecting rod  66 , as best shown in  FIG. 3 . As also shown in  FIG. 3 , the cam track  62  is at a “low point” causing the spray nozzle  55  to spray water at a maximum distance. 
         [0016]    As the cam plate  46  is rotated, the cam track  62  lifts the connecting rod  66  to cause the spray head and spray nozzle  55  to rotate downward, thus spraying water to a minimum distance nearest to the sprinkler apparatus  10 . 
         [0017]    Calculations show that the cam driven vertical oscillation sprinkler apparatus  10  can be designed to deliver a constant volume of water per square foot of watered surface. This control is provided by the unique cam track design and resulted accurate water distribution. Therefore, uniform water distribution can be provided with less water and overwatering to compensate for dry areas is eliminated. 
         [0018]    With reference now to  FIGS. 1-9 , 
       Cam Track Design: 90° (Corner) Spray 
     Assumptions: 
       [0019]    Water flow rate is constant=Q 
         [0020]    Spray head is 4″ above ground 
         [0021]    Spray angle is +30° to −30° 
         [0022]    Average spray distance is 20 ft. with ±4 ft. distribution (See  FIGS. 4-5 ) 
         [0023]    On revolution of the cam ( 46 ) will cause the nozzle ( 54 ) to make one vertical oscillation cycle. 
         [0024]    To have equal volume of water per unit average of irrigation, the following must be true: 
         [0000]    
       
                 
         
             
             
         
       
       
         
           
             Q=Volume flow (ft 3 /sec) 
             t=Time (sec) 
             R=Avg. spray radius 
           
         
       
     
         [0028]    Thus, the amount of time the spray is at a given radius, R, is directly proportional to that radius. 
         [0000]        t=πR/ 2 Q    
         [0029]    The cam track ( 62 ) must be designated to rotate the nozzle ( 54 ) in a manner to achieve the above. In the preferred embodiment, the relationship between these is: (See  FIG. 6 ) 
         [0030]    For a given cam design, 
         [0000]        h   1   −h   0 =2 Tan 30°( x )
 
         [0031]    Since spray radius R is a spray angle, then Rαh and t/R must be constant. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0032]    Cam plate  46  rotates through 360°. For a given angle θ, the cam track height (h) above h 0  is illustrated in  FIG. 8 . 
         [0033]    Since the cam plate rotates at constant rate, time (t) a rotation angle (θ) ∴ θh= constant 
       Cam Design 
       [0034]    Example: 4″ pop-up
       x=0.4″   h=0.462″@180° cam   assume w=360°/min   Total cycle time=30 sec (180°)       
 
         [0000]    
       
         
               
               
               
               
               
               
             
           
               
                   
               
               
                 Head 
                 Spray 
                 Arc 
                 Time 
                   
                 Water 
               
               
                 Angle 
                 Distance 
                 Length 
                 Interval 
                 % Total 
                 Vol./Avg. 
               
               
                   
               
             
             
               
                 +30° 
                   20 ft. 
                   31 ft. 
                   5 sec. 
                   27% 
                 5Q/31 = .16Q 
               
               
                 +20° 
                 16.8 ft. 
                 26.4 ft. 
                 4.25 sec.  
                   23% 
                 .16Q 
               
               
                 +10° 
                 13.5 ft. 
                 21.2 ft. 
                 3.4 sec. 
                 18.8% 
                 .16Q 
               
               
                  +0° 
                   10 ft. 
                 15.7 ft. 
                 2.5 sec. 
                 13.8% 
                 .16Q 
               
               
                 −10° 
                  7.2 ft. 
                 11.3 ft. 
                 1.8 sec. 
                  9.9% 
                 .16Q 
               
               
                 −20° 
                 3.83 ft. 
                  6.0 ft. 
                   1 sec. 
                  5.5% 
                 .16Q 
               
               
                 −30° 
                  0.6 ft. 
                  .94 ft. 
                 .15 sec. 
                  .8% 
                 .16Q 
               
               
                   
                   
                   
                   
                 18.1 sec. 
               
               
                   
               
             
          
         
       
     
       Use 0.26Q for 30 sec. cam. 
       [0039]    Example of cam track design to deliver a constant amount of water per sq. ft. of irrigated flat surface. 
         [0000]                                                                Degrees           Head   Spray   Water Arc   % Cam   Rotation       Angle   Dist.   Length   Time   (½ Cycle)   Cam “Lift” h                   +30°     20 ft.     31 ft.    27%   48°   0       +20°   16.8 ft.   26.4 ft.    23%   41°   x(Tan 30° −                           Tan 20)       +10°   13.5 ft.   21.2 ft.   18.8%    34°   x(Tan 30° −                           Tan 10)        +0°     10 ft.   15.7 ft.   13.8%    25°   X Tan 30°       −10°    7.2 ft.   11.3 ft.   9.9%   18°   X(Tan 30° +                           Tan 10)       −20°   3.83 ft.    6.0 ft.   5.5%   10°   X(Tan 30 + Tan                           20)       −30°    0.6 ft.    .94 ft.   0.8%    4°   2x Tan 30                       180°                     
A scale drawing of this case track is shown in  FIG. 9 .
 
         [0040]    Although there has been hereinabove described a specific pop-up sprinkler with vertical oscillation in accordance with the present invention for the purpose of illustrating the manner in which the invention may be used to advantage, it should be appreciated that the invention is not limited thereto. That is, the present invention may suitably comprise, consist of, or consist essentially of the recited elements. Further, the invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein. Accordingly, any and all modifications, variations or equivalent arrangements which may occur to those skilled in the art, should be considered to be within the scope of the present invention as defined in the appended claims.