Abstract:
A stream redirecting device for a sprinkler comprising a shell-shaped body having a generally semi-circular shape in plan, with opposite inlet and outlet side edges, said body extending outwardly and upwardly from a base at a lower end and then upwardly and inwardly to a distal, arcuate edge at an upper end, with a maximum radius between said base and said arcuate edge; an inside surface of said shell-shaped body formed with a plurality of grooves between said inlet side edge and said outlet side edge, extending in a generally radial direction with entry ends adjacent said base and exit ends at said distal, arcuate edge; and wherein said grooves are formed with circumferential exit angles that vary substantially uniformly in opposite directions from a center one of said plurality of grooves to first and last of said plurality of grooves at said opposite inlet and outlet side edges, respectively.

Description:
BACKGROUND 
       [0001]    This invention relates to rotary irrigation sprinklers and specifically, to a stream deflector that limits the distribution of a stream emitted by the sprinkler spray plate to less than the 360-degree circle pattern that would otherwise be irrigated by the stream. 
         [0002]    In agricultural irrigation systems, rotary-type sprinklers are used to irrigate large areas of land; and for much of the interior portions of the field to be irrigated, a full 360-degree circular pattern is used with good results. There are instances, however, where one or more sprinklers are located close to the edge of the field, for example, along a roadway, where it is desired to limit the normal 360-degree (or full-circle) pattern of the one or more sprinklers to avoid undesirable and wasteful watering of the roadway (or other structure(s) along the edge of the field). 
         [0003]    There are, of course, mechanically and/or electrically reversible sprinklers with adjustable stops to achieve a desired arcuate pattern, less than full circle. In addition, simple “road guards” or other stream deflectors have been employed to inhibit a full-circle pattern by deflecting the stream emitted by the sprinkler spray plate back onto the field within a limited portion of the rotation of the spray plate. In one example, the deflector is attached to a rotary sprinkler, and includes a substantially semi-circular, generally concave shell formed with grooves on its interior (concave) surface that receive and redirect the stream back towards the area just watered, thus protecting the area behind the sprinkler from the emitted stream (see U.S. Pat. No. 4,191,331). 
         [0004]    A problem associated with deflectors similar to that described in the &#39;331 patent is that the redirected stream is not uniformly distributed over the remaining pattern area exposed to the stream. By way of example, if the full-circle, normal pattern area is to be reduced to a half-circle pattern, a uniformity problem arises that is related to the groove configuration on the deflector. As will be explained further herein in connection with  FIG. 14 , the deflector grooves lie on a radius drawn on or near an imaginary center of the arcuate deflector (that may correspond to the sprinkler spray plate axis), and the grooves are substantially straight in a radial direction from their inlet ends, through the concave portion of the deflector shell, to their outlet ends. As a result, a stream entering the inlet side edge of the deflector, to the left of center as the nozzle rotates, is redirected generally toward the outlet side of the deflector, but the outlet stream traces a line angled away from the outlet side edge of the deflector. Similarly, as the stream moves across and within the deflector grooves, eventually impinging on the last groove on the outlet side of the deflector, the stream is redirected back toward the inlet side but, again, tracing a line angled away from the inlet side edge of the deflector. As a result, there are angled or wedge-shaped gaps extending from opposite sides of the deflector that do not receive redirected water, while the center area between these two gaps, is watered by the redirected stream, resulting in an unacceptable lack of uniformity across the area directly in front of the sprinkler/deflector. 
         [0005]    There remains a need therefore, for a simple, easy-to-install, and inexpensive road guard or deflector that substantially eliminates or at least minimizes the nonuniformity issue associated with prior road guards or deflectors. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    In accordance with a first exemplary but nonlimiting embodiment, the invention provides a stream deflector for a sprinkler comprising a generally concave, shell-shaped body having a generally semi-circular shape in plan, with opposite inlet and outlet side edges, the body extending outwardly and upwardly from a base at a lower end and then upwardly and inwardly to a distal, arcuate edge at an upper end, with a maximum radius between the base and a distal, arcuate edge; an inside surface of the shell-shaped body formed with a plurality of grooves between the inlet side edge and the outlet side edge, extending in a generally radial direction with entry ends adjacent the base and exit ends at the distal, arcuate edge; and wherein the grooves are formed with circumferential exit angles that vary substantially uniformly in opposite directions from a center one of the plurality of grooves to first and last of the plurality of grooves at the opposite inlet and outlet side edges, respectively. 
         [0007]    In another aspect, the invention relates to a sprinkler comprising a housing assembly supporting a rotatable spray plate provided with a stem adapted to emit a stream in a substantially radially outward and upward direction when the spray plate rotates about an axis; and a stationary stream deflector separably mounted on the housing assembly, the stream deflector provided with a shell-shaped body having a generally semi-circular shape in plan, with opposite inlet and outlet side edges, the body extending outwardly and upwardly from a base at a lower end and then upwardly and inwardly to a distal, arcuate edge at an upper end, and having a maximum radius between the base and the distal, arcuate edge; an inside surface of the shell-shaped body formed with a plurality of grooves extending substantially radially between the inlet side edge and the outlet side edge, with entry ends adjacent the base and exit ends at the distal, arcuate edge; the entry ends of the grooves located to sequentially receive the stream emitted from the spray plate as the spray plate rotates about the axis; and wherein the grooves are formed with circumferential exit angles that vary substantially uniformly in opposite directions from a center one of the plurality of grooves to first and last of the plurality of grooves at the opposite inlet and outlet side edges, respectively. 
         [0008]    In another aspect the invention relates to a stream deflector for a sprinkler comprising a substantially concave shell-shaped body provided with a plurality of generally radially-extending grooves between inlet and outlet side edges of the shell-shaped body, wherein at least a first and last of said generally radially-extending grooves are shaped to redirect streams back across the shell-shaped body, substantially parallel to a vertical plane extending across said shell-shaped body, adjacent, and substantially equally spaced from, said inlet and outlet side edges. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of a rotary sprinkler supporting a deflector device in accordance with an exemplary but nonlimiting embodiment of the invention; 
           [0010]      FIG. 2  is a perspective view of the deflector shown in  FIG. 1 , removed from the sprinkler; 
           [0011]      FIG. 3  is a front elevation of the deflector shown in  FIGS. 1 and 2 ; 
           [0012]      FIG. 4  is a partial, enlarged perspective view of the deflector shown in  FIG. 2 ; 
           [0013]      FIG. 5  is a partial, simplified plan view of the deflector shown in  FIGS. 1-3 , with an upper portion of the deflector removed to better illustrate the lower ends of the deflector grooves; 
           [0014]      FIG. 6  is a partial, simplified plan view of the deflector shown in  FIG. 5 , with an upper portion of the outer shell shown in transparency to better illustrate the upper end of the deflector grooves; 
           [0015]      FIG. 7  is an exploded assembly view of the deflector shown in  FIG. 3 ; 
           [0016]      FIG. 8  is another partial enlarged perspective view of the deflector shown in  FIG. 2 , showing a seam between upper and lower, separable portions of the deflector; 
           [0017]      FIG. 9  is a partial front elevation of the sprinkler and deflector shown in  FIG. 1 , showing generally how a stream emitted from the spray plate is redirected by the deflector; 
           [0018]      FIG. 10  is a plan view of the deflector attached to a sprinkler, and showing a stream emitted from the sprinkler spray plate just prior to entering the inlet side of the deflector; 
           [0019]      FIG. 11  is a top plan view similar to  FIG. 10  but showing the stream now within the first groove on the inlet side of the deflector, and redirected across the outlet side of the deflector; 
           [0020]      FIG. 12  is a top plan view similar to  FIG. 11  but showing the stream at the mid-point of the deflector and redirected across the sprinkler axis and substantially perpendicular to a plane extending across the front of the deflector; 
           [0021]      FIG. 13  is a top plan view similar to  FIG. 12  but showing the stream exiting the last groove at the outlet side of the deflector, and redirected across the inlet side of the deflector; and 
           [0022]      FIG. 14  is a plan view similar to  FIG. 13  but also showing, for comparison purposes, an exit stream emitted by a known deflector device. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]      FIG. 1  illustrates a rotary-type sprinkler  10  supporting a stream deflector  12  in accordance with an exemplary but nonlimiting embodiment of the invention. The sprinkler  10  includes a rotatable spray plate  14  supported on a shaft  16  ( FIGS. 5 ,  6  and  9 ) that is received within a first sprinkler housing  18 . The first housing  18  includes an upper portion  20  which encloses and supports a viscous brake  22  to slow the rotation of the shaft  16  and the spray plate  14  in a well-known manner (see, e.g., commonly-owned U.S. Pat. No. RE 33,823). The sprinkler  10  also includes a second housing  24  provided with internal threads by which the sprinkler can be mounted on, for example, a riser secured to a mobile irrigator (not shown). The second housing  24  also mounts a nozzle (not shown) that aligns and engages the spray plate  14  upon assembly of the first and second housings. In that regard, a lower annular ring  26  of the first housing  18  connects to the upper portion  20  via a plurality (four in the exemplary embodiment) of struts  28 , and is configured to enable a “push-and-turn” attachment to the second housing  24  in a known manner. 
         [0024]    As best appreciated from  FIG. 5 , the offset configuration of the spray plate stem  30  causes the spray plate  14  and shaft  16  to rotate about the axis of the shaft when water is emitted from the spray plate. In this exemplary and well-known sprinkler construction, the spray plate  14  emits a single stream in a radially outward and upward direction as it rotates with the shaft  16 , the stream passing through the spaces created by the struts  28 . 
         [0025]    With further reference to  FIG. 2 , the stream deflector  12  includes an open-topped dome or shell  32  (also referred to as a generally concave, shell-shaped body) formed with interior grooves  34  that redirect the stream emitted from the spray plate stem  30 . The deflector  12  is also formed with a substantially semi-circular base  36  incorporating flexible arms  38 ,  40  extending away from the deflector dome or shell  32 . The upper edge of the base  36  is formed with an inwardly directed flange  42  that merges into a solid, non-grooved base portion  44  of the shell  32 , and the lower edge of the base is formed with an inwardly directed flange  46 , thus forming an inwardly-facing and substantially U-shaped slot  48  within the base  36 . The non-grooved base portion  44  of the shell  32  is interrupted by a pair of notches  50 ,  52 , the purpose for which will be described further below. The vertical wall  54  of the slot is formed with inwardly directed, tapered tabs  56 ,  58  and adjacent apertures  60 ,  62 , respectively ( FIG. 3 ). The arms  38 ,  40 , terminate at their respective distal ends with ribbed, angled surfaces  64 ,  66  adapted to be engaged by a user&#39;s fingers when removing the deflector from the sprinkler as described further herein. 
         [0026]    To attach the deflector  12  to the sprinkler  10 , the lower flange  46  of the deflector is aligned with a peripheral, annular slot  68  ( FIGS. 1 and 9 ) at the interface of the first and second housings  18 ,  24  of the sprinkler  10 , and loosely pushed into the slot until resistance is felt where the tapered tabs  56 ,  58  engage the lower annular ring  26 . Note that the ring  26  is provided with four, equally spaced apertures  70  (one visible in each of  FIGS. 1 and 9 ). Continued lateral pushing of the deflector  12  will cause the arms  38 ,  40  to flex outwardly as the tapered tabs  56 ,  58  ride over the ring  26  and snap into two of the apertures  70 . Approximately half of the ring  26  is now seated within the slot  48 , with two of the struts  28  seated in notches  50 ,  52 , such that the deflector  12  is securely but removably attached to the sprinkler  10 . To remove the deflector  12 , the user will simply push on the surfaces  64 ,  66  to flex the arms  38 ,  40  outwardly to disengage the tabs  56 ,  58  from the apertures  70 , permitting the deflector to be pushed laterally out of engagement with the sprinkler. 
         [0027]    The generally concave, shell-shaped body  32  is formed with a compound-curved surface as best appreciated from  FIGS. 1-4 ), curving upwardly and radially outwardly from a smaller radius at the base  36  (and thus outwardly from the sprinkler axis), and then upwardly and radially inwardly to a larger radius at a peripheral edge  33 . Each of the grooves  34  follows this contour between entry and exit ends to thereby effectively reverse the direction of the stream as it travels along the deflector grooves as described in greater detail below. 
         [0028]    In order to facilitate an understanding of specific and important aspects of the groove configuration on the interior side of the shell  32 , a vertical reference plane P1 is shown in  FIG. 6  (and  FIGS. 10-14 ) extending across the front of the deflector, and through the center axis of the sprinkler, i.e., the axis of the shaft  16 . For purposes of this disclosure, reference numeral  16  may be considered as representing the shaft, the shaft axis and the sprinkler axis. A mid-point of the deflector is defined by a second vertical plane P2 extending perpendicularly to plane P1, and also passing through the shaft axis  16 . Relative to the plane P1, the deflector extends substantially 170 degrees from an inlet side edge to an outlet side edge  74 , the edges each offset from the plane P1 by approximately five degrees. Thus, plane P1 is also parallel to (and equally spaced from) a line connecting the inlet and outlet side edges  72 ,  74 . To further facilitate the description of the groove configuration, certain of the grooves are separately labelled as grooves  341 ,  347  and  353  (see, for example,  FIGS. 1-7 ) as explained below. 
         [0029]    Between the inlet and outlet side edges  72 ,  74 , respectively, the grooves  34  are arranged to receive a stream exiting the spray plate stem  30  and to redirect the stream back onto the field as the stream moves sequentially through the grooves, from the inlet side edge  72  to the outlet side edge  74 . Each groove  34  has an entry end  76  and an exit end  78 . In order to avoid overcrowding, reference numerals  76 ,  78  are used sparingly in  FIGS. 2-4 ,  6  and  8 . As described herein, a first groove  341  adjacent the inlet side edge  72  receives the stream S (see  FIG. 11 ) as the spray plate  14  rotates about its axis in a clockwise direction. A seventh, mid-point groove  347  lies in the plane P2. A thirteenth groove  353  adjacent the outlet side edge  74  is the last groove to receive the stream before the stream exits the deflector. All the grooves  34  have substantially the same width dimensions, except for the lead-in edge of the first groove  341  and the lead-out edge of the last groove  353 . Each groove also has a circumferential “exit angle”, i.e., the angle at which the stream is redirected back onto the field as it exits the groove. As will be explained further below, the exit angles decrease substantially uniformly from the first groove  341  to the mid-point groove  347 , and then increase substantially uniformly from the mid-point groove  347  to the last groove  353 . In other words, the groove configurations on either side of the mid-point groove  347  are substantially mirror images of each other. 
         [0030]    For purposes of this disclosure, and with reference to  FIG. 6 , the exit angle EA for each groove may be defined by the intersection of a first line  82  passing through the sprinkler axis  16  and a point at the center of the entry end  76  of the groove (see, for example, point  77  in  FIG. 4 ), and a second line  80  extending along the center of the exit end  78  of the groove. This angle may be considered to represent the amount of offset from a straight, radially oriented groove. For the illustrated embodiment, the exit angle will decrease about 16 degrees for each groove, from groove  341  to groove  347  where the exit angle is zero. As noted above, the grooves and respective exit angles to the right of the mid-point groove  347  are a substantial mirror image of the grooves and exit angles to the left of the mid-point groove  347 . In order to achieve the desired exit angles, the circumferential curvature of each groove also changes between the entry end and the exit end  78  (see  FIGS. 1-6 ). For the first groove  341  with the largest exit angle, the curvature as defined by the arcuate side surfaces of the groove is more pronounced because it is desirable to maintain a smooth path for the stream as it flows through the groove. Thus the groove  341  curves first in one direction toward the plane P1 (or toward the inlet side edge  72 ) and then away from the plane P1 (or away from the inlet side edge  72 ) to finally arrive at the desired exit angle. As the exit angle decreases, the degree of circumferential curvature within each groove also decreases, so that for groove  347 , where the exit angle is zero, there is essentially no circumferential curvature in the groove. From groove  347  to groove  353 , the curvatures are mirror images of those in grooves  341  to  347 . 
         [0031]    Referring to  FIG. 7 , the deflector  12  in the exemplary embodiment is of two-piece construction, with upper and lower portions  84 ,  86 , respectively, joined by two or more screws  88  along facing horizontal edges  90 ,  92  with the assistance of alignment pins  94  and holes  96  (labeled as such only in  FIG. 7 , again to avoid overcrowding of reference numerals in the various figures). 
         [0032]    Turning to  FIG. 8 , it can be seen that the grooves  34  at their exit ends  78 , in the upper portion  84 , are slightly enlarged relative to the grooves in the lower portion  86 , creating a step or shoulder  98  facing outwardly along a seam  100  created by the joined edges  90 ,  92 . This arrangement insures smooth flow of the stream by eliminating the possibility of an inwardly facing shoulder resulting from a slight mismatch of the upper and lower portions  84 ,  86 , that would disturb the exiting stream. Nevertheless, the curvature of the groove side walls carries over from the lower portion to the upper portion, and sets the exit angles for the various grooves. 
         [0033]      FIG. 9  illustrates generally the manner in which a stream S emitted by the spray plate stem  30  is redirected back across the sprinkler  10  and onto the field being irrigated. It will be appreciated that the groove shapes in both the upper and lower portions  84 ,  86  are responsible for the exit angles as defined above. The upper portion  84  also determines the elevation angle of the stream relative to ground. 
         [0034]    The sequence of stream movement through the deflector from the inlet side edge  72  to the outlet side edge  74  will now be described in connection with  FIGS. 10-13 .  FIG. 10  shows the stream S travelling in a clockwise direction, adjacent the inlet side edge  72 , about to enter the deflector. Note that the stream extends substantially parallel to and behind the plane P1. If the plane P1 also represents the edge of the field being irrigated, it will be appreciated that a narrow portion of the land or roadway behind the plane/edge will be wetted by the stream. This is intended to be a “safety factor” in that, if an allowance is not made for wind, it is quite likely that some of the field along the edge will not receive any water. 
         [0035]      FIG. 11  shows the stream S entering and exiting the first groove  341 ; and because of the exit angle established by the groove configuration described above, the stream is redirected across the sprinkler, behind the plane P1, and slightly behind the outlet side edge  74  of the deflector. 
         [0036]      FIG. 12  shows the stream rotated further in the clockwise direction to the groove  347  where the exit angle is zero degrees. As a result, the stream both enters and exits the groove substantially along the plane P2. It will be understood of course, that the area between the stream as shown in  FIG. 11  and the stream as shown in  FIG. 12  will be filled in uniformly as the stream enters and exits each of the grooves between groove  341  and  347 . 
         [0037]      FIG. 13  shows the stream S entering and exiting the last groove  353 , and because of the mirror-image groove configuration on opposite sides of the plane P2, the stream S is redirected across the sprinkler, behind the plane P1 and slightly behind the inlet side edge  72 . 
         [0038]    By way of comparison,  FIG. 14  shows how a stream S1 is redirected from the last groove in the prior deflector construction. Stream S2 represents the stream location as it enters the deflector. It can be seen that a wedge-shaped gap G1 is created between the streams S1 and S2 that is underwatered. The stream S3 represents the stream redirected from the last groove  353  in accordance with the exemplary embodiment of this invention, greatly reducing the underwatered gap from G1 to G2. 
         [0039]    Variations in the described deflector are contemplated, depending on the associated sprinkler construction and the desired sprinkling pattern. For example, the groove shapes in the upper portion  84  of the deflector may be altered to achieve a specific pattern, and the separable nature of the upper portion provides a simple and relatively inexpensive vehicle for implementing such variations. 
         [0040]    In addition, the manner in which the upper and lower portions  84  and  86  are joined may also vary to include any suitable attachment mechanism. Similarly, the manner of attachment of the deflector to the sprinkler may be adapted to suit different sprinklers. 
         [0041]    While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements.