US 3716192 A
An irrigation sprinkler head having two sets of nozzle holes arranged one above the other, the top nozzle holes being inclined upwardly at an angle to attain maximum range, and being designed to produce minimum turbulence so that the streams are coherent and break up at a considerable distance out from the head. The lower nozzle holes throw their streams at a slightly flatter angle for shorter range, and are designed to produce some turbulence so as to cause their respective streams to break up at a shorter distance out from the head. The streams issuing from the lower nozzle holes fan out laterally and strike a deflector shelf having a flatter angle than the streams, and this causes a portion of the streams to break up immediately to cover the area closest to the head.
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Description (OCR text may contain errors)
United States Patent [191 Hunter 1 EXTENDED RANGE SPRINKLER HEAD Edwin J .Hunter, Riverside, Calif.
 Assignee: Moist OMatic Division of Toro Manufacturing Corporation, Minneapolis, Minn.
 Filed: May 27, 1971  Appl.No.: 147,515
 US. Cl. ..239/205, 239/498, 239/568 [51 Int. Cl. ..B05b 1/34  Field of Search ..239/200, 201, 202, 203, 204,
[451 Feb. 13,1973
3,603,512 9/1971 Ham ..239/558 X Primary Examiner-M. Henson Wood, Jr.
Assistant Examiner-Michael Mar Attorney-Herbert E. Kidder [5 7 ABSTRACT An irrigation sprinkler head having two sets of nozzle holes arranged one above the other, the top nozzle holes being inclined upwardly at an angle to attain maximum range, and being designed to produce minimum turbulence so that the streams are coherent and break up at a considerable distance out from the head. The lower nozzle holes throw their streams at a slightly flatter angle for shorter range, and are designed to produce some turbulence so as to cause their respective streams to break up at a shorter distance out from the head. The streams issuing from the lower nozzle holes fan out laterally and strike a deflector shelf having a flatter angle than the streams, and this causes a portion of the streams to break up immediately to cover the area closest to the head.
9 Claims, 6 Drawing Figures PATENTEDFEBIBIQYS 3.716192 SHEET 3 or 3 75 INVENTOR.
Eon/0v J. HUNTER BY W AGENT EXTENDED RANGE SPRINKLER HEAD BACKGROUND OF THE INVENTION The present invention relates generally to irrigation sprinkler heads, and more particularly to a fixed-position sprinkler head specifically designed for maximum range, with extremely uniform precipitation rate over the entire area covered by the head. In its preferred form, the invention is embodied in a pop-up sprinkler head, but this is not an essential part of the invention in its broadest aspect.
Conventional fixed-position sprinkler heads have sought to achieve uniform coverage in either of two ways: (1) by directing a plurality of streams of water at varying angles to the horizontal; or (2) by directing streams of water radially outward from the head at the same angle to the horizontal and relying upon the break-up of the water streams to cause some of the water to fall close to the sprinkler head',-and some to reach out for a considerable distance. In the case of the plurality of streams of water leaving the sprinkler head at varying angles to the horizontal, those streams that are discharged at the optimum angle (usually about 30 degrees above the horizontal), have the maximum range, and all other angles of discharge fall short of this distance, so that they cover the area from the sprinkler head out to the area of maximum range. However, maximum range has heretofore been limited by the fact that the streams of water issuing from the sprinkler head have had a tendency to break up into individual droplets almost immediately upon leaving the nozzle holes, owing to turbulence in the streams, and this breaking of the streams causes them to lose velocity rapidly, which shortens their trajectory. On the other hand, those streams of water aimed at closer range must break up before they hit the ground, so as to avoid having a solid stream of waterfall onto the ground at one point, causing considerable scouring of the soil. In prior sprinkler heads, all of the jet streams were of the same characteristics, (i.e'., more or less coherent for good range) and the breakup of the short range streams was accomplished by shooting the streams high into the air. However, this type of spray pattern is adversely affected by variations in the water pressure. Pressure appreciably below the optimum results in coherent streams without proper breakup, whereas pressure much .above the optimum results in excessively fine breakup of the stream, giving a fine mist which drifts with the slightest wind.
In the case of the sprinkler head that directs all of its streams of water at the same angle to the horizontal, there is an objectionable lack of uniformity between the precipitation rate for the area close in to the sprinkler head and that for the more distant areas, with the result that some areas of the ground are overwatered and some are underwatered.
SUMMARY OF THE INVENTION The primary object of the invention is to provide a new and improved sprinkler head having the extended range to cover a large area, and at the same time, good uniformity of precipitation rate from the sprinkler head out to the outer limits of its coverage.
Another object of the-invention is to provide a popup sprinkler embodying a spray head having one set of nozzles specifically designed for maximum range, and
another set of nozzles designed to produce uniform coverage and good breakup of the streams, for the area from the sprinkler head out to the area covered by said one set of nozzles.
A further object of the invention is to provide a sprinkler head having at least one row of nozzles, all similar to one another, each of which throws a first stream of water to a considerable distance out from the sprinkler head to cover a distant area, and a second stream of water having considerably less range and immediate breakup of the stream, to cover the area from the sprinkler head out to said distant area. Thus, the one row of sprinkler nozzles covers a considerable area of ground with an extremely uniform precipitation rate, owing to the fact that each nozzle throws two streams of water, one having characteristics that make it carry for an extended range of coverage, and the other having characteristics that make it better suited for close range coverage.
Still another object of the invention is to provide an irrigation sprinkler head of the class described, which can be molded of plastic, and is simple and inexpensive to manufacture. Moreover, being made of plastic, the present sprinkler head is not subject to corrosion, and is relatively resistant to liming.
These and other objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of the prefered embodiments thereof, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a cut-away view of an improved pop-up sprinkler head embodying the principles of the invention, showing the sprinkler head installed in a permanent underground sprinkler system, with the pop-up spray head shown in phantom lines in its extended position;
FIG. 2 is an enlarged axial section through the popup spray head, showing the strainer in phantom lines;
FIGIS is a plan view of the area covered by the sprinkler head, showing the overlapping areas covered by the two sets of nozzle holes;
FIG. 4 is an exploded view of the pop-up head shown in FIG. 2;
FIG. 5 is a greatly enlarged, fragmentary sectional view through the nozzle portion of the pop-up head, showing the two different sets of nozzle holes, and the streams of water issuing from them, said streams being depicted in phantom lines; and
FIG. 6 is a fragmentary sectional view, taken at 6-6 in FIG. 5, drawn to a somewhat smaller scale.
DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, the sprinkler head of the invention is designated in its entirety by the reference numeral 10, and comprises a cylindrical housing 12, which contains a pop-up spray head 14. The housing 12 is preferably molded of a relatively rigid plastic, such as high density polyethylene, and is formed with an internally threaded inlet neck 16 at its bottom end, to receive a riser pipe 18 which is connected to a source of water under pressure. A cap 20 is screwed onto external threads at the top end of the housing, and the pop-up head 14 slides up and down through a circular opening 22 in the cap, which is sealed by means of a sealing ring 24. On the inside, housing 12 is provided with a central bore 26, which defines a cylindrical chamber.
The pop-up spray head 14 is an elongated cylindrical body made up of three parts: a main body 28, nozzle ring 30, and cap 32, all held together by a screw 34 that passes through a central hole 36 in the cap, and screws into an internally threaded tube 38 that is mounted in the center of the body 28 on a plurality of angularly spaced, radial spokes 40. The main body 28 is a thinwalled cylindrical tube, the outside diameter of which is a little smaller than the inside diameter of chamber 26 so as to provide room for a helical spring 42.
Spring 42 surrounds the tubular body 28, and its bottom end bears against a radial flange 44 projecting from the bottom end of the tube. The top end of spring 42 bears against the radial flange portion 46 of seal 24, as best shown in FIGS. 1 and 2. The outer edge of seal flange 46 is clamped between cap 20 and the top end of housing 12 (FIG. 1), and projecting upwardly and downwardly from the inner edge of the flange are thin, tapered sealing lips 48, which lie snugly against the outer surface of body 28. Spring 42 urges the spring head 14 downwardly so as to retract it into the housing 12, and the pressure of the spring is overcome by the hydraulic pressure of the water, which pushes the spray head up to the extended position shown in phantom lines in FIG. 1. Seated within the body 28 and held in place therein by frictional fit is a water strainer 49, which is frusto-conical in shape. Strainer 49 takes out any grains of sand or other foreign matter that would clog the nozzles.
In the top end of spray head 14 are two rows of nozzle orifices, 50 and 52, which are formed by the top end of body 28, nozzle ring 30, and cap 32, as best shown in FIG. 5. The spray head shown in the drawings is for a quarter-circle coverage, and therefore the nozzle orifices extend for only 90 degrees around the circumference, as seen in FIG. 6. However, the nozzles may extend all the way around the spray head for a full 360 degree coverage, or for any desired angular coverage.
The top nozzle orifices 50 are defined between a conical bottom surface 54 on the bottom edge of cap 32, and a mating conical surface 56 on the top side of nozzle ring 30. Theangle that the conical surfaces 54, 56 are inclined up from the horizontal is preferably 2926'A, which has been found to be the optimum angle for maximum range of water streams of the type shown here.
Formed in the top surface 56 of the nozzle ring is a plurality of narrow, radial slots 58, which are preferably spaced apart from one another by the angular distance of 9. The bottom surface 60 of each slot, for the outer two-thirds of its length, is inclined at an angle of 2637 from the horizontal, making an included divergent angle of 249 between the top and bottom surfaces of the slot. The sides of the slots 58 are parallel to one another, and are preferably spaced apart about 0.022 inch. At the entry end of the slot 58, the bottom surface has a gently sloping and curving ramp 62, which leads the water smoothly into each slot with a minimum of turbulence. In passing through the relatively long and narrow slot 58, any turbulence in the water is further supressed, and the stream 64 that issues from each of the nozzle orifices 50 is a solid, coherent stream that carries for the maximum distance through the air before it breaks up into separate droplets. The area covered by the streams of water 64 is represented by the area bracketed at A in FIG. 3, which is the area ranging from 20' to 35' out from the sprinkler head 10.
.The lower nozzle orifices 52 are formed by narrow, radial slots 66, which are formed in the bottom edge of the nozzle ring 30. Preferably the slots 66 are the same in number as slots 58, and are likewise spaced apart from one another by the angular distance of 9. The top surface 68 of each slot 66 is inclined at an angle of about 25 up from the horizontal, which makes it a slightly flatter angle than the roof surface 54 of slots 58. As a result, the streams of water 70 issuing from nozzle orifices 52 have a flatter angle to the horizontal than streams 64, and therefore have a shorter range than the latter. In addition to its flatter trajectory, the stream 70 has a certain amount of turbulence as it leaves the nozzle orifices 52, and therefore tends to break up into separate droplets at a much closer distance to the sprinkler heads than the stream 64. This turbulence is the result of several design factors which will now be described.
In FIG. 5, it will be noted that nozzle ring 30 is more than twice as thick as the wall of body 28. The top edge of body 28 is recessed on its inner side, forming an annular shoulder 72, upon which the bottom end of the nozzle ring 30 seats. Shoulder 72 is square, and forms a sharp comer at 74, which extends transverse to the direction of water flow as the water enters the slots 66. A second sharp corner is formed at 76 by the top edge of body 28, and these two sharp corners 74 and 76 produce turbulence in the water as it flows through slots 66.
The bottom edge of nozzle ring 30 is recessed on its outer edge, forming a downwardly facing shoulder, or deflector shelf 76, which projects below the top surface 68 on each side of the slot. Shelf 76 is inclined at a still' flatter angle than surface 68, and its angle to the horizontal is from 6 to 20; the preferred angle being 12.
As the stream of water leaves the space where it is confined between the side walls of the slot 66, the stream tends to fan out slightly at its sides, as shown in phantom lines in FIG. 6. These fanned-out side portions of the stream strike the deflector shelf 76 and are deflected downwardly to a flatter angle than stream 70. The downwardly deflected portions of the water stream are designated by the reference numeral 78. In addition to being deflected downwardly, streams 78 arebroken up by their impact against the deflector shelf 76, and thus the stream 78 is actually a shower of droplets, which reach out to about the 15' circle in FIG. 3. The area covered by stream 78 is shown by the bracket C.
The operation of the invention is believed to be selfevident from the foregoing description. The outermost area A to be covered by precipitation is reached by the streams of water 64 issuing from the upper row of nozzle orifices 50, which are coherent streams inclined upwardly at the optimum angle for maximum range. The streams 64 are coherent because they are non-turbulent as a result of smooth entry into the slots 58, and the relatively large length-to-width ratio of the slot. The intermediate area B is covered by streams 70, which are inclined at a flatter angle to the horizontal, and which are also somewhat turbulent because of the shorter slot length, and because of the sharp corners over which the water flows. Because of their greater turbulence, streams 70 break up at a shorter distance out from the sprinkler head than is the case with streams-64. The innermost area C is covered by the spray 78 which results from impact of the outer side portions of streams 70 against the deflector shelf 76.
The pop-up action of the spray head 14 is caused by hydraulic pressure acting against the head 14 which is slidable within the cylindrical-chamber 26. When the water is turned on, the spray head is lifted against the pressure of spring 42 to the elevated position shown in phantom lines in FIG. 1, where it remains until the water is shut off.
Although the preferred form of the invention is the embodiment shown in the drawings, the invention might also take another form, in which the spray head has only a single row of nozzle orifices of the type shown in FIG. 5 at 52. Such a spray head would have an effective radius of coverage of about 25 feet from the sprinkler, which means that the sprinklers wouldbe spaced somewhat closer together than in the case of the illustrated embodiment. The one row of nozzles 52 gives good uniform coverage out to the 25 foot distance owing to the way that it throws two streams of water 70 and 78; the former having characteristics that make it carry for an extended range, and the latter having characteristics that make it better suited for close range coverage.
While I have shown and described in considerable detail whatl consider to be the preferred form of my invention, it will be understood by those skilled in the art that various changes may be'madein the shape and arrangement of the several parts of the device, and that such details are not intended to limit the scope of the claims.
1. A fixed-position sprinkler head comprising a hollow body, the interior of which is connected to a source of water under pressure;
at least one set of nozzle orifices provided in the walls of said body, each of said nozzle orifices being shaped andarranged to throw a jet stream of water upwardly and outwardly at a first angle to the horizontal;
each of said nozzle orifices having generally parallel side walls and a roof surface inclined upwardly at an angle to the horizontal substantially the same as said first angle; and means disposed in the path of said jet stream to intercept a small portion of the latter and direct it downwardly, so that said small portion leaves said sprinkler head at a flatter angle than said jet stream and is broken up by said means into droplets, thereby providing uniform precipitation coverage from the sprinkler head out to the area covered by said jet streams said means comprising a downwardly facing impact surface which is impacted'by a small portion of said jet stream at one side of the nozzle orifice.
2. A sprinkler head as in claim 1, wherein said impact surface is disposed at an angle to the horizontal slightly less than said first angle.
3. A sprinkler head as in claim 1, wherein each of said nozzles has generally parallel side walls and a roof surface inclined upwardly at an angle to the horizontal substantially the same as said first angle; and
said means comprising a downwardly facing deflector shelf extending circumferentially around said body at a level just below the roof of the nozzle orifice at the exit end of the latter, said deflector shelf being inclined to the horizontal at an angle slightly less than the roof angle of the nozzle orifice;
the water issuing from each nozzle orifice below said deflector shelf tending to fan out laterally and impinge against the shelf, thereby breaking up the water into droplets which leave the sprinkler head at a flatter angle than the main jet stream, so as to provide uniform precipitation coverage from the sprinkler head out to the area covered by the main jet streams.
4. A sprinkler head as in claim 1, which further includes means in the nozzle orifice for producing a limited amount of turbulence in the water passing through it, whereby the stream of water issuing from the orifice has a tendency to fan out and thereby strike said impact surface.
5. A sprinkler head as in claim 1, which further includes a second set of nozzle orifices that are inclined at a second angle to the horizontal, such that the initial trajectory angle of the jet streams issuing therefrom causes the streams to carry for a greater distance than the streams issuing from said one set of nozzles, said second set of nozzle orifices being shaped and arranged to produce coherent, non-turbulent jet streams which carry for a considerable distance without breaking up.
6. A sprinkler head as in claim 5, wherein each of the nozzle orifices in said second set has generally parallel sides and a roof surface inclined upwardly at second angle to the horizontal, said orifices each having a smoothly rounded entry and a relatively large lengthto-width ratio.
7. A sprinkler head as in claim 3, which further includes a second set of nozzle orifices that are inclined at a second angle to the horizontal which is slightly greater than said first angle, each of the nozzle orifices in said second set having generally parallel side walls and a roof surface inclined upwardly at said second angel, said orifices each having a smoothly rounded entry and a relatively large length-to-width ratio, so that said second set of nozzles produces coherent, non-turbulent jet streams that carry for a considerable distance without breaking up, whereas said first-named set of nozzle orifices produces somewhat more turbulent and less coherent jet streams that carry for an intermediate distance, while the portions of said last-mentioned'jet streams that impact said deflector shelf produce a broken-up spray that covers the area close in to the sprinkler head.
8. A sprinkler head as in claim 7, wherein said body consists of a tubular member, a nozzle ring, and a cap superimposed on one another and joined together by fastening means, said cap having a conically tapered bottom surface which mates with a correspondingly tapered top surface on said nozzle ring, said mating surfaces being inclined upwardly from the horizontal at said second angle for long range streams of water, said top surface of said nozzle ring having a plurality of anthat water flowing through the slots is thrown into turbulence prior to leaving the exit end of the slot.
9. A sprinkler head as in claim 8, wherein said conically tapered bottom surface of said cap is inclined to the horizontal at an angle of about 26; the roof of the slots in the bottom of said nozzle ring is inclined to the horizontal at an angle of about 25; and said reflector shelf is inclined to the horizontal at an angle of from 6 to 20.