US3454225A

US3454225A - Sprinkler head having adjustable precipitation rate

Info

Publication number: US3454225A
Application number: US627089A
Authority: US
Inventors: Edwin J Hunter
Original assignee: Toto Mfg Corp
Current assignee: Toto Mfg Corp
Priority date: 1967-03-30
Filing date: 1967-03-30
Publication date: 1969-07-08
Anticipated expiration: 1986-07-08

Description

v July 8, 1969 E. J. HUNTER 3,454,225

SPRINKLER HEAD HAVING ADJUSTABLE PRECIPITATION RATE Filed March so. 1967, v I Sheet of 2 IV'IA/A II/III/III/I All lNl/E'A/TOE EDWIN J. HUNTEE JYWE/QMW July 8, 1969 J. HU NTER A 3,454,225

I SPRINKLER HEAD HAVING ADJUSTABLE PRECIPITATION RATE Filed March so, 1967 A Sheet 2 of 2 INVEN r02 v [ROW/IV J Hem/r52 y 44M 541M United States Patent U.S. Cl. 239-205 9 Claims ABSTRACT OF THE DISCLOSURE A spray head for an irrigation sprinkler having a plurality of angularly spaced discharge orifices characterized by similar, generally triangular exit sections, each bounded by converging sides defining an apex, and a base side opposite the apex; and means for adjusting the spacing between the apices and base sides of the respective exit sections to vary the effective areas of these sections without altering their geometric proportions, thereby to regulate the precipitation rate of the sprinkler without appreciably affecting its overall coverage, spray pattern, or water distribution within the spray pattern. An improved pop-up sprinkler embodying the spray head and adapted for use in a permanent underground sprinkler system.

Background of the invention This invention relates generally to irrigation devices, and more particularly to an improved sprinkler head having novel, generally triangular discharge orifices which are adjustable to vary the precipitation rate of the spray head without appreciably altering its overall coverage, spray pattern, or water distribution within the spray pattern. The invention relates also to an improved pop-up sprinkler embodying the spray head and adapted for use in a permanent underground sprinkler system.

A wide variety of irrigation sprinklers have been devised. The existing sprinklers, however, are characterized by certain inherent deficiencies which the present invention seeks to overcome. Generally speaking, irrigation sprinklers may be classified as either fixed discharge, or moving discharge, sprinklers. A typical fixed discharge sprinkler has a normally stationary spray head which directs either a number of discrete diverging streams of water, or a generally continuous fan-shaped spray of water spreading outwardly from the spray head over a given angle which may range from a few degrees to a full 360, depending upon the area to be covered. A moving discharge sprinkler, on the other hand, has a movable spray head, which directs one or more water streams outwardly from the head in a given direction, or directions, relative to the head, and which is driven in a rotary, oscillatory, or other cyclic motion to cause the water streams to sweep over the area to be irrigated.

Moving discharge sprinklers are superior to the fixed discharge type from the standpoint of low precipitation rate, and a moving discharge sprinkler may be designed to distribute a relatively small flow of water over a relatively large area. The existing fixed discharge sprinklers, on the other hand, continuously deliver a relatively large flow of water to a relatively small area and thus produce a relatively high precipitation rate over the area. However, moving discharge sprinklers tend to be complex in construction, costly to manufacture, subject to wear and malfunction, sensitive to water-flow rates and pressures, and their coverage is adversely affected by wind. Moreover, these sprinklers are ill-suited to small and/0r irregularly shaped areas, and are generally incapable of accurate trimming, that is, spraying along but not ap- "ice preciably beyond the border of an irrigation area, particularly an irregular border. Accordingly, moving discharge sprinklers are not totally satisfactory for many uses, notably in permanent underground lawn sprinkler systems.

Fixed discharge sprinklers, on the other hand, are characterized by maximum simplicity, low cost, reliability, immunity to wear, and the ability to irrigate small or irregular areas and to accurately trim the borders of such areas. The chief disadvantage of fixed sprinkler heads is that they are relatively inflexible with respect to varying the precipitation rate. This is an important disadvantage when it is considered that the water requirements of a yard are not the same over its entire area. One area may require more water than another owing to differences in drainage, plant coverage, root density in the soil, and exposure to sun and wind. Fixed sprinklers are usually operated in groups from a common control valve, which may be manually controlled or operated by an automatic controller. In either case, all of the sprinklers in a group go on and off together, and therefore run for the same length of time. Consequently, they all deliver approximately the same amount of water to their respective areas of coverage, with the result that some areas requiring less water are overwatered, while other areas requiring more water are underwatered.

Various attempts have been made in the past to provide means for adjusting the precipitation rate of the individual sprinkler heads, so that the distribution of water can be tailored to the needs of the yard. One such attempt has been to provide means (usually in the form of an adjustable valve upstream from the sprinkler head) for varying the water pressure to each sprinkler head. The disadvantage of this approach is that the volume of water delivered by a sprinkler head is proportional to the square root of the pressure. At the same time, the spray pattern is greatly influenced by water pressure. Reducing the pressure appreciably below the optimum results in coherent streams without proper breakup, whereas increasing the pressure much above optimum results in excessively fine breakup of the stream, giving a fine mist which drifts with the slightest wind. For example, a sprinkler head which is designed to deliver 2.0 g.p.m. at 20 p.s.i., will deliver 1.75 g.p.m. at 15 p.s.i., or 2.45 g.p.m. at 30 p.s.i. This is only slightly greater than 50 percent more volume at 30 p.s.i. than at 15 p.s.i., and is achieved at the expense of the spray pattern, which is adversely affected by such variation in pressure. Moreover, the water requirements of different areas in a yard may vary by as much as 3 to 1, and it is therefore obvious that adjusting the volume of a sprinkler head by varying the water pressure is totally impractical.

Another attempt to vary the output of a sprinkler head has been to vary the diameters of the spray orifices. This has not been satisfactory, however, as small orifices tend to deliver fine, coherent streams of water which do not break up into a uniform spray pattern, and the small orifices are subject to liming up rapidly.

Thus, there has heretofore been no satisfactory means for regulating the precipitation rate of individual sprinkler heads over a wide range and without adversely affecting the spray pattern, so that a group of sprinkler heads operating simultaneously can be adjusted to deliver varying rates of precipitation to different parts of the yard according to the specific needs of their respective areas of coverage.

Summary of the invention The primary object of the invention is to provide an improved fixed discharge irrigation sprinkler head, which is adjustable over a relatively wide range of discharge volumes, to vary the precipitation rate according to the water needs of the area covered, without appreciably altering the overall coverage of the head, its spray pattern, or the water distribution within the spray pattern.

Another object of the invention is to provide an improved fixed discharge adjustable sprinkler head of the character described, which is capable of producing a well broken up spray pattern, even at the minimum flow rate.

A further object of the invention is to provide an improved pop-up sprinkler embodying a spray head of the character described, and which is characterized by optimum simplicity of construction, economy of manufacture, and reliability of operation.

Other objects, advantages, features of the invention will become readily apparent to those skilled in the art as the description proceeds,

Description of the drawings FIGURE 1 is a side elevation of an improved pop-up sprinkler according to the invention, illustrating the sprinkler installed in a permanent underground sprinkler system and the novel fixed discharge spray head of the sprinkler in its extended position;

FIGURE 2 is an enlarged axial section through the pop-up sprinkler of FIGURE 1, illustrating in solid lines, the spray head in its retracted position within the sprinkler, and in phantom lines, the spray head in its extended position;

FIGURE 3 is a greatly enlarged fragmentary sectional view, taken at 33 in FIGURE 2;

FIGURE 4 is an enlarged axial section through the upper extremity of the sprinkler head of the invention;

FIGURE 5 is a side elevation, slightly reduced in scale, showing an adjustable cap embodied in the sprinkler head of FIGURE 4;

FIGURE 6 is a bottom plan view of the sprinkler head cap, taken on the line 6 6 in FIGURE 5;

FIGURE 7 is a view similar to FIGURE 6, illustrating the cap of a modified sprinkler which emits a water spray through an angle approximating 270";

FIGURE 8 is a view similar to FIGURE 6, illustrating the cap of a further modified sprinkler head, which emits a water spray through an angle approximating 180;

FIGURE 9 is a view similar to FIGURE 6, illustrating the cap of a further modified sprinkler head, which emits a water spray through an angle approximating 90;

FIGURE 10' is a side elevation, on a slightly reduced scale, of the upper end of the sprinkler head in FIGURE 4, which shows the head adjusted to deliver water at the maximum rate of precipitation;

FIGURE 11 is a view similar to FIGURE 10, illustrating the sprinkler head cap adjusted to deliver water at a very low precipitation rate;

FIGURE 12. is a horizontal section, taken on line 12- 12 in FIGURE 4; and

FIGURE 13 is an enlarged fragmentary sectional view, taken at 13-13 of FIGURE 11, illustrating in particular, the action of a deflector ring in the spray head, which is designed to disperse or break up the water emerging from the sprinkler head at relatively low flow rates.

Description of the preferred embodiment One important aspect of the invention is concerned with an adjustable volume sprinkler head having a spray pattern, the distribution of which is ideally suited to the usual sprinkler head layout wherein the circles of coverage of separate sprinkler heads in a group overlap to some extent, and in which the area of coverage and spray pattern are not appreciably affected by varying the precipitation rate. In general terms, this sprinkler comprises a spray head, represented in the drawings by the spray head 10, having a water passage 12 opening to the ex terior of the head and connected to a source of water under pressure, and at least one discharge orifice 14 communicating with the passage to direct streams of water outwardly from the spray head. The orifice 14 is characterized by an effective exit section 16 of generally triangular shape bounded by converging sides 18 which define an apex 20 and a base side 22, opposite the apex. Orifice 14 is thus effective to discharge a water stream which has a generally triangular cross-section as it emerges through the orifice exit section 16. Orifice adjusting means 24 are provided for adjusting the spacing between the apex 20 and side 22 of the exit section, by relative movement of the apex and base side toward and away from one another along a direction line normal to the base side and passing through the apex, thus to vary the effective area of the exit section, without altering its geometric proportions. In the particular spray head 10 illustrated, the converging sides 18 of the orifice section 16 meet to define the apex 20 which, accordingly, is relatively sharp. It will become evident from the ensuing description, however, that the apex 20* may be relatively flat or rounded to some degree. Accordingly, it will be understood that the expression apex as used herein, is intended to encompass all of these various apex configurations,

While a spray head embodying the invention might conceivably have a single discharge orifice 14-, a typical spray head will have a multiplicity of circumferentially disposed orifices. These several orifices are substantially identical in shape and have essentially identical, generally triangular exit areas 16. The orifice adjusting means 24 is effective to adjust the effective areas of the several orifice exit sections 16 simultaneously without altering their geometric proportions, and in such a way that the several exit sections have substantially equal areas in all positions of adjustment. As will appear from the ensuing description, the several orifices of the spray head are circumferentially spaced about the spray head in such a way as to provide the head with the desired spray pattern. The illustrated spray head 10, for example, has 16 orifices which are uniformly spaced around the circumference of the head to provide the latter with a full 360* spray pattern. FIGURES 7, 8 and 9 illustrate modified orifice arrangements which provide efiective spray patterns of 270, 180 and respectively. In some cases, a spray head according to the invention may be provided with two diametrically opposed groups of orifices, which provide the head with two separate, oppositely directed spray areas or patterns. A spray head of this latter type, for example, is useful for watering long, narrow areas.

During operation of the sprinkler, water flows upwardly through passage 12 and issues laterally through the orifices 14 in a number of divergent water streams that have triangularly-shaped cross-sections as they emerge from the orifice sections 16. Each of these streams breaks up into a spray of relatively fine drops as it recedes from the head, forming an evenly dispersed, conical spray pattern of approximately 22 /2 degrees angular spread. The rate of flow through each of the orifices 16 (and therefore the head as a whole) may be regulated over a considerable range, of the order of 10 to 1, by adjustment of the orifice-adjusting means 24 to regulate the eifective areas of the orifice exit sections 16.

As explained earlier, a second aspect of the invention is concerned with an improved pop-up sprinkler embodying the adjustable spray head. In general terms, this popup sprinkler, which is designated in its entirety by the reference numeral 24, comprises a cylindrical housing 26 having a lower inlet 28 for connection to a source of water under pressure, and an upper opening 30 slidably receiving the spray head 10. The spray head is normally retracted in its solid-line retracted position as shown in FIGURE 2, by a spring 32, and is extended to its brokenline position by Water pressure. When retracted, the upper end of the spray head containing the discharge orifices 14 is disposed within the opening 30, substantially flush with the upper end of the housing 26. Within the housing is a strainer 34, of unique construction, which removes particles and other foreign matter from the water flowing to the spray head, that otherwise might block the spray head orifices 14.

Referring now to FIG. 4, spray head is seen to comprise inner and outer

slidably telescoping members

36 and 38. The inner member 36 has a number of V-shaped openings, or slots 40, formed in its bottom end, which communicate with the water passage 12, and have their apex ends extending beyond one edge of the outer member 38 to define a series of spray head orifices 14. At its upper end, the member 38 has an annular edge 42, which extends across the openings 40 to define the base sides 22 of the orifice exit sections 16. Orifice adjusting means 24 is effective to adjust the

members

36, 38 axially with respect to one another and thereby regulate the effective areas of the triangular orifice exit sections 16 without altering their geometric proportions. The exit sections of the illustrated orifices conform to isosceles triangles, the medial planes of which, i.e., planes normal to the base sides and passing through the apices, contain the longitudinal axis of the

members

36, 38.

In the particular spray head 10 illustrated, the outer telescoping member 38 is a generally tubular body containing the water passage 12. The lower end of this body is open and flared outwardly to form a shoulder 44. The upper end of the body is also open, and is counterbored at 46. Inner telescoping member 36 is, essentially, a cap having a closed upper end and an open lower end, fitting slidably with light frictional fit, within the counter-bore 46 of the outer member. The cap has a main, generally cylindrical body 48, the upper end of which is externally reduced to form a body extension 50. Fitted on and cemented t0 the body extension 50 is a cover 52, having a radial sealing flange 54 about its upper end. Below this flange, the cover has substantially the same external diameter as the cap body 48. The upper end face of the body extension 50 and the top wall of the cap cover 52 are axially spaced, to define therebetween a chamber 56. The cover 52 has a central hole 58, opening into this chamber.

The orifice adjusting means 24 of the illustrated spray head comprises a tubular, internally threaded stem 60, which is firmly joined at its lower end by a number of angularly spaced, radial spokes 66 to the upper end of tubular member 38, just below the counterbore 46. The stem 60 extends axially beyond the upper end of member 38 and passes through a central bore 68 in the spray cap body 48, in free-sliding engagement therewith. Threaded into the stem 60 is an adjustment screw 70, the shank of which extends through a reduced opening 72 in the upper end of the cap body extension 50, and a head 74 which is located within the cap chamber 56. The slot in screw head 74 is accessible through opening 58, for engagement with a screwdriver or the like. It is evident that rotation of the screw 70 causes the spray head cap to be adjusted axially relative to the spray head body 38.

The lower end of the spray head cap 36 has a number of pointed, downwardly narrowing, tooth-like formations 76 which define therebetween the V-shaped slots 40. Each tooth has an outer surface 78 with a cylindrical curvature conforming to that of the outer surface of the cap body 48, and two planar side faces 80, which con-verge inwardly toward the central axis of the cap. These side faces of each tooth formation meet along a relatively sharp meeting edge 82. As best shown in FIG. 4, the meeting edges 82 extend at acute angles relative to the cap axis and lie in a common conical plane generated about the axis. The tooth formations 76 thus have a three-sided, generally pyramidal shape. The tooth formations 76 are integrally joined along their radially inner edges to a coaxial, externally conically tapered sleeve 83, which projects downwardly from the under side of cap body 48. This sleeve slides on threaded stem 60, and defines, with the surrounding wall of spray head body 38, an effective, tapered annular inlet connecting the water passage 12 to the orifices 14. It is now evident, therefore, that the orifices 14 open laterally to the exterior of the spray head through their exit sections 16, and axially to the water passage 12 through the annular inlet defined between the spray head body 38 and the cap sleeve 81. For reasons to be explained presently, the cap 36 mounts a spray deflector or dispersing ring 84 having a lower, annular beveled edge face 86. This ring is preferably adjustable axially relative to the cap, as by threading the ring on the cap body 48 in the manner shown, although it might be fixed, as will be explained hereinafter.

Housing 26 has a central bore defining a cylindrical chamber 88, within which are contained the strainer 34, spring 32, and pop-up spray head 10. Projecting downwardly from the bottom end of housing 26 is a stem 90, through which the inlet 28 passes, and stem is adapted "for connection to a fitting, such as the illustrated tee coupling 92. The upper end of housing 26 is externally threaded to receive a removable cap 94, and spray head opening 30 extends centrally through this cap.

The strainer 34 within housing 26 comprises a perforate, generally cylindrical, cup-shaped body 96, the upper end of which has an outwardly directed radial sealing flange 98. Sealing flange 98 extends out across the upper annular edge of housing 26, and is clamped between the latter edge and the housing cap 94. The strainer body is constructed of a plastic, which is somewhat elastic, so that the strainer flange 98 yields slightly under the clamping pressure exerted on the flange by cap 94, to provide an effective seal between the cap and the sprinkler housing 26. This sealing feature of the strainer flange may be enhanced by providing the flange with an upstanding annular sealing ridge 98a, for seating against the cap, as shown. Preferably the cylindrical wall 96 of the strainer 34- has a number of axially spaced, circumferentially extending, reinforcing ribs 34a formed on its outer surface, and cut through the wall between the ribs 34a is a large number of angularly spaced, very narrow, longitudinally extending slots 99 (see FIG. 3), through which the water flows in passing from chamber 88 to the interior of spray head 10. Slots 99 serve as very fine strainer passages, but because of their great number, they offer little resistance to the flow of water. As best seen in FIG. 2, the strainer surrounds and is coaxial with spray head 10 when the latter is retracted, as shown in solid lines in the drawing. In this regard, it will be recalled that tthe spray head slides vertically through the opening 30 in sprinkler cap 94 in moving between its extended and retracted positions. Spring 32, which yieldably returns the spray head to its retracted position, surrounds the spray head be tween the latter and the strainer 34. At its lower end, the spring seats against lower spray head shoulder 44, and at its upper end against the under side of the housing cap 94. Retraction of the spray head is limited by the upper spray head flange 54, which seats against the upper surface of the cap, as shown. Extension of the spray head is limited by engagement of the shoulder 44 with the bottom end of a sleeve 100, which projects downwardly from the upper side of housing cap 94 and surrounds and defines the cap opening 30.

When the spray head I10 has less than a full 360 spray pattern, such as the spray patterns produced by the ori fice arrangements of FIGURES 7 through 9, it is necessary to restrain the spray head against rotation on its central axis relative to the sprinkler housing 26. This may be accomplished in various ways. In the particular spray head illustrated in the drawings, the spray head flange 44 has a notch 101 formed in its outer edge, which slidably engages a longitudinal key 102 projecting inwardly the inner surface of the cylindrical wall of the strainer 96 along one side thereof. As its flange 98 is tightly clamped between the cap '94 and the top edge of the housing body 26, the strainer 96 is thereby held against turning, and the engagement of the key 102 in notch 101 therefore prevents turning of spray head 10.

The pop-up sprinkler 24 is designed for use in an underground sprinkler system, such as that shown in FIG. 1. When installed, the sprinkler is buried to the level indicated, wherein its cap 94 is substantially flush with the ground. Normally, the spray head of the sprinkler is retracted into the sprinkler housing. The head is then shielded against damage, and its upper rim is substantially flush with housing cap 94 so as not to interfere with persons or objects on the surface. Moreover, seating contact of the spray head flange 54 with sprinkler housing cap 94 effectively seals the cap opening 30 against the entrance of dirt, and other debris into the strainer 96. Perhaps even more importantly, it seals the sprinkler head against leakage of water out of the body 26, due to draining of the system from sprinkler heads at higher elevations when the water has been turned off. This is an important feature of the present invention, as it prevents evaporation of water from the spray head, with consequent deposit of lime on the outer surface of the spray head body 10 and in the orifices 16. Lime deposits on the spray head body would cause sticking, which might interfere with the pop-up action, while deposits in the orifices 16 would affect both the spray pattern and the volume of water delivered by the sprinkler head. By sealing the opening 30 and keeping the chamber 88 filled with Water, the sprinkler head 10 is kept constantly submerged in water which prevents formation of deleterious lime deposits thereon.

When water under pressure is delivered to the sprinkler 24, the pressure of the water urges the spray head 10 to its extended position. In this position, the lower spray head shoulder 44 seats against the lower end of the cap sleeve 100, to seal the spray head to the sleeve. Water entering the spray head flows upwardly through its passage :12 and is then discharged laterally, or radially, from the orifices 16 to irrigate the surrounding area. As noted earlier, the spray head member 36 has a full 360 spray pattern. The orifice arrangements embodied in the modifified

spray head members

36a, 36b and 360 of FIGURES 7 through 9 produce, respectively spray patterns of 270, 180 and 90 angular extent. Various other orifice arrangements are possible, such as that referred to earlier, which includes two diametrically opposed groups of orifices for watering relatively long narrow areas.

The several water streams issuing through the spray head orifices 14 have generally triangular cross-sections as they emerge from the triangular orifices 16. These triangular orifices, and the triangular water streams produced thereby, have several advantages. Thus, it has been found that the water streams emerging from the spray head break up and disperse in a more effective manner, giving a distribution pattern that is particularly wellsuited to the usual sprinkler head layout, wherein the area covered by each head overlaps the areas of adjacent heads. In a typical spray head according to the invention, for exmple, each orifice 16 covers an arc of approximately 22 /2 degrees, whereby the spray head having a full 360 spray pattern, such as spray head 10, will have 16 uniformly circumferentially spaced orifices. Spray heads having the modified caps of FIGURES 7 through 9 will have a reduced number of orifices proportional to the angular extent of their respective spray patterns.

Another and highly important advantage of the triangular shape of the orifice exit sections 16 resides in the fact that the effective areas of these sections, and hence the precipitation rate of the spray head as a whole, may be regulated over a substantial range, typiclly n the order of a 1 ratio, without altering the geometric proportions of the exit sections. Regulation of the effective areas of the exit sections, of course, is accomplished by rotating the adjusting screw 70 in one direction or the other, to retract the cap into or extend the cap from the tubular spray head body 38. This adjustment of the cap is effective to adjust the spacing between the apices 20 of the orifice exit sections 16 and the upper edge 42 of the spray head body 38, which defines the base sides 22 of the exit sections, thus to vary the effective areas of the sections. FIGURES 10 and 11 illustrate two different positions of adjustment of the cap 36 corresponding, respectively, to a maximum precipitation rate and a minimum precipitation rate. It has been found that this adjustment of the effective areas of the orifice exit sections Without altering their geometric proportions is effective to regulate the precipitation rate of the sprinkler head Without appreciably altering its coverage, spray pattern, or the distribution of water throughout the spray pattern.

A further distinct advantage of the triangular exit sections 16 of the spray head orifices 14 is that the exit sections may be restricted, as in FIG. 11, to produce a spray of extremely low flow rate which is at the same time, well broken-up and uniformly dispersed throughout the spray pattern. Thus, even at extremely low flow rates, the present spray head does not discharge coherent water streams which might tend to erode the soil at the points of impact of the streams with the soil, as do the existing irrigation sprinklers. The deflector ring 84 of the present spray head aids in the break-up and dispersion of the Water streams emerging from the spray head at low flow rates. In FIG. 13, it will be observed that the velocity components, indicated by the arrows V1 and V2, of the water streams emerging through the orifices, cause the streams to issue in an outward and upward direction. Deflector ring 84 is adjusted to a position wherein the lower beveled edge face 86 of the ring is disposed to intercept only the upper portions of the emerging streams. When the sprinkler head is adjusted for minimum flow rate, as in FIG. 11, that portion of the stream issuing from each orifice 16 which impinges against the underside 86 of the ring 84 is a relatively large proportion of the whole, and therefore the deflecting and spreading effect of the ring is at its maximum. On the other hand, when the head is adjusted for maximum flow rate, as in FIG. 10, that portion of the stream impinging against the ring 84 is a relatively small proportion of the whole, and the deflecting and spreading effect of the ring is consequently at its minimum. Thus, the ring 84 is effective only at low flow rates, when it is most needed, and at higher flow rates its influence is negligible. As noted earlier, the deflector ring 84 is preferably adjustable relative to the spray head cap 36, so that it may be positioned for optimum dispersion of the emerging water streams under any given minimum water pressure and flow rate conditions, although it is also contemplated that the ring 84 might be molded integrally with the cap body 48.

It is evident that, when the spray head 10 has a full 360 spray pattern, it is immaterial whether or not the spray head cap 36 rotates relative to the housing 24 during operation of the sprinkler. However, when the spray head has less than a full 360 spray pattern, as in the case of the embodiments shown in FIGURES 7 through 9, it is essential that the cap be restrained against rotation relative to the housing. This is accomplished by having the notch 101 in the lower spray head shoulder 44 engage the rib 102 of the strainer 34, which effectively keys the spray head against rotation relative to the sprinkler housing 26. The frictional engagement of the spray head cap 36 in the counterbore 46 of the spray head body 38 restrains the cap against rotation relative to the spray head body.

While I have shown and described in considerable detail what I believe to be the preferred form of my invention, it will be understood by those skilled in the art that various changes may be made in the shape and arrangement of the several parts without departing from the scope of the invention.

I claim:

1. An irrigation sprinkler head comprising slidably telescoping inner and outer members having opposed edges which cooperate to define a generally triangularlyshaped discharge orifice in the side of said sprinkler head,

through which a stream of water is discharged in a radial direction;

said outer member comprising a generally tubular body containing a pasageway connected to a source of water under pressure, said passageway being open at one end of said body;

said inner member comprising a cap having an open cylindrical end fitting slidably within said pasageway, and an opposite closed end;

said open cylindrical end having a generally V-shaped opening communicating with said passageway and having an apex extending axially beyond said one end of said body to define two sides of said triangular orifice;

said outer member having an annular edge at said one end thereof extending acros ssaid opening to define the base side of said orifice; and

means for axially adjusting said cap relative to said body for the purpose of varying the eifective area of said orifice without altering the geometric proportions thereof.

2. An irrigation sprinkler head according to claim 1, wherein said open cylindrical end of said cap has a plurality of circumferentially spaced, generally V-shaped openings communicating with said passageway, the apex ends of which extend in the same axial direction of said members beyond said one end of said outer member; and

said annular edge of said outer member extending across all of said openings to define the base sides of said orifices.

3. A sprinkler according to claim 2, wherein:

said body includes as tubular stem extending coaxially beyond said one end thereof;

said cap has a central bore slidably receiving said stern and a sleeve defining said bore and surrounding said stem;

said sleeve has an externally conically tapered surface defining with said body an annular, axially tapered inlet to said orifices; and

said orifice adjusting means comprise a screw carried by said cap and threaded in said stem.

4. A spray head according to claim 1, including:

a deflector on said spray head above said orifice and having a lower edge projecting across the apex end of said orifice exit section.

5. A spray head according to claim 4, wherein:

said deflector comprises a ring threaded on said spray head for axial adjustment relative to said spray head.

6. A pop-up sprinkler comprising:

a tubular housing having a lower water inlet and an axial opening through its upper end;

a spray head axially slidable within said opening between a retracted position wherein the upper end of said spray head is substantially flush with the upper end of said housing, and an extended position wherein said spray head projects above said housing;

said spray head comprising a lower tubular body having a passagway opening to the interior of said housing, and a cap coaxially disposed at the upper end of said body, said cap having a lower end slidably fitted in the upper end of said body and an upper closed end;

said cap having a number of circumferentially spaced,

generally V-shaped openings having apex sides extending axially beyond said upper end of said body to define a plurality of substantially identical discharge orifices;

said spray head body having an upper annular edge extending across said openings to define the base sides of said orifices, each of said orifices having an effective exit section of generally triangular shape bounded on two sides by the converging sides of said V-shaped openings and on the base side by said annular edge;

orifice adjusting means for effecting simultaneous relative adjustment of the respective orifice apices and base sides toward and away from one another to vary the axial spacing therebetween and thereby the effective areas of said exit sections without altering the geometric proportions of said exit sections, comprising means for axially adjusting said cap relative to said body;

means for limiting axial movement of said spray head relative to said housing between said retracted and extended positions; and

means for yieldingly retaining said spray head in said retracted position, whereby said spray head is extended by water pressure in said housing.

7. A sprinkler according to claim '6, wherein:

said housing includes a lower, generally cup-shaped body and an upper cap threaded on the upper end of said body;

said housing opening extends centrally through said cap; and

said sprinkler further comprises a generally cup-shaped strainer coaxially disposed within said housing in surrounding relationship to said spray head, and having an upper, radially outwardly directed flange clamped between said housing cup and cap to form a seal therebetween 8. A sprinkler according to claim 6, wherein:

a deflector ring surrounding said cap above said orifices and having a lower annular edge extending across the apex ends of said orifices;

said orifices and deflector ring being disposed within said housing opening when said spray head is in said retracted position; and

means for axially adjusting said deflector ring relative to said cap.

9. A pop-up sprinkler comprising:

a housing including a lower, generally cup-shaped body and a cap threaded on the upper end of said body; said cap having a central opening extending therethrough;

a spray head slidable in said opening between a retracted position within said housing wherein the upper end of said spray head is substantially flush with the upper surface of said cap, and an extended position wherein said spray head projects a distance above said cap; and

a generally cup-shaped strainer coaxially disposed within said housing and surrounding said spray head, said strainer including an upper, radially directed flange clamped between said housing body and said cap.

References Cited UNITED STATES PATENTS 1,853,805 4/1932 Elder 239205 2,075,589 3/1937 Munz 239-204 X 2,125,978 8/1938 Arbogast 239204 X M. HENSON WOOD, JR., Primary Examiner.

MICHAEL Y. MAR, Assistant Examiner.

US. Cl. X.R.