attention is directed to fig1 of the drawing , which provides a perspective view of an exemplary sprinkler 22 for watering a non - circular , irregular shaped lawn , such as lawns illustrated in fig1 and 20 . in fig1 , and 20 , it can be seen that sprinkler 22 is set up to water non - circular parcel of land 24 . in such parcel 24 , it can be seen that when sprinkler 22 is watering along relatively short radials r a , r b , and r c , the amount of water is needed along such radial lengths per unit of time is not as much as would be required for the same unit of time along the longer radial lengths r d , r e , and r f as shown in fig2 . to address this problem , we have developed a novel sprinkler 20 in which a base 28 is provided having an upper housing 30 rotatably attached thereto . in an embodiment , the upper housing 30 may be set up mechanically to rotate in a selected direction as indicated by reference arrow 32 in fig1 . as upper housing 30 rotates , the water flow rate 34 from nozzles n ( see fig2 ) increases or decreases , or says constant , or stays off , as required in order to regulate , limit , or prevent water from being delivered nozzles n . for the watering of relatively short radials r a , r b , and r c as shown in fig1 , the amount of water provided through nozzles n may be reduced , during the time that the group of nozzles n rotates through such angular direction ( s ). for the watering of relatively long radial lengths r d , r e , and r f , the water flow rate 34 increases , in order to provide more water to the nozzles n for watering along the relatively longer radials r d , r e , and r f . novel construction of sprinkler 22 , which enables such metered delivery of water to a parcel of land 24 will be further described below . attention is directed to fig1 , which shows a vertical perspective view for an embodiment of sprinkler 22 . the sprinkler 22 includes a base 28 , which relative to upper housing 30 is stationary . note , however , as mentioned below and shown in fig1 , an apparatus such as sprinkler 22 may be fitted with an outer housing 22 h surrounding upper housing 30 p , and slidingly secured in a pressurizable receiver 44 ( shown in broken lines in fig1 ) that is sized and shaped to receive at least a pop - up base 28 p therein , to vertically house and slidingly cradle the pop - up base 28 p . in such a pop - up configuration , upon pressurization by water , the base 28 p rises vertically in the direction of reference arrows 46 from the pressurizable receiver 44 , to provide a pop - up sprinkler 22 p . seals 48 such as o - rings and end stops 50 , and / or other working elements may be provided in a conventional manner for pop - up sprinklers , as known to those of skill in the art , and need not be further addressed herein . as seen in fig1 , and more clearly indicated in fig1 , in an embodiment , the outer housing 22 h may be cylindrical in shape . in an embodiment , the outer housing 22 h has an outer diameter od approximately corresponding to the spacing between distal ends 51 of nozzles n in first group a and second group b of nozzles n , which are oriented at one hundred eighty degrees ( 180 °) from each other . returning now to fig1 , a rotatable upper housing 30 is mounted on sprinkler base 28 . at least one sprinkler nozzle assembly a 1 is secured to and rotatable with the upper housing 30 . in most embodiments , a plurality of nozzle assemblies such as nozzle assemblies a 1 , a 2 , a 3 , and a 4 as shown in fig1 , will be provided . in various embodiments , nozzle assemblies may be provided in groups . for example , nozzle assemblies a 1 , a 2 , a 3 , and a 4 constitute a first or a group of nozzle assemblies . in an embodiment a group may arranged in a vertically aligned fashion , as shown in fig1 , where a 1 , a 2 , a 3 , and a 4 are located one above the other , along vertical centerline c a . in various embodiments , pressurized water may enter at the bottom inlet 56 as indicated by reference arrow w . attention is directed to fig2 , which shows a vertical cross sectional view of an embodiment for a sprinkler 22 . pressurized water w is received at inlet 56 of lower housing 58 of base 28 . the lower housing 58 has an inner sidewall 60 that contains pressurized water w . the base 28 has an inlet turbine 62 operably fixed therein . a gear train 64 having an output gear 66 responsive to the inlet turbine 62 is provided . in an embodiment , output gear 66 is a pinion gear that drives annular gear 67 in upper housing 30 . in an embodiment , portions of the gear train 64 may be sheltered from flow of water w by a gear housing 68 . a mount 70 is supported by the base 28 , and has a receiver 71 therein sized and shaped for receiving a stationary cam shaft 72 . a stationary cam shaft 72 is affixed to the mount 70 , and extends upwardly . as visible in fig1 , the mount 70 may include a mounting key 74 , which prevents the cam shaft 72 from turning . as visible in the cross - sectional view of cam shaft 72 shown in fig1 , in an embodiment , the cam shaft 72 may be provided with an inwardly extending keyway slot 76 , which is defined by a vertically extending keyway wall 78 , seen in fig1 and 11 . the cam shaft 72 has associated therewith at least one cam surface s . in various embodiments , a plurality of cam surfaces s 1 , s 2 , s 3 , s 4 , etc ., ( see the seven cams in fig1 and 18 , for example , which include s 5 , s 6 , and s 7 ) and the like are provided by cam elements e 1 , e 2 , e 3 , e 4 , ( and the like ) respectively . each of cam elements e 1 , e 2 , e 3 , and f 4 , has a respective cam element thickness t . in various embodiments , the cam elements e 1 , e 2 , e 3 , and e 4 , may be detachably affixed to the cam shaft 72 . in an embodiment , as seen in fig1 , 13 , and 14 , a plurality of retaining clamps 80 may be provided . in such an embodiment , pairs of retention grooves 82 , are provided , spaced apart a distance g . and , pairs of retaining clamps 80 are provided . the pairs of retention grooves are spaced apart a distance g , which is approximately equal to said thickness t of cam elements e 1 , e 2 , e 3 , e 4 , ( and the like ). in an embodiment , one retaining clamp 80 in each pair of retaining clamps 80 is secured to the cam shaft 72 below a cam element e 1 , e 2 , e 3 , e 4 , ( and the like ), and one retaining clamp 80 in each pair of retaining clamps 80 is secured to the cam shaft 72 above a cam element e 1 e 2 , e 3 , e 4 , ( and the like ). in this manner , each of the cam elements e 1 , f 2 , e 3 , f 4 , ( and the like ) is secured at a selected vertical location along the cam shaft 72 . in various embodiments , the cam elements e 1 , f 2 , e 3 , e 4 , ( and the like ) each has an inner sidewall 84 . in various embodiments , the inner sidewall 84 may have a key structure 86 therein . the key structure 86 is sized and shaped for interlocking sliding engagement with the keyway slot 78 in cam shaft 72 . thus the key structure 86 and the keyway slot 78 cooperate to prevent the cam elements e 1 , e 2 , e 3 , f 4 , ( and the like ) from rotary movement . as further described elsewhere herein , each cam element e 1 , e 2 , e 3 , e 4 , ( and the like ) is sized and shaped to provide cam surfaces s 1 , s 2 , s 3 , s 4 , ( and the like ) which interact with corresponding cam followers f 1 , f 2 , f 3 , f 4 ( and the like ) for movement of the respective cam followers by the associated cam elements , to correlate water delivery quantity through an associated sprinkler nozzle assembly a 1 , a 2 , a 3 , a 4 ( and the like ) for watering a surface of a land parcel 24 having a selected size and shape . the upper housing 30 is rotatably coupled to the sprinkler base 28 . the upper housing 30 is driven by the output gear 66 , which may be configured as a pinion gear , to drive an annular gear 67 inside the lower end of upper housing 30 . the upper housing 30 is configured for receiving water w from the base 28 . the upper housing 30 is provided with at least one sprinkler nozzle assembly a , which is secured to housing 30 and rotatable therewith . in most embodiments , a plurality of nozzle assemblies a will be provided , in groups of nozzle assemblies a , b , c , d , etc , wherein each group will have multiple nozzles therein . for example , a group a may have nozzles numbered from a 1 to a x , with x being a positive integer . likewise , a group b of nozzle assemblies may be provided in a group b numbered from b 1 to b x , where x is a positive integer . in an embodiment , as noted in fig1 and 18 , numbering of x in groups may be provided in even numbers only , or in odd numbers only , as similar number for cam elements may proceed sequentially , with both even and odd integers , as such cam elements may be configured to a single nozzle n on a side of the upper housing 30 , or multiple nozzles n on the upper housing 30 . at least one sprinkler nozzle assembly a is secured to and rotatable with the upper housing 30 . as seen in fig3 , 4 , and 5 , in an embodiment , a sprinkler nozzle assembly a 1 , etc , may include a corresponding nozzle n 1 and a spring loaded valve v , which includes a spring 90 which biases a cam follower f 1 ( similar numbering and function in other sprinkler nozzle assemblies need not be repeated ) in an open direction . the cam follower f 1 includes , at its distal end 91 , a valve surface 92 for regulating or stopping flow of water w therethrough , when valve surface 92 is seated against seat 94 . more generally , the spring loaded valve v 1 and a cam follower f 1 are responsive to a cam surface s 1 to adjust the spring loaded valve v 1 between an open position wherein water passes therethrough , and a closed position wherein water flow is substantially prevented therethrough . a cam surface s 1 may regulate flow between an open position , as illustrated in fig5 , and closed position as seen in fig3 , by placing the cam follower at an intermediate position as seen in fig4 . in various embodiments , the upper housing 30 may have at least a first side with a first group of nozzles n provided thereat , such as group a as noted in fig1 or 17 . and , in an embodiment , the upper housing may also have a second side with a second group of nozzles n thereon , such as group b as noted in fig1 and 18 . likewise , further groups such as a group c of nozzles n , or a group d of nozzles n , may be provided . more generally , the upper housing may have a plurality of sizes , such as x sides , wherein x is a positive integer , and wherein a group of sprinkler nozzle assemblies is provided on each of said x sides . as seen by comparing fig1 and fig2 , in a group of sprinkler nozzle assemblies , nozzles n are provided having a selected outlet diameter d . the selected outlet diameter d may vary amongst nozzles in any group of sprinkler nozzle assemblies a , b , etc ., as dictated by water delivery requirements for the particular service to the land parcel 24 . in an embodiment , such outlet diameters d may have diameters d 1 , d 2 , d 3 , d 4 as shown in fig2 , wherein such diameters d are increasingly smaller at increasing mounting heights . or , as shown in fig1 , diameters d may be configured to be increasingly smaller at decreasing mounting heights . when sprinkler nozzle assemblies are mounted in groups a , b , etc ., such groups may be mounted in vertically aligned arrays , one above the other . more generally , nozzles n in each sprinkler nozzle assembly a may have nozzle diameters d selected to deliver water a selected range of radial distances r from the sprinkler 22 , for watering a surface of a land parcel 24 having a selected size and shape . yet more generally , the nozzles n in sprinkler 22 each have nozzle diameters d , which in co - operation with the groups of sprinkler nozzle assemblies a , b , c , etc . and with associated cam elements e , deliver a selected volume of water along a selected radial for a radial distance r from the sprinkler 22 , for watering a surface of a land parcel 24 having a selected size and shape . lawn 24 may be irrigated using a lawn sprinkler 22 as described herein in order to water the irregularly shaped lawn while minimizing or substantially eliminating watering of areas beyond the perimeter 25 of the lawn 24 . further , in one embodiment , a relatively uniform volume of water per unit area ( e . g ., gallons per square foot of lawn 24 in a given period of time , or alternate measurement such as inches of rainfall equivalent over the irrigated area in a given period of time ) may be provided to lawn 24 , using sprinkler 22 , or its pop - up type sprinkler equivalent , 22 p . it is to be appreciated that the various aspects , features , structures , and embodiments of a lawn sprinkler with flow regulator for substantially uniform delivery of water on a volume per square foot of lawn as described herein is a significant improvement in the state of the art . the lawn sprinkler design is simple , reliable , and easy to use . although only a few exemplary aspects and embodiments have been described in detail , various details are sufficiently set forth in the drawing figures and in the specification provided herein to enable one of ordinary skill in the art to make and use the invention ( s ), which need not be further described by additional writing . in the foregoing description , numerous details have been set forth in order to provide a thorough understanding of the disclosed exemplary embodiments for providing lawn sprinklers for watering irregularly shaped parcels . however , certain of the described details may not be required in order to provide useful embodiments , or to practice selected or other disclosed embodiments . further , the description may include , for descriptive purposes , various relative terms such as surface , adjacent , proximity , near , on , onto , and the like . such usage should not be construed as limiting . terms that are relative only to a point of reference are not meant to be interpreted as absolute limitations , but are instead included in the foregoing description to facilitate understanding of the various aspects of the disclosed embodiments . various items in the apparatus and in the method ( s ) described herein may have been described as multiple discrete items , in turn , in a manner that is most helpful in understanding such aspects and details . however , the order of description should not be construed as to imply that such items or sequence of operations are necessarily order dependent , or that it is imperative to fully complete one step before starting another . for example , the choice of where and how to mount a set of nozzles , or selection of outlet diameters of such nozzles , may be determined by a particular parcel to be watered , and may be different as regards installation particulars amongst various situations , for example , depending on water pressure available , and the amount of water desired to be directed to the parcel . further , certain details of installation may not need to be performed in the precise or exact order of presentation herein . and , in different embodiments , one or more items may be performed simultaneously , or eliminated in part or in whole while other items may be added . also , the reader will note that the phrase “ an embodiment ” has been used repeatedly . this phrase generally does not refer to the same embodiment ; however , it may . finally , the terms “ comprising ”, “ having ” and “ including ” should be considered synonymous , unless the context dictates otherwise . various aspects and embodiments described and claimed herein may be modified from those shown without materially departing from the novel teachings and advantages provided by developments described herein , and may be embodied in other specific forms without departing from the spirit or essential characteristics thereof . embodiments presented herein are to be considered in all respects as illustrative and not restrictive or limiting . this disclosure is intended to cover methods and apparatus described herein , and not only structural equivalents thereof , but also equivalent structures . modifications and variations are possible in light of the above teachings . therefore , the protection afforded to this invention should be limited only by the claims set forth herein , and the legal equivalents thereof .
a sprinkler . a sprinkler nozzle assembly is coupled to a base for rotating movement . a stationary cam with cam surface engages a cam follower which open and close valves to regulate water flow as selected angles of rotation . in an embodiment , a pop - up sprinkler is provided , and the moving components are part of the riser . a turbine drive mechanism is coupled to an upper housing on which a plurality of sprinkler nozzle assemblies are affixed . the drive mechanism includes water driven impeller and a gear train adapted for operatively driving the upper housing , and associated sprinkler nozzle assemblies .