Abstract:
A drive mechanism for a swiveling fan-jet sprinkler comprising a water-driven turbine, a reduction gear drive and, on the final drive shaft of the latter, a rotary cam member cooperating with a cam follower on the nozzle cylinder. The rotary cam member is preferably a swash plate with an elliptical torus-like rim, engaged by a fork-shaped cam follower. The mechanism may include adjustability of the swivel angle of the nozzle cylinder through a swash plate with an adjustable inclination on the final drive shaft.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to irrigation sprinklers and, more particularly, to a swiveling fan-jet sprinkler of the type which has a slowly oscillating horizontal nozzle cylinder with a row of jet nozzles arranged in a fan-tail pattern, and which uses a water-driven turbine to produce the swiveling movement of the nozzle cylinder. 
     2. Description of the Prior Art 
     Swiveling sprinklers of the type under consideration are known from the prior art. They are commonly used for the watering of lawns or for the irrigation of vegetable and flower beds, having the advantageous capability of covering an area of generally square or rectangular outline. 
     It is also known that the swiveling movement of the nozzle cylinder can be derived from the kinetic energy of the flowing water by utilizing the latter to drive a small turbine which, through the intermediary of a reduction gear and crank drive, produces the desired swiveling motion of the nozzle cylinder about its own axis. Such a device is disclosed in U.S. Pat. No. 3,647,140. The prior art device has the shortcoming of necessitating a considerable number of component parts for the reduction gear and crank drive. A second shortcoming is related to the limitations of such a crank drive in terms of the adjustability of the total angle covered by the swiveling motion. 
     SUMMARY OF THE INVENTION 
     Underlying the present invention is the primary objective of proposing an improved drive mechanism for a swiveling fan jet sprinkler which is simpler in design and therefore less expensive and which, additionally, offers a convenient means for adjusting the swivel angle of the nozzle cylinder. 
     The present invention proposes to attain this objective by suggesting an improved drive mechanism for a swiveling fan jet sprinkler which has a turbine and, as part of a reduction gear drive, a final drive shaft arranged transversely to the axis of the nozzle cylinder. The final drive shaft carries a rotary cam member in median alignment with an axial plane through the nozzle cylinder, and the nozzle cylinder carries a cam follower cooperating with the rotary cam member to produce the desired swiveling motion. 
     In a preferred embodiment of the invention, the rotary cam member is a swash plate with a generally elliptical torus-like rim, and the nozzle cylinder carries a fork-shaped cam follower which engages the torus rim from opposite sides. Alternatively, the swash plate may have a radially open groove engaging a follower with appropriately rounded oppositely oriented flanks. 
     By way of a further improvement, the present invention suggests a simple mechanism for adjusting the total angle over which the nozzle cylinder is rotated, by adjusting the inclination of the swash plate in relation to the axis of the final drive shaft. 
     In a modification of the preferred embodiment, the rotary cam member may be a cam cylinder with a sinusoidal groove which is engaged by a cam follower with rounded or spherical drive surfaces. 
     The cam follower on the nozzle cylinder is preferably an integral part of the nozzle cylinder itself. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further special features and advantages of the invention will become apparent from the description following below, when taken together with the accompanying drawings which illustrate, by way of example, embodiments of the present invention which are represented in the various figures as follows: 
     FIG. 1 shows, in a partially cross-sectioned elevational view, a swiveling fan-jet sprinkler with a swivel drive embodying the present invention; 
     FIG. 2 shows a swash plate, as part of the swivel drive of the sprinkler of FIG. 1; 
     FIG. 3 shows a portion of the nozzle cylinder of the sprinkler of FIG. 1; 
     FIG. 4 is a transverse cross section through the nozzle cylinder of FIG. 3, taken along line V--V thereof; 
     FIGS. 5 through 7 show three different operational positions, at one-quarter turn intervals, of the swash plate and the cooperating cam follower on the nozzle cylinder of the swivel drive of FIGS. 1-4; 
     FIG. 8 shows a modification of the embodiment of FIGS. 1-7, featuring angle adjustment means for the swash plate of the swivel drive; 
     FIG. 8a shows the adjustment means of FIG. 8 in a side view; 
     FIG. 9 shows the fan-jet sprinkler of FIG. 1 with a longitudinally cross-sectioned housing and a modified swivel drive embodying the present invention; and 
     FIG. 10 shows a cam and a cam follower, as part of the swivel drive of the sprinkler of FIG. 9. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings, FIGS. 1 and 10 show a swiveling lawn sprinkler of the fan-jet type, the sprinkler having a closed sprinkler housing 11 supported by a sprinkler stand 10. The housing 11 has a hose connector 12 for the supply of pressurized water to the sprinkler. In the upper part of the sprinkler housing 11 is arranged a horizontal nozzle cylinder 13 which extends outwardly from the housing 11, carrying on its exposed length portion a row of nozzle openings 42, arranged at varying angles. The water which enters the sprinkler through the hose connector 12 exits through the nozzle openings 42 in the form of a series of diverging water jets 15, forming a fantail-shaped spray pattern. 
     The pressurized water flowing through the sprinkler is utilized to impart to the nozzle cylinder 13 a reciprocating swiveling motion. For this purpose, the nozzle cylinder 13 is rotatably supported in the sprinkler housing 11 by means of two axially spaced swivel bearings 18 and 19. The axial position of the nozzle cylinder 13 is determined by an end face on one extremity of the nozzle cylinder 13 which abuts against a face of the swivel journal 18 (FIG. 1) and by a retaining ring 16 which forms an abutment shoulder cooperating with a sealing ring on the inside of the swivel journal 19. The exposed extremity of the nozzle cylinder 13 is capped by means of a removable cylinder cap 14. 
     As can best be seen in FIG. 9, the sprinkler housing 11 accommodates a drive mechanism which utilizes the kinetic energy of the flowing pressurized water to produce the earlier-mentioned swiveling motion of the nozzle cylinder 13. For this purpose, the hose connector 12 has a nozzle-shaped inlet bore which produces a water jet. In the path of this water jet is arranged a turbine wheel 36 which is connected to a reduction gear drive 39 consisting of multiple reduction gear pairings. The turbine wheel 36 thus drives a final drive shaft 38 of the reduction gear drive which is arranged horizontally below and at right angles to the cylinder nozzle 13. 
     While FIG. 1 does not specifically show a turbine wheel and a reduction gear drive, it should be assumed that the same or a similar drive as shown in FIG. 9 is also used in the embodiment of FIG. 1. Both embodiments of the sprinkler have their final drive shaft 38 arranged in substantially the same relationship to the nozzle cylinder 13. They differ, however, in the mechanism which translates the rotary motion of the final drive shaft 38 into a swiveling motion of the nozzle cylinder 13. The device which accomplishes this in the embodiment of FIG. 1 is shown in FIGS. 2-7. 
     As can be seen in FIGS. 2 and 5, the final drive shaft 38 carries a swash plate 31 which has a torus rim 31d attached to a central hub 31a by means of two radial spokes 31b. The torus rim 31d has a peripheral outline of elliptical shape, defining a plane b--b which is inclined by a small angle α from a radial plane c--c through the median of the swash plate 31. The torus rim 31d thus forms two oppositely outwardly facing annular cam surfaces 31c which form a laterally undulating cam path in relation to the median radial plane c--c. The latter coincides with a plane through the londitudinal axis a--a of the nozzle cylinder 13 (FIG. 1). 
     Vertically above the swash plate 31, the nozzle cylinder 13 forms a follower fork 13a with two oppositely inwardly facing drive surfaces, as part of a radial slot in engagement with the cam surfaces 31c of the swash plate 31. As can be seen in FIGS. 5 through 7, the elliptical shape of the torus rim 31d has the result of maintaining the driving contact points between the cam surfaces 31c of the swash plate 31 and the drive surfaces of the follower fork 13a in the vicinity of the periphery of the latter. The follower fork 13a has the same outer shape as the nozzle cylinder 13 itself, being an integral portion of the latter in the form of an axially narrow remnant of the cylinder profile formed between two sector-shaped deep radial recesses 20 of the nozzle cylinder 13 (FIG. 3). 
     The elliptical peripheral shape of the swash plate 31, in addition to its simplicity, has the advantageous feature of producing a more desirable angular diaplacement pattern for the swiveling displacements of the nozzle cylinder 13, for a more even distribution of the spray within the area to be covered by the sprinkler. 
     FIGS. 8 and 8a show a modification of the drive arrangement of FIGS. 5 and 7, inasmuch as the inclination angle α of the swash plate 31&#39; is made adjustable. The spokes 31b of FIG. 2 have been replaced with a transverse pivot shaft 43 which is seated in an enlarged portion of the final drive shaft 38&#39; and extends in alignment with the small diameter of the ellipse of the torus rim 31d. The latter is centered in relation to the shaft 38&#39; by means of two sleeves 60 (FIG. 8a). 
     Radially outside the final drive shaft 38&#39;, the swash plate 31&#39; has a cross member 61 to which is pivotably attached an adjustment link 41 which connects the swash plate 31&#39; to a threaded adjustment spindle 40. The latter reaches through a threaded bore of the sprinkler housing 11 from the outside thereof, thus making it possible to conveniently increase or decrease the angle α in a continuous fashion, thereby correspondingly increasing or decreasing the total angular swiveling displacement of the nozzle cylinder 13. 
     The drive arrangement of the embodiment of FIGS. 9 and 10 differs from the arrangement of the previously described embodiment, inasmuch as the swash plate 31 has been replaced with a cam cylinder 35 on the final drive shaft 38, the latter having a peripheral cam groove 37 defining two oppositely oriented cam surfaces facing each other. The cam groove 37 is of generally sinusoidal outline and symmetric in relation to the median radial plane d--d of the cam cylinder 35. Cooperating with the opposing flanks of the cam groove 37 is a follower arm 13b of the nozzle cylinder 13 whose extremity 13c has oppositely outwardly facing spherical drive surfaces which cooperate with the curved flanks of the cam groove 37. 
     From the foregoing, it should be understood that, as an alternative to the cam cylinder 35, it is also possible to use a swash plate with a radially open peripheral groove similar to that which is shown in FIG. 10. Such a swash plate could either have a fixed inclination, or it could be adjustable in the manner of the swash plate 31&#39; of FIGS. 8 and 8a. While the nozzle cylinder 13 of the embodiments shown in the drawing is a straight cylinder, the latter could, of course, also be of the upwardly curved type, similar to some known prior art devices. 
     Lastly, it should be understood, that the foregoing disclosure describes only preferred embodiments of the invention and that it is intended to cover all changes and modifications of these examples of the invention which fall within the scope of the appended claims.