Field of the Invention

[0001 ] The present invention relates to sprinkler systems. It is envisaged primarily for use in irrigation and the supply of reticulated water, but is considered to have wider application including in the provision of herbicides, fertilisers and other reticulated liquids.

Background to the Invention

[0002] It is known to use rotating sprinklers for irrigation and related purposes. Such sprinklers are arranged to rotate about a vertical axis during operation, supplying water to a circular area centred on the sprinkler.

[0003] The degree of rotation of a rotating sprinkler can be limited. It is known, for instance, to locate a rotation sprinkler in a corner of a lawn being watered, with rotation limited to 90°. Generally speaking, such a sprinkler includes a mechanism to return the sprinkler to a ‘start’ position after 90° of rotation.

[0004] Although 180° and 90° are the most common rotation limitations, it is known to provide sprinklers where the permissible rotation can be set at any desired level.

[0005] The outer boundary of the area irrigated by a rotating sprinkler is necessarily circular, or part circular. This causes a variety of inefficiencies in operation: either the sprinklers are set to ensure coverage of an area, which means that some areas will overlap with those watered by neighbouring sprinklers and some water will fall outside the boundary, such as on paving; or else the sprinklers are set to minimise wastage which means that some areas will not be reached at all.

[0006] The present invention seeks to provide a means to efficiently water areas having a geometrical shape not conducive to traditional rotating sprinklers. Summary of the Invention

[0007] According to one aspect of the present invention there is provided a liquid delivery apparatus including a liquid delivery means arranged to rotate about a first axis, and a geometric template arranged to rotate about a second axis; the liquid delivery means and the geometric template being arranged to rotate at the same angular speed; the geometric template having a boundary; the liquid delivery apparatus including a first operating arm arranged to pivot around a pivot point, the first operating arm having an outer end remote from the pivot point, the outer end being arranged to engage with the boundary of the geometric template such that the first operating arm is arranged to pivot about the pivot point in response to changes in the distance between the second axis and the boundary of the geometric template near the first operating arm; the liquid delivery apparatus including a tuning member, the tuning member being connected to the first operating arm, the tuning member having a tuning means arranged to set the relative positions of the first operating arm and the tuning member; the liquid delivery apparatus having an associated valve arranged to control the pressure of liquid supplied to the liquid delivery means, the valve being connected to a second operating arm, the second operating arm having a first end arranged to selectively change the degree of opening of the valve and a second end arranged to engage with the tuning member; such that the degree of opening of the valve varies with the distance from the second axis to the geometric template boundary.

[0008] It will be appreciated that this permits the distance from the first axis to the outermost point of water delivery to be correlated to the distance from the second axis to the geometric template boundary.

[0009] It will also be appreciated that the first axis and the second axis may be aligned, such that the geometric template and the liquid delivery means rotate about a common axis. [0010] It is preferred that the tuning member is a tuning arm, the tuning arm being arranged to pivot about an anchoring point on the first operating arm, the tuning arm being angled with respect to the first operating arm, the tuning means being arranged to permit setting of the angle between the tuning arm and the first operating arm.

[0011 ] In a preferred embodiment, the tuning means includes a threaded bolt arranged to engage with a nut, the nut fixed in position relative to the first operating arm.

[0012] The liquid delivery apparatus preferably includes a biasing means, which may be a tension spring. In a preferred embodiment, the biasing means acts between the second operating arm and the pivot point.

[0013] In a preferred embodiment the tuning arm has a generally flat outer surface, with the second operating arm having a roller located at its second end, the roller arranged to move along the outer surface of the tuning arm.

[0014] The outer end of the first operating arm preferably has an engaging means to engage with the boundary of the geometric template. The engaging means is preferably a roller. In a preferred embodiment, the engaging means of the first operating arm is located at the anchoring point of the tuning arm.

[0015] The liquid delivery means may be coupled to a first toothed gear, with the geometric template coupled to a second toothed gear. In a preferred embodiment the first and second toothed gears may be connected by interconnecting gears. Alternatively, the first and second toothed gears may be connected and operated by means of a continuous chain.

[0016] Other operating mechanisms may include belt drives, worm drives, direct drive mechanisms and the like. The operating mechanism may be powered by an electrical motor or by other means including a hydraulic motor and being driven by water pressure. [0017] The geometric template may be arranged to counter-rotate with respect to the liquid delivery means.

Discussion of Prior Art

[0018] US patent number 3,451 ,623 describes a lawn sprinkler having a liquid delivery means with a valve which is opened to a desired degree by a single operating arm associated with a geometric template. There is no provision for tuning of the lawn sprinkler.

[0019] US patent number 2,999,643 describes an irrigation device combining a circular spray with a rotating jet, with means for varying the proportion of water delivered to the circular spray and to the rotating jet. There is no valve which is operated by an operating arm.

[0020] US patent number 6,079,637 describes a sprinkler having an arm which rotates with a sprinkler head around a fixed template.

[0021 ] US patent number 6,834,814 describes an adjustable pattern irrigation system having an arm which rotates with a sprinkler head around a fixed template.

Brief Description of the Drawings

[0022] It will be convenient to further describe the invention with reference to preferred embodiments of the present invention. Other embodiments are possible, and consequently the particularity of the following discussion is not to be understood as superseding the generality of the preceding description of the invention. In the drawings:

[0023] Figure 1 is a first upper perspective of a liquid delivery apparatus in accordance with the present invention;

[0024] Figure 2 is a second upper perspective of the liquid delivery apparatus of Figure 1 ; [0025] Figure 3 is a lower perspective of the liquid delivery apparatus of Figure 1 ;

[0026] Figure 4 is a top view of the liquid delivery apparatus of Figure 1 ;

[0027] Figure 5 is an under view of the liquid delivery apparatus of Figure 1 ;

[0028] Figure 6 is a top view of a tuning arm from within the liquid delivery apparatus of Figure 1 , shown in a first position;

[0029] Figure 7 is a top view of the tuning arm of Figure 7, shown in a second position;

[0030] Figure 8 is a top view of the liquid delivery apparatus of Figure 1 , schematically shown in operation using a first geometric template;

[0031 ] Figure 9 is a top view of the liquid delivery apparatus of Figure 1 ; schematically shown in operation using a second geometric template;

[0032] Figure 10 is a top view of the liquid delivery apparatus of Figure 1 ; schematically shown in operation using a third geometric template; and

[0033] Figure 11 is a lower perspective of an alternative embodiment of a liquid delivery apparatus in accordance with the present invention.

Detailed Description of Preferred Embodiments

[0034] Referring to the Figures, Figures 1 to 5 show a liquid delivery apparatus 10 having a liquid delivery means in the form of a sprinkler 12 and a control means 14. The sprinkler 12 and control means 14 are each located atop a base plate 16.

[0035] The sprinkler 12 is positioned atop a first rotating shaft 18, which is supported by a first circular bearing 20 extending from atop the base plate 16. The first rotating shaft 18 is coupled to a first toothed gear 22 located underneath the base plate 16. The arrangement is such that as the first toothed gear 22 rotates relative to the base plate 16, the sprinkler 12 rotates about a first axis. The first axis corresponds to that of the rotating shaft 18.

[0036] The sprinkler 12 is supplied with water (or any other desired liquid) via a supply pipe 24. The supply pipe 24 has a first vertical portion 26 extending directly beneath the rotating shaft 18, a first horizontal portion 28 extending away from the first vertical portion 26; a second vertical portion 30 extending upwardly from an end of the first horizonal portion 28 remote from the first vertical portion 26, and a second horizontal portion 32 which extends away from an upper end of the second vertical portion 30 in a direction generally perpendicular to that of the first horizontal portion 28.

[0037] The second horizontal portion 32 is located such that an upper most portion thereof is generally level with the base plate 16. The second horizonal portion 32 includes a valve casing 34 which houses a ball valve, operable by rotation of an upper pin 38 which is generally parallel to the first rotating shaft 18.

[0038] The control means 14 includes a second rotating shaft being a drive shaft (not shown), which is supported by a second circular bearing 42 passing though the base plate 16. The drive shaft is operated by an electric motor 44.

[0039] The drive shaft has an upper receiving surface on which a geometric template can be mounted. In the arrangement of Figures 1 to 8 the geometric template is a square plate 46. The arrangement is such that the drive shaft rotates about a second axis which is parallel to the first axis (that is, the axis the first rotating shaft 18), with the square plate 46 locating in a plane perpendicular to the second axis, that is, being horizontal.

[0040] The drive shaft is coupled to a second toothed gear 48 located underneath the base plate 16. The arrangement is such that as the second toothed gear 48 rotates relative to the base plate 16, the square plate 46 rotates about the second axis. [0041 ] The first toothed gear 22 and the second toothed gear 48 are the same size, with the same number of teeth.

[0042] A first intermediate toothed gear 50 is arranged to mesh with the first toothed gear 22. A second intermediate toothed gear 52 is arranged to mesh with both the first intermediate toothed gear 50 and the second toothed gear 48. In this way, the first rotating shaft 18 and the drive shaft are constrained to counter-rotate.

[0043] The control means 14 includes a first operating arm 54 which extends inwardly from an edge of the base plate 16 generally towards the drive shaft. The first operating arm 54 has a first end 56 mounted to a pivot point 58 located at the edge of the base plate 16. The first operating arm 54 has a second end 60 remote from the first end 56.

[0044] The first operating arm 54 has an engaging means 62 mounted towards the second end 60. The engaging means 62 is arranged to seat against an outer boundary of the square plate 46. In the embodiments shown, the engaging means 62 is a vertical-axis roller. As will be detailed below, the first operating arm 54 is effectively biased towards the drive shaft. This means that as the square plate 46 rotates, the engaging means 62 bears against the boundary of the square plate 46. As the effective radius of the square plate 46 (that is, the distance from the second axis to the boundary of the square plate 46) changes, the first operating arm 54 is caused to pivot about the pivot point 58.

[0045] A second operating arm 70 has a first end 72 coupled to the upper pin 38 of the ball valve. The second operating arm 70 has a second end 74 on which a guide member in the form of a vertical-axis guide roller 76 is mounted. The operating arm 70 is arranged to pivot about a central axis of the upper pin 38. The arrangement is such that lateral movement of the guide roller 76 causes rotation of the upper pin 38, and thus varies the degree to which the ball valve is opened. [0046] The second operating arm 70 is arranged to rotate the upper pin 38 in response to pivoting of the first operating arm 54 about the pivot point 58. The degree to which this occurs is controlled by a tuning member and associated tuning means, the mechanism for which is detailed in Figures 6 and 7.

[0047] The tuning member is formed by a tuning arm 80 in conjunction with an adjustment means 82. The tuning arm 80 has a first end 84 arranged to pivotally mount to the first operating arm 54, and a second end 86 which extends away from the first end 84 is in a direction generally towards the pivot point 58.

[0048] The tuning arm 80 has a straight outer edge 88 extending between the first end 84 and the second end 86, the outer edge 88 being arranged to face away from the square plate 46. The tuning arm 80 has a straight inner edge 90 opposed to the straight outer edge 88.

[0049] The tuning arm 80 is mounted to the first operating arm 54 at an anchoring point. The anchoring point coincides with the engaging means 62.

[0050] The adjustment means 82 includes a threaded adjustment bolt 92. The adjustment bolt 92 sits within a nut 94 fixed to the first operating arm 54, and has an outer end 96 located against the inner edge 90 of the tuning arm 80. The arrangement is such that forward rotation of the adjustment bolt 92 through the nut 94 causes the outer end 96 to bear against the inner edge 90 of the tuning arm 80, causing rotation of the tuning arm 80 about the anchoring point, and increasing a relative angle of the first operating arm 54 and the tuning arm 80.

[0051 ] It will be appreciated that when the adjustment bolt 92 is withdrawn to its greatest extent the tuning arm 80 will be nearly parallel to the first operating arm 54. When the adjustment bolt 92 is inserted to its greatest extent the tuning arm 80 will be nearly perpendicular to the first operating arm 54. [0052] The guide roller 76 of the second operating arm 70 is arranged to seat against the straight outer edge 88 of the tuning arm 80.

[0053] A biasing means in the form of a tension spring 100 extends between a midpoint of the second operating arm 70 and the pivot point 58 on the base plate 16. The tension spring 100 urges the guide roller 76 against the tuning arm 80, which in turn urges the engaging means 62 against the square plate 46.

[0054] Rotation of the drive shaft causes rotation of the square plate 46. As the square plate 46 rotates, the distance from the second axis to the periphery of the square plate 46 changes (when viewed along, for instance, a line between the first axis and the second axis).

[0055] As the distance from the second axis to the periphery of the square plate 46 increases, the edge of the square plate 46 bears against the engaging means 62, pushing it away from the second axis and causing rotation of the first operating arm 54 relative to the pivot point 58.

[0056] This, in turn, causes the outer edge 88 of the tuning arm 80 to bear against the guide roller 76, pushing the guide roller 76 away from the second axis.

[0057] This results in rotation of the second operating arm 70 about the axis of the upper pin 38 and hence a rotation of the upper pin 38, and in an increased opening of the valve in the valve casing 34.

[0058] As the distance from the second axis to the periphery of the square plate 46 decreases, the tension spring 100 causes the guide roller 76 to stay bearing against the outer edge 88 of the tuning arm 80, and the engaging means 62 to continue to bear against the edge of the square plate 46. This results in rotation of the second operating arm 70 in the counter direction, and a partial closing of the valve in the valve casing 34. [0059] The ball valve controls the water pressure available to the sprinkler 12. It will therefore be appreciated that the distance the water travels from the sprinkler is correlated to the degree to which the ball valve is open.

[0060] Using the tuning member, it is possible to arrange the movement of the ball valve in response to rotation of the drive shaft such that the distance travelled by water from the sprinkler is proportional to the distance from the second axis to the square plate 46. As the sprinkler 12 is constrained to rotate with the square plate 46, the result is the delivery of water into a square space 110 centred on the first axis. This can be seen in Figure 8. It should be noted that the size of the liquid delivery apparatus 10 is greatly exaggerated in this drawing for clarity.

[0061 ] As noted above, the square plate 46 can be removed and replaced by another geometric template. Figure 9 shows an example (with the same exaggerated proportions of Figure 8) where an oval-shaped plate 112 has replaced the square plate 46. The same principles of proportionality arise, meaning that water can be delivered into an oval area 114 centred on the first axis.

[0062] It will be appreciated that any two-dimensional shape can be accommodated by a geometric template being a scaled reproduction of the area concerned. Figure 10 shows an irregular-shaped plate 116 used instead of the square plate. The result is distribution of water in an area 118 corresponding in shape to the shape of the plate 116 (again, with the same exaggerated proportions of Figure 8).

[0063] It will also be appreciated that the plate 46, 112, 116 must be correctly angled with respect to the direction of the sprinkler 12 to ensure correct correspondence. This can be achieved and adjusted through the connection of the plate 46, 112, 116 to the drive shaft. In the embodiment of the drawings this can be achieved through fixing the connection plate 46, 112, 116 in position using a locating pin 47. [0064] It will further be appreciated that although the above description refers to control of water pressure, control of water volume and flow rate can be equivalently achieved.

[0065] Figure 11 shows an alternative to the intermediate toothed gear 50, 52 arrangement shown in Figures 3 and 5. In the embodiment of Figure 11 , the first toothed gear 22 and the second toothed gear 48 are connected by a continuous chain 120.

[0066] In this embodiment, the first rotating shaft 18 and the drive shaft are constrained to rotate in unison, with the continuous chain 120 driving the first toothed gear 22.

[0067] Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.