Regulation 3.2 AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR AN INNOVATION PATENT ORIGINAL Name of Applicant: Toro Australia Pty Limited Actual Inventors: Christopher Alan Appleton William Gordon Milne Address for Service: C/- MADDERNS, GPO Box 2752, Adelaide, South Australia, Australia Invention title: A STREAMLINED SUPPORT ELEMENT FOR A SPRINKLER The following statement is a full description of this invention, including the best method of performing it known to us.
This invention relates to a streamlined support element for a sprinkler, and in particular to support elements for sprinklers which are positioned within or that interrupt the flow path of a sprinkler. BACKGROUND OF THE [NVENTION 5 Sprinklers generally use a rotating stream of water to irrigate an area around the sprinkler. Various means are used to distribute water around a sprinkler but the most common is a rotating nozzle that directs a stream of water away from the sprinkler. In addition to a discrete stream of water, other deflecting means may be used which distribute a 10 continuous fan of water that is essentially a constant flow rate at all points around the periphery or segments of the sprinkler where the water is being distributed. For example, a stream of water may impinge upon a deflector plate that distributes water within a desired sector or around the sprinkler. For the purposes of this description, the term "stream" is to include the above described forms of 15 distribution around the sprinkler and any other form of distribution where water is projected away from the sprinkler. Some sprinklers have elements which are located within the flow of water or where the flow of water passes across the element. For example, some sprinklers use a horizontal bridge to support a 20 spinning element between an outlet nozzle and the bridge. The bridge in turn is supported via a support element or post. In some sprinklers, a single post is used, or the bridge may be supported by a pair of posts either side of the sprinkler. Generally, these posts, which are intersected by the stream from the sprinkler, have a triangular 25 cross-section with apex of the triangle being the first point that intersects the flow of the stream. This is desirable to prevent any splashing where water would otherwise be directed significantly away from the direction of travel or not be distributed away from the sprinkler in the desired manner. 30 However, even though very acute angles are used for the triangular cross-section, there is still significant deviation of flow away from the intended path on either side of the support. This results in what is known as an area of "shadow" on either side of the sprinkler where no water falls. Obviously, this shadow area becomes progressively wider as the distance from the sprinkler increases. 35 2 In addition, even though the triangular cross-section has an acute angle, there is still splashing which causes water to fall directly beneath the sprinkler which therefore results in excessive pooling of water directly beneath the sprinkler. 5 Accordingly, it would be desirable to overcome the above-mentioned problems to reduce the area of shadow and to significantly reduce the pooling effect beneath the sprinkler, or at the least provide a useful alternative to known sprinklers. Other objects and advantages of the present invention will become apparent from the following 10 description, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed. SUMMARY OF THE INVENTION In one aspect, the invention is a support element for a sprinkler having a streamlined cross-section 15 that minimises the deflection of a stream of water away from the support element as the stream passes across the support element. For the purposes of this description, streamlining will include convex surfaces which act to minimise the deflection of the stream of water as it leaves the post away from its intended path. 20 However, streamlining, in certain circumstances may include flat or concave surfaces where this achieves the desired result which is minimal deflection of the stream away from the support so as not to cause an area of shadow beyond the support and/or not to increase the amount of water which falls immediately below the sprinkler. 25 The cross-section of the support may have varying degrees of curvature on either side of the support. This is to take into account slight curvature of the stream as it travels away from the sprinkler. In the case of the continuous stream caused by a rotating jet, the stream tends to curve away from 30 the direction of rotation of the rotating element. This in turn means that water within the stream impinges against the two surfaces quite differently by comparison between when the stream approaches the support and when the stream then leaves the support. Accordingly, the apex where the two curved sides of the support meet on both sides of the support 35 and the line formed between these two apexes may be at an angle with respect to a line radiating 3 directly away from the centre of rotation of the sprinkler. This of course may vary depending on the nature of the stream being intersected by the support and the characteristics of the water flow either side of the support. 5 In a further aspect, the invention may be said to reside in a support element for a sprinkler producing a rotating stream of water, the support element comprising a streamlined cross-section that minimises the deflection of the stream away from the support element as the stream passes across the support element. 10 In a further aspect, the invention may be said to reside in a sprinkler adapted to produce a rotating stream of water, and comprising a support element having a streamlined cross-section that minimises the deflection of the stream away from the support element as the stream passes across the support element. 15 In a further aspect, the invention may be said to reside in a sprinkler having at least one support thereon including; a water outlet that rotates and directs a stream of water radially around the sprinkler; and a support having a streamlined cross-section that minimises the deflection of the stream of water away from the support as the stream passes across the support. 20 In a still further aspect, the invention may be said to reside in a sprinkler comprising a support and a water outlet that rotates and directs a stream of water outwardly therefrom as it rotates, so that the stream issuing from the outlet will intersect the support, said support having a streamlined cross section that minimises the deflection of the stream of water away from the support as the stream 25 passes across the support. In one form, the support has a cross-section of aerofoil shape. In order for the invention to be fully understood, a preferred embodiment will now be described. 30 However, it is to be realised that the scope of the invention is not restricted to the features of this embodiment and that modifications are possible that would still be treated as being within the scope of the invention disclosed in this application. BRIEF DESCRIPTION OF THE DRAWINGS 35 The embodiment is illustrated in the accompanying drawings in which: 4 Figure I shows a side view of a sprinkler having a bridge located over the outlet with a pair of supports on either side of the outlet, Figure 2 shows a cross-section view of Figure 1, Figure 3 shows the cross-section of a prior art support typically used and which results in 5 the distribution pattern shown in Figure 4, Figure 4 shows a plan view of water distribution around a prior art sprinkler, Figure 5 shows a cross-sectional view of a support in accordance with the invention, Figure 6 shows the distribution pattern achieved by the invention, and Figure 7 shows a cross-section view of Figure I with a diagrammatic representation of 10 water streamlines. In the following description, like reference characters designate like or corresponding parts throughout the several views of the drawings. 15 DETAILED DESCRIPTION OF THE DRAWINGS Figures 1 and 2 show a sprinkler incorporating the invention. The streamline cross-section may take any suitable form and one particular form will be shown and described in this embodiment. Figure I shows a sprinkler 10 incorporating an embodiment of the invention. The sprinkler 10 has a 20 water inlet I I that directs a pressurised stream of water into a nozzle rotating diverter 12 that directs a stream of water substantially horizontally away from the sprinkler 10. The rotating diverter has a channel that forces a change of direction of the stream of water prior to leaving the rotating diverter 12. This creates a force which causes the rotating diverter 12 to spin. 25 The rotating diverter 12 is restrained for rotation between a recess 13 within which the rotating diverter 12 is journalled and a bridge member 14 within which a shaft 15 on the rotating diverter 12 is journalled for rotation. This journalling of the rotating diverter 12 between the recess 13 and the bridge member 14 supports it for rotation in the sprinkler and also resists the upward force of the pressurised water entering inlet 11. 30 The pair of projections 17 project substantially horizontally from the water inlet II. A pair of supports 18 extends between the ends of the projection 17 and the ends of the bridge member 14 thereby supporting the bridge member above the rotating diverter 12. 35 The sprinkler 10 is designed to distribute water through 360 degrees around the sprinkler. 5 Accordingly, the stream of water issuing from the rotating diverter 12 will intersect the supports 18. This may also be the case in respect of sprinklers which are designed to distribute water over an area of less that 360 degrees but still have a support located within the water stream. 5 As seen in Figure 3, the supports 18 in the past have used triangular cross-sections. However, the triangular cross-section tends to deflect water away from the intended path, or causes disrupted flow or splashing resulting in water falling vertically from the sprinkler. This in turn results in a water distribution pattern as shown in Figure 4. Also, there is significant pooling of water below the 10 sprinkler. According to this embodiment, the cross-section of the support is streamlined as shown in Figure 5. The streamlining comprises a first curved surface 19 and a second curved surface 20 on the other side of the support. The first and second curved surfaces 19 and 20 join at the leading edge 21 and 15 the trailing edge 22. The degree of curvature of the first and second curved surfaces 19 and 20 are varied to accommodate the characteristics of the water stream flowing past the support 18. In addition, the centre line of the support cross-section, defined by a line extending between leading and trailing 20 edges 21 and 22, is offset with respect of the centre line extending through the recess 13 to also vary the angle that the first and second curved surfaces 19 and 20 are presented to the water stream in accordance with the angle of approach of the stream coming from the rotating diverter 12. As illustrated in Figure 7, there is a degree of curvature of the water stream issuing from the rotating diverter 12 which in turn requires support 18 to have a preferred orientation with respect to the 25 water stream. It has been found that the cross-section of the support 18 shown in Figures 2, 5 and 7 provide a vast improvement over the prior art cross-section shown in Figure 3. Much better water distribution is achieved as shown in Figure 6 and there is significantly less splashing resulting in reduced pooling 30 underneath the sprinkler. The increased distribution and prevention of pooling vastly increases the efficiency of water distribution which in turn has significant benefits to the plants being irrigated. Throughout the specification and the claims that follow, unless the context requires otherwise, the words "comprise" and "include" and variations such as "comprising" and "including" will be 6 understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers. The reference to any prior art in this specification is not, and should not be taken as, an 5 acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge. It will be appreciated by those skilled in the art that the invention is not restricted in its use to the particular application described. Neither is the present invention restricted in its preferred 10 embodiment with regard to the particular elements and/or features described or depicted herein. It will be appreciated that various modifications can be made without departing from the principles of the invention. Therefore, the invention should be understood to include all such modifications in its scope. 7