AU645593B2 - Sprinkler - Google Patents

Description

J Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

0.

00 0 g 0* 0 0 •r •o o •oo o Name of Applicant: LEONARD JEFFERSON BLEE Actual Inventor: LEONARD JEFFERSON BLEE Address for Service: R K MADDERN ASSOCIATES, 345 King William Street, Adelaide, South Australia, Australia Invention title: "SPRINKLER" Details of Associated Provisional Application No: Application No PK 1845 dated 21st August, 1990 The following statement is a full description of this invention, including the best method of performing it known to me.

1 This invention relates to a sprinkler of the type which might be used to water lawns of domestic dwellings, for irrigation purposes, and for other purposes, but the invention is not limited to the application to which it is applied.

Prior art sprinklers known to the Applicant are very dependent on water pressure and flow rates in order to obtain a reasonable area of coverage, and this applies particularly when two or more units are operated simultaneously from one supply, as for example in the case of automatic irrigation systems.

Performance of known sprinklers in windy conditions is unpredictable as spray coverage can change from one moment to the next leading to wastage of water on adjoining areas, this being due to variable winds.

Heretofore, in order to achieve a long throw of water in irrigation, a nozzle having a small aperture is usually employed in order to obtain maximum water jet velocity. As a consequence, the resulting fine jet of water tends to develop o 0 *2D small droplets which expose a maximum area for given volume 0 .0 and a significant proportion of water used is lost due to evaporation while in transit between the sprinkler and vegetation. When the fine spray droplets finally reach the ground, there is a tendency for the water not to penetrate 60..95 properly into the ground but rather the small droplets can sit on top of the ground, and this is exacerbated if tl.e 00 0 ground is of the "non-wetting" type.

It is already known however that if drop size can be increased many times to the equivalent for example to heavy rain drops, the effectiveness of the watering for a given ,0:0 volume of water can be increased very considerably. The 0* 0 larger drop size, surface area exposes less for a given volume, and consequently the proportion of water lost to evaporation while in transit will be reduced.

The larger drop size also has more inertia and is less prone to deviation from the intended path due to the effect of wind, and this allows the area of coverage to be more 2 closely defined. In the case of non-wetting soil, the water droplet will penetrate deeper into the surface dust layer and better penetration of underlying soil is achieved.

The only prior art sprinklers known to the Applicant capable of producing a stream of large drops employ rotating arms fitted with oscillating vanes which intercept the water stream and also produce rotation. However, there are problems in providing an even water distribution over the entire area of coverage.

In some applications, sprinklers rely mostly upon constriction of water flow to reduce the amount of water, and the constriction has previously been achieved by a small diameter tube or orifice, or the provision of a tortuous path for the water fVow. This is very unsatisfactory if the water is not clean be.ause of a tendency to develop blockages, and another object of the invention is to provide a sprinkler which, in small size, will have less tendency to block.

Briefly in this invention, a sprinkler has a body with a base portion and a top portion, and a liquid flow conduit extending through the base portion to the top portion and vi\ +krIo- cct openi.agto an upwardly diverging conical wall at the top end of the conduit, which defines an upwardly facing annular recess, and the recess contains an impeller having a complementary annular downwardly converging wall which 25 includes an indentation extending from the centre of the impeller to an outer portion, the shapes and dimension of the conical walls and indentation being such that, in use, liquid entering the sprinkler passes through the conduit, between complementary conical surfaces, and discharges near the impeller periphery.

This arrangement can be used for either very small or 00 0 very large sprinklers and for a range of sprinklers therebetween, but the range of sprinklers only needs to be small because of the simplicity of changing from a small throw to a large throw. If the impeller is only loosely retained in the recess, and for example a blockage tends to occur, upon turning the water on, the impeller will be lifted -3 l ,i ,9 from the recess, and thereby the sprinkler is self-cleaning to quite a considerable degree.

Another advantage of the invention is that the impeller can be retained within the recess without any need for any positive location means, and the hydrodynamic forces of water flowing between the impeller and recess walls can separate the surfaces which would otherwise be bearing surfaces, and this in turn provides a very low friction and minimum wear.

If no bearing or retention means are used, or if the retention means only loosely retain the impeller against accidental displacement, then by having the diameter of the impeller greater than that of the water flow throat, the dislodgement force imparted to the impeller due to the upwardly flowing liquid which is restricted by the impeller can be made less than a retaining force which is due to the difference between the atmospheric pressure and the low 6 pressure imparted to the impeller by liquid flow between the °0 complementary surfaces. Use is made of this "Bernoulli 0: effect" in most applications of-this invention.

W'2 While the invention need not necessarily include the abovementioned details, an embodiment is described hereunder in some further detail with reference to and is illustrated in the accompanying drawings in which: Fig 1 is a top view of a sprinkler; 55 Fig 2 is a section taken on line 2-2 of Fig 1; Fig 3 is a bottom view of the sprinkler impeller shown in Figs 1 and 2; Fig 4 is a top view of swirl imparting means contained 5.

within the sprinkler body and showing the deflecting surfaces; Fig 5 is a section taken on line 5-5 of Fig 4; and Fig 6 is a bottom view of Fig In this embodiment, a sprinkler 10 comprises a hollow body 11 which has a base portion 12 and top portion 13.

Within the body there is a centrally located liquid flow conduit generally designated 14 which extends from the base 4 v portion 12 to the top 13 and which opens at its upper end into an upwardly facing recess 15 which is defined by upwardly diverging conical wall 16.

Within the recess 15 there is located an impeller 19 which comprises a plurality of indentations 20 (three being shown in this embodiment). The impeller 19 is also provided with a conical surface 21 which is generally but not necessarily completely complementary to the surface 16, and as best seen in Fig 2, between the indentations 20 there are provided lands 22 which lie contiguous with the walls 16 of recess 15, excepting for a film of water which lies between them when the sprinkler is in use.

While the indentations can be radial or curved, in Fig 3 the indentations 20 are not quite radial but are slightly offset from radii of the impeller 19 and by an amount which will influence rotation of the impeller when water passes between the impeller and the recess walls 16. Its rotational .0 velocity will have an influence on the length of throw of S water and the higher the speed the smaller the throw.

As shown in the illustrated embodiment, there are provided deformable vanes 25 which loosely retain the impeller 19 in the recess 15, although vanes are not necessary. However, the vanes 25 if angled as shown in Figs 2 and 3 will assist in creating a high rate of rotation if that 5 is required for example for a small area of coverage.

Below the recess walls 16, the conduit 14 converges upwardly, so that the upwardly converging walls 27 co-operate with the walls 16 to form a throat 28, while at the lower end cf the walls 27 there is provided a swirl imparting device 29 (shown in detail in Figs 4, 5 and and this swirl imparting device 29 has a conical undersurface 30 containing a slot 31 which opens into tangential slots 32 so that liquid which rises through the conduit 14 enters the space defined by the converging walls 27 with a degree of swirl. The impeller 19 can spin or rotate slowly depending upon the requirements of the application, without any direct contact with the body 11 and with a very high degree of control.

Notwithstanding this however, the liquid moving upwardly through the conduit 14 past the throat 28 will nevertheless have an upward component of force due to its pressure and this could in some instances otherwise dislodge the impeller excepting that the flow of water betwee. the walls 16 of the upwardly facing recess 15 and the conical surface 21 of the impeller creates a sub-atmospheric pressure so that atmospheric pressure reacting on the upper surface of the impeller is sufficient to retain the impeller in place when it is in use. Thus the flow of water imparts a positional force to the impeller, not only in that it separates the contiguous conical surfaces and avoids direct contact of those surfaces while the impeller rotates, but also a positional force in the sense that it controls rotation of the impeller.

The cost of the sprinkler will be seen to be very low, and experiments have indicated that an excellent throw is achieved of large diameter water drops which can be arranged 9.

by varying the above described parameters to give a very even coverage of irrigation. When not in use, the impeller rests on recess 15 and this acts to prevent ingress of foreign matter and insects.

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Claims (9)

1. A sprinkler comprising a body having a base portion and a top portion, a wall defining a liquid flow conduit extending through the body from the base portion to the top portion, said wall converging between the base and top portion to define a throat, and above the throat being conical and diverging at the top end of the conduit where it defines an upwardly facing annular recess, an impeller having a generally annular downwardly converging conical wall generally complementary in shape to the conical recess wall and positionable to be contiguous therewith, said converging conical wall containing an indentation which extends from near the centre of the impeller and opens at an outer portion, the shapes and dimensions of said conical walls and the impeller indentation being such that, in use, liquid entering the sprinkler passes through the conduit, between said contiguous complementary conical walls, and discharges through the indentation at an outer portion of the impeller, and also imparts a positional force to the impeller.

2. A sprinkler according to claim 1, wherein, when in use, an upward dislodgement force imparted to the impeller due to passage of liquid S2o deflected thereby is less than a retaining force due to the difference between o•:i atmospheric pressure and low pressure imparted to the impeller by liquid flow o S.between the complementary surfaces,

3. A sprinkler according to claim I or claim 2 wherein there :are at least three said indentations, and the impeller conical wall comprises 25 lands between the indentations which define with the conical recess wall a small space within which liquid separates the lands from the recess wall when S, the sprinkler is in use, said liquid discharging mainly through the slots as discrete streams.

4. A sprinkler according to any one of claims 1 to 3 further comprising swirl imparting means below the throat which impart swirl to liquid entering the throat, and that said swirl assists in producing a positional force on the impeller.

5. A sprinkler according to claim 1 wherein said swirl imparting means comprises an insert within said conduit below said throat having swirl imparting deflecting surfaces.

6. A sprinkler according to claim 4 or claim 5 wherein said impeller comprises deflectable vanes insertable through said throat only upon to deflection and loosely and releasably retain said impeller to said body.

7. A sprinkler according to any preceding claim wherein said indentation or indentations are offset with respect to radii from an axis of impeller rotation by an amount which determines rotational motion to the impeller.

8. A sprinkler according to claim 1, wherein there is a plurality of said impeller indentations.

9. A sprinkler substantially as hereinbefore described with reference to and as illustrated in the ar" -panying representations. J:: 4 .S ATED this 15th day of November 1993 LEONARD JEFFERSON BLEE By his Patent Attorney KEN MADDERN ABSTRACT A sprinkler (10) has a body (11) with a base portion (12) and a top portion and a liquid flow conduit (14) extending through the base portion to the top portion and opening to an upwardly diverging conical wall (16) at the top end of the conduit, which defines an upwardly facing annular recess and the recess (15) contains an impeller (19) having a complementary annular downwardly converging wall (21) which includes indentations (20) extending from the centre of the impeller to an outer portion, the shapes and dimension of the conical walls and indentations being such that, in use, liquid entering the sprinkler passes through ,l the conduit, between complementary conical surfaces, and discharges at the impeller periphery. S 0 *se S S