Patent Description:
The invention also relates to a method of delivering an irrigation liquid sprinkler device.

Systems have been long known in the field of irrigation systems which comprise a self-propelled load-bearing truss moving along a portion of soil to be irrigated via one or more motorized wheels.

The system generally comprises a feed line for feeding an irrigation liquid, which is connected to a plurality of central sprinkler devices for distributing the liquid over the soil.

Typically, such device comprises a support structure with a fitting connected to the feed line having a liquid jet-dispensing nozzle.

The device further comprises a baffle plate that faces the nozzle and is adapted to intercept the jet of liquid from the feed line and to radially divert it to uniformly deliver it to a circular area of soil to be irrigated.

Generally, the irrigation system comprises at least one sprinkler device of the aforementioned type which is mounted at its end to generate a semicircular water jet to increase the irrigated area of the system.

Typically, this type of device is called "end spray" and comprises a short-range fan-shaped jet having a high degree of atomization and hence a lower effectiveness due to a large amount of liquid being swept away by the wind.

In addition, liquid distribution is not optimal and the irrigation liquid falls heavily at the end of each moving jet, especially at low pressures, resulting in a high application intensity and possible risk of damage to the soil and/or runoff conditions.

In an attempt to at least partially obviate this drawback, sprinkler devices have been developed in which the irrigation liquid is distributed radially by a series of channels in rotation.

<CIT> discloses a liquid sprinkler device for use in irrigation systems of the above described type having a support structure with an upper portion that has a nozzle adapted to channel an irrigation liquid in the longitudinal direction to a delivery plate arranged below the nozzle and rotated by liquid pressure.

Namely, this known device is a wobbling device, which means that the plate both rotates on itself and undergoes a nutation motion about an axis inclined to the axis of rotation.

The support structure and the plate have respective surfaces which are adapted to interact with each other and have a first magnet joined to the structure and a second magnet joined to the delivery plate and placed close to the first magnet.

The first and second magnets are mounted in opposite positions such that a magnetic repulsion force promotes triggering of the rotation of the sprinkler device when the irrigation liquid impinges thereupon.

A first drawback of this arrangement is that the contact surfaces of the various parts of the emitting device are exposed to wear, which leads to the generation of oscillating vibrations of the plate and ultimately to failure of the device, with uneven distribution of the jet of liquid over the area of the soil to be irrigated.

Also, a further drawback of this solution is that, due to the wear of these contact surfaces, the emitting member is required to be periodically replaced, which will increase the maintenance costs of the system.

Furthermore, during periodic maintenance of the diffuser device, the operation of the system is stopped, and the soil remains unirrigated for a given time, which will reduce the growth of crops.

In an attempt to at least partially obviate these drawbacks sprinkler devices have been developed, which comprise an irrigation liquid deflecting element to avoid irrigation of the area of the soil that has been already irrigated by the central sprinkler devices of the structure of the system.

Nevertheless, this type of baffles causes the irrigation liquid to fall thereunder and create a pool, thereby preventing the uniform irrigation required for crop optimization.

In view of the prior art, the technical problem addressed by the present invention is to irrigate the soil over an angularly restricted area to obtain an even liquid application with reduced application intensity.

The object of the present invention is to obviate the above drawback, by providing a liquid-sprinkler device for gravity-based irrigation systems and a method of delivering an irrigation liquid using a liquid sprinkler device, that are highly efficient and relatively cost-effective.

A particular object of the present invention is to provide a liquid sprinkler device and a method of delivering an irrigation liquid as described hereinbefore, that can distribute the liquid in a sector portion of the soil.

Yet another object of the present invention is to provide a liquid-emitting device as described hereinbefore that has a remarkably long life.

A further object of the present invention is to provide a sprinkler device and a method of delivering an irrigation liquid as described above, that allow uniform application of the liquid with a lower application intensity.

These and other objects, as better explained below, are fulfilled by a liquid sprinkler device for gravity-based pivot or linear irrigation systems as defined in claim <NUM>, which comprises a support structure having a first portion with a nozzle defining a longitudinal axis for generating a jet of liquid and a second portion with a baffle plate pivoted thereto and facing the nozzle.

In a peculiar aspect of the invention, the support structure comprises drive means having at least one first magnet moving with a reciprocating oscillatory motion due to a negative pressure generated by the liquid that flows through the nozzle; the drive means are adapted to move the plate along and force it to pivot with a reciprocating oscillatory motion about the longitudinal axis through a predetermined angle, to deliver the liquid over a sector area of the soil.

The plate comprises at least one second magnet facing the at least one first magnet of the drive means, with respective concordant and mutually attracting polarities.

Furthermore, the support structure of the device has a fitting, upstream from the nozzle, for connection to a liquid supply line whose inside diameter is greater than the inside diameter of the nozzle to form a narrower portion that can create the negative pressure.

With this combination of features the sprinkler device can distribute liquid over a sector-shaped area of the soil.

Advantageous embodiments of the invention are obtained in accordance with the dependent claims.

Further features and advantages of the invention will become more apparent upon reading the following detailed description of a few preferred non-exclusive embodiments of a liquid sprinkler device for gravity-based pivot or linear irrigation systems and a method of delivering an irrigation liquid for gravity-based pivot or linear irrigation systems using a sprinkler device, which are described as a non-limiting example with the help of the accompanying drawings in which:.

Referring to the figures, <FIG> shows a sprinkler device for delivering an irrigation liquid for gravity-based pivot or linear irrigation systems of the invention, generally designated with numeral <NUM>, which is designed for distribution of an irrigation liquid F, generally water, over a soil G to be irrigated.

In particular, the sprinkler device <NUM>, which is of the "end sprayer" type, may be connected to the outer free end <NUM> of an irrigation liquid feed line <NUM> mounted to a truss structure <NUM> of a "center pivot" irrigation system <NUM>, which is displaceable by means of one or more motorized wheels R, as shown in <FIG>.

In a first embodiment not encompassed by the wording of the claims, as shown in <FIG>, the sprinkler device <NUM> comprises a support structure <NUM> having an elongate portion 6A adapted to be secured to the truss structure of the substantially vertical irrigation system having a first portion 6B extending therefrom and designed to receive a first substantially cylindrical nozzle <NUM> with an inside diameter d<NUM> and with a substantially vertical axis L, configured to generate a jet of liquid directed downwards as indicated by arrow F.

A second portion 6C extends from the elongate portion 6A and has a baffle plate <NUM> pivoted thereto and partially facing the first nozzle <NUM> to divert and radially deliver the jet of liquid F.

The baffle plate <NUM> is pivotally mounted to the upper end of a pin <NUM> inserted in an appropriate seat of the second portion 6C and having an axis X<NUM> substantially parallel to the longitudinal axis L to be able to pivot about such axis X<NUM>.

The plate <NUM> may be located at a given distance <NUM> from the first nozzle <NUM> and may have an inlet portion 8A facing the first nozzle <NUM> and connected to a diverting outlet portion 8B.

In particular, the diverting outlet portion 8B may have at least partially radial grooves <NUM> and with ends facing upwards, to ensure enhanced radial guidance and more uniform delivery of the irrigation liquid.

Preferably, the outlet portion 8B of the baffle plate <NUM> has a peripheral portion with a substantially semicircular plan shape extending through an angle δ of about <NUM>° such that, as the plate <NUM> pivots with a reciprocating oscillatory motion β at a predetermined angle γ, the liquid F is distributed within an angle γ + δ ranging from <NUM>° to <NUM>°, preferably from <NUM>° to <NUM>° corresponding to the sector area S of the soil G to be irrigated.

As shown in <FIG>, which show a top view of the sprinkler device <NUM> without the first portion 6B of the support structure <NUM>, the predetermined angle γ ranges from <NUM>° to <NUM>°, and is preferably about <NUM>°.

Therefore, the jet of liquid F generated by the first nozzle <NUM> and diverted by the baffle plate <NUM> which pivots with a reciprocating oscillatory motion is distributed over the sector area S with extended range of the device <NUM> and enhanced liquid atomization, resulting in improved distribution over the soil.

The first nozzle <NUM> may be connected to the feed line <NUM> which feeds the liquid F under pressure by means of a fitting <NUM> fixed to the portion 6B and having an inside diameter d<NUM> that is greater than the diameter d<NUM> of the first nozzle <NUM>.

According to the invention, a second nozzle <NUM> is provided, which is other than the first nozzle <NUM>, operates therewith and has a narrower portion downstream from its inlet to create a Venturi-induced negative pressure.

In the first embodiment, the second nozzle <NUM> is interposed between the fitting <NUM> and the first nozzle <NUM> and is coaxial with both.

Preferably, the second nozzle <NUM> has a substantially frustoconical shape with an inlet <NUM>' having the same diameter d<NUM> as the fitting <NUM> and with the outlet <NUM>" having an inside diameter d<NUM> that is smaller than the inside diameter d<NUM> of the first nozzle <NUM>.

Furthermore, while the inlet <NUM>' of the second nozzle <NUM> is sealingly connected to the fitting <NUM> with an O-ring, its outlet <NUM>" fits into the inlet <NUM>' of the first nozzle <NUM> with a small radial and axial clearance.

Moreover, an annular intake manifold 12A is formed around the second nozzle <NUM> in fluid communication with the narrower portion via the radial and axial clearance between the two nozzles <NUM>, <NUM>.

Thus, the flow of the fluid F through the first nozzle <NUM> and the second nozzle <NUM> creates a Venturi-induced negative pressure, generally referenced D, at the narrower portion of the second nozzle <NUM>.

According to the invention, drive means <NUM> are provided, which act on the baffle plate <NUM> to control its reciprocating pivotal motion about the axis X<NUM> and comprise t least one first magnet <NUM> which is adapted to move with a reciprocating rectilinear motion having an amplitude Δ in response to the negative pressure D generated by the liquid F that flows through the first nozzle <NUM>.

A second magnet <NUM> faces this first magnet <NUM> and is substantially similar thereto and accommodated in a cavity of an appendage 8C which radially extends outwards from the first portion 8A of the baffle plate <NUM>.

Conveniently, the two magnets <NUM>, <NUM> are arranged in such position as to have concordant, mutually attracting polarities P<NUM>, P<NUM>.

Thus, as a result of the reciprocating straight motion Δ of the first magnet <NUM>, the second magnet <NUM>, and hence the baffle plate <NUM> will be driven along into a reciprocating oscillatory motion β about its own axis of rotation X<NUM> by magnetic attraction.

Furthermore, the first magnet <NUM> is fixed to an actuator member <NUM> which is slidingly and sealingly accommodated in a first chamber <NUM> located in the second portion 6C of the support structure <NUM>.

In a preferred embodiment of the invention, a pair of mutually facing first magnets <NUM>', <NUM>" with concordant and mutually attracting polarities P<NUM> are provided instead of a single magnet <NUM>, to respectively increase the attraction force with the second magnet <NUM> of the plate <NUM>.

As more clearly explained hereinafter, the drive means <NUM> may comprise a valve element <NUM> having a third magnet <NUM> that faces the first magnet <NUM> and is slidingly accommodated in a second chamber <NUM> also located in the portion 6C of the support structure <NUM>. That is, the third magnet <NUM> of the valve element <NUM> faces the first magnet <NUM> of the actuator member <NUM> with opposed, mutually repelling polarities P<NUM>, P<NUM>.

Thus, the valve element <NUM> may be designed to move with a reciprocating oscillatory motion Δ<NUM> opposite to the reciprocating oscillatory motion Δ<NUM> of the actuator member <NUM> in response to the repulsion force between the first <NUM> and third <NUM> magnets.

Conveniently, the first chamber <NUM> may comprise first limit stop surfaces 17A, 17B for the actuator member <NUM>, the latter being designed to move with a reciprocating oscillatory motion Δ<NUM> between the aforementioned first limit stop surfaces 17A, 17B.

Preferably, such limit-stop surfaces 17A, 17B may comprise guide means, not shown, which are adapted to prevent the actuator member <NUM> from pivoting in response to the magnetic forces involved during its movement.

Similarly, the second chamber <NUM> may comprise second limit stop surfaces 20A, 20B for the valve element <NUM>, the latter being designed to move with a reciprocating oscillatory motion Δ<NUM> between the corresponding second limit stop surfaces 20A, 20B.

Conveniently, a primary channel <NUM> is provided in the portion 6A of the support structure <NUM> and has a first end 21A formed in the portion 6B and connected to the intake manifold 12A, and a second primary end 21B formed in the portion 6C of the support structure <NUM>.

Therefore, the actuator element <NUM> and the valve element <NUM> are free to slide transversely within their respective chambers <NUM>, <NUM> between their respective limit stop surfaces 17A, 17B; 20A, 20B with a reciprocating oscillatory motion due to the negative pressure D in the primary channel <NUM>.

As shown in <FIG> and <FIG>, a pair of secondary channels <NUM>, <NUM> are formed in the portion 6C of the structure <NUM> on each side of the primary channel <NUM>, each having a first end 22A, 23A in fluid communication with the first chamber <NUM>, and a second end 22B, 23B connected to the second chamber <NUM>.

In particular, at the second chamber <NUM>, the first ends 22A, 23A of the secondary channels <NUM>, <NUM> are formed near the second end 21B of the primary channel <NUM> and the second ends 22B; 23B are connected to the first sliding chamber <NUM> near the first limit stop surfaces 17A, 17B.

As clearly shown in <FIG>, the valve element <NUM> may comprise a slot-shaped cavity <NUM> which is designed to alternately connect the primary channel <NUM> with the secondary channels <NUM>, <NUM>, in particularly to alternately connect the second end 21B to one of the second ends 22B, 23B.

In one embodiment of the invention, a fourth magnet <NUM> may be provided, adjacent and parallel to the third magnet <NUM> and mounted on the opposite side of the second primary end 21B and the first secondary ends 22A, 23A.

The fourth magnet <NUM> may be mounted in such position that its polarity P<NUM> will be parallel to and concordant with the polarity P<NUM> of the third magnet <NUM> to promote a repulsion force and push the slot-shaped cavity <NUM> of the valve element <NUM> toward the first end 21B of the primary conduit and the first ends 22A, 23A of the secondary conduits and assist their sealing effect.

As best shown in <FIG>, the second chamber <NUM> must be connected via a vent channel <NUM> communicating with the outside for the inflow and outflow of the volume of air in the chamber <NUM>, moved by the valve element <NUM>.

The vent channel <NUM> may comprise a first end 26A in fluid communication to the second chamber <NUM>, as shown in <FIG> and <FIG>, and a second end 26B connected to the outside via a filter <NUM>, as shown in <FIG> and <FIG>.

In addition, by acting on the filter <NUM>, the section of the end 26B of the vent channel <NUM> may be changed, which allows the volume of air in the second chamber <NUM> and, as a result, the speed of movement of the valve element <NUM> and the reciprocating oscillatory motion β of the baffle <NUM> to be also changed.

An example of the reciprocating oscillatory movement of the actuator member <NUM> and of the valve element <NUM> generated by the negative pressure D will be now described, with reference to <FIG>.

The liquid F that flows through the second nozzle <NUM> generates a negative pressure D in the intake manifold 12A, which negative pressure is communicated through the main channel <NUM> to the second chamber <NUM> and the slot-shaped cavity <NUM> of the valve element <NUM> establishes fluid communication between the second primary end 21B and the first end 23A of the secondary channel <NUM>.

Thus, the negative pressure D is communicated to the corresponding second secondary end 23B and hence to the first chamber <NUM> to move the actuator member <NUM> toward the limit stop surface 17B under the negative pressure D, as shown in <FIG>.

The transverse movement of the actuator member <NUM> toward the limit stop surface 17B, and hence the first magnet <NUM>, causes the valve element <NUM> to move in the opposite direction due to the repulsion force between the first <NUM> and third <NUM> magnets, thereby pushing the valve element <NUM> toward the opposite limit stop surface 20A, as shown in <FIG>.

This transverse movement of the valve element <NUM> and hence of the slot-shaped cavity <NUM> establishes fluid communication between the second primary end 21B of the primary channel <NUM> and the first secondary end 22A of the secondary channel <NUM>.

Thus, the negative pressure D is communicated to the corresponding second end 22B and hence to the first chamber <NUM> to move the actuator member <NUM> toward the first limit stop surface 17A under the negative pressure D, as shown in <FIG>.

This will cause a reciprocating rectilinear oscillatory motion Δ of the actuator member <NUM> which will drive via the first magnet <NUM> the second magnet <NUM> and cause the plate <NUM> to pivot with a reciprocating oscillatory motion β.

It has been experimentally shown that the oscillation movements of the inventive sprinkler device <NUM> are triggered from a very low negative pressure D of the order of <NUM>.

A further aspect of the invention provides a method of delivering an irrigation liquid F for gravity-based pivot or linear irrigation systems <NUM> using a sprinkler device <NUM> as described above.

The method of the invention includes a first step of a) causing the liquid F to flow through the second nozzle <NUM> and the first nozzle <NUM> and a Venturi-induced negative pressure to be generated in the intake manifold 12A, and a second step of b) connecting the intake manifold 12A with the second chamber <NUM> via the primary conduit <NUM> to create a negative pressure therein.

The method further comprises a step of c) connecting the second chamber <NUM> with the first chamber <NUM> via the secondary conduits <NUM>, <NUM> once the valve element <NUM> has contacted one of the second limit stroke surfaces 20A, 20B and the slot -shaped cavity <NUM> connects the primary channel <NUM> with the first secondary end 22A, 23A of one of the secondary channels <NUM>, <NUM>.

This is followed by a step of d) moving the actuator member <NUM> toward one of the first limit stop surfaces 17A, 17B inside the first chamber <NUM> by the negative pressure D generated in the primary conduit <NUM>, and a step of e) moving the valve element <NUM> toward the opposite second limit stop surface 20B, 20A by the magnetic repulsion between the first <NUM> and third <NUM> magnets and f) connecting the slot-shaped cavity <NUM> between the primary channel <NUM> and the second secondary end 23B, 22B of the opposite secondary channel <NUM>, <NUM>.

Steps d), e) and f) are repeated until the irrigation liquid F creates a negative pressure D in the primary channel <NUM>, and the drive means <NUM> drive the baffle plate <NUM> into rotation with a reciprocating oscillatory motion β about the longitudinal axis L through the predetermined angle γ, to distribute the liquid F over a sector area S of the soil G.

<FIG> show a second embodiment of the sprinkler device of the invention, which basically differs from the first embodiment in that the first nozzle <NUM> and the second nozzle <NUM> are in such positions as to generate a jet of liquid directed upwards and indicated by the arrow F'.

The other main elements of the device are essentially unchanged, apart from certain formal aspects, and are thus designated by the same reference numbers.

In this embodiment, the first nozzle <NUM> and the passage 7A has a substantially frustoconical shape and the second nozzle <NUM> is not coaxial with the first nozzle <NUM> and has a substantially cylindrical shape but has a narrower portion, like in the first embodiment, between the two portions <NUM>' and <NUM>", for generating a Venturi-induced negative pressure.

The first nozzle <NUM> generates a uniform and high-flow jet which is directed toward the baffle plate <NUM> and is diverted and distributed by its radial portion 8B.

As shown in <FIG>, the first outlet <NUM>" of the first nozzle <NUM> has a smaller cross-sectional area than the first inlet <NUM>'.

Moreover, a peripheral edge 7B of the first passage 7A at the first outlet <NUM>" is non-circular and comprises an arched portion and a straight portion. The peripheral edge 7B of the first passage 7A at the first outlet <NUM>" is defined by a semicircle having ends connected by the straight portion.

As shown in <FIG>, the first nozzle <NUM> has a rib connected to the straight portion of the peripheral edge 7B of the first passage 7A.

Moreover, in this embodiment, the second nozzle <NUM>, which is not coaxial with but offset from the first nozzle <NUM>, is used to generate the negative pressure D, although it takes a minor part in directing a secondary jet toward the baffle plate <NUM>.

This negative pressure D is transferred to the intake manifold 12A which is in turn connected via the channels <NUM>, 21A, 21B to the chambers <NUM> and <NUM> where the actuator member <NUM> and the valve element <NUM> are accommodated.

The method of operation of this second embodiment does not differ from that of the first embodiment to a substantial extent and will not be repeated herein.

It will be apparent from the foregoing that the liquid sprinkler device and the delivery method of the invention fulfill the intended objects and specifically can irrigate the soil over an angularly restricted area with uniform liquid delivery and reduced application intensity.

The device and method of the invention are susceptible to a number of changes or variants, within the inventive concept disclosed in the annexed claims.

While the device and method have been described with particular reference to the accompanying figures, the numerals referred to in the disclosure and claims are only used for the sake of a better intelligibility of the invention and shall not be intended to limit the claimed scope in any manner.

Reference herein to "one embodiment" or "the embodiment" or "some embodiments" indicates that a particular characteristic, structure or element that is being described is included in at least one embodiment of the inventive subject matter.

Furthermore, the particular characteristics, structures or elements may be combined together in any suitable manner to provide one or more embodiments, as long as these embodiments fall under the scope of the appended claims.

Claim 1:
A sprinkler device (<NUM>) for delivering an irrigation liquid (F) in gravity-based pivot or linear irrigation systems (<NUM>) of the pivot or linear type, said sprinkler device (<NUM>) comprising a support structure (<NUM>) which has:
• a first nozzle (<NUM>) defining a longitudinal axis (L), for generating a jet of liquid (F), said first nozzle (<NUM>) having an inlet (<NUM>') and an outlet (<NUM>") connected by a passage (7A), and
• a second nozzle (<NUM>) offset from the first nozzle (<NUM>), said second nozzle (<NUM>) having an inlet (<NUM>') and an outlet (<NUM>") connected by a passage,
said support structure (<NUM>) having a baffle plate (<NUM>) pivoted thereto and facing said first (<NUM>) and second (<NUM>) nozzles,
characterized in that it comprises drive means (<NUM>) having at least one first magnet (<NUM>) moving with a reciprocating rectilinear motion (Δ) due to a negative pressure (D) generated by the liquid (F) that flows through a narrower portion between the inlet (<NUM>') and the outlet (<NUM>") of said second nozzle (<NUM>), said drive means (<NUM>) being able to move said plate (<NUM>) along, and impart a reciprocating pivotal thereto (β) about an axis (Xi) parallel to said longitudinal axis (L) through a predetermined angle (γ), to distribute the liquid (F) over a sector area (S) of the soil (G),
the passage (7A) of said first nozzle having at the outlet (<NUM>") of said first nozzle (<NUM>) a peripheral edge (7B) that is defined by a semicircle having ends connected by a straight portion, a central part of the straight portion separating the outlet (<NUM>") of the first nozzle (<NUM>) from the outlet (<NUM>") of said second nozzle (<NUM>).