Patent Description:
Agricultural and/or industrial irrigation systems are known in the art, which systems comprise a liquid supply line connected to a plurality of sprinkler devices for distributing a jet of such liquid to a soil portion to be irrigated or cooled.

One requirement of these known systems is to distribute a substantially constant amount of liquid to a given soil portion, to irrigate or cool it in an approximately uniform manner.

The sprinkler devices may be either stationary, to always distribute the liquid over the same soil portion, or movable relative to the supply conduit for substantially constant speed sweeping of a given cultivated surface.

Almost all the sprinklers for use in irrigation systems afford jet nozzle selection to adapt liquid distribution to the needs of the particular soil or crop.

Nevertheless, uniform liquid distribution requires a substantially constant jet pressure, regardless of the nozzle that is mounted to the sprinkler.

For this purpose, a pressure regulator connected to the supply line is typically installed upstream of the nozzle, with liquid having a relatively constant pressure value, set by the user or the supply line, at its outlet.

A typical regulator has a housing having a stationary valve seat therein and a movable tubular valve member which has an inlet edge adapted to interact with the valve seat to define a pressure regulating port.

The valve member is equipped with an annular diaphragm defining a liquid regulating chamber with the housing to move the valve member and vary the regulating port based on the liquid pressure, to maintain this pressure substantially constant.

<CIT> discloses a pressure regulating device as described hereinbefore. The axis of the valve seat and the axis of the inlet and outlet ports are inclined to each other to reduce the risk that grass or other materials may block the movement of the valve stem, thereby causing sudden pressure drops. In addition, the valve seat is joined to the housing by a single strut to reduce liquid flow resistance.

<CIT> by the Applicant hereof discloses a pressure regulating device, also as described hereinbefore, in which the liquid flow at the outlet has a substantially constant pressure under all operating conditions.

In this regulator the axis of the valve seat is offset but parallel to that of the valve member and to that of the end fittings of the housing.

In addition, the valve seat is joined to the housing by a pair of struts, whereby the seat is stronger and more resistant to pressure changes acting on the regulator. This configuration improves the liquid flow conditions along the walls of the housing and reduces the risk that impurities may be retained in the liquid. Nevertheless, transverse offsets of all components of the structure create obstacles to the liquid flow.

A problem of all these known regulators is the presence of obstacles along the liquid path, essentially consisting of the valve body which projects in cantilever fashion into the liquid collection chamber downstream of the inlet fitting. This causes drags and losses, thereby decreasing the effectiveness of the regulator and of the hydraulic circuit as a whole.

In view of the prior art, the technical problem addressed by the invention is deemed to consist in reducing drags inside the regulator.

The object of the present invention is to solve the aforementioned technical problem and obviate the above discussed drawback, by providing a pressure regulator that is highly efficient and relatively cost-effective.

A particular object of the present invention is to provide a pressure regulator that can reduce friction inside the regulator.

A particular object of the present invention is to provide a pressure regulator that facilitates passage through its internal cavity upstream and downstream from the valve member.

These and other objects, as more clearly shown hereinafter, are fulfilled by a liquid pressure regulator as defined in claim <NUM>, which comprises a housing defining a longitudinal axis and having an inlet portion and an outlet portion, a substantially tubular valve member slidingly accommodated inside said housing and having a longitudinal axial passage and an upstream end with a liquid inlet edge, a valve body fixed inside the inlet portion with a seat configured to interact with the inlet edge of the valve member and to form a port of variable width therewith, wherein the inlet portion of the housing comprises an inlet fitting for connection to a liquid supply line and a collection chamber directly downstream from the inlet fitting, the valve body comprising a cantilever element extending transverse from the inner wall of the collection chamber, first and second deflection means being successively arranged between the inlet fitting and the inlet edge to facilitate flow conveyance toward the port and the longitudinal passage of the valve member.

In one embodiment, the first deflection means comprise a pair of struts for bracing the connection of said cantilever element to the inner wall of said chamber.

In one embodiment, the second deflection means comprise a plurality of deflecting slides arranged on the periphery of said cantilever element and oriented toward the center of said chamber to convey the liquid toward said port and impart a rotating vortex motion to the flow.

With these deflection means, the flow of liquid directed toward the port and toward the axial passage of the valve member is improved by reducing the drag and the flow through the regulator.

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

Further features and advantages of the invention will be more apparent from the detailed description of a preferred, non-exclusive embodiment of a liquid pressure regulator of the invention, which is described as a non-limiting example with the help of the annexed drawings, in which:.

Particularly referring to the above figures, a liquid pressure regulator of the invention is described, which is generally referenced <NUM>.

As a non-limiting example, the regulator <NUM> may be installed in irrigation systems for uniform distribution of a liquid, e.g. water, over a predetermined area to be irrigated or cooled, not shown.

As used hereinafter, the term "upstream" refers to a backward position with respect to the direction of the liquid flow through the regulator and the term "downstream" refers to a forward position with respect to the direction of the flow through the regulator.

The regulator device <NUM> may be installed upstream from one or more sprinklers with nozzles, not shown, for the jet of liquid to be delivered at a substantially constant pressure, substantially irrespective of the size of the delivery nozzles that are mounted to the sprinklers.

As shown in <FIG>, the pressure regulator <NUM> of the invention generally comprises a housing <NUM> defining a longitudinal axis L and having an inlet portion <NUM> and an outlet portion <NUM> for the liquid, with respective inlet fitting <NUM> and outlet fittings <NUM> internally threaded for connection to a liquid supply line and to a sprinkler, both not shown, with the flow direction being designated by arrows IN and OUT, respectively.

In the embodiment as shown in the figures, the housing <NUM> is hollow and defines an interior compartment <NUM> which extends between the inlet fitting <NUM> and the outlet fitting <NUM>.

The end portions <NUM>, <NUM> may have a slightly flared shape with respective connecting flanges <NUM>, <NUM> having holes <NUM> for removable connection, for example by means of screws <NUM>.

As clearly shown in <FIG>, a stationary valve body <NUM> is provided inside the compartment <NUM> of the housing <NUM> and has a curved surface <NUM> inclined toward the outlet and an opposite substantially flat surface perpendicular to the longitudinal axis L defining a valve seat <NUM>.

The compartment <NUM> houses a tubular valve member <NUM> with a central passage <NUM>, which is able to slide in two directions along the axis L.

The valve member <NUM> has an upstream end <NUM> with an inlet edge <NUM> for the liquid and a downstream end <NUM> with an outlet edge <NUM> from which the liquid exits after passing through the central passage <NUM>.

The seat <NUM> of the valve body <NUM> is configured to interact with the inlet edge <NUM> of the valve member <NUM> and define a port <NUM> therewith for the passage of the liquid in response to the flow demand by the nozzle or distributor downstream from the regulator.

Toward its downstream end <NUM>, the valve member <NUM> has a flange <NUM> with an annular groove <NUM> facing the inlet fitting <NUM>.

In addition, a sleeve <NUM> is inserted between the valve member <NUM> and the inner surface of the housing <NUM> and has a collar <NUM> near its upper end with a calibrated central hole having the function to axially guide the valve member <NUM>.

In order to ensure a perfectly axial movement of the valve member <NUM>, longitudinal ribs <NUM> of calibrated thickness are formed on the outer surface of its downstream end <NUM>.

An annular groove <NUM> is formed on the face of the collar <NUM> that faces the outlet fitting <NUM> and two annular grooves are formed on the opposite face to accommodate respective O-rings R<NUM> and R<NUM> forming a seal with respect to the inlet portion <NUM> of the housing <NUM>.

A helical spring <NUM> is provided in a peripheral position with respect to the valve member <NUM>, with ends accommodated in the groove <NUM> of the flange <NUM> and in the groove <NUM> of the collar <NUM> respectively, to bias the valve member <NUM> toward the outlet fitting <NUM> with a calibrated force F<NUM> directed toward the outlet fitting <NUM>, as determined by the elastic constant of the spring <NUM>.

As best shown in <FIG>, the inlet portion <NUM> comprises a collection chamber <NUM> located directly downstream from the inlet fitting <NUM>, and the valve body <NUM> comprises a cantilever element <NUM> which transversely extends from the inner wall <NUM>' of the collection chamber <NUM>.

As best shown in <FIG>, chamber <NUM> defines a diametral geometric plane Ω passing through the longitudinal axis L.

According to the invention, first deflection means <NUM> and second deflection means <NUM> are successively arranged between the inlet fitting <NUM> and the inlet edge <NUM> of the valve member <NUM> to facilitate flow conveyance toward the port <NUM> and toward the longitudinal passage <NUM> of the valve member <NUM>.

As best shown in <FIG>, the first deflection means <NUM> comprise a pair of struts <NUM> for bracing the connection of the cantilever element <NUM> to the inner wall <NUM>' of the collection chamber <NUM>.

Preferably, the struts <NUM> have a substantially constant thickness s and an upper edge <NUM>' inclined toward the downstream region to facilitate the flow toward the chamber <NUM>.

Advantageously, the cantilever element <NUM> has an upstream surface <NUM>' impinged upon by the flow and inclined with respect to the longitudinal axis L, and the struts <NUM> substantially have the shape of fins decreasing in height from the inner wall <NUM>' of the chamber <NUM> toward the upstream surface <NUM>' of the cantilever element <NUM>, so that the flow is not hindered and is channeled toward the port <NUM>, as best shown in <FIG>.

As best shown in <FIG>, the fin-shaped struts <NUM> extend along planes π, Ψ substantially parallel to the longitudinal axis L and symmetrically spaced with respect to the diametral geometric plane Ω to thereby form a sliding channel <NUM> therebetween for conveying the flow toward the space of the chamber <NUM> that is not occupied by the valve body <NUM>, without hindering it.

Preferably, the planes π, Ψ of the fin-shaped struts <NUM> form a lateral deflection angle α with the diametral geometric plane Ω to facilitate flow conveyance on opposite sides from the diametral geometric plane Ω.

The lateral deflection angle α ranges from <NUM>° to <NUM>° and is preferably about <NUM>°.

As best shown in <FIG>, <FIG>, the second deflection means <NUM> comprise a plurality of deflecting slides <NUM> arranged on the periphery of the cantilever element <NUM> and oriented toward the center of the chamber <NUM> to convey the liquid toward the port <NUM> and impart a rotating vortex motion to the flow.

The deflecting slides <NUM> are rigidly joined to an annular insert <NUM> that is designed to be positioned on the bottom of the chamber <NUM>, as best shown in <FIG>. Specifically, the annular insert <NUM> abuts the upstream edge of the sleeve <NUM> and the deflecting slides <NUM> are formed on the inner wall <NUM>' of the annular insert <NUM>.

According to a particular aspect of the invention, the deflecting slides <NUM> are angularly equidistant and their circumferential width increases from upstream to downstream to favor the emptying of the chamber <NUM>.

Thus, the drag in the liquid flow on the parts of the regulator <NUM> is reduced, and the flow is accelerated toward the center of the chamber <NUM>.

It will be appreciated that the first deflection means <NUM> and the second deflection means <NUM> facilitate, individually and in combination with each other, flow conveyance toward the port <NUM> and the longitudinal passage <NUM> of the valve member <NUM>.

The above-described configuration eliminates the drawbacks of prior art regulators in that it ensures a uniform flow of the incoming liquid toward the port <NUM>, thereby advantageously improving the hydraulic efficiency of the device and increasing the duration of the regulator <NUM> over time.

Therefore, the pressure regulator <NUM> of the invention, unlike prior art pressure regulators, does not have obstacles along the path of the liquid and does not cause drags and/or losses, thereby increasing the effectiveness of the regulator and the hydraulic circuit as a whole.

<FIG> shows a chart of the inlet pressure Pinlet and the outlet regulated pressure Poutreg of a regulator <NUM> having the first <NUM> and second deflection means <NUM> of the present invention and of a regulator without the first and second deflection means. Both pressures Pinlet and Poutreg are detected by suitable sensors, for example KELLER AG LEO digital pressure gages.

Due to the improved hydraulic flow inside the chamber <NUM>, the outlet regulated pressure Poutreg of the regulator <NUM> having the first <NUM> and second deflection means <NUM> is able to reach the nominal pressure in shorter times, which remains almost unchanged as the inlet pressure Pinlet increases.

This figure shows that the regulator <NUM> having the first <NUM> and the second deflection means <NUM> reaches the nominal pressure at a lower inlet pressure value "A" as compared with a regulator of the prior art without such means, which reaches its nominal pressure at inlet pressure "B" that is higher than the inlet pressure "A". The difference between the pressures A and B represents the hydraulic efficiency differential of the regulator with the deflection means <NUM>, <NUM> with respect to the one without such means.

The liquid pressure regulator of the invention is susceptible to a number of changes and variants, within the inventive concept disclosed in the appended claims. All the details thereof may be replaced by other technically equivalent parts, and the materials may vary depending on different needs, without departure from the scope of the invention.

While the liquid pressure regulator has 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.

Claim 1:
A coaxial liquid pressure regulator (<NUM>), comprising:
- a housing (<NUM>) defining a longitudinal axis (L) and having an inlet portion (<NUM>) and an outlet portion (<NUM>);
- a substantially tubular valve member (<NUM>) slidingly accommodated inside said housing (<NUM>) and having a longitudinal axial passage (<NUM>) and an upstream end (<NUM>) with an inlet edge (<NUM>) for the liquid;
- a valve body (<NUM>) fixed inside said inlet portion (<NUM>) defining a seat (<NUM>) configured to interact with said inlet edge (<NUM>) of said valve member (<NUM>) and form therewith a port (<NUM>) having a variable width (W);
wherein said inlet portion (<NUM>) comprises an inlet fitting (<NUM>) for connection to a liquid supply line, and a collection chamber (<NUM>) directly downstream of said inlet fitting (<NUM>), said collection chamber (<NUM>) defines a diametral geometric plane (Ω) which passes through said longitudinal axis (L);
wherein said valve body (<NUM>) comprises a cantilever element (<NUM>) transversely extending from the inner wall (<NUM>') of said collection chamber (<NUM>);
wherein first deflection means (<NUM>) and second deflection means (<NUM>) are successively arranged between said inlet fitting (<NUM>) and said inlet edge (<NUM>) to facilitate flow conveyance toward said port (<NUM>) and said longitudinal passage (<NUM>);
wherein said first deflection means (<NUM>) comprise a pair of struts (<NUM>) for bracing the connection of said cantilever element (<NUM>) to the inner wall (<NUM>') of said chamber (<NUM>);
wherein said struts (<NUM>) extend along planes (π, Ψ) substantially parallel to said longitudinal axis (L) and symmetrically spaced apart from said diametral geometric plane (Ω),
characterized in that said extension planes (π, Ψ) form a lateral deflection angle (α) with said geometric plane (Ω) to facilitate flow conveyance on opposite sides from said diametral geometric plane (Ω), an annular insert (<NUM>) being designed to be positioned on the bottom of said chamber (<NUM>) and has an inner lateral wall (<NUM>'), said second deflection means (<NUM>) comprising a plurality of deflecting slides (<NUM>) formed on the inner wall (<NUM>') of the annular insert (<NUM>) and is arranged on the periphery of said cantilever element (<NUM>), said plurality of deflecting slides (<NUM>) being oriented toward the center of said chamber (<NUM>) to convey the liquid toward said port (<NUM>) and impart a rotating vortex motion to the flow.