ROTARY JET NOZZLE ASSEMBLY FOR PRESSURE CLEANING DEVICES

Abstract

Rotary jet nozzle assembly (1) for pressure cleaning devices, comprising: a housing (2) extended along a first longitudinal axis (X) between an inlet (3) and an outlet (4) of a washing liquid, defining therein a containment chamber (5) of the washing liquid in fluid communication with the inlet (3); a support (10) rotatable within said containment chamber (5) and about the first longitudinal axis (X) due to the effect of the washing liquid coming from the inlet (3); a nozzle body (20) extended along a second longitudinal axis (Y) inclined with respect to the first longitudinal axis (X) and traversed by a delivery duct (28), the nozzle body (20) being associated with the support (10) and driven in rotation thereby; and a counterweight, integral with the support (10) and arranged in a position that is eccentric and opposite the nozzle body (20) with respect to the first longitudinal axis (X).

Claims

1. A rotary jet nozzle assembly for pressure cleaning devices, comprising: a housing extended along a first longitudinal axis between an inlet and an outlet of a washing liquid, defining therein a containment chamber of the washing liquid in fluid communication with said inlet; a support fully rotatable about said first longitudinal axis within said containment chamber, due to the effect of the washing liquid coming from said inlet; a nozzle body extended along a second longitudinal axis inclined with respect to the first longitudinal axis and traversed by a delivery duct, said delivery duct opening upstream on the containment chamber and opening downstream in a delivery opening arranged, in use, at said outlet of the housing, said nozzle body being associated with said support and driven in rotation thereby; a counterweight, integral with said support and arranged in a position that is eccentric and opposite the nozzle body with respect to the first longitudinal axis, to balance said nozzle body during the rotation of the support about the first longitudinal axis; wherein said counterweight is made of a first material and said support is made of a second material, said first material being different from said second material.

2. The nozzle assembly according to claim 1, wherein said first material has a higher specific weight than said second material.

3. The nozzle assembly according to claim 2, wherein said first material is a metallic material, the second material being a polymeric material or a polymer matrix material.

4. The nozzle assembly according to claim 3, wherein said support is made by molding and said counterweight is made by machining.

5. The nozzle assembly according to claim 1, wherein said support comprises a coupling seat adapted to receive said counterweight, said counterweight comprising at least one coupling portion shaped so as to be wedged in the coupling seat of said support.

6. The nozzle assembly according to claim 5, wherein said counterweight further comprises at least one balancing portion integral with said coupling portion, said balancing portion having a different cross section, the balancing portion being shaped so as to dynamically balance the mass of said nozzle body.

7. The nozzle assembly according to claim 4, wherein said nozzle body comprises a downstream end at which said delivery opening opens and an upstream end associated with said support; said support comprising a nozzle body seat arranged in a position eccentric and opposite said coupling seat with respect to the first longitudinal axis of said housing; the upstream end of said nozzle body being introduced within said seat for nozzle body.

8. The nozzle assembly according to claim 1, wherein said nozzle body comprises a downstream end at which said delivery opening opens and an upstream end associated with said support; said nozzle assembly further comprising at least one elastic element acting on said support adapted to keep, in use, said downstream end of said nozzle body in abutment against a sliding seat arranged at said outlet.

9. The nozzle assembly according to claim 1, wherein said support comprises a turbine hit and driven in rotation by at least a part of the washing liquid coming from the inlet of said housing.

10. The nozzle assembly according to claim 9, wherein said housing comprises therein at least one main passage and at least one by-pass passage which connect said inlet to the containment chamber, wherein said at least one main passage and said at least one by-pass passage open to distinct areas of the containment chamber, the sole washing liquid passing through said main passage hitting the turbine and driving it in rotation.

11. The nozzle assembly according to claim 10, wherein said support is rotatably mounted on a pin integral to the housing which extends along said first longitudinal axis, said turbine comprising a blading which surrounds said pin; said at least one main passage opening to a first area interposed between said pin and said blading, said at least one by-pass passage opening to a second area arranged between said blading and a side wall of said housing.

12. The nozzle assembly according to claim 11, wherein said at least one main passage traverses said pin.

13. The nozzle assembly according to claim 12, wherein said pin extends from a support base integral with said housing; an interspace being formed inside said containment chamber between said support base and said side wall said at least one by-pass passage opening to said interspace.

14. The nozzle assembly according to claim 3, wherein the metallic material is brass.

15. The nozzle assembly according to claim 6, wherein the different cross section of said balancing portion is less than the cross section of said coupling portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0062] FIG. 1 shows a longitudinal section view of a first embodiment of a rotary jet nozzle assembly according to the present invention;

[0063] FIG. 2 shows a perspective view of a rotor of the nozzle assembly of FIG. 1;

[0064] FIG. 3 shows a longitudinal section view of the rotor of FIG. 2;

[0065] FIG. 4 shows a perspective view of a support/counterweight unit of the nozzle assembly of FIG. 1;

[0066] FIG. 5 shows a further perspective view of a support/counterweight unit of the nozzle assembly of FIG. 1;

[0067] FIG. 6 shows a longitudinal section view of the unit of FIG. 5;

[0068] FIG. 7 shows a perspective view of a rotor in a second embodiment of the invention;

[0069] FIG. 8 shows a longitudinal section view of the rotor of FIG. 7;

[0070] FIG. 9 shows a perspective view of a rotor in a third embodiment of the invention;

[0071] FIG. 10 shows a longitudinal section view of the rotor of FIG. 9.

DETAILED DESCRIPTION

[0072] Referring to the enclosed FIGS. 1-6, reference number 1 generically identify a first embodiment of the nozzle assembly according to the present invention.

[0073] The nozzle assembly 1 is arranged to generate a rotary liquid jet, preferably but not exclusively in pressure washing applications. The assembly can thus be applied in pressure washing machines, in particular high-pressure washing machines, namely with working pressures comprised between 25 and 1000 bar, such as for instance the pressure washers.

[0074] Hereinafter we will refer, without any limiting purpose, to the latter application wherein the nozzle assembly 1 is mounted at the end of a lance that can be gripped by the user in order to deliver a conical jet of washing liquid, usually water, in the direction of a surface to be washed.

[0075] The nozzle assembly 1 comprises a housing 2 which extends along a first longitudinal axis X and defines a containment chamber 5 therein.

[0076] The housing 2 is in particular defined by two pieces assembled to each other: a housing body 2b and an inlet fitting 2c.

[0077] The housing body 2b has a side wall 2a which delimits the containment chamber 5. Said housing body 2b has a substantially tubular shape which tapers towards a downstream end, where the outlet 4, from which the washing liquid is delivered, is defined.

[0078] The tubular housing body 2b has, opposite the outlet 4, an opening within which the inlet fitting 2c is screwed, which is thus arranged to close the upstream housing 2.

[0079] A sealing gasket is provided between housing body 2b and inlet fitting 2c to ensure the water impermeability of the housing 2.

[0080] The fitting 2c has an internal cavity 2d which, besides defining the inlet 3 for the washing liquid, is arranged in fluid communication with the containment chamber 5, as it will be hereinafter discussed in detail.

[0081] The fitting 2c is arranged at said inlet 3 for coupling with a washing tool, for instance a pressure washer lance which can be gripped by an operator.

[0082] The housing 2 is in turn inserted within a protective casing 11 and kept inserted therein by interposing a ring nut 11a at the inlet 3. Both the protective casing 11 and the ring nut 11a have a protective function of the content.

[0083] The fitting 2c has a support base 15 which is arranged laterally in contact with the side wall 2a of the housing body 2b and which delimits upstream the containment chamber 5.

[0084] The support base 15 defines, inside the containment chamber 5, a shoulder from which a pin 18 extends, coaxially to the first longitudinal axis X.

[0085] The support base 15 has, peripherally to the above shoulder, a chamfer defining an interspace 14 between the support base 15 itself and the side wall 2a of the housing body 2b.

[0086] The nozzle assembly 1 moreover comprises, inside the containment chamber 5, a rotor comprising a support 10, a counterweight 30 and a nozzle body 20.

[0087] The support 10 is rotatably mounted above the pin 18, and is therefore arranged to rotate about the first longitudinal axis X. The nozzle body 20 and the counterweight 30 are integrally supported by said support 10 and driven in rotation together with it.

[0088] The nozzle body 20 extends along a second longitudinal axis Y between an upstream end 24 thereof, constrained to the support 10 by simply lying thereon, and a downstream end 23 thereof which abuts against a sliding seat 7 arranged at the outlet 4 of the housing 2.

[0089] Both the sliding seat 7 and a corresponding nozzle tip 20b are made of low friction coefficient material, for instance ceramic or tungsten carbide.

[0090] The entire support 10 is pushed in the direction of the outlet 4 of the housing 2 by an elastic element 6, in this case a disc spring, arranged between the shoulder of the support base 15 and a bottom surface of the support 10. The action of the disc spring keeps the nozzle tip 20b in constant contact against the sliding seat 7 thereof, thus avoiding shocks that could result in the breakage of these relatively fragile elements.

[0091] The support 10 comprises in turn a turbine 19, equipped with a blading 19b which coaxially surrounds the pin 18. As it will be clearer hereinafter, the turbine 19 is arranged to be hit by a flow of washing liquid which drives in rotation the entire rotor.

[0092] The above nozzle body 20, extended along a second longitudinal axis Y inclined with respect to the first longitudinal axis X of the housing 2, is therefore driven in rotation keeping in contact with the sliding seat 7 by tracing a revolution cone which is coaxial to the first longitudinal axis X.

[0093] The nozzle body 20 is traversed by a delivery duct 28 which extends axially between an access opening 26 at the upstream end 24 and a delivery opening 22 at the downstream end 23, placed in fluid communication with the outlet 4 of the housing 2.

[0094] The washing liquid entering from the inlet 3 after having passed through the inlet cavity 2d, is divided into two alternative passages, a main passage 12 and a by-pass passage 13, both of which open to the containment chamber 5.

[0095] The main passage 12 radially traverses the pin 18 and opens to the containment chamber 5 close to the pin 18 itself surrounded by the blading 19b of the turbine 19. The portion of liquid which passes through said passage is thus directed towards the blading 19b, driving it in rotation in its movement towards the side wall 2a.

[0096] From here, the liquid continues into the containment chamber 5, then it enters the nozzle body 20 from which it exits at the outlet 4.

[0097] Instead, the by-pass passage 13 branches off from a portion of the inlet cavity 2d upstream with respect to the pin 18, and opens at the above chamfer, namely to a peripheral annular interspace 14 upstream of the turbine 19.

[0098] The washing liquid which passes through the by-pass passage 13 continues directly towards the nozzle body 20 and from here to the outlet 4, without passing through the blading 19b of the turbine 19.

[0099] As a skilled person may well understand, in this way, by suitably sizing the main passage 12 and the by-pass passage 13 (preferably in a flow ratio of 3 to 1), it is possible to limit the steady rotation speed of the nozzle body 20 even at high flow rates and pressures, thus reducing the nebulization phenomenon which affects the impact force of the jet in the embodiments according to the prior art.

[0100] Indeed, the liquid passing through the by-pass passage 13, though defining the overall output flow rate, does not contribute to the rotation speed of the turbine 19. The meeting of this liquid with that coming from the main passage 12 produces a turbulence at the blading 19b, which tends to slow down the turbine 19.

[0101] As it can be better seen from FIGS. 4 and 5, the support 10 has, downstream of the turbine 19, a nozzle body seat 25, which is U-shaped for receiving the upstream end 24 of a nozzle body 20, in an eccentric position with respect to the first longitudinal axis X.

[0102] The support 10 also has a coupling seat 21 arranged to receive a counterweight 30. Said coupling seat 21 is arranged in a position opposite the nozzle body seat 25 with respect to the first longitudinal axis X.

[0103] The above introduced counterweight 30 has the purpose of dynamically balancing the eccentric mass of the nozzle body 20 during its rotation, namely it is sized to reduce the resulting moment of the rotor with respect to the first longitudinal axis X as much as possible—ideally to zero.

[0104] In the first embodiment, the counterweight 30 is inserted with interference fit within the coupling seat 21.

[0105] Moreover, the support 10 is made of polymeric or polymer matrix material so as to minimize wear during the rotation about the metal pin 18. The choice of the material is also such as to make the support 10 by molding from a specifically shaped mold.

[0106] In this way, once the mold has been defined and produced, it is possible to easily reproduce by molding the support 10 to be used in each nozzle assembly 1.

[0107] In the first embodiment, the support 10 is made of a technical plastic suitable for the application.

[0108] The counterweight 30 is instead made of a material different from the support 10 and having a higher specific weight. Said material is preferably a metallic material and in the embodiment herein described brass is used.

[0109] The use of a metallic material, such as brass, allows obtaining the counterweight 30 by machining, for instance by turning, starting from a unique piece, for instance a bar. In this way, by varying the processing performed to make the piece, it is possible to obtain a counterweight having a desired shape and mass.

[0110] Generally, the nozzle assemblies as the one described must work at different flow rates using nozzles of different sizes and masses. The use of a metallic material, easily processable and customizable, thus allows realizing different counterweights to be used under the various use conditions to adequately balance the mass of the nozzle body during the rotation.

[0111] In the first embodiment, the counterweight 30 is made of two contiguous portions: a coupling portion 31 shaped so as to be inserted with interference fit within the coupling seat 21 of the support 10 and a balancing portion 32 specifically shaped so as to have mass, shape and sizes such as to counter-balance the nozzle body 20 during the rotation.

[0112] In particular, in the first embodiment the counterweight 30 has a coupling portion 31 having a cross section corresponding to the cross section of the coupling seat 21 thus realizing a fixed constraint. The balancing portion 32 has instead a cross section less than the coupling portion 31 made by machining.

[0113] As it may be noticed from FIGS. 2 and 4, the balancing portion has a particular semi-cylindrical shape, whose longitudinal axis is parallel to the first longitudinal axis X of the housing 2 when the counterweight 30 is inserted in the coupling seat 21.

[0114] The counterweight 30 thus formed may be replaced by another counterweight having a same coupling portion, or at least that may be wedged in the coupling seat 21, and a different balancing portion.

[0115] In a second embodiment, a nozzle assembly otherwise identical to the one described above adopts a different rotor, illustrated in FIGS. 7-8.

[0116] In this embodiment, the counterweight 30′ has a coupling portion 31′ insertable into the coupling seat 21 and a balancing portion 32′ having a different shape, in particular with a crown-arch cross section.

[0117] In a third embodiment, a nozzle assembly otherwise identical to the one described above adopts a different rotor, illustrated in FIGS. 9-10.

[0118] In this case the counterweight 30″ has a spherical shape embedded within the coupling seat 21 of the support 10.

[0119] Obviously, a skilled person can make several changes and variants to the above described invention, in order to meet contingent and specific needs, all of them by the way contained in the scope of protection of the invention as defined by the following claims.