GB2295535A

GB2295535A - Dishwasher with oscillating jets

Info

Publication number: GB2295535A
Application number: GB9524188A
Authority: GB
Inventors: Pont Paolo Da
Original assignee: Elbi International SpA
Current assignee: Elbi International SpA
Priority date: 1994-12-02
Filing date: 1995-11-27
Publication date: 1996-06-05
Also published as: ITTO940985A1; DE19544985A1; SE9504300L; SE9504300D0; IT1267638B1; GB9524188D0; ITTO940985A0; FR2727615A1

Description

A DISHWASHER

DESCRIPTION

2295535 The present invention relates to a dishwasher comprising a support housing defining a washing chamber which can hold crockery and in which water-spraying means are provided for directing water in jets towards the crockery, in operation.

In an existing dishwasher, a hydraulic pump driven by an electric motor pumps water towards (at least) one perforated hollow rotor supported for rotation in the washing chamber. The rotor has a plurality of nozzles constituted by suitably-shaped and oriented holes. In operation, the rotor rotates by reaction and its nozzles direct respective ray-like jets of water towards the crockery.

The number, shape, relative arrangement and orientations of the nozzles have to be determined precisely in order to spray water towards the surf aces of the crockery effectively in operation.

Although the arrangement and orientation of the nozzles or holes in the rotor or rotors are thought out carefully, the jets of water emitted nevertheless "cover" fairly, a limited spatial region.

An object of the present invention is to provide a dishwasher in which a more effective and spatially more extensive spraying of water towards the crockery takes place.

This object is achieved, according to the invention, by a dishwasher of the type specified above, characterized in that the water-spraying means comprise a plurality of 2 spray nozzles with oscillating jets which can direct respective jets of water oscillating cyclically along predetermined paths towards the crockery.

In one embodiment, a dishwasher according to the invention comprises at least one rotor mounted for rotating in the washing chamber and having a plurality of oscillating-jet spray nozzles.

In another embodiment, a dishwasher according to the invention has no rotors and the jets of water are sprayed towards the crockery by means of a plurality of oscillating-jet spray nozzles mounted on at least one wall of the washing chamber and/or at least one crockery basket.

The oscillating-jet spray nozzles are advantageously of the stationary type, that is, of the type without moving parts described, for example, in US patent 4,463,904.

Further characteristics and advantages of the invention will become clear from the following detailed description given purely by way of nonlimiting example with reference to the appended drawings, in which:

Figure 1 is a part i ally-sec tioned, perspective view of a dishwasher according to the invention, Figure 2 is a part i all y-sectioned, perspective view of another dishwasher according to the invention, Figure 3 is a front view taken on the arrow III of Figure 2 s, Figure 4 is a perspective view of an oscillating-jet spray 3 nozzle used in a machine according to the invention, and Figure 5 is a view sectioned on the line V-V of Figure 4.

With reference to Figure 1, a dishwasher 1 according to the invention comprises a substantially parallelepipedal support housing 2 defining a washing chamber 3 having a front opening 4 with which a drop-down closure door 5 is associated. Supported in the washing chamber 3 in known manner are, for example, two crockery baskets 6 which can be pulled out at least partially by sliding through the front opening 4.

The machine 1 has, in known manner, a pipe 7 for admitting a quantity of water drawn from the water mains to the chamber 3. A discharge pipe 8 enables the bath contained in the washing chamber 3 to be discharged after each prewashing, washing and rinsing operation. An electric pump 9 driven by an electric motor 10 is housed in the machine housing 2 in known manner.

At least one rotor 11, mounted for rotating in the washing chamber, is supplied, in known manner, with water drawn from the bottom of the chamber.

In the embodiment shown, the rotor 11 is supported rotatably by a vertical tubular rod 12.

In the embodiment of Figure 1, the rotor 11 bears a plurality of oscillating-jet spray nozzles, indicated 13, which can direct respective jets of water oscillating cyclically along predetermined paths towards the crockery. These spray nozzles are advantageously of the stationary type, that is, without moving parts, for example, of the type which is described in detail in US 4 patent 4, 463, 904 and which will be described partially below with reference to Figures 4 and 5.

In summary, in operation, the spray nozzles 13 emit respective jets of water in directions oscillating cyclically between two boundary directions which intersect at a predetermined angle at the outlet for the jet. In other words, the jet of water emerging from each of these spray nozzles is "spread out" within the angle defined between the boundary directions.

The use of spray nozzles of this type first of all enables a spatially more extensive region to be struck by the jets of water emerging from the rotor with more effective spraying of the crockery. Moreover, as a result of the oscillation of the directions of the water jets within the angles defined between the associated boundary directions, the directions in which the jets strike the crockery are not generally constant so that the jets can remove dirt from the crockery more efficiently.

The various spray nozzles can receive water by means of respective separate supplies and, in particular, may be supplied in a pulsed manner possibly with phase differences between one spray nozzle and another or between groups of spray nozzles.

The oscillation of the jet of water emerging from each spray nozzle also prevents blockage of the outlet for the jet and this may even permit the use of pumping means with relatively less power.

Although the dishwasher shown in Figure 1 has a single rotor, clearly the invention is not limited to such an embodiment but naturally extends comprising a plurality of such rotors.

to embodiments Moreover, although Figure 1 shows spray nozzles only on the upper portion of the rotor 11, these spray nozzles may be arranged differently on the rotor, particularly also on the lower surface or face, as well as on its sides.

Figures 2 and 3 show a variant of the dishwasher according to the invention. In this variant, the washing chamber does not have a rotor for spraying water towards the crockery. Instead of one or more rotors, the dishwasher 1 of Figures 2 and 3 comprises a plurality of oscillating-jet spray nozzles 13 of the type defined above, fixed in predetermined positions on the walls of the washing chamber 3. Alternatively, or in addition, oscillating-jet spray nozzles may also be mounted on one or both crockery baskets 6.

In addition to the advantages inherent in the use of oscillating-jet spray nozzles, the embodiment of Figures 2 and 3 has the further advantage which results from the absence of rotors. The presence of these rotors in fact reduces the useful space for crockery and forces the user to position the crockery with care in order to prevent it from interfering with the movement of the rotors in operation.

As shown in Figure 3, the oscillating-jet spray nozzles 13 may be disposed both on the side walls, and on the ceiling of the washing chamber 3. The orientations of the oscillating jets can be determined at the design stage in order to optimize the spraying of the water towards the crockery according to various circumstances 6 such as the number of crockery baskets and their relative arrangement.

Figure 4 shows by way of example, a spray nozzle 13 usable in a dishwasher according to the invention. This device comprises a body 14, for example, of plastics material, with a tubular connector 15 for receiving water under pressure. An end face 14a of the body 14 of the spray nozzle has an outlet opening 16.

The connector 15 communicates with a duct 17 in the body 14 which terminates in an opening indicated 18 in Figures 4 and 5. This opening faces a chamber 19 defined inside the body (Figure 5) and communicating, through a narrow portion 19a, with an oscillation chamber 20. The opening 16 for emitting the jet is formed at the opposite end of the oscillation chamber 20 to the chamber 19.

Two feed-back ducts 21 and 22 extend essentially parallel to the oscillation chamber 20 between lateral openings 23, 24 of the chamber 20 adjacent the narrow portion 19a and openings 25, 26 near the outlet opening 16.

The cross-section of the oscillation chamber 20 in the plane of the section shown in Figure 5 diverges progressively towards the outlet opening 16. This section is defined, in particular, between two shaped walls 27 and 28.

In operation, a flow of water under pressure is supplied to the spray nozzle 13 through the inlet connector 15 and then reaches the chamber 19 and, through the narrow portion 19a, the oscillation chamber 20. By means of a known mechanism (known, for example, from US patent 4,463,904) the flow of water in the chamber 20 t-owards the opening 16 takes place alternately adjacent the wall 7 27 and adjacent the wall 28. When the f low of water moves adjacent the wall 27, the jet of water emerging from the opening 16 is directed essentially in the direction indicated X in Figures 4 and 5. In this situation, a recirculation of water is created through the feed-back duct 21 from the opening 25 towards the opening 23. This recirculation flow has the effect of displacing the flow of water from the wall 27 to the wall 28 of the oscillation chamber 20 and, as soon as this takes place, the flow of water emerging from the opening 16 is directed essentially in the direction Y. In this condition, the water recirculates through the feed-back duct 22 from the opening 26 towards the opening 24, tending to return the f low of water to the vicinity of the wall 27. In operation, a jet of water oscillating cyclically between the boundary directions X and Y as shown qualitatively in Figure 4 emerges from the opening 16 of the spray nozzle 13.

The brief description given above of the structure and operation of an oscillating-jet spray nozzle is not intended to be exhaustive since the invention excludes the selection of the specific spray nozzles used. This description is therefore provided purely by way of example.

Naturally, the principle of the invention remaining the same, the forms of embodiment and details of construction may be varied widely with respect to those described and illustrated purely by way of non-limiting example, without thereby departing from the scope of the present invention.

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Claims

1. A dishwasher (1) comprising a support housing (2) defining a washing chamber (3) which can hold crockery and in which water-spraying means (11; 13) are provided for directing water towards the crockery in jets, in operation, characterized in that the water-spraying means comprise a plurality of spray nozzles (13) with oscillating jets which can direct respective jets of water oscillating cyclically along predetermined paths towards the crockery.

2. A dishwasher according to Claim 1, in which the waterspraying means comprise at least one rotor (11) which is supported for rotating in the washing chamber (3) and can emit a plurality of jets of water towards the crockery, characterized in that the at least one rotor (11) bears a plurality of spray nozzles (13) with oscillating jets.

3. A dishwasher according to Claim 1 or Claim 2, characterized in that at least some of the spray nozzles (13) with oscillating jets are mounted on at least one wall of the washing chamber (3).

4. A dishwasher according to any one of the preceding claims, in which at least one crockery basket (6) is supported in the washing chamber (3), characterized in that at least some of the spray nozzles (13) with oscillating jets are carried by the at least one crockery basket (6).

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5. A dishwasher according to any one of the preceding claims, characterized in that the spray nozzles (13) with oscillating jets are of the stationary type.

6. A dishwasher substantially as hereinbefore described with reference to and as shown in Figs. 1, 4, and 5, or Figs, 2, 3, 4, and 5-of the acccapanying drawings.