Improved water stop device

Abstract

 The water stop device comprises a solenoid valve having a body (10), an inlet pipe (12) and an outlet pipe (14), a flexible inner water flow tube (16) and a flexible outer safety tube (20) arranged around the inner tube (16), so as to define an annular air gap (22). Both the inner tube (16) and the outer tube (20) arc of corrugated type. The proximal end (18) of the inner tube (16) faces the distal end (26) of the outlet pipe (14) in such a way that the respective longitudinal axes (24) coincide, and the ends (18, 26) can be associated with one another by means of a tubular sleeve (28) arranged, sealed, coaxially on their exterior. Advantageously, the sleeve (28) is made of polymeric material and is produced by a co-moulding technique.

Description

[0001] The present invention relates to a water stop device for a domestic electrical appliance, such as a dishwasher or a washing machine.

[0002] In more detail, a water stop device comprises: a solenoid valve having a body, an inlet pipe and an outlet pipe, a flexible inner water flow tube having a proximal end associated with the outlet pipe and a flexible outer safety tube arranged around the inner tube so as to define, between the aforesaid inner and outer tubes, an annular air gap.

[0003] In case of necessity, the water stop device makes it possible, as a result of closure of the solenoid valve, to interrupt the water supply to the domestic electrical appliance. Moreover, in the event of breakage of the inner tube, the outer tube may in any case contain the outgoing flow of water and convey it inside the domestic electrical appliance, avoiding flooding of the surroundings.

[0004] According to the prior art, the inner water flow tube is a tube of crosslinked PVC or rubber with walls having a linear profile, while the outer tube is of a different type. The structure and the materials conventionally used for the inner tube mean that the cross-section of this latter tends to become blocked when the tube is bent. Moreover, providing two different types for the inner tube and the outer tube complicates the logistical operations of supply and disposal.

[0005] For the purpose of remedying such drawbacks, the subject of the present invention is a water stop device of the type indicated at the beginning of the present description and characterized in that both the inner tube and the outer tube are of corrugated type.

[0006] The use of a single type of tube simplifies the logistical supply and disposal operations. In addition, the corrugated tubes have flexibility properties generally better than those of the tubes of crosslinked PVC or rubber, and have the advantage that their cross-section is not liable to become blocked when they are bent. Moreover, they are more economical and more easily disposable than the tubes of crosslinked PVC or rubber.

[0007] A material typically used for making the corrugated tubes is polypropylene, the use of which provides a further advantage. Polypropylene is in fact one of the plastics materials regarded as being most suitable for avoiding the release of contaminating substances into the water with which the tubes of the water stop devices typically come into contact.
Other advantages and features of the present invention will become clear from the following detailed description, provided by way of non-limiting example with reference to the appended drawings, in which:

Figure 1 is a view in longitudinal section of a water stop device according to the invention,

Figure 2 is a perspective view of some components of the water stop device of Figure 1, and

Figure 3 is a perspective view in section along the line III-III of Figure 2.

[0008] A water stop device for a domestic electrical appliance comprises a solenoid valve having a body 10, an inlet pipe 12 and an outlet pipe 14. A flexible inner water flow tube 16 has a proximal end 18 facing a distal end 26 of the outlet pipe 14. A flexible outer safety tube 20 is arranged around the inner tube 16 so as to define, between the tubes 16, 20, an annular air gap 22, in which may be housed an electric cable (not shown in the drawings) for supplying power to the solenoid valve.

[0009] Both the inner tube 16 and the outer tube 20 are of corrugated type and are preferably made of polypropylene.

[0010] The longitudinal axes 24 of the inner tube 16 and of the outlet pipe 14 coincide and the proximal end 18 of the inner tube 16 and the distal end 26 of the outlet pipe 14 are associated with one another by means of a tubular sleeve 28 arranged, sealed, coaxially on their exterior.

[0011] The sleeve 28 is made of polymeric material and is preferably produced by means of a co-moulding technique which is known per se. According to this technique, the opposed ends 18, 26 of the inner tube 16 and of the outlet pipe 14 are placed in a mould cavity into which there is then injected the molten polymeric material which, once solidified, assumes the shape of the sleeve 28 and encloses the ends 18, 26 from the outside.

[0012] Protruding radially from the proximal end of the sleeve 28 is an annular flange 30, within a portion of which an axial hole 32 is provided for the passage of an electric cable for supplying power to the solenoid valve. In this way it is possible to avoid having to use a further component functioning as a cable fairlead gasket, further reducing the cost of the water stop device. On the radially outermost circumferential surface of the flange 30 the proximal end 34 of the corrugated outer tube 20 is further fitted.

[0013] A resilient band 36 clamps an intermediate circumferential portion of the sleeve 28 against the portion of outlet pipe 14 arranged radially inside it, so as to minimise the risk of the inner tube 16 and the sleeve 28 becoming forcibly separated from the outlet pipe 14 as a result of a pulling action.

[0014] Overall, owing to the use of the two tubes of corrugated type 16, 20, the water stop device of the invention proves economical and suitable for ensuring a constant flow cross-section even if the tubes 16, 20 were to be subjected to very severe bending.

[0015] Naturally, the principle of the invention remaining the same, the details of construction and forms of embodiment may be varied widely with respect to those described purely by way of example, without thereby departing from the scope claimed.

Claims

1. A water stop device for a domestic electrical appliance, comprising: a solenoid valve having a body (10), an inlet pipe (12) and an outlet pipe (14), a flexible inner water flow tube (16) having a proximal end (18) associated with said outlet pipe (14) and a flexible outer safety tube (20) arranged around the inner tube (16) so as to define, between said inner tube (16) and outer tube (20), an annular air gap (22),

said device being characterized in that both the inner tube (16) and the outer tube (20) are of corrugated type.

2. A device according to claim 1, characterized in that said corrugated inner tube (16) and outer tube (20) are made of polypropylene.

3. A device according to any one of the preceding claims, characterized in that the proximal end (18) of said inner tube (16) faces the distal end (26) of the outlet pipe (14) in such a way that the respective longitudinal axes (24) coincide, and said ends (18, 26) are associated with one another by means of a tubular sleeve (28) arranged, sealed, coaxially on their exterior.

4. A device according to claim 3, characterized in that said sleeve (28) is made of polymeric material and is produced by a co-moulding technique, by placing said opposed ends (18, 26) in a mould cavity and injecting therein the molten polymeric material which, once solidified, assumes the shape of the sleeve (28) and encloses said ends (18, 26) from the outside.

5. A device according to claim 3 or claim 4, characterized in that, protruding radially from the proximal end of said sleeve (28) is an annular flange (30), within a portion of which an axial hole (32) is provided for the passage of an electric cable for supplying power to the solenoid valve.

6. A device according to claim 5, characterized in that the proximal end (34) of said outer tube (20) is fitted onto the radially outermost circumferential surface of said flange (30) of the sleeve (28).

7. A device according to any one of the preceding claims 3 to 6, characterized in that a resilient band (36) clamps an intermediate circumferential portion of said sleeve (28) against the portion of outlet pipe (14) arranged radially inside it.

Drawing