WATER SUPPLY DEVICE

Abstract

 Water supply device for an electric appliance connected to water mains, comprising a body (1) that defines an inner cavity (19) and, within the inner cavity (19), a flow conduit (26) for water from an inlet (21) to an outlet (20, 22, 24), wherein an overflow window (13) communicating with the inner cavity (19) is formed through an outer wall (11) of the body (1), the overflow window (13) having a lower edge (131) defining a spillover level (H) above which water accumulated in the inner cavity (19) spills out of the body (1). At the lower edge (131) of the overflow window (13) there is arranged a rib (14) extending from the lower edge (131) of the overflow window (13) outwardly of the body (1), wherein the rib (14) has a ramp upper surface (14') having a variable cross-sectional profile along the direction of the lower edge (131) of the overflow window (13).

Description

[0001] The present invention refers to a water supply device - commonly referred to in technical jargon as an "air break" - for electric appliances connected to water mains, such as dishwashers and washing machines.

[0002] More specifically, such a device comprises a body that defines an inner cavity and, within the inner cavity, a flow conduit for water from an inlet to an outlet. The inlet is generally configured to be connected to a water mains supply hose-set. The supplied water is then divided within the supply device into various flows that may be directed, for example, to a softener device for the softening and formation of a regeneration brine, respectively, or directly to the washing tank.

[0003] In general the supply device has an overflow window formed through an outer wall of the body and communicating with the inner cavity. Such overflow window has a lower edge defining a spillover level above which water accumulated in the inner cavity spills out of the body of the supply device.

[0004] The standard EN 61770:2009/A12:2022 "Electric appliances connected to the water mains - Avoidance of backsiphonage and failure of hose-sets" specifies the requirements for domestic and professional appliances that prevent the backflow of non-potable water into the water mains. Such standard furthermore specifies the requirements for those hose-sets used for connecting such appliances to those water mains that supply water at a pressure no greater than 10 bar.

[0005] EN 61770 and the WRAS (Water Regulations Advisory Scheme) also provide that, in order to simulate the case of a failure of the hydraulic system of the electrical appliance, all of the outlets must be closed except the overflow window.

[0006] Therefore, in supplying the hydraulic system with a charge valve, the water should flow out of the overflow window, and two seconds after closing the aforesaid charge valve, the level of residual water within the body of the supply device must be equal to the overflow level (ideally).

[0007] In the case wherein the level within the body of the supply device is greater than the overflow level, as a result also of the surface tension of the water, the window must be increased by a dimension according to a formula dictated by the certifying body. Nevertheless, in some cases it may be impossible, or undesirable, to increase the dimensions of the windows, in particular for space reasons.

[0008] One object of the present invention is that of resolving the drawbacks highlighted above from the prior art.

[0009] According to the invention, such object is achieved by virtue of the fact that at the lower edge of the overflow window there is arranged a rib extending from the lower edge of the overflow window outwardly of the body, wherein the rib has a ramp upper surface having a cross-sectional profile variable along the direction of the lower edge of the overflow window.

[0010] By virtue of such an arrangement it is possible to ensure that water is able to drain away within the period of time stipulated by the standards, also in the case wherein surface tension is created, and without requiring an increase in the dimensions of the overflow window.

[0011] A further subject matter of the invention is an electric appliance for connecting to a water mains comprising a supply device of the type indicated above.

[0012] Further features and advantages of the present invention will become clear from the detailed description that follows, given purely by way of non-limiting example and with reference to the accompanying drawings, in which:

Fig. 1 is a side elevation view of a device of the invention;

Fig. 2 is a perspective view in detail of an overflow window which is not claimed;

Fig. 3 is a sectional view of the overflow window of Fig. 2;

Fig. 4 is a perspective view of an overflow window according to the invention;

Fig. 5-7 are sectional views of the overflow window of Fig. 4; and

Fig. 8 is a perspective view of a further overflow window which is not claimed.

[0013] A water supply device will now be described for an electric appliance connected to water mains, such as a dish-washing machine, commonly known as an "air break". The supply device has a hollow body 1 made of a plastic material having a flattened shape and presenting a plurality of outer walls, in particular two major side walls 11, 12 (wherein only one thereof is visible in Fig. 1), two minor side walls 15, a bottom wall 16 and a top wall 18. Through one of the major walls, indicated with 11, in a manner that is known per se, an aspiration hole 20 is obtained for connecting the supply device to a tank of the electric appliance, in particular a washing tank. The body 1 may be a single part or else it may be formed from multiple parts that are assembled together, for example a main part and a cover that is fixed to such main part.

[0014] Protruding, in a manner that is known per sé, from below the body 1 are a first inlet conduit 21 configured to be connected to a mains water supply tube (not shown), and two outlet conduits 22 and 24. A first conduit 24 may serve, for example, for sending water to be decalcified to a decalcifier (not shown) and a second conduit 22 may serve, for example, for sending to the decalcifier water that is necessary for the formation of a regeneration brine.

[0015] From facing surfaces of the main side walls 11 and 12 transverse walls branch off that define one or more flow conduits 26 of water from the inlet conduit 21 to the outlets defined by the hole 20 and the conduits 22 and 24. In embodiments that are not shown, but that are nonetheless conventional, the outlets may be present in numbers and with an arrangement that differ from those shown. In general, therefore, at least one conduit 26 may be defined from amongst one inlet and at least one outlet 20, 22, 24. The details of the internal hydraulic circuit of the supply device that divides the water supplied by the tube 30 into flows that are designated for the outlets 20, 22, 24 are not described here insofar as they are conventional and well known to a person skilled in the art.

[0016] Again, in a manner that is known per se, an air gap 32 is arranged upon the flow conduit 26. As is known, the standards, for example the standard EN 61770, classify anti-backflow systems on the basis of the suitability thereof to prevent the return to the mains of the aforesaid liquids classified within the categories from 2 to 5 and specify the features thereof.

[0017] For example, in anti-backflow systems for liquids in category 4 and 5, an unpressurized nozzle 32' is provided wherefrom water falls freely into a collecting chamber 19' (a chamber that is defined within the inner cavity 19 of the supply device) with a minimum distance between the surface of the water collected and the nozzle of at least 20 mm, or else an upper nozzle directing water towards a second nozzle (not shown) spaced apart from a free gap in air of at least 20 mm operating at ambient pressure. All of such systems are commonly referred to as an "air gap" and are obtained within an environment at atmospheric pressure.

[0018] Through one of the outer walls of the body 1, in particular one of the main side walls 11, 12, an overflow window 13 is obtained communicating with the inner cavity 19 of the body 1. The overflow window 13 defines the maximum obtainable water level within the supply device and places the supply device in communication with the ambient pressure. In particular, the overflow window 13 is arranged below the air gap 32, or sideways relative to the air gap 32. In any case the lower edge 131 of the overflow window 13 must be below the nozzle 32' of the air gap 32 (and, in particular, at a distance of at least 20 mm therefrom) or else, in the case wherein the air gap 32 is defined by a gap between two nozzles, below the first nozzle or upper nozzle (and, in particular, at a distance of at least 20 mm therefrom).

[0019] Fig. 2 and 3 show an overflow window which is not claimed. The portion of the supply device wherein it is applied in a simplified way.

[0020] The overflow window 13 is delimited by a peripheral edge comprising a rectilinear lower edge 131 defining a spillover level H above which water accumulated in the inner cavity 19 spills out of the body 1, as indicated by the arrow F.

[0021] At the lower edge 131 of the overflow window 13 a rib 14 is arranged, extending from the lower edge 131 of the overflow window 13 inwardly of the body 1. The rib 14 extends over the entire length of the lower edge 131, or over a part thereof, and in the direction of depth it may extend far enough to connect the main side walls 11 and 12 therebetween. Within the inner cavity of the body 1 are thus defined two apertures or passages 111 arranged on respective opposite flanks of the rib 14. The rib 14 may also extend by a value greater than the length of the lower edge 131, the important point is that on at least one of the flanks thereof an aperture 111 is defined. At least one portion 141 of the rib 14 is at the same level as the spillover level H, and therefore of the lower edge 131 of the overflow window 13.

[0022] A flow of water that spills over therefore flows from the aperture 111, bypasses the rib 14 and spills out from the overflow window as indicated by the arrow F. The water level therefore remains below the rib 14 and all possible surface tensions remain only on the sides thereof. The water level on the plane of the spillover level H is thus equal to zero.

[0023] The rib 14 may be implemented as a single part with the respective wall or with both of the walls 11, 12. The rib 14 may alternatively be made in the form of an insert that is assembled on the respective wall or else on both of the walls 11, 12.

[0024] According to the embodiment shown, the rib 14 may be perpendicular to the respective wall or to both of the walls 11, 12. The rib 14 may alternatively be inclined for or against the flow F flowing out of the two apertures 111, 111.

[0025] According to the embodiment shown, the rib 14 may be a single element. The rib 14 may alternatively be formed from multiple segments interspersed with spaces between adjacent segments.

[0026] Fig. 4 to 7 show an embodiment of the overflow window according to the invention. The portion of the supply device wherein it is applied in a simplified way. For convenience, elements corresponding to those of the foregoing example not claimed have been assigned the same numerical references.

[0027] The overflow window 13 is delimited by a peripheral edge comprising a rectilinear lower edge 131 defining a spillover level H above which the water accumulated in the inner cavity 19 spills out of the body 1, as indicated by the arrow F.

[0028] At the lower edge 131 of the overflow window 13 a rib 14 is arranged, extending from the lower edge 131 of the overflow window 13 outwardly of the body 1. According to an alternative embodiment, the rib 14 may extend inwardly of the body 1. The rib 14 extends over the entire length of the lower edge 131, or a part thereof. At least one portion 141 of the rib 14 is on the same plane as the spillover level H, and therefore the same as the lower edge 131 of the overflow window 13, more precisely the inner side of the lower edge 131.

[0029] The rib 14 has a ramp upper surface 14'. In particular, at a distal side of the rib 14, the upper surface 14' of the rib 14 has a profile sloping downward in a direction from one side edge to the other side edge of the overflow window 13 (see Fig. 4). At the inner side of the lower edge 131 of the overflow window 13 the profile of the upper surface 14' of the rib 14 is horizontal and coincides with the spillover level H. Consequently, the cross-section of the rib 14' defines a ramp ascending outwardly (against the outflow from the window 13 - Fig. 5) at one of the side edges of the overflow window 13, and a ramp descending outwardly (with the outflow from the window 13 - Fig. 7) at one of the side edges of the overflow window 13, with a gradual transition from one profile to the other in the intermediate positions (Fig. 6).

[0030] A stream of overflowing water arrives at the highest point of the rib 14 to then drain away as indicated by the arrow F. Thus, on the plane of the spillover level H, the water level is equal to zero.

[0031] The rib 14 may be made as a single part with the respective walls 11 or 12. Alternatively, the rib 14 may be made as an insert assembled upon the respective wall 11 or 12.

[0032] Fig. 8 shows another overflow window which is not claimed. The portion of the supply device wherein it is applied in a simplified way. For convenience, elements corresponding to those of the foregoing embodiments have been assigned the same numerical references.

[0033] The overflow window 13 is delimited by a peripheral edge comprising a lower rectilinear edge 131.

[0034] At the lower edge 131 of the overflow window 13, there is arranged at least one notch 132 formed in the lower edge 131 of the overflow window 13 and defining a spillover level H above which the water accumulated in the inner cavity 19 spills out of said body 1, as indicated by the arrow F. The remaining portion 141 of the lower edge 131 of the window 13 is above the plane of the spillover level H. Water that overflows drains from the notch 132 as indicated by the arrow F. Thus, on the plane of the spillover level H, the water level is equal to zero.

[0035] The notch 132 is preferably in the shape of a semicircle, but may assume other shapes and has a length that is less than the length of the lower edge 131 of the overflow window 13.

[0036] In the embodiment shown, the notch 132 may be a single notch. Alternatively, the notch 132 may be composed of several notches that are interspersed therebetween.

[0037] Without prejudice to the principle of the invention, the embodiments and the details of construction may vary widely with respect to that which has been described and illustrated purely by way of non-limiting example, without thereby departing from the scope of protection of the invention as defined in the appended claims. In particular, those elements described in relation to specific embodiments or examples which are not claimed may be combined, where compatible, with elements described in relation to other embodiments or examples which are not claimed.

Claims

1. Water supply device for an electric appliance connected to water mains, comprising a body (1) which defines an inner cavity (19), an inlet (21) and an outlet (20, 22, 24) and, within the inner cavity (19), a flow conduit (26) for water from the inlet (21) to the outlet (20, 22, 24), wherein an overflow window (13) communicating with the inner cavity (19) is formed through an outer wall (11) of the body (1), the overflow window (13) having a lower edge (131) defining a spillover level (H) above which the water accumulated in the inner cavity (19) spills out of said body,
characterized in that, at the lower edge (131) of the overflow window (13), there is arranged at least one rib (14) extending from the lower edge (131) of the overflow window (13), outwardly of the body (1), wherein the rib (14) has a ramp upper surface (14') having a cross-sectional profile variable along the direction of the lower edge (131) of the overflow window (13).

2. Device according to claim 1, wherein the rib (14) comprises at least one portion (141) arranged on the same horizontal plane as the spillover level (H).

3. Device according to claim 1 or 2, wherein the rib (14) defines in the inner cavity (19) at least one aperture or passage (111) arranged on a respective flank of the rib (14).

4. Device according to claim 3, wherein the rib (14) connects two opposite outer walls (11, 12) of the body (1) to each other.

5. Device according to any of the preceding claims, wherein along a part of the rib (14) said ramp upper surface (14') has an outwardly ascending profile and along another part of the rib (14) said ramp upper surface (14') has an outwardly descending profile.

6. Device according to any of the preceding claims, wherein an air gap (32) is arranged in said flow conduit (26), said air gap comprising an unpressurized nozzle (32') from which water falls freely into a collecting chamber at ambient pressure (19'), or an upper nozzle directing the water towards a lower nozzle spaced away from the upper nozzle by a free gap in air operating at ambient pressure.

7. Device according to claim 6, wherein the overflow window (13) is arranged below the air gap 832), or sideways relative to the air gap (32).

8. Device according to claim 6 or 7, wherein the lower edge (131) of the overflow window (13) is arranged below the unpressurized nozzle (32') or below the upper nozzle.

9. Electric appliance to be connected to water mains and comprising a water supply device according to any of the preceding claims.

Drawing