ITTO990126A1 - PERFECTED ANTI-FLOODING SAFETY DEVICE. - Google Patents

Description

Description of the industrial invention entitled:

"ANTI ALL AG AMENT OR IMPROVED SAFETY DEVICE"

SUMMARY

An anti-flooding safety device, in particular for domestic appliances, of the type comprising is described

- a first duct (6,9,10) for the transit of a liquid, at least partially enclosed within a second duct (7), between said first duct (6,9, 10) and said second duct (7) being defined as a 'interspace (18,18A, 18B) suitable to retain leakage liquid which eventually emerges from said first duct (6,9,10);

- interception means (19), provided on said first duct (6,9,10) and susceptible of movement from a first position, in which the transit of the liquid within said first duct (6,9,10) is allowed, to a second position, in which the transit of the liquid within said first duct (6,9, 10) is prevented;

- sensor means (21) placed in said interspace (18,18A, 18B) or in hydraulic communication with it, adapted to detect the presence of liquid within the interspace (18,18A, 18B) and to consequently determine the passage of said interception means (19) from said first position to said second position. According to the invention:

- said sensor means (21) are normally operative to oppose the passage of said interception means (19) from said first position to said second position, - following their contact with any liquid present in said interspace (18,18A, 18B), said sensor means (21) are able to decrease in consistency or solidity, to allow said interception means (19) to assume said second position.

DESCRIPTION

The present invention refers to an anti-flooding safety device for domestic appliances, in particular for washing machines.

It is known that, for example, in the field of washing machines, such as washing machines and dishwashers, there is generally the risk of flooding the house, following a sudden loss of the washing liquid loading system; the causes of these unexpected leaks may, for example, be due to faults in the internal devices of the machine (solenoid valves or jammed loading pressure switch, etc.) or to breakages of the washing liquid supply pipes.

In order to avoid such risks, anti-flooding safety devices are known, which allow to carry out an almost continuous control of the presence of any liquid leaks; they mainly operate by blocking, through appropriate means of interception, the flow of water from the water network to the user apparatus, when suitable sensor means detect a leak.

A first type of these safety devices generally provides at least one solenoid valve, located at the beginning of a water supply duct from the water mains, and a suitable sensor means, arranged in a liquid collection tray located below the washing tank. to the user apparatus; in this application, the sensor means are typically constituted by a micro switch, whose switching is produced by the raising of a float, or by the expansion of a sector of anhydrous sponge which, upon coming into contact with leaking water, increases by volume.

The safety device also comprises an external tube, which encloses the aforementioned duct for loading water from the water mains, and is in communication with the aforementioned collection tray; this external tube is designed to make the water flowing out of the loading duct flow into the collection tray, in the event of the latter being broken, and the consequent intervention of the sensor means is such as to cause the solenoid valve to close.

In some known safety devices of the type mentioned above, pneumatically operated valves are used instead of electric valves, fed by means of a suitable electric pump.

The electrically operated safety devices of the type mentioned above, although effective on average, have the drawback of being rather complex and expensive, and presuppose that the washing machine is prepared for this purpose with specific means (collection tray with sensors, electrical power connector for the solenoid valve of the anti-flooding device, hydraulic connector for the external pipe of the anti-flooding device).

Anti-flooding safety devices of the aforesaid type are also known which, instead of electric valves or valves controlled by means of electric pumps, use only basic mechanical components.

The mechanically operated devices, in addition to the drawbacks mentioned above, have further problems due to the remote positioning of the. sensor and actuator means with respect to the water flow shut-off valve.

In fact, between the sensor means and the valve, connection or transmission systems must be provided, which, by their nature, are exposed to risks of breakage, wear and jamming; the systems themselves are complex to build, install and assemble, so that they do not agree both with the needs of technical assistance and with the needs of end users.

A second type of anti-flooding safety devices is also known, to which the present invention refers in a particular way, simpler and cheaper than the previous one, and particularly widespread, according to which the use of mechanically operated valves is envisaged, and the The gap defined between the water loading duct and the external tube is also closed at the lower end, that is, in the part next to the washing machine.

In this case, sensor and actuator means are provided, suitably arranged within the interspace (usually in the region of a valve body for connection to a tap) which, on the one hand, detect a leak and, on the other, act mechanically. a shutter; in practice, in case of breakage of the water loading duct to the appliance, the leaking water gradually collects in the cavity, until it reaches the sensor - actuator means which, detecting the leak, cause the shutter to close , with the consequent interruption of the flow of water from the water mains to the loading duct.

In such applications, the sensor-actuator means typically consist of an anhydrous sponge element, the expansion of which, following contact with the leaking water, generates a force used to determine the closing movement of the shutter.

It should be emphasized that sponges of the type normally used for this purpose are able to expand even when they come into contact with minimal quantities of water; this is mainly allowed by their remarkable absorption capacity and by their characteristic "shape memory".

Very schematically, for the purposes of making these sensor elements, the spongy material that constitutes them is originally soaked in water, in order to obtain their expansion condition; the so wet piece is then compressed substantially along its expansion direction and subsequently dried.

The sponge piece is thus blocked, due to the rigidity induced by drying, in a condition of preload, and is apt to assume its original shape again, when it is brought into contact with a liquid.

It should be noted that a sponge element a few millimeters thick in anhydrous condition is capable of expanding by several centimeters; consequently, these elements are able to function directly both as sensors and as actuators.

In document DE-A-36 18 258, for example, an anti-flooding safety device of the aforementioned type is described, in the valve body of which a shutter system is provided, designed to close a water passage opening. This system comprises a shutter, axial to the passage opening, and a rod which keeps the shutter in the normal opening position of the passage opening, where the rod is susceptible of movement along a direction substantially perpendicular to the direction of movement of the passage. 'shutter; this rod is kept in the normal working position by a spring and an anhydrous and compressed sponge element is associated with it; the movement of the rod can take place in the same direction of expansion as the sponge element. In the event that a leak occurs from the filling tube, the water collected within the cavity reaches the sponge element, causing its volume to expand; the sponge is oriented so that its expansion occurs in a specific direction and generates a force sufficient to overcome the opposite reaction of the aforementioned spring, thus causing a movement of the rod that frees the shutter; the shutter can then close the water passage opening, thus interrupting the flow of the same to the washing machine.

From document DE-A-37 43 842 a similar device is known, in which the anhydrous sponge element is directly associated with an appendage of the shutter, which is kept in the normal opening position by a spring; the sponge element is bound to expand in the same direction of axial movement as the shutter. In this application, in case of leakage from the loading duct, the expansion of the sponge element generates a force which, overcoming the opposing force of the spring, directly produces the downward movement of the shutter, in closing the relative opening. passage of water.

From document EP-A-0 609 842 a similar anti-flooding safety device is also known, where the shutter actuation means comprise a pair of magnets of equal opposite polarity, the first magnet being associated with the shutter and the second magnet being associated with a component that carries the sponge element.

In normal operating conditions, a spring tends to keep the component that carries the sponge element, and therefore the second magnet, close to the first magnet; in this way, the repulsion force between the magnets themselves keeps the shutter in an open position for a water passage port.

In the event of a leak, the consequent expansion of the sponge element generates such a force as to overcome the action of the spring and cause a displacement of the component carrying the sponge element, and therefore of the second magnet; in this way, failing the repulsion action of the second magnet on the first magnet, the shutter is free to move to a closed position of the aforementioned passage opening, thus interrupting the flow of water.

Even though the aforementioned solutions, although reliable, have some drawbacks related to the fact that the sponge element must constitute a real actuation force producing organ, in order to perform the actuation function of the safety device.

As mentioned, in the solutions mentioned above, the sponge element is responsible for generating the force necessary to allow the actuator to close; for example, in the case of DE-A-36 18 258, the sponge element must be able to generate sufficient force to overcome the opposite reaction of a spring and move a rod on which the shutter is pressed; The same applies to DE-A-37 43 842 and EP-A-0 609 842. where the expansion of the sponge element must be able to overcome the opposing force of a spring.

In addition to this, it should be considered that the implementation based on the use of sponge elements can be negatively affected by friction in the movement of the various parts of the device.

For example, in the case of DE-A-36 18 258, the control rod is subject to its own movement frictions, which the expansion of the sponge element must overcome; in the case of DE-A-37 43 842 there is no control rod, but friction remains due to the presence of sealing rings on the shutter; it is then clear that the realization of the shutter is in itself more complex, as it must include a specific appendix, to which a special container of the sponge element is solidly associated; in the case of EP-A-0 609 842, the component carrying the sponge element must be guided horizontally, in order to ensure the orientation of the second magnet, with the consequent movement friction.

In this regard, it should be noted that the various springs provided by known devices must be of modest force, since this force must be overcome by the simple actuation force released by the expansion of the sponge; the limited force that can be developed by these springs can be another reason for criticality in the intervention of known devices, also due to the aforementioned frictions to which the moving parts may be subject. It is therefore clear that, in order to be able to use springs capable of developing greater power, larger sponge sectors must be used.

From what has been described above it can be seen that the sponge element, constituting a real actuation force producing organ, must be sized appropriately, in order to be able to generate sufficient force for the purpose; in this regard it should be considered that, in some devices according to the known art, several distinct sponge elements must be placed in series with each other.

It is clear that, the greater the dimensions that the sponge element must have, or the greater the number of sponge elements used, the greater the final costs of manufacturing the safety device will be.

The aforementioned drawbacks can also negatively affect the dimensions of the valve body, in which the shutter and the anhydrous sponge element are normally contained; as mentioned, in fact, the anhydrous sponge element has a substantial bulk volume even before its expansion.

An additional problem of the aforementioned solutions is then due to the need to provide more pieces to obtain the actuation of the shutter (as is the case of DE-A-36 18 258 and, above all, of EP-A-0 609 842), or complicate the realization of the latter (as in DE-A-37 43 842), with a consequent increase in costs and in the dimensions of the valve body.

In this regard, it should also be considered that, in general, the thrust action produced by the expansion of an anhydrous sponge element, intended to produce an actuation, may not be extremely reproducible in a predetermined manner; hence the need in known solutions to also provide means to appropriately "guide" the expansion of the sponge in the desired direction and / or provide for an oversizing of the sponges aimed at ensuring a certain intervention of the actuator means.

The present invention aims to solve one or more of the aforementioned drawbacks and to indicate an anti-flooding safety device, of the type comprising a first duct for the passage of a liquid, at least partially enclosed within a cavity, of improved and more efficient construction. , compact and economical with respect to known devices which perform the same functions.

In this general context, an object of the present invention is to indicate an anti-flooding safety device of the aforementioned type using leakage sensing means having small dimensions and costs compared to known devices that perform the same functions, in particular also for the case in which the sensor means used are of the same type used according to the known art.

Another object of the present invention is to indicate an anti-flooding safety device of the aforementioned type which uses a reduced number of components and has a low cost compared to known devices which perform the same functions. Another object of the present invention is to indicate an anti-flooding safety device of the type mentioned in which the leak sensing means must not generate forces, or thrusts, capable of producing an actuation necessary for the operation of the device itself, the latter being delegated to other components of the device.

Another object of the present invention is to indicate an anti-flooding safety device that can guarantee a greater actuation force, and therefore a certainty of intervention, compared to known devices that perform the same functions, while using sensor means for loss of dimensions. lower than in the known art. Another object of the present invention is to indicate an anti-tying safety device of the aforementioned type in which elastic elements or springs capable of developing forces greater than the forces that can be developed by the elastic elements used in known safety devices that fulfill the requirements can be used. same functions, in order to allow greater certainty of intervention.

Another object of the present invention is to indicate an anti-flooding safety device of the aforementioned type which uses components of a simplified design and geometry with respect to known devices which perform the same functions.

Another object of the present invention is to indicate an anti-flooding safety device of the aforementioned type which provides for a minimum number of moving parts, practically constituted solely by the shut-off means of a liquid passage port. Another purpose of the present invention is to indicate an anti-flooding safety device of the aforementioned type in which the positioning of the sensor means is achieved through elements of a simplified structure with respect to the known art, while ensuring the necessary intervention precision.

Another object of the present invention is to indicate an anti-flooding safety device of the aforementioned type whose leak sensing means are suitably protected from the environment.

In order to achieve one or more of these purposes, the subject of the present invention is an anti-flooding safety device incorporating the characteristics of the attached claims which form an integral part of the present description.

Further objects, characteristics and advantages of the present invention will become clear from the detailed description that follows and from the attached drawings, provided purely by way of non-limiting example, in which:

- Fig. 1 schematically represents in side view - an anti-flooding safety device according to the present invention;

Fig. 2 schematically shows a plan view of the anti-flooding safety device of Fig. 1;

- <■> Fig. 3 schematically represents in perspective view the anti-flooding safety device of Fig. 1;

- Fig. 4 schematically represents a section, according to the axis A-A of Fig. 2, of the anti-flooding safety device according to the present invention;

- Fig. 5 schematically represents a section, according to the B-B axis of Fig. 2, of the anti-flooding safety device according to the present invention, in a first operating condition;

- Fig. 6 schematically represents an enlarged detail of the section of Fig. 5; - Fig. 7 schematically represents a first enlarged detail of a section, similar to that of Fig. 4, relating to a possible variant of a component of the invention,

- Fig. 8 schematically represents a section, according to the axis B-B of Fig. 2, of the anti-flooding safety device according to the present invention, in a second operating condition;

- Fig. 9 schematically represents an exploded view of the anti-flooding safety device of Fig. 1;

- Fig. 10 schematically represents an enlarged detail of the section of Fig. 4; - Fig. 11 schematically represents a section, according to the C-C axis of Fig. 4, of the anti-flooding safety device according to the present invention;

- Fig. 12 schematically represents an enlarged detail of the section of Fig. 11;

- Fig. 13 schematically represents a section, according to the axis D-D of Fig. 4, of the anti-flooding safety device according to the present invention;

- Fig. 14 schematically represents a section, according to the E-E axis of Fig. 4, of the anti-flooding safety device according to the present invention;

- Fig. 15 schematically represents in section a part of a device of. anti-flooding safety according to a second variant of the present invention, in a first operating condition;

- Fig. 16 schematically shows in section the part of the anti-flooding safety device of Fig. 15 in a second operating condition.

With particular reference to Figs. 1-3, 1 indicates as a whole an anti-flooding safety device for household appliances, in particular for a washing machine, made according to the dictates of the present invention.

At its first end, the device 1 comprises a first fitting 2, for connection to the tap (not shown) of a supply network for a liquid, typically water; at the other end of the device 1 there is a second fitting 3, for connection to a special connection provided on the washing machine to which the device itself must be associated.

A valve body 4 is associated with the fitting 2, immediately downstream from this, within which means for intercepting the water flow and sensor means are arranged, suitable for detecting the presence of leaking water inside the device 1, and consequently allowing the activation of the interception means (the interception means and the sensor and actuator means will be described in detail below); the valve body 4 has an external casing 5.

6 indicates a first tube which, together with the passages inside the valve body 4, defines a duct for loading the water from the water supply to the washing machine; as will become clear below, this duct extends in practice from the connector 2 to the connector 3.

7 indicates a second tube, which extends between the casing 5 of the valve body 4 and a terminal element 8 forming part of the fitting 3, and which completely surrounds the tube 6; as will become clear below, the aforementioned water loading duct is completely enclosed within a complex defined by the tube 7 and by a cavity defined between the valve body 4 and the relative casing 5; in this way, a gap is therefore defined within the device 1, described below, having the function of collecting any leaking water that eventually comes out of the tube 6, following a break in the latter.

Preferably, the internal tube 6 is made of reinforced rubber, while the external tube 7 is of the corrugated type made of plastic material.

In Figs. 4-14 the device 1 and its component parts are illustrated in greater detail, by means of sectional and exploded views.

As can be seen in Figs. 4, a first passage 9 and a second passage 10, in hydraulic communication with each other, are defined within the valve body 4, which is made in a single piece of thermoplastic material; as can also be seen in the example depicted in Fig. 11, steps 9 and 10 are not coaxial with each other.

From Figs. 4 and 9 it can be seen how the valve body 4, at the upper end of the passage 9, is shaped to define a flanged part 11; Below this flanged part 11, two half-rings 12 are associated with the valve body 4, also made of thermoplastic material and threaded in their external part.

The fitting 2 consists of a ring 13, made of thermoplastic material, the internal passage of which is threaded at both ends; the lower thread of the ring nut 13 is suitable for screwing on the half-rings 12 coupled together, while the upper thread of the ring nut 13 is suitable for screwing to the aforementioned tap of the water supply.

14 indicates a flow regulator, of a type and operation known in itself, placed in a special housing defined at the upper end of passage 9; as can be seen in Fig. 9, the flow regulator comprising a plate 14A equipped with calibrated passages, visible in the sections of Fig. 4 and 5, and a membrane 14B made of elastic material; above the flow regulator 14 there is then a filter 15, also of a per se known type, and equipped with a sealing gasket 15A.

As can be understood, in particular from Figs. 4 and 5, the flow regulator 14 is kept within its housing by means of the filter 15, and the position of the latter is guaranteed by the ring nut 13 which presses on at least part of the outer perimeter of the gasket 15 A.

The valve body 4, at the lower end of the passage 10, is shaped to define a coupling 16 for the inner tube 6; as can be seen in Figs. 4 and 9, the upper end of the tube 6 is threaded onto the coupling 16, and the precise connection between the two parts is then ensured by means of a closing clamp 17, which can be fixed by crimping or crimping.

In the case exemplified in the figures, the upper end of the outer tube 7 is shaped to directly define the casing 5 of the valve body 4; as can be seen, the casing 5 is provided with a groove 5A along its circumference, suitable for receiving a clamp 5B for tightening the casing itself to the valve body 4.

In this way, and as can be seen in Fig. 4, between the assembly consisting of the valve body 4 and the tube 6, and the assembly consisting of the tube 7 with the casing 5, a gap 18 is defined.

With particular reference to Figs. 4, 5 and 9, 19 indicates as a whole a shutter member, which is essentially constituted by a suitably shaped rod in thermoplastic material.

The upper end of the shutter 19 has a 19A termination, suitable for insertion in a central seat of the flow regulator 14.

Below this termination 19A, the shutter 19 has an occlusion element 19B, with a substantially double frusto-conical shape, along the maximum circumference of which a sealing ring 19C is provided; the occlusion element 19B, in particular at its sealing ring 19C, is of such dimensions as to be able to rest on an underlying narrowing 9A of the passage 9 within which the occlusion element 19B is positioned; as you can imagine, the closure of the occlusion element 19B on the narrowing 9A causes the interruption of the hydraulic connection between passage 9 and passage 10, and therefore the interruption of a flow of water towards the washing machine.

A rod part, indicated by 19D, of the obturator 19 is partially inserted in a sliding seat 20, defined as passing through the valve body 4 starting from the bottom of the passage 9, so that the lower end of the same rod part 19D rests on a sensor or support element 21; in the exemplified case, this sensor or support element 21 consists of an element in compressed anhydrous sponge, of the known type and normally used in anti-flooding safety devices, which is supported by an appendix 22 of the valve body 4 which extends into the interspace 18.

As can be seen in the detail of Fig. 6, in the preferred version of the invention the lower end of the rod part 19D of the shutter is practically planted on the sensor or support element 21 in sponge; for this purpose, as can be seen in Fig. 6 and 9, the lower end of the rod part 19D defines a pointed relief, indicated with 19E.

The portion of the rod part 19D which is inserted in the seat 20 is equipped with sealing gaskets 19F, for example of the O-ring type, while on the portion that protrudes into the interspace 18 there is a spring M, constrained to the shutter 19 a means of a 19H stop; in particular, the lower portion of the rod part 19D has a narrowing of section, indicated with 19L in Fig. 9, on which the abutment 19H is able to be constrained, for example by means of a snap coupling; in the exemplified case, the abutment 19H is internally hollow and has a substantially cylinder shape, the lower edge of which is slightly flanged, to create on one side a support step for the lower end of the spring M, and on the other side a further bearing surface for the shutter 19 on the element 21.

As can be seen, therefore, the spring M operates between the valve body 4 and the striker 19H integral with the shutter 19, in the sense of pushing the latter downwards, i.e. on the sensor or support element 21.

19M indicates a limit stop crown, defined in the shutter 19 between the occlusion element 19B and the portion of the rod part 19D which is inserted in the seat 20; this crown 19B has a diameter greater than that of the sliding seat 20, in order to limit the downward stroke of the shutter 19, for the purposes that will become clear later.

As previously mentioned, in the case exemplified in the figures, the sensor or support element 21 is made of compressed anhydrous sponge.

As mentioned, this sponge element 21 is placed on a special appendix 22 defined by the valve body 4 and positioned within the interspace 18; as can be seen in Figs. 4, 5 and 9, this appendix 22 has openings laterally, indicated with 22A, which are also visible in Figs. 13 and 14; from the figures, and in particular from Fig. 6, it can also be seen that in the appendix 22 a pointed relief 22C is advantageously defined, facing the sponge element 21, in correspondence with the position in which the latter must be housed ; the sponge element 21 is practically planted on this pointed relief 22C.

According to the invention, and unlike the known art, the sponge element 21 is not used to generate the energy or force necessary to produce the displacement of a given organ of the device; on the contrary, this element 21 is used to maintain or support this organ in a certain position, possibly in contrast to the action of an elastic element, and to allow the same organ to move as a result of the expansion of the element 21.

As previously mentioned, the force that can be generated by the expansion of a sponge element, or by several sponge elements placed in series with each other, is very modest; on the contrary, a sponge element is, in anhydrous conditions, capable of contrasting, along its surfaces perpendicular to those facing the direction of expansion, an external force several times higher than that generated by the expansion itself. For example, the same sponge element can generate, along its expansion direction, a force of a few hectograms, but is able to contrast, in anhydrous conditions and according to a direction substantially perpendicular to those of expansion, external forces of a few kilograms. (a compressed anhydrous sponge element having dimensions of about 20 x 10 x 7 mm is able to withstand a weight of about 30 Kilograms).

Based on the aforementioned considerations, according to the invention, the sponge element is therefore intended for:

- when dry, keep in a certain position, by means of at least its two surfaces perpendicular or in any case angled with respect to the direction of expansion, a member of the safety device susceptible to movement; in such conditions, the sponge element opposes the force of movement of the organ along the aforementioned two surfaces;

- when wet, and therefore following expansion and / or softening, allow the said organ to move; in these conditions, the expansion causes a significant reduction in the consistency of the sponge element along the aforementioned two surfaces, or a reduction in the ability of the sponge element itself to oppose the force of movement of the organ.

Therefore, according to the invention, the sponge sensor element 21 is suitably oriented towards the inside of the device 1, in such a way that its expansion takes place in a direction substantially perpendicular or in any case angled with respect to the direction of movement of the operating organ. directly on the element 21 itself, which is the shutter 19.

In the specific case of the examples shown, the two aforementioned surfaces are the upper and lower ones of the sponge element 21; the lower surface rests on the appendix 22, while the shutter 19 rests on the upper surface; on the basis of what has been previously clarified, therefore, the element 21 is able to easily maintain the shutter 19 in the open condition of the passage 9, despite the action of the spring M and the downward thrust which the shutter itself is imparted by the incoming water at step 9.

From Figs. 4, 13 and 14 it can be seen how a first lateral surface of the sponge element 21 is substantially resting on or in any case adjacent to the vertical wall 4A of the body 4, from which the appendix 22 departs horizontally and in which the passage 10 is defined .

The opposite side surface of the sponge element 21 is instead turned towards the inside of the interspace 18.

From Figs. 5, 13 and 14 it is instead possible to note the absence of constraints facing the other two lateral surfaces of the sponge element 21 which, according to the invention, are the two surfaces along which the element itself is intended to expand. ; note, for example from Fig. 5, that the free space on the sides of each of these two side surfaces is at least double compared to the section of the sponge element 21 when dry.

With regard to the positioning of the sponge element 21, it should finally be noted that, in addition or as an alternative to the pointed relief 22C of the appendix 22, a pointed element 22D could also be provided on the vertical wall 4A, in order to further guarantee the correct positioning of the element 21 itself; this possible variant of the invention is illustrated in the section of Fig. 7.

It should be noted in this regard that the pointed reliefs 19E, 22C and / or 22D have the function of maintaining the sponge element 21 in the correct operating position, without however causing obstacles or friction contrary to its expansion.

As can be seen, therefore, in the exemplified case, the sponge element 21 acts as a support or retaining means for the shutter 19, to prevent it from sliding downwards under normal conditions, under the combined action of the spring M and water entering the device 1.

In this regard, it should also be emphasized that, in the device according to the invention, the sponge sensor element 21 is provided, when dry, to counteract the expansion or release force of an elastic element (M) and, when wet, to allow such elastic element (M) to expand or release. On the contrary, in the solutions according to the known art, a sponge element is arranged to allow, when dry, the release or expansion condition of an elastic element and, when wet, to compress this elastic element.

Furthermore, according to the invention, the sponge sensor element is suitable for being, so to speak, penetrated by the actuator rod allowing the latter to have a further travel space which, under the action of the spring M , is used to switch to closed conditions.

Returning to Fig. 4 and 5, it can be seen how the dimensions of the portion of the valve body 4 in which the seat appendix 22 is defined are such that this delimits, in the upper part of the interspace 18, a first chamber 18 A; note that this chamber 18A is not hermetically sealed with respect to the interspace 18, given the presence of the openings 22 A of the appendix 22.

Again in Fig. 4, 23 indicates a passage, extending parallel to the seat 20, adapted to put the first chamber 18A in communication with a second chamber 18B, adjacent to the passage 9, for housing a vent valve 24; this vent valve 24 is also visible in Fig. 11 and, on a larger scale, in the details shown in Figs. 10 and 12.

The vent valve 24 is equipped with a sealing ring 24A and is provided with first hooking teeth 24B with inclined walls, visible in Fig. 10, suitable for exerting a mild holding action in the relative seats 18B 'defined in the chamber 18B.

The bleed valve 24 is also provided with second stop teeth 24D, visible in Fig. 12, which are provided to limit the movement of the valve towards the outside of the chamber 18B, making an abutment on suitable surfaces 18B "defined in the latter. last.

Under normal operating conditions of the device 1, the vent valve 24 is in the closed position, as shown in the various figures, so as to hermetically seal, thanks to its sealing ring 24A, the internal cavity of the device 1, consisting of the interspace 18, from chamber 18A and chamber 18B, with respect to the environment.

Upon the occurrence of a leak, which corresponds to a progressive accumulation of water: within the interspace 18, the vent valve 24, under the increasing pressure of the air; within the cavity itself, it is made to slide towards the outside of the chamber 18B, freeing the coupling teeth 24B, and opening a calibrated passage (visible in the lower part of Fig. 10); in this way, an outflow of air from the cavity 18 towards the external environment is allowed, which is necessary in order to allow the water deriving from a leak from the tube 6 to rise in the interspace itself, in order to determine the expansion of the element 21 and consequently avoid possible risks of failure of the outer tube 7 due to overpressures:

Note that the aforementioned passage for the outflow of air is also calibrated in order to avoid any excessive leaks of water from it; in any case it must be said that the high expansion speed of the element 21 generally allows to obtain a very rapid closure of the shutter 19, minimizing the aforementioned risk of water leaking from the device 1.

As can be seen in Figs. 4 and 9, the fitting 3 consists of a body 25 in thermoplastic material, defining an internal duct; a first end of the body 25 defines a flange 26, for sealing a threaded ring nut 27, used for fixing the device 1 to the washing machine; between the end of the body 25 and the ring nut 27 there is a gasket 28, visible in Fig. 9.

The second end of the body 25 is shaped to define a coupling 29 for the inner tube 6; as can be seen in Figs. 4 and 9, the lower end of the tube 6 is threaded onto the coupling 29, and the precise connection between the two parts is then ensured by means of a closing clamp 30, which can be fixed by crimping or crimping.

Between the flange 26 and the coupling 29, the body 25 defines the aforementioned terminal element 8, which has a groove 8A used for sealing the lower end of the outer tube 7; the lower end of the tube 7 ends in a respective junction casing 7A, provided with a groove 7A '(see in particular Fig. 9).

For fastening purposes, the junction casing 7A is inserted on the terminal element 8, so that the respective grooves 7A 'and 8A coincide; a clamp 31 is then tightened in the groove 7A ', designed to achieve the necessary hermetic seal of the outer tube 7 on the terminal element 8.

As can be understood, the assembly of the anti-flooding safety device 1 according to the example provided is very simple, and takes place in the following ways; a) insertion of the shutter 19, already equipped with the relative sealing rings 19C and 19F in the relative sliding seat 20;

b) insertion of the spring M on the rod part 19D of the shutter that protrudes below the seat 20, and fixing the striker 19H on the narrowing 19L; c) lifting the shutter 19, for example by means of a traction exerted on the termination 19A and positioning the sponge element 21 on the relative positioning appendix 22, in the manner and according to the orientation previously described and illustrated, taking care that, after the release of the shutter 19, the pointed relief 19E of the shutter 19, the pointed relief 22C of the appendix 22, or possibly the pointed relief 22D of the wall 4A, are planted in the body of the sponge element 21;

d) insertion of the vent valve 24, already equipped with the relative sealing ring 24A, in the relative chamber 18B;

e) positioning of the flow regulator 14 and filter 15 at the upper end of the duct 9, so that the central seat of the flow regulator 14 is engaged on the termination 19A of the shutter 19;

f) associating the half-rings 12 to the valve body 4 and screwing the ring nut 13 onto them;

g) association of the upper end of the inner tube 6 to the coupling 16 and tightening of the clamp 17;

h) association of the casing 5 defined at the upper end of the outer tube 7 to the valve body 4, by means of the clamp 5B;

i) association of the ring nut 27 to the body 25, with the interposition of the gasket 28; l) association of the lower end of the inner tube 6 to the coupling 29 of the body 25 and tightening of the clamp 30;

m) association of the casing 7 A defined at the lower end of the outer tube 7 to the closing element 8 of the body 25, by means of the clamp 31.

As for step c), it should be noted that, if the valve body 4 has the relief 22C, the sponge element 21 will initially be positioned slightly higher than the appendix 22, to then be planted on the relief 22C and resting on the appendix 22 under the thrust of the shutter 19, when this is released from its raised position (possibly also by virtue of an external downward thrust exerted on the shutter); naturally, following the aforementioned operations, also the relief 19E of the shutter 19 will be planted on the upper surface of the element 21.

In the event that the valve body 4 instead presents the relief 22D on the vertical wall 4A, the element 21 can be directly placed on the appendix 22, and slid linearly towards the wall 4A, to plant itself on the relief 22D; also in this case, when the element 21 is released and / or pushed downwards, the relief 19E of the shutter will be planted on the upper surface of the element 21.

The operation of the anti-flooding safety device according to the present invention, in normal operating conditions, is as follows.

Given the opening of the tap of the water mains to which device 1 is connected, the water is free to flow within the loading duct defined by passages 9 and 10, from tube 6 and, obviously, from the passage inside the body 25.

Note that this water flow is normally enabled by the opening of a special filling solenoid valve located inside the washing machine to which device 1 is connected; this solenoid valve, which is present in practically every washing machine, is subjected to the control of a programmer or timer of the machine itself. As mentioned, the obturator 19 is kept in the opening of the passage 9 by means of the sponge element 21, which opposes the action of the spring M and the downward thrust that the same obturator is imparted by the water entering the device 1. As previously described, the interspace 18 in which the anhydrous sponge element 21 is contained is hermetically sealed; this fact allows to completely isolate the element 21 from the environment and the humidity present in it, in order to ensure a high degree of maintenance of the optimal operating characteristics of the element 21 itself.

The operation of the device 1 according to the invention, in case of breakage or leakage from the inner tube 6, is instead the following.

The leaking water that comes out of pipe 6, penetrating into the interspace 18, exerts an increasing compression of the air contained therein.

This increase in the air pressure within the interspace 18 is such as to produce the movement of the vent valve 24, which normally seals hermetically, thanks to the sealing ring 24A and the engagement of the teeth 24B in the respective seats 18B ', interspace itself; the air from the interspace 18 is free to draw through the grooves 22A, and then reach the chambers 18A and 18B, and finally the external environment. The vent valve 24 is then pushed by the air pressure to slide towards the outside of the chamber 18B, overcoming the mild seal exerted by means of the dents 24B; this movement of the valve 24 frees, as mentioned, a calibrated passage, which allows the outflow of the air contained in the interspace 18-18A-18B towards the environment.

The air outlet therefore allows further water leaking from pipe 6 to easily penetrate the interspace 18, and gradually fill the latter; this water is free to rise along the interspace 18 until it reaches the openings 22A and comes into contact with the sponge element 21.

The sponge element 21, by absorbing the water, rapidly increases in volume, according to the direction of expansion as previously defined; in this way, a rapid loss of the initial solidity characteristics of the sponge element 21 is determined, ie its yielding, or softening, or decrease in its consistency between its upper and lower surfaces; this failure is naturally favored and made rapid by the downward thrust produced by the shutter 19.

Following this failure, the element 21 is no longer able to exercise its own action of retaining or supporting the shutter 19, which therefore slides downwards penetrating inside the element 21, until the element of occlusion 19B, with the relative sealing ring 19C does not come into contact with the narrowing 9A, and is maintained there by the pressure of the water entering from the fitting 2 and by the spring M; the duct 9 is thus closed, and this prevents the further inflow of water towards the tube 6.

As already mentioned, the expansion speed of the element 21, and therefore the decrease of its consistency, generally allows the rapid closure of the shutter 19, before the leaking water can rise up to the chamber 18B; in this way, therefore, the risks of water leaks from the device 1 are reduced.

It should also be noted that the excessive downward excursion of the shutter 19 is limited by means of the end stroke crown 19M, which also prevents the sealing rings 19F from coming out of the sliding seat 20.

It is clear that the sensor or support element 21 can also be made of a material other than anhydrous sponge, such as for example a suitable paper, or a mixture of fibers, or materials of vegetable origin, or a cellulose product, possibly including suitable binding agents and / or preservatives or, more generally, any material subject, in case of soaking, to a rapid decrease in its consistency, i.e. a rapid failure or loss of the initial characteristics of solidity.

This material can be porous or permeable, and in general characterized by a capillary surface tension that facilitates the absorption of liquid.

This material should also have sufficient mechanical characteristics to withstand the stresses due to impacts and / or falls to which the device 1 may occasionally be subjected, for example during transport and / or sale (it should be considered in this regard that the anti-flooding safety devices they are often sold as spare parts, in shops or department stores, and therefore subject to manipulation); in particular, the material constituting the sensor or support element 21 should resist falls of the device 1 from heights in the order of at least one meter.

For the aforementioned reason, for example, the element 21 should preferably be of the non-soluble type, given the fragility of this type of materials.

It should also be noted that, to allow a shutter to be supported by a soluble-type leak sensor, the latter should be given a high degree of robustness, and for this purpose the soluble material would have a high compactness and density; however, this need would considerably reduce the capacity and speed of dissolution of the sensor, thus determining a delayed intervention of the safety device, with the consequent loss of water from it or even the breakage of its external tube, due to the considerable pressure that it would take place in the collection cavity.

From the above description the characteristics of the present invention are therefore clear. The advantages of the same are also clear from the description made.

According to the invention, the leak sensor, which forms the support means 21, allows an extremely compact realization of the device 1. In this perspective, it is in fact underlined that the dimensions of the element 21 can be significantly smaller than those of the sectors of anhydrous sponge commonly used on known anti-flooding safety devices.

In known devices, in fact, a sponge element is responsible for generating a force capable of producing the implementation of the device; for this reason, the sponge element provided in the known art must be of sufficient size for the purpose, so much so that in some cases more sponge elements must be arranged in series with each other.

In the case of the present invention, on the contrary, the element 21 can be significantly smaller, as it is entrusted with a simple support function; this function is exercised by the element 21 along a direction substantially perpendicular or in any case angled with respect to its direction: of expansion; as said, in the device according to the invention, the sensor element: in sponge 21, when dry, counteracts the expansion or release force of an elastic element M and, when wet, allows this elastic element M to expand or release.

On the contrary, in the solutions according to the known art, a sponge element is arranged to allow, when dry, the expansion condition of an elastic element and, when wet, to compress this elastic element.

Furthermore, in the known art there are no examples in which the shutter means penetrate inside the space occupied by the leakage sensor 21, when this is in dry conditions.

This approach of using a sponge element, opposite to that obtained from the known art, means that it can be used to withstand loads of several kilograms.

From the above, therefore, it is clear how the element 21 according to the invention can be small in size.

In consideration of the fact that the element 21 according to the invention is able to withstand loads of several kilograms, it is then clear that the elastic means 19H, to which the element 21 opposes, can be of the type suitable for generating a force. clearly higher than the forces allowed according to the known art; this allows greater certainty of intervention of the safety device, in order to obtain the closure of the shutter. Note, for example, that for the aforementioned reason, the effect of any friction produced by the 19F gaskets are absolutely irrelevant.

In addition, despite its small size, the material constituting the sensor element 21 is able to resist and maintain its mechanical characteristics and intervention rapidity unchanged even as a result of impacts, falls or vibrations to which the device 1 could occasionally be subject.

Finally, it should be noted that the anti-flooding safety device 1 according to the example provided for the invention is of particularly simple and safe operation, since there is practically only one moving interception means (19), aided by a simple elastic element ( M).

The components of the liquid flow interception system are therefore limited in number and of simplified geometry; it should be noted that this advantage is further enhanced by the fact that the element 21 can be a component in its own right, which does not necessarily have to be connected to, and movable with, a member of the device (as is the case with DE-A -36 18258), or housed in a special container (as is the case of DE-A-3743 842 or EP-A-0609 842).

There are also very few moving parts, which leads to a drastic reduction in operating friction; as mentioned, however, the problem of friction can be practically eliminated by using springs or elastic elements of considerable power. From the above it also follows that the cost of the anti-flooding safety device 1 according to the invention is particularly low, by virtue of the use of simple elements, of high industrial repetitiveness and small dimensions compared to the known art.

It is clear that numerous variants are possible for the man skilled in the art to the anti-flooding safety device described as an example, without departing from the novelty principles inherent in the inventive idea.

In a particularly advantageous version of the present invention, in which the vent valve 24 is provided, the side walls of the latter could be of a different color from that of the valve body 4 (for example red with respect to gray); this in order to visually signal, and extremely effectively, the loss that has occurred, when the side walls of the same vent valve 24 protrude from the valve body 4 as a result of the action of air pressure; in fact, it is clear in this regard that, following the safety intervention of the device 1, the vent valve 24 remains in the open condition.

It should also be noted that, instead of the valve 24, the device 1 according to the invention could at least be equipped with a simple vent hole, in a position similar to that in which said valve 24 is located, in order to allow the water loss of going up along the interspace 18; in this regard, it should be considered that, in general, the perfect isolation of the sponge element 21 from the environment is not an indispensable condition for guaranteeing the correct operation of the device: a sponge element can in fact be freely in contact with the environment (obviously not in contact with a liquid or vapor) without substantial loss of its intervention characteristics.

In any case, for this purpose, in one of its advantageous embodiments, the element 21 could comprise a film casing with a predetermined resistance to breaking, i.e. such as to resist the possible and modest expansion of the anhydrous sponge caused by environmental humidity, and by on the other hand, break quickly when the sponge is hit by water.

This envelope, indicated schematically with 21A in Fig. 9, can for example consist of paper with characteristics of good mechanical resistance to the hygroscopic conditions of normal operation of the device, but not sufficient to withstand the thrust generated by the expansion of the sponge, when hit. from leaking water. Said casing can be made of any suitable material, including synthetic material, with possibly perforated surface and / or with pre-established breaking lines, calibrated to withstand as long as the stress induced by the expansion of the sponge, from the inside towards the outside of the same casing, does not exceed a certain value, which can only be reached as a result of expansion due to contact with water.

The envelope could be of the partially permeable type and / or provided not to cover all the surfaces of the element 21; in particular, with reference to the constructive example previously provided, the casing could only surround the lateral surfaces of the element 21, leaving instead exposed the upper and lower surfaces of the same, which are in contact with the shutter 19 and the appendix 22 respectively.

It should be noted that the presence of the aforementioned casing for the sponge element 21 does not cause practically any increase in the size of the same, so as to still guarantee all the advantages listed above.

It is then clear that the basic principle of the invention can also be advantageously used with actuation systems other than those previously described as an example.

For example, in Figs. 15 and 16 illustrate, by means of schematic sections, a first possible variant embodiment of the present invention, of the type indicated in EP-A-0 609 842; in these figures the same reference numbers of the previous figures are used in part to indicate technically equivalent elements. In this embodiment, the means for actuating the shutter of the device comprise a pair of magnets having the same opposite polarities, and the shutter itself is not configured as a rod.

In Fig. 15, 19 ”indicates an obturator member, used to occlude the passage 9 in case of leakage of the duct; this shutter member 19 "is subjected at the top to the thrust of a spring M 'and at the bottom it has a first magnet 40.

41 indicates a second magnet, of equal polarity with respect to the first magnet, and placed below it; note that between the two magnets 40 and 41 there is a continuous wall 4B of the valve body 4.

The second magnet 41 is housed in a drawer 42, which is supported in a position close to the first magnet 40 by an underlying sponge element 21; this element is completely similar to that indicated and described with reference to the previous figures. Note that also in this case the element 21 is positioned on an appendix 22 of the valve body 4, equipped with a pointed relief 22C on which the same element 21 is planted; likewise, in the lower part of the drawer 42 a pointed relief 42E is defined, suitable to be planted in the element 21.

M "indicates a spring, which operates between the wall 4B and the drawer 42, in the sense of pushing the latter downwards; clearly, and as previously explained, the element 21 can easily withstand the load of this spring M ", even if it is considerable. Even in the case of the proposed variant, the sponge element 21 is suitably oriented, according to the indications previously provided, that is, so that the. its expansion occurs in a direction substantially perpendicular to the direction of movement of the drawer 42, and to the direction of thrust of the spring M ".

The condition illustrated in Fig. 15 is that of normal operation of the safety device; in this situation, the repulsion action between the two magnets 40 and 41 having the same opposite polarity keeps the shutter 19 "in the opening of the passage 9 (the repulsion areas are schematically represented by the curved magnetic field lines that depart from the facing sides of the magnets).

In the event that a leak occurs within the duct, the water that goes up the interspace 18 comes into contact with the sponge element 21, causing it to expand.

This expansion causes a decrease in the consistency of the element 21, or its ability to withstand a load along a direction substantially perpendicular to its own direction of expansion.

The drawer 42 is therefore free to move downwards, also by virtue of the action of the spring M ", so that the area where the magnetic field is generated by the second magnet 41 with respect to the first magnet 40 is moved downwards. Since the magnetic field produced by the second magnet 41 is perceptible in a limited area, the downward movement of the second magnet 41 means that there is no longer a repulsion force exerted on the first magnet 40.

Consequently, also the first magnet 40 can move downwards, under the action of the spring M 'and the thrust of the water entering the device, causing the closure of the passage 9 by the shutter 19 ".

This intervention condition of the device is illustrated in Fig. 16.

Even if the variant referred to in Figs. 15 and 16 substantially involves the use of the same number of components provided according to the known solution referred to in EP-A-0 609 842, it is clear that the same allows to achieve all the other advantages of the invention previously stated.

Among these the reduced dimensions of the element 21 must once again be mentioned, with the advantages deriving from this, and the possibility of using springs, and in particular the spring M ", capable of generating a much higher force than expected. from the known art, in order to increase the certainty of intervention of the device and make the friction problems in the movement of the drawer 42 negligible.

It should be noted that the basic concept of the invention, as applied in the case of the variant of Figs. 15 and 16, it can also be used if two magnets whose equal polarities are opposite are susceptible to movement in mutually perpendicular directions, i.e. with a movement of the magnet 40 in a vertical direction, and a movement of the magnet 41 in a horizontal direction. .

In this perspective, the sponge element 21, suitably oriented, can be arranged laterally to the drawer 42, and the spring M "can be arranged horizontally, to push said drawer 42 in a direction perpendicular to the direction of movement of the first magnet 40.

In the event of a water leak, therefore, the decrease in the consistency of the element 21 allows the horizontal movement of the drawer 42, under the thrust of the spring M ", so that the repulsion area exerted by the second magnet 41 with respect to the first magnet 40 is translated laterally with respect to the original position.

Consequently, even the first magnet 40 can move downwards, under the action of the spring M 'and the thrust of the water entering the device, causing the closure of passage 9 by the shutter 19 ".

However, it is clear that numerous other variants are possible for people skilled in the art to the anti-flooding safety device for household appliances, in particular for washing machines, described as an example, without thereby departing from the novelty areas inherent in the inventive idea.

Previously, reference was made to the use of compressed type anhydrous sponge; however, it is clear that the sensor element 21 according to the invention could also be made of dried anhydrous sponge when it is already in an expanded condition; it is clear that in this case, even if the starting dimensions of the element 21 are greater than previously described, the material constituting the piece is exactly the same, and therefore without any increase in costs. Even in this application, however, in the event of contact with leaking water, the already expanded anhydrous sponge element 21 will tend to yield rapidly, under the effect of the spring, without substantial volume expansion, precisely by virtue of the fact that the itself is already in a condition of expansion. As mentioned, the material constituting the element 21 may be of various kinds, provided it is of a type suitable for creating a non-fragile structure, suitable for softening when in contact with a liquid.

Finally, it should be noted that, according to a possible further variant of the invention, alternatively or in addition to a spring, the closure of the shutter and / or the yielding of the element 21 could be favored by associating a weight to the shutter itself, or by realizing the shutter with a material having a specific weight sufficient for the purpose; this embodiment variant is obviously valid also for the purpose of making the drawer 42 of Figs. 15 and 16.

From this perspective, therefore, the sensor element 21 is operative to maintain or support the interception means 19 in the respective open position in contrast to the gravity action of a weight, associated with the sensor element itself and / or associated or inherent. to the means of interception 19.

Finally, it should be noted that on the appendix 22 suitable means could be provided, such as for example reliefs, to indicate and / or guide, during the assembly phases of the device 1, to the correct orientation of the element 21, in order to avoid an incorrect positioning of the latter, but without however constituting an obstacle to its expansion.

Claims (67)

CLAIMS 1. Anti-flooding safety device, in particular for household appliances, of the comprising type - a first conduit (6,9,10) for the transit of a liquid, at least partially enclosed within a second conduit (7), between said first conduit (6,9,10) and said second conduit (7) being defined an interspace (18,18A, 18B) suitable to retain leakage liquid which eventually emerges from said first conduit (6,9,10); - interception means (19), provided on said first conduit (6,9,10) and susceptible of movement from a first position, in which the transit of the liquid within said first conduit (6,9,10) is allowed, to a second position, in which the transit of the liquid within said first duct (6,9,10) is prevented; - sensor means (21) located in said cavity (18,18A, 18B) or in hydraulic communication with it, able to detect the presence of liquid within said cavity (18,18A, 18B) and to consequently cause the passage of said means of interception (19) from said first position to said second position, characterized in that - said sensor means (21) are normally operative to oppose the passage of said interception means (19) from said first position to said second position, - following their contact with any liquid present in said interspace (18,18A, 18B), said sensor means (21) are able to decrease in consistency or solidity, to allow said interception means (19) to assume said second position. 2. Device, according to claim 1, characterized by the fact that said sensor means (21) are normally operative to maintain or support said interception means (19) in said first position in contrast to the action of a force. 3. Device according to claim 2, characterized in that said force is produced by an elastic element and / or by the thrust of the liquid entering said first conduit (9,10). 4. Device, according to claim 1, characterized by the fact that said sensor means (21) are operative to maintain or support said interception means (19) in said first position in contrast to the action of a force of gravity. 5. Device according to claim 4, characterized in that said force of gravity is induced by a weight, in particular associated with said sensor means (21) and / or associated or inherent to said interception means (19). 6. Device, according to claim 1, characterized in that support means are provided which keep said interception means (19) in said first position, said support means being made by said sensor means (21). 7. Device according to claim 1, characterized in that said sensor means (21). they are made with a material subject, in case of liquid soaking, to a softening and / or a rapid decrease of its consistency or its initial characteristics of solidity. 8. Device, according to claim 1, characterized in that said sensor means (21) are made of a material having mechanical characteristics suitable for resisting stresses due to impacts and / or falls and / or vibrations to which the device (1) it may occasionally be subject. 9. Device, according to claim 6 or 7, characterized in that said material comprises paper and / or a mixture of fibers and / or a material of vegetable origin and / or a cellulose product, with the possible addition of binding agents and / or preservatives. 10. Device, according to at least one of the preceding claims, characterized in that said material is of the porous or permeable type and / or has a capillary surface tension that facilitates the absorption of liquid. 11. Device according to at least one of the preceding claims, characterized in that said material comprises a spongy material. 12. Device according to at least one of the preceding claims, characterized in that said material is not of the soluble type. 13. Device, according to claim 1, characterized in that said sensor means comprise an anhydrous sponge element (21). 14. Device according to claim 13, characterized in that said anhydrous sponge (21) is dried in the compressed state. 15. Device according to claim 7 or 13, characterized in that said material or anhydrous sponge (21) is of the expanded type. 16. Device according to claim 1 or 13, characterized in that at least a part of said interception means (19) is directly in contact with and / or resting on said sensor means or sponge element (21). Device, according to claim 1 or 13, characterized in that said sensor means or sponge element (21) are able to expand in volume according to a first substantially predefined direction, when in contact with said liquid present in said cavity (18.18A, 18B). 18. Device according to the preceding claim, characterized in that the consistency of said sensor means or sponge element (21) decreases according to a second direction, angled and / or perpendicular with respect to said first direction of expansion. 19. Device, according to claims 16 and 17, characterized in that the surface of said sensor means or sponge element (21) which is in contact with said interception means (19) is substantially parallel with respect to said first direction of expansion . 20. Device according to claims 16 and 17, characterized in that said interception means (19) rest on said sensor means or sponge element (21) in a direction which is substantially perpendicular to said first direction of expansion. 21. Device, according to claim 1 or 13, characterized in that said sensor means or sponge element (21) are a separate component. 22. Device, according to claim 1 or 13, characterized in that said sensor means or sponge element (21) are not provided to generate forces, or thrusts, aimed at causing a displacement of said interception means (19). 23. Device according to at least one of the preceding claims, characterized in that a valve body (4) is provided with which said interception means (19) are associated. 24. Device according to at least one of the preceding claims, characterized in that said interception means comprise a shutter member (19; 19 ", 40-42). 25. Device according to the preceding claim, characterized in that said shutter member (19; 19 ") comprises an occlusion element (19B). 26. Device, according to claim 26, characterized by the fact that said shutter member (19; 19 ") comprises a sliding element (19D; 42), for resting on said sensor means or sponge element (21). 27. Device, according to the preceding claim, characterized in that said sensor means or sponge element (21) are oriented in such a way that the expansion occurs in a direction substantially perpendicular or in any case angled with respect to the direction of movement of said sliding element (19D; 42). 28. Device according to claims 25 and 26, characterized in that said sliding element (19D) and said occlusion element (19B) are mutually integral and / or in a single piece. 29. Device, according to claims 23 and 26, characterized in that said sliding element (19D) is at least partially inserted in a seat (20), defined as passing through a wall of said valve body (4). 30. Device, according to the preceding claim, characterized in that sealing means (19F) are provided on the portion of said sliding element (19D) inserted in said in the seat (20). 31. Device, according to at least one of the preceding claims, characterized in that said elastic means comprise a spring (M) operating between said valve body (4) and said sliding element (19D), in particular on the end of the latter which it rests on said sensor means or said sponge element (21). 32. Device, according to at least one of the preceding claims, characterized by the fact that said elastic element or spring (M) constitutes an energy producing element for the implementation of said interception means (19). 33. Device, according to claim 5, characterized by the fact that said weight constitutes an energy producing element for the implementation of said interception means (19). 34. Device, according to claim 31, characterized in that said sliding element (19D) is associated with an abutment (19H) which creates a constraint for one end of said spring (M). 35. Device, according to at least one of the preceding claims, characterized in that an appendix (22) is provided on which said sensor means or sponge element (21) are positioned, said appendix (22) being in particular part of said body valve (4). 36. Device, according to the previous claim, characterized by the fact that said appendix (22) has one or more slots (22A) to favor the soaking of said sensor means or sponge element (21). 37. Device, according to claim 1 or 13, characterized in that positioning means (19E, 22C, 22D) are provided to keep said sensor means or sponge element (21) in its correct operating position, without however determining obstacles or frictions to its expansion. 38. Device, according to the preceding claim, characterized in that said positioning means comprise one or more pointed projections (19E, 22C, 22D), suitable to be planted in said sensor means or sponge element (21). 39. Device, according to the previous claim, characterized by the fact that said positioning means comprise at least a first pointed relief (19E) defined at one end of said sliding element (19D). 40. Device, according to claims 35 and 38, characterized in that said positioning means comprise at least a second pointed relief (19E) defined in said appendix (22), in correspondence with the position in which said sensor means or sponge element (21) are placed. 41. Device, according to claims 23 and 39, characterized in that said positioning means comprise at least one pointed relief (22D) defined in said valve body (4) and facing in a direction substantially perpendicular to said first pointed relief ( 19E). 42. Device, according to at least one of the preceding claims, characterized in that vent means (24) are provided, to allow, in the event of a leak from said first duct (6,9,10), an outflow of air from said interspace (18,18A, 18B) towards the external environment, in order to allow the leaking liquid to rise up into said cavity (18,18A, 18B) and to avoid the risk of subsidence to said external duct (7). 43. Device, according to the preceding claim, characterized in that said vent means comprise a vent valve (24) which - in normal operating conditions of the device, it is closed to isolate said cavity (18,18A, 18B) from the external environment; - in case of leakage from said internal duct (6,9,10) it is able to open under the increasing air pressure within said cavity (18,18A, 18B). 44. Device according to the preceding claim, characterized in that said vent valve (24) is able to maintain once its open condition has been reached. 45. Device, according to at least one of the preceding claims, characterized in that the side walls of said vent valve (24) are of a different color compared to said valve body (4), in order to signal the intervention of said device safety (1). 46. Device, according to at least one of the preceding claims, characterized by the fact that said sensor means or sponge element (21) comprise a film envelope (21 A) of predetermined resistance to breaking, in particular such as to resist any and modest expansion of sensor means or sponge element (21) caused by ambient humidity, and to break rapidly as a result of the expansion of said sensor means or sponge element (21) when these come into contact with liquid. 47. Device according to the preceding claim, characterized in that said wrapper (21 A) comprises paper or a synthetic material, with possibly perforated surface and / or with predetermined breaking lines. 48. Device, according to claim 46 or 47, characterized in that said casing (21 A) is of the partially permeable type and / or provided not to cover all the surfaces of said element (21). 49. Device, according to claim 1 or 13, characterized in that said interception means comprise a first and a second magnet (40,41) having their opposite polarities, the first magnet (40) being associated with a shutter organ (19 ") SO. Device, according to the preceding claim, characterized in that in normal operating conditions of the device (1), said second magnet (41) is kept in a position close to said first magnet (31) by means of said sensor means or element in sponge (21) and in contrast to the action of an elastic element (M "), the repulsion action between said magnets (40,41) keeping said shutter member (19") in a first position in which the passage of the liquid in said first conduit (6,9, 10) it is allowed. 51. Device, according to the preceding claim, characterized in that, in the event of loss, the decrease in consistency of said sensor means or sponge element (21) allows said second magnet (41) to move under the action of said elastic element (M "), thus moving the repulsion area exerted by said second magnet (41) with respect to said first magnet (40) and allowing said shutter (19") to assume a second position in which the passage of the liquid in said first duct (6,9,10) is prevented. 52. Device according to the previous claims from 49 to 51, characterized in that said magnets (40,41) are movable along the same axial direction. 53. Device according to the preceding claims from 49 to 51, characterized in that said magnets (40, 41) are movable in mutually perpendicular or in any case angled directions. 54. Method of operating an anti-flooding safety device, in particular for household appliances, of the type comprising a first duct (6,9, 10) for the transit of a liquid, at least partially enclosed within a second duct (7) , between said first duct (6,9,10) and said second duct (7) an interspace (18,18A, 18B) being defined for retaining leakage liquid that eventually emerges from said first duct (6,9,10 ), where on said first duct (6,9,10) interception means (19) are provided, able to interrupt the transit of the liquid following a detection of the presence of the latter within said cavity (18,18 A, 18B), said detection being carried out by means of sensor means (21) placed in said interspace (18,18A, 18B) or in hydraulic communication with it, characterized in that - in conditions of normal operation of the device (1) said sensor means (21) have a consistency or solidity sufficient to maintain said interception means (19) in a first position, in which the transit of the liquid within said first duct (6, 9.10) is allowed, - the detection of the presence of liquid within said interspace (18,18A, 183) is determined by a decrease in consistency or solidity of said sensor means (21) when in contact with liquid, said decrease in consistency or solidity allowing the passage of said interception means (19) in a second position, in which the transit of the liquid within said first duct (6,9,10) is interrupted. 55. Method, according to claim 54, characterized in that said sensor means (21) are normally operative to counteract the release force of an elastic element (M) and that, following their contact with any liquid present in said interspace (18,18A, 18B), said sensor means (21) allow said elastic element (M) to release. 56. Method according to claim 54 or 55, characterized in that said sensor means (21) are adapted to absorb liquid, rapidly increasing in volume according to a first predefined direction, and causing a softening, and / or a rapid loss of their initial characteristics of solidity or consistency, along a second direction, substantially perpendicular or in any case angled with respect to the chosen first direction. 57. Method, according to claim 54 or 55, characterized in that said sensor means (21) are able to absorb water even without substantial volume expansions, to cause a softening and / or a rapid loss of their initial solidity characteristics or consistency. 58. Method, according to claim 54, characterized by the fact that said sensor means (21) are not used to directly generate an energy or force necessary to produce the displacement of a component of the safety device. 59. Method of assembling an anti-flooding safety device, in particular for household appliances, of the type comprising a first duct (6,9,10) for the transit of a liquid, at least partly partially enclosed within a second duct (7) , between said first duct (6,9,10) and said second duct (7) an interspace (18,18A, 18B) being defined for retaining leakage liquid that eventually emerges from said first duct (6,9,10 ), where on said first duct (6,9,10) interception means (19) are provided, able to interrupt the transit of the liquid following a detection of the presence of the latter within said cavity (18,18A, 18B ), said detection being carried out by means of sensor means (21) placed in said interspace (18,18A, 18B) or in hydraulic communication with it, characterized by the fact which includes at least the following steps: a) positioning said interception means (19) in a valve body (4); b) positioning, in said valve body (4), of an elastic element (M) adapted to actuate said interception means (19) towards a closing position of said first conduit (6,9,10); c) positioning of a sensor element (21) adapted to detect the presence of liquid within said interspace (18,18A, 18B); d) constraint of said sensor element (21) in said gap (18,18A, 18B), so that said sensor element (21) keeps said interception means (19) in an opening position of said first duct (6, 9.10). 60. Assembly method, according to claim 59, characterized by the fact that for the purpose of carrying out step c), said interception means (19) are raised in contrast to the action of said elastic element (M). 61. Mounting method, according to claim 59, characterized in that said sensor element (21) is fixed on said support surface (22) by means of pointed reliefs (19E, 22C, 22D) defined in said interception means (19) in said support surface (22) and / or in said valve body (4). 62. Mounting method, according to at least one of the preceding claims, characterized in that said sensor element (21) is initially positioned slightly higher than said support surface (22), and is then planted on a pointed relief ( 22C) defined therein, under a thrust of said interception means (19). 63. Mounting method, according to at least one of the preceding claims, characterized in that said sensor element (21) is placed directly on said support surface (22) and made to slide linearly towards a wall (4A) of said valve body (4 ), to be planted on a pointed relief (22D) defined herein. 64. Anti-flooding safety device, in particular for household appliances, of the comprising type - a first conduit (6,9,10) for the transit of a liquid, at least partially enclosed within a second conduit (7), between said first conduit (6,9,10) and said second conduit (7) being defined an interspace (18,18A, 18B) suitable to retain leakage liquid which eventually emerges from said first duct (6,9,10); - interception means (19), provided on said first duct (6,9,10) and susceptible of movement from a first position, in which the transit of the liquid inside said first duct (6,9, 10) is allowed, to a second position, in which the transit of the liquid within said first duct (6,9,10) is prevented; - sensor means (21) located in said interspace (18,18A, 18B) or in hydraulic communication with it, suitable for detecting the presence of liquid within said interspace (18.18 A, 18B) and consequently causing the passage of said interception means (19) from said first position to said second position, characterized in that - said sensor means (21) are normally operative to oppose the passage of said interception means (19) from said first position to said second position, - following their contact with any liquid present in said interspace (18,18A, 18B), said sensor means (21) are able to leave space for said interception means (19,40,41,42) so that they can pass from said first to said second position. 65. Anti-flooding safety device, in particular for domestic appliances, according to the teachings of the present description and the annexed drawings. 66. Method of operating an anti-flooding safety device, in particular for household appliances, according to the teachings of the present description and of the annexed drawings. 67. Method of assembling an anti-flooding safety device, in particular for household appliances, according to the teachings of the present description and of the annexed drawings.