Field of application

The present invention relates to a hermetic safety solenoid valve for fluids with controlled opening, i.e., a valve for fluids which, being always closed, is temporarily opened with the excitation of an electromagnetic action; at the end of the excitation the valve closes, as is known, due to the action of the pressurized fluid present in the pipe in which the valve is positioned. Furthermore, the solenoid valve is made hermetic in the pipe in which it is inserted.

Background Art

The state of the art comprises safety solenoid valves in which both the opening and closing steps are included, timed, and controlled to cause a behaviour desired by the manufacturer for opening and blocking the passage of fluid in the pipe.

The prior art comprises EP0765450A1 which describes an embodiment of opening or closing delay timing of the solenoid valve shutter with position control of a differential shutter with the occlusion of a discharge hole, so as to keep the valve closed due to the difference in forces on the faces of the valve shutter. A loading hole puts the fluid delivery in connection with the compensation chamber which, unlike areas on which the fluid pressure acts, keeps the valve closed. When the coil is operated, a controlled piston rises, releasing the discharge of the compensation chamber and, therefore, opening the valve as the sudden discharge of the compensation chamber allows the differential shutter to open. The effect of controlling the position of a differential shutter in this document is obtained by creating a second compensation chamber and winding passageways of the pressurized fluid to intervene on the compensation of the thrusts on the shutter, so as to obtain a timing in the opening or even obtain a pre ordered delay for use with a specific fluid for which the solenoid valve is intended.

Moreover, these valves include obtaining the movement of the piston for controlling the yielding of the compensation chamber(s) in a direction parallel to the shutter axis with the consequence that the solenoid valve, as a whole, has an external “T” or even “L" shape, so as to encumber the space around the point of the pipe where the solenoid valve is positioned.

Said solenoid valves, if used in environments where space is not a limit, do not present problems of use, but if instead used in confined environments, such as modern appliances: clothing washing machines, dishwashers and other appliances, where the reduction of dimensions is very desired, leads to seek this reduction of space.

In fact, solenoid valves are used in the pipes connecting household appliances to the water mains, such as clothing washing machines and dishwashers, which are activated by the appliance. These solenoid valves are inserted in pipes made with an inner tube which conducts the pressurized water for supplying the appliance, and an outer tube, generally corrugated to contain any leaks, and in which the supply wire of the same coil runs from the appliance to the low voltage solenoid valve, which is placed immediately downstream of the connection with the water supply tap.

In the prior art, a solenoid valve from WO 2013/118050 is known which has an axial shape with a movable shutter placed between a compensation chamber and the shutter edge to close or open the passage of the water towards the appliance. The actuation occurs through a movable piston, housed in the compensation chamber and protected by an elastic gasket to avoid the deposit of small debris or solid bodies which may be present in the water so as to be able to block the controlled motion of the movable piston in the liner thereof and prevent the movement thereof. The construction has significant dimensions given by the shape of the removable valve body.

Furthermore, these solenoid valves, having to be suitable for treating different fluids and requiring different construction specifications, can be made of various materials, either metal for gaseous fluids or also plastic and similar materials for liquids. In all these uses, the reduction of the spatial dimensions of the valve requires a specific study for the fluid in question. Moreover, being able to define as linear a shape as possible of the solenoid valve, i.e. , similar to an "I", allows to make the solenoid valve in a faster and simpler manner both in the construction of the parts and in the assembly thereof.

The embodiment of the prior document WO 2013/118050, albeit with linear shape, is also very cumbersome due to the need to include the additional protections described and for a creation in separable parts during construction and future repair. That is, even if designed for the association with a water connection pipe of a household appliance, this solenoid valve has excessive dimensions in relation to the necessary and available fluid flow rate for a household appliance and, given the removable construction, has a limit on safety and tampering.

Finally, a further limitation of the known art is also found in the safety solenoid valves in which the movable piston can be immersed in the treated fluid, but the electromagnetic-action coil on the movable piston must necessarily be outside the contact with the treated fluid so as to avoid circuit contaminations or possible damage between fluid and electromagnetic coil. Furthermore, the reciprocal position between the movable shutter, piston occluding the discharge hole of the compensation chamber, and the fixed part, i.e. , the support of the edge of the membrane forming the shutter, does not allow an assembly in a single direction in the solenoid valves known in the art.

Thus, the current constructions of the valve body, of the electromagnetic coil prevent a significant improvement in the construction mode of the hermetic safety solenoid valves so as to make it extremely safe, of minimal dimensions, so that it can be housed in the outer corrugated tube of the hydraulic connection of a household appliance.

This state of the art is subject to considerable improvements with regard to the possibility of creating a hermetic safety solenoid valve for fluids with controlled opening, which overcomes the aforementioned limits of the prior art and allows to obtain a shape of the solenoid valve which is easier to assemble, protected from tampering and safe in operation as well as waterproof.

Therefore, the technical problem underlying the present invention is to obtain a safety solenoid valve for fluids with controlled opening in relation to the reciprocal position between the fluid supply and output channels from the shutter body, so as to obtain the valve body with a substantial position in line with the fluid input and output connections to and from the pipe on which the solenoid valve is placed so that it is linear and with an almost axial-symmetrical outer shape.

Furthermore, a refinement of the known art is necessary in obtaining a hermetic safety solenoid valve in which the electromagnetic coil, while remaining outside the valve body, acts from the outside on the piston controlling the opening and closing of the discharge hole for the compensation chamber of the membrane shutter and, as mentioned, must act in a direction parallel to the axis of the pipe connections, and i.e., corresponding to the expected direction of motion for the shutter, allowing to obtain a solenoid valve of minimum overall dimensions and with a perfectly hermetic seal.

An inherent object of the preceding technical problem is to obtain the assembly of the electromagnetic coil in the safety solenoid valve axially, i.e., in the direction of the movable piston and in a direction parallel to the axis of the pipe and the motion expected for the shutter.

A further and not last object of the present invention is to obtain a valve body of the hermetic safety solenoid valve in plastic material so as to be rendered impermeable to internal water leaks or those from inside a water supply pipe of the household appliance.

Summary of the Invention

This problem is solved, according to the present invention, by a hermetic safety solenoid valve for fluids with controlled opening comprising: a shutter closed by a movable equipment and a gasket with suspension membrane, to make the movable equipment movable from an open position to a closed position; a compensation chamber fed by a loading hole in the gasket with membrane and in the movable equipment and a discharge hole, made in the movable equipment, closed following the action of a piston and with a gasket, to cause the motion of the movable equipment; a coaxial electromagnetic coil placed axially in the position of the piston, made, at least in part, of ferromagnetic material; in which the solenoid valve has a fluid inlet duct and an outlet duct both made parallel and flanked to the axis of the electromagnetic coil so as to obtain an outer wall of the tubular-shaped valve body; a piston containment and guide liner being housed in the electromagnetic coil with a motion reciprocal and parallel to the direction of said inlet and outlet ducts; in which at least one radial duct upstream or downstream of the shutter and the movable equipment is placed to connect at least one of the fluid inlet or outlet ducts; in which at least one of said fluid inlet or outlet ducts from the valve body is made coaxial to the shutter axis, the movable equipment and the electromagnetic coil; and in which the piston liner is inserted in the valve body and made irreversibly integral upon assembly; the seat compartment of the electromagnetic coil is filled with fixing and insulating resin so as to make it waterproof by embedding the electromagnetic coil therein.

In a further embodiment, both the fluid inlet and outlet ducts from the valve body can be made coaxial to the shutter axis, the movable equipment and the electromagnetic coil.

Moreover, in an improved embodiment the compensation chamber is obtained by means of a central bell enclosing the shutter and the movable equipment; the inlet duct feeds said radial ducts from a gap outside the central bell.

Furthermore, in a further variant of the preceding embodiments, between the shutter and the outlet duct there is an inner discharge duct of the shutter with passage inside the electromagnetic coil.

Moreover, in a specific perfected embodiment the movable piston is made divided into two parts joined by a stem of which one part, made of ferromagnetic material and subject to the electromagnetic action of the coil, is housed in an axial liner inside the central outlet duct; the stem of the divided piston crosses the movable equipment and determines an annular discharge hole of the shutter compensation chamber; the opposite part is housed in the compensation chamber with the loading spring and an inner annular gasket to obtain the closure of the annular discharge hole.

Furthermore, in a preferred embodiment the inlet duct is placed in permanent connection to the loading hole for the compensation chamber and the outlet duct is placed parallel and lateral to the valve and the electromagnetic coil.

Still further in a further embodiment, the compensation chamber is obtained by means of an occlusion wall, enclosing the shutter and the movable equipment; the inlet duct feeds at least one radial duct from a lateral passage to the annular loading chamber; the movable equipment has housed therein, on the side of the compensation chamber, a central containment and guide liner of the central movable piston; a central column, prominent from the compensation chamber, positions the central movable piston and the spring interposed at the electromagnetic coil.

Finally, a preferred embodiment has the central liner of the movable equipment, with the central movable piston, placed inside the outlet duct at the electromagnetic coil and the outlet duct and coil is coaxial thereto.

Further features and advantages of the present invention, in the creation of a hermetic safety solenoid valve for fluids with controlled opening, will be apparent from the following description of some constructive forms and embodiments, given by way of non-limiting example, with reference to the eight attached drawings.

Brief description of the drawings

Figure 1 depicts a schematic sectional view of a first embodiment of a safety solenoid valve according to the invention: the electromagnetic coil is in line with the valve body made in two parts and made irreversibly integral with the assembly with the outlet duct parallel to the valve body axis; the shutter is in the closed position;

- Figure 2 depicts a schematic sectional view of the first embodiment of Figure 1 , here in the open position with the electromagnet excited and the piston retracted and with the shutter open;

- Figure 3 depicts a schematic sectional view of the parts forming the valve body of the first embodiment of Figures 1 and 2 separated from each other, with the electromagnetic coil depicted;

- Figure 4 depicts a schematic sectional view of the movable components of the solenoid valve of the first embodiment separated from each other;

- Figure 5 depicts a schematic sectional view of a second embodiment of a safety solenoid valve according to the invention: all the components of the solenoid valve are in line with the valve body itself with the outlet duct parallel to the valve body axis but made inside between the movable piston and the electromagnetic coil acting on the piston through the outlet duct; the shutter is in the closed position;

- Figure 6 depicts a schematic sectional view of the second embodiment of Figure 5, here in the open position with the electromagnet excited and the piston raised to open the shutter;

- Figure 7 depicts a schematic sectional view of the parts forming the valve body of the second embodiment of Figures 5 and 6 separated from each other, with the electromagnetic coil depicted;

- Figure 8 depicts a schematic sectional view of the movable components of the solenoid valve of the second embodiment separated from each other; here the piston has been broken down to show the inner components of the two parts thereof;

- Figure 9 depicts a schematic sectional view of a third embodiment of a safety solenoid valve according to the invention: all the components of the solenoid valve are parallel to the valve body itself with the outlet duct inside between the movable piston and the electromagnetic coil acting on the piston through the outlet duct; the fluid loading duct is lateral and parallel to the shutter which is in the closed position;

- Figure 10 depicts a schematic sectional view of the third embodiment of Figure 9, here in the open position with the electromagnet excited and the piston raised to open the shutter;

- Figure 11 depicts a schematic sectional view of the parts forming the valve body of the third embodiment of Figures 9 and 10 separated from each other, with the electromagnetic coil depicted;

- Figure 12 depicts a schematic sectional view of the movable components of the solenoid valve of the third embodiment separated from each other;

- Figure 13 depicts a schematic sectional view of a fourth embodiment of a safety solenoid valve according to the invention: all the components of the solenoid valve are in line with the valve body itself with the inlet duct parallel and outside of the electromagnetic coil acting on the piston; the fluid loading duct is lateral and parallel to the shutter which is in the closed position;

- Figure 14 depicts a schematic sectional view of the fourth embodiment of Figure 13, here in the open position with the electromagnet excited and the piston raised to open the shutter;

- Figure 15 depicts a schematic sectional view of the parts forming the valve body of the fourth embodiment of Figures 13 and 14 separated from each other, with the electromagnetic coil positioned close to the seat thereof;

- Figure 16 depicts a schematic sectional view of the movable components of the solenoid valve of the fourth embodiment separated from each other.

Detailed description of some preferred embodiments

In Figures 1, 2, 3 and 4 a first embodiment 1 of solenoid valve is visible in which a first-embodiment electromagnetic coil 2 is positioned in line with the fluid inlet duct 3 towards the valve 4, itself, which comprises a first- embodiment movable equipment 5 and shutter 6; the equipment is provided with two passage holes: a first loading hole 7 for a first-embodiment compensation chamber 8 and a second discharge hole 9, coaxial to the first-embodiment movable equipment 5 of the shutter, and in contact with a first-embodiment movable piston 10 subject to the electromagnetic action of a first-embodiment armature 11 , associated with the first-embodiment electromagnetic coil 2; in the closed position, Figure 1 ; the first-embodiment movable equipment 5 is in contact with the seat of the shutter 6 by means of an annular gasket with membrane 12; the piston pushed by a spring 13 is in contact with the discharge hole 9 by means of a head gasket 14; the annular membrane 12 suspends the first-embodiment movable equipment 5 of the valve 4 and allows it to move from the closed position to the open position, Figure 2. Downstream of the shutter 6 is a discharge chamber 16 connected with a radial duct 17 towards an outlet duct 18.

The first-embodiment valve body 19, of the valve 4, is made in two parts: a first-embodiment first part P1 comprises the inlet duct 3, the shutter 6, the discharge chamber 16 and the radial duct 17; and a first-embodiment second part S1 which comprises the first-embodiment compensation chamber 8, the axial sliding and guide liner 20 of the first-embodiment piston 10, and flanked by only one side of the axial liner 20 the outlet duct 18. The axial liner 20 has the seat of the first-embodiment piston 10 in connection with the first-embodiment compensation chamber 8, i.e. , the piston 10 and the spring 13 are inside the first- embodiment compensation chamber. The first-embodiment electromagnetic coil 2 is housed on the outer diameter of the axial piston containment and guide liner 20, by means of a usual type of cradle 21 of the coil; to protect the first-embodiment electromagnetic coil 2 in the first-embodiment second part S1, a lateral protection wall 22 is made on the opposite side with respect to the outlet duct 18. The two parts of the valve body are irreversibly made integral upon assembly so as to enclose the aforementioned components; moreover, the housing compartment 25 of the electromagnetic coil is sealed with fixing and insulating resin and from which only the wires 26 for the electrical connection of the coil exit.

In the descriptions of the following embodiments, components having the same shape and functionality are referenced with the same numerical reference.

In Figures 5, 6, 7 and 8 a second embodiment 30 of solenoid valve is visible in which a second-embodiment electromagnetic coil 31 is positioned in line with the fluid inlet duct 3 towards the valve 32 itself, which comprises a second-embodiment movable equipment 33, a shutter 6 and two passage holes: a first loading hole 7 for a second-embodiment compensation chamber 34 and a second annular discharge hole 35, for the passage of a stem 36 of the divided movable piston 37, which also crosses the shutter 6; the divided movable piston is subject to the electromagnetic action of a second-embodiment armature 38, associated with the second-embodiment electromagnetic coil 31; in the closed position, Figure 5; the second-embodiment movable equipment 33 is in contact with the seat of the shutter 6 by means of the annular gasket with membrane 12, which suspends the second-embodiment movable equipment 33 of the valve 32 and allows it to move from the closed position to the open position, Figure 6. Downstream of the shutter 6 is placed an inner discharge duct 40, in parallel position, to an inner axial liner 41 with the divided movable piston 37 pushed by a spring 13 for closure, housed with the first part of the divided movable piston 37 in a guide 39 placed in line in the second-embodiment compensation chamber 34 and in contact with the annular discharge hole 35 by means of an inner annular gasket 42 of said divided movable piston. A central outlet duct 43 allows the fluid to flow downstream of the valve 32, when open. The ferromagnetic part 44 subject to the magnetic field of the divided piston 37 is connected to the piston stem 36 after the assembly of the annular gasket with membrane 12, the second- embodiment movable equipment 33 and the inner annular gasket 42, fixing the stem 36 in the ferromagnetic part 44.

The second-embodiment valve body 45 of the valve 32 is made of three parts: a second-embodiment first part P2 comprises the inlet duct 3, an outer cylindrical wall 46 to contain the second-embodiment second part S2 on which are made the shutter 6, a loading chamber 47, with radial ducts 17 from the outside and in connection with the inlet duct 3, and the inner axial sliding and guide liner 41 of the divided movable piston 37, with the inner discharge duct 40 laterally flanked; a second-embodiment third part T2 is interposed between the two preceding parts to make the central bell 48 enclosing the second-embodiment compensation chamber 34. The inner axial liner 41 has the seat of the second, ferromagnetic part 44 of the divided movable piston 37, housed downstream of the shutter 6, but in connection with the other half of the divided piston by means of said stem 36, inside the second-embodiment compensation chamber 34, i.e., the first part of the divided movable piston and the spring 13 are inside the second- embodiment compensation chamber and the second ferromagnetic part 44 is inside the inner axial liner 41. The second-embodiment electromagnetic coil 31 is housed on the outer diameter of the inner axial liner 41 also comprising the inner discharge duct 40.

In Figures 9, 10, 11 and 12 a third embodiment 50 of solenoid valve is visible in which a second-embodiment electromagnetic coil 31 is positioned in line with the third-embodiment fluid outlet duct 51 from the valve 52 itself, which comprises a third-embodiment movable equipment 53 to close a shutter 6 and provided with two passage holes: a first loading hole 7 for a third- embodiment compensation chamber 54 and a second central discharge hole 55, coaxial to the third-embodiment movable equipment 53, protruding with the central containment and sliding liner 56 of a central movable piston 57 beyond the shutter 6 in the third-embodiment outlet duct 51; the central movable piston 57 is subjected to the electromagnetic action of a second-embodiment armature 38, associated with the second-embodiment electromagnetic coil 31; in the closed position, Figure 9; the third-embodiment movable equipment 53 is in contact with the seat of the shutter 6 by means of an annular gasket 12 with annular membrane and suspends the third-embodiment movable equipment 53 of the valve 52 and allows the movement thereof from the closed position to the open position, Figure 10. Upstream of the shutter 6 is placed an inlet duct 3, in a parallel and laterally displaced position, by a lateral passage 58 and a radial duct 17; the central movable piston 57 is pushed by a spring 13, housed on a central column 59, in the third-embodiment compensation chamber 54 to push the central movable piston 57 against the third-embodiment discharge hole 55, by means of a gasket 60 opposite the spring on said central movable piston. Said third-embodiment outlet duct 51 is wider and coaxial to said central liner 56, and allows the fluid to flow downstream of the valve 52, when opened.

The third-embodiment valve body 61 of the valve 52 is made of two parts: a third-embodiment first part P3 comprises the inlet duct 3, an occlusion wall 62 of the third-embodiment compensation chamber 54 from which the seat of the annular gasket with membrane 12 extends and an outer wall 63 to contain the third-embodiment second part S3 on which the shutter 6 is axially made, an annular loading chamber 64 to the shutter, and the third-embodiment outlet duct 51 in which the prominent central liner 56 is housed free from the third- embodiment movable equipment 53. The second-embodiment electromagnetic coil 31 is housed on the outer diameter of the third-embodiment outlet duct 51 thus acting on the central movable piston 57 through the central liner 56 and the third- embodiment outlet duct 51.

Similarly, in Figures 13, 14, 15 and 16, a fourth embodiment 70 of solenoid valve is visible in which a first electromagnetic coil 2 is positioned in line with the fluid inlet duct 3 towards the valve 71, positioned opposite the inlet duct, which comprises a fourth-embodiment movable equipment 72, a shutter 6, and has two passage holes: a first loading hole 7 for a fourth-embodiment compensation chamber 73 and a fourth-embodiment second discharge hole 74, coaxial to the movable equipment of the shutter, and in contact with a first- embodiment movable piston 10 subject to the electromagnetic action of a first- embodiment armature 11, associated with the first-embodiment electromagnetic coil 2; in the closed position, Figure 13; the fourth-embodiment movable equipment 72 is in contact with the seat of the shutter 6 by means of an annular gasket with membrane 12; the first-embodiment movable piston is pushed by a spring 13 is in contact with the fourth-embodiment discharge hole 74 by means of a head gasket 14; said annular membrane gasket 12 suspends the fourth movable equipment 72 of the valve 71 and allows the movement thereof from the closed position to the open position, Figure 14. Together with the shutter 6 there is a fourth-embodiment shutter chamber 75 connected with radial duct 17 towards a loading gap 76, closed between an outer cylindrical wall 77 and the fourth- embodiment compensation chamber 73, and in turn connected, with lateral loading channel 78, parallel to said first-embodiment electromagnetic coil 2, with the inlet duct 3.

The fourth-embodiment valve body 79 of the valve 71 is made of three parts: a fourth-embodiment first part P4 comprises the inlet duct 3, the lateral loading channel 78, and the loading gap 76, delimited by the outer cylindrical wall 77; a fourth-embodiment second part S4 comprises the fourth-embodiment shutter chamber 75, the shutter 6, a radial duct 17, a fourth-embodiment outlet duct 80; a fourth-embodiment third part T4 is interposed between the two preceding parts to make a central bell 48 to enclose the fourth-embodiment compensation chamber 73 and the axial sliding and guide liner 20 of the first-embodiment movable piston 10. The axial liner 20 has the seat of the first-embodiment movable piston 10 in connection with the fourth-embodiment compensation chamber 73, i.e, . the first- embodiment movable piston 10 and the spring 13 are inside the fourth- embodiment compensation chamber 73. The first-embodiment electromagnetic coil 2 is housed on the outer diameter of the axial containment and guide liner 20 of the first-embodiment movable piston, by means of a usual type of cradle 21 of the coil; the first-embodiment electromagnetic coil 2 and the cradle 21 thereof are inserted radially, in the fourth-embodiment first part P4 at the lateral loading channel 78 before insertion, in the axial direction of the fourth-embodiment third part T4 with the axial liner 20 in the fourth-embodiment first part P4 of the valve body 79.

The connections in the fluid inlet and outlet duct are indicated generically since they are linked to the type of fluid treated. The depicted embodiment corresponds to a tap connection for water connection. The embodiments have been provided for a liquid, water, and for use in household appliances, i.e. , the parts depicted of the aforementioned valve bodies of the valves 19, 32 52 and 71 are made of plastic material and joined with laser or ultrasonic welding.

The assembly of the safety solenoid valve for fluids with controlled opening of the various described embodiments occurs with the following composition steps of the parts.

In the first embodiment, Figures 1-4, the movable parts are inserted M in the order of spring 13, first-embodiment movable piston 10, with head gasket inside the axial liner 20; then the gasket with membrane 12 is assembled on the first-embodiment movable equipment 5 so as to be installed in the special seats obtained in the first-embodiment first part P1 and in the first- embodiment second part S1 for the composition thereof with motion M1 and the fixing occurs between the two first P1 and second S1 parts of the first embodiment. The joined parts, being made of plastic material, are fixed by integral welding in an irreversible manner, such as laser or ultrasonic welding, at the contact edges between the aforementioned parts. The first-embodiment electromagnetic coil 2 is finally axially assembled A on the outer diameter of the axial liner 20 inside the housing compartment 25 and completely immersed with fixing and insulating resin; therefore, said electromagnetic coil is irreversibly made integral with the body of the solenoid valve.

The second embodiment, Figures 5-8, the movable parts are first assembled A2 on the stem 36 of the divided piston 37 in order by inserting the inner annular gasket 42, the second-embodiment movable equipment 33 on which the gasket with membrane 12 is already assembled, and then the stem 36 is inserted inside the ferromagnetic part 44, second part of the divided piston, and fixed by interlocking or welding or screwing; the assembled divided movable piston 37 is provided with the spring 13 and inserted M in the guide 39 of the second- embodiment third part T2 inside the central chamber 48; then the subset obtained by housing the gasket with membrane 12 on the edge of the second-embodiment compensation chamber 34 and simultaneously on the edge of the loading chamber 47 so as to be installed in the aforementioned special seats for the composition thereof with motion M2; subsequently the two first P2 and second S2 parts of the second embodiment are fixed with the axial introduction inside the outer cylindrical part 46 on the second-embodiment first part P2 of said subset. The joined parts, being made of plastic material, are fixed by integral welding in an irreversible manner, such as laser or ultrasonic welding, at the contact edges between the aforementioned parts. The second-embodiment electromagnetic coil 31 is finally axially assembled A on the outer diameter of the central outlet duct 43 inside the housing compartment 25 and completely immersed with fixing and insulating resin; therefore, said electromagnetic coil is irreversibly made integral with the body of the solenoid valve.

Thus the third embodiment, Figures 9-12, the movable parts are assembled A3 in the third-embodiment movable equipment 53 in the order of annular gasket with membrane 12, opposite gasket 60 and central movable piston 57 and spring 13 inside the central liner 56 of the third-embodiment movable equipment 53, therefore, with assembly M the set of equipment is inserted in the third-embodiment outlet duct 51, positioning the gasket with membrane 12 in the seat on the edge of the annular loading chamber 64 of the third-embodiment second part S3, so as to be installed in the special seat obtained in the third- embodiment first part P3 of the third-embodiment compensation chamber 54 with the composition thereof with motion M3; the fixing of the two first P3 and second S3 parts of the third embodiment occurs with the axial introduction inside the outer wall 63 on the aforesaid third-embodiment first part P3 of the third-embodiment second part S3 with the movable parts and the movable equipment and movable piston set assembled thereon. The joined parts, being made of plastic material, are fixed by integral welding in an irreversible manner, such as laser or ultrasonic welding, at the contact edges between the aforementioned parts. The second- embodiment electromagnetic coil 31 is finally axially assembled A on the outer diameter of the third-embodiment outlet duct 51 inside the housing compartment 25 and completely immersed with fixing and insulating resin; therefore, said electromagnetic coil is irreversibly made integral with the body of the solenoid valve.

Finally, in the fourth embodiment, Figures 13-16, the movable parts are inserted M in the order spring 13, first-embodiment movable piston 10, with head gasket 14 inside the axial liner 20 present in line with the fourth- embodiment third part T4; then the gasket with membrane 12 is assembled on the third-embodiment movable equipment 72 so as to be installed in the special seats obtained in the fourth-embodiment third part T4 and in the fourth-embodiment second part S4 with the composition thereof with motion M4. The first- embodiment electromagnetic coil 2 is finally mounted radially R in the special compartment parallel to the lateral loading channel 78 and in line with the outer cylindrical wall 77; said first-embodiment electromagnetic coil 2 is fixed to the assembly of the fourth-embodiment third part T4 with the assembly indicated below and cannot be removed except by destroying the constituent parts of the valve body 79. Then, the fixing of the two first P4 and second S4 parts of the fourth embodiment occurs with the axial introduction inside the outer cylindrical wall 77 on the aforementioned fourth-embodiment first part P4 of the fourth- embodiment second part S4 with the fourth-embodiment third part T4 and the movable parts of the movable equipment and movable piston assembled thereon. The joined parts, being made of plastic material, are fixed by integral welding in an irreversible manner, such as laser or ultrasonic welding, at the contact edges between the aforementioned parts. The first-embodiment electromagnetic coil 2 remains blocked on the outer diameter of the axial liner 20 and inside the housing compartment 25, completely immersed with fixing and insulating resin; therefore, said electromagnetic coil is irreversibly made integral with the body of the solenoid valve. The advantages in the use and assembly of a safety solenoid valve for fluids with controlled opening in the embodiments described herein are evident when considering the minimum dimensions of each embodiment in addition to the radial dimensions of each which is almost axially symmetrical. The installation even in narrow passages, such as in the water connection pipes of modern appliances, can be obtained simply and easily so as to reduce the technical spaces in modern domestic appliances where minimizing space in the construction thereof is highly desired. Moreover, the hermetic constitution eliminates operating uncertainty and possible tampering with the solenoid valve and the tube for water supply to the appliance.

Furthermore, the creation and assembly with the four described embodiments allow a considerable limitation of the number of components, the creation difficulty thereof and, even more so, given the general action with axial assembly motion, also an automation of the assembly of the individual parts and/or subsets described; in fact, all the assembly operations can be automated, comprising the pouring of the fixing resin and waterproofing of the housing compartment 25 of the coil both outwards, against the penetration of external liquids, and also from the inside, especially in the fourth embodiment where said resin makes the connection of the liner 20 of the movable piston 10 waterproof when housed through the wall of the second part S4 towards the housing compartment 25 of the coil, blocking infiltrations from the underlying loading gap 76 under pressure. That is, the hermetic safety solenoid valves described herein, in each of the four embodiments described, allow to make the production and assembly thereof extremely easy and economical, as well as the use thereof extremely safe to prevent any tampering.

Obviously, a person skilled in the art, in order to satisfy specific and contingent requirements, may make numerous modifications to a hermetic safety valve for fluids with controlled opening, as previously described, all nevertheless falling within the scope of protection of the present invention as defined by the following claims.