Hydraulic device comprising a check valve and related household appliance

Abstract

Hydraulic device (1) for a circuit (P) for the circulation of a flow of fluid in a household appliance (A), comprising : at least one inlet (11), whereat a fluid arrives at an inlet pressure (Pin); and at least one outlet (12), whereupon a continuous backpressure (Pbp) acts; and sealing elements (13), adapted to allow the fluid to circulate in the circuit (P) without any leakage; and a check valve (2) comprising : a valve body (3) defining a passage duct (32), through which a fluid can flow, in turn comprising : an inlet (321) adapted to allow the fluid to flow in at the inlet pressure (Pin); at least one outlet (323) subjected to the backpressure (Pbp); and an intermediate portion (322) connecting the inlet (321) and the outlet (323), and defining a first chamber (324); a piston ( 4 ), located in the first chamber (324) adapted to slide within the first chamber (324) to allow the fluid to flow from the inlet (321) towards the outlet (323); a thrust element (5), adapted to move the piston (4) in order to allow the fluid to flow only from the inlet (321) to the outlet (323). The valve body (3) comprises a second chamber (33), which is always at atmospheric pressure, in communication with the first chamber (324). The piston (4) comprises at least one sealing element (6) to prevent part of the fluid in the first chamber (324) from flowing into the second chamber (33). The thrust element (5) is located in the second chamber (33) and operates at atmospheric pressure, acting upon the second portion (42) of the piston (4). The check valve (2) is a vertical valve.

Description

[0001] TITLE : HYDRAULIC DEVICE COMPRIS ING A CHECK VALVE AND

[0002] RELATED HOUSEHOLD APPLIANCE .

[0003] The present invention relates to a hydraulic device adapted to be included in a circuit for the circulation of a flow of fluid in a household appliance , comprising a check valve subj ect to backpressure , which backpres sure may also be continuous over time .

[0004] The present invention also concerns a household appliance comprising said hydraulic device .

[0005] It is known that check valves must allow a fluid to flow in one direction only, preventing it from flowing in the opposite direction .

[0006] Ideally, when the inlet pressure drops , said check valve should close to prevent a flow of fluid in the undesired direction from being established in the hydraulic device that comprises such check valve .

[0007] It is also known that , however, conditions may arise during transient phases in which the check valve may not operate correctly and may let some fluid flow in the undesired direction, thus not properly performing its task .

[0008] This problem is particularly felt whenever in the hydraulic device there is a backpressure acting upon the outlet of the check valve . This problem gets even worse when the backpressure at the valve outlet is continuous over time .

[0009] Furthermore , this problem becomes particularly apparent when the outlet of the check valve is perpendicular to the axis of extension of the valve body .

[0010] There is an ever increasing demand for hydraulic devices compris ing check valves capable of avoiding hydraulic stoppage phenomena when the pressure or f low rate at the inlet decreases in the presence of a backpressure at the outlet .

[0011] Also , no hydraulic devices are known in the art which comprise check valves wherein the valve outlet is perpendicular to the extension of the valve body and / or to the direction of motion of the obstructer, e . g . a vertical check valve with a radial outlet .

[0012] The present invention aims at solving the above- mentioned technical problems by providing a hydraul ic device comprising a check valve that can operate in the presence of a continuous backpressure , while proving safe and reliable .

[0013] One aspect of the present invention relates to a hydraulic device having the features set out in the appended claim 1 .

[0014] A further aspect of the present invention relates to a household appliance having the features set out in claim 10 .

[0015] Auxiliary features of the hydraulic device and household appliance are set out in the appended dependent claims .

[0016] The features and advantages of the hydraulic device and household appliance will become clear and apparent in light of the following description of several possible embodiments thereof , provided herein merely by way of nonlimiting example , as well as from the annexed drawings , wherein :

[0017] • Figures 1A and IB show sectional views along a vertical plane of one possible embodiment of a check valve comprised in a hydraulic device according to the present invention, wherein Figure 1A shows the check valve in the closed condition, and Figure IB shows the check valve in the open condition;

[0018] • Figure 2 shows a sectional axonometric view of the check valve , illustrated in Figures 1A and IB, comprised in a hydraulic device according to the present invention;

[0019] • Figure 3 shows a sectional view along a vertical plane of one possible embodiment of a hydraulic device according to the present invention in the form of a section of a hydraulic circuit ;

[0020] • Figures 4A and 4B show further possible embodiments of a hydraulic device according to the present invention, wherein : Figure 4A shows a hydraulic device in the form of a selector valve ; Figure 4B shows a hydraulic device in the form of a section of a hydraulic circuit comprised in a more complex hydraulic device ;

[0021] • Figures 5A and 5B show, by way of non-limiting example , two household appliances in which the hydraulic device according to the present invention may be included; in particular, Figure 5A shows a dishwasher ; Figure 5B shows an HVAC system .

[0022] With reference to the above-listed figures , reference numeral 2 designates a check valve as a whole and as such . Reference numeral 1 designates a hydraulic device as a whole and as such . Reference "A" designates a household appliance as a whole and as such .

[0023] Said hydraulic device 1 according to the present invention is suitable to be inserted in a hydraulic circuit "P" , in particular a circuit "P" for the circulation of a flow of fluid in a household appliance "A" . Said hydraulic device 1 according to the present invention comprises: at least one inlet 11, whereat a fluid arrives at an inlet pressure "Pin", and at least one outlet 12.

[0024] Said at least one inlet 11 is, for example, a radial inlet or an axial inlet.

[0025] Said at least one inlet 11 is located at a first height along a vertical axis "Z".

[0026] A continuous backpressure "Pbp" acts upon said at least one outlet 12.

[0027] Said outlet 12 is located at a second height along said vertical axis "Z".

[0028] In particular, said second height is different from said first height.

[0029] Said hydraulic device 1 according to the present invention further comprises sealing elements 13, adapted to allow the fluid to circulate in said circuit "P" at the desired pressure and / or flow rate, without any leakage.

[0030] Said hydraulic device 1 according to the present invention comprises at least one check valve 2.

[0031] Said check valve 2 comprises a valve body 3 defining a passage duct 32, through which said fluid can flow, along a direction of the flow of said fluid.

[0032] Said passage duct 32 in turn comprises: an inlet 321, adapted to allow said fluid to flow in at said inlet pressure "Pin"; at least one outlet 323, adapted to allow said fluid to flow out, and subject to a continuous backpressure "Pbp" in operation. Preferably, during the normal operation of said check valve 2, said backpressure "Pbp" is lower than, or at most equal to, said inlet pressure "Pin". Said passage duct 32 further comprises an intermediate portion 322 connecting said inlet 321 and said outlet 323 . Said intermediate portion 322 defines a first chamber 324 .

[0033] Said check valve 2 further comprises a piston 4 . Said piston 4 is located, at least partly, in said first chamber 324 . Said piston 4 is adapted to slide within said first chamber 324 to selectively allow the fluid to flow from said inlet 321 towards said outlet 323 . Said check valve 2 further comprises a thrust element 5 . Said thrust element 5 is adapted to move said piston 4 within said first chamber 324 , in order to allow the fluid to flow only in the direction from said inlet 321 to said outlet 323 .

[0034] Said check valve 2 is a vertical valve extending along said axis " Z" .

[0035] In said check valve 2 , said valve body 3 comprises a second chamber 33 . Said second chamber 33 is always at atmospheric pressure .

[0036] Said second chamber 33 is in communication, in particular in fluidic communication, with said first chamber 324 . Said valve body 3 is , in fact , so shaped as to define said first chamber 324 and said second chamber 33 communicating with each other .

[0037] In said check valve 2 , according to the present invention, said piston 4 comprises at least one sealing element 6 . Said at least one sealing element 6 i s adapted to prevent part o f the fluid in said first chamber 324 from flowing into said second chamber 33 , whatever the position taken by said piston 4 in said first chamber 324 . In the absence of said piston 4 comprising said at least one sealing element 6 , in fact , said second chamber 33 is in fluidic communication with said first chamber 324 . In said check valve 2 , according to the present invention, said piston 4 comprises : a first portion 41 facing said first chamber 324 ; and a second portion 42 facing said second chamber 33 .

[0038] Said thrust element 5 is located in said second chamber 33 . Said thrust element 5 operates at atmospheric pressure , which pressure is lower than that of the incoming flow, in particular lower than said inlet pressure "Pin" . Said thrust element 5 acts upon said second portion 42 of said piston 4 .

[0039] Hydraulic device 1 according to the present invention comprises a unidirectional check valve 2 , by means of which a given flow rate o pressure at said inlet 321 o f passage duct 32 of valve body 3 , in particular corresponding to a known inlet pressure "Pin" acting upon said inlet 11 of hydraulic device 1 , can move said piston 4 , preferably causing it to slide , within said first chamber 324 , thereby allowing the fluid to reach outlet 323 , so as to obtain a predetermined fluid flow also through said outlet 323 , and hence through said outlet 12 of hydraulic device 1 .

[0040] Check valve 2 comprised in hydraulic device 1 according to the present invention is unidirectional , and does not allow the fluid to flow from said outlet 323 towards said inlet 321 , thus preventing the fluid from flowing back from said outlet 12 to said inlet 11 of hydraulic device 1 .

[0041] The present invention avoids the risk that the fluid might flow from said outlet 12 to said inlet 11 of hydraulic device 1 even when a backpressure "Pbp" , e . g . a known backpressure "Pbp" , is continuously present at said outlet 12 . Check valve 2 comprised in hydraulic device 1 according to the present invention allows the fluid to flow in the desired direction even in the presence of a continuous backpressure acting upon said outlet 12 of the hydraulic device , because that part which ensures the return of said piston 4 , particularly said thrust element 5 , works at a pressure that is always lower than that of the incoming flow of fluid, which equals said inlet pressure "Pin" . A truly unidirectional check valve 2 is thus obtained .

[0042] The present invention also makes it possible to simpli fy the assembling of the hydraulic device 1 , since said thrust element 5 of said check valve 2 is located in a second chamber 33 , which is di f ferent from said first chamber 324 where said piston 4 moves .

[0043] The present invention is also applicable to hydraul ic circuits "P" where the inlets and the outlets are disposed at di f ferent levels .

[0044] Preferably, said thrust element 5 is designed to act upon said piston 4 in such a way as to prevent the fluid from flowing from said outlet 323 to said inlet 321 , and hence from said outlet 12 to said inlet 11 of hydraulic device 1 , said check valve 2 being a normally-closed check valve .

[0045] In hydraulic device 1 according to the present invention, when said inlet pressure "Pin" , or a predetermined flow rate , is present at said inlet 11 , and is therefore also present at said inlet 321 of passage duct

[0046] 32 of valve body 3 of said check valve 2 , it will cause said piston 4 to move , preferably by sliding downwards , along said axis " Z" in said first chamber 324 , thus allowing the fluid to reach outlet 323 of said check valve 2 , and hence said outlet 12 of said hydraulic device 1 . In this manner, the present invention makes it pos sible to obtain a predetermined flow rate of fluid also at said outlet 12 of hydraulic device 1 . Preferably, as long as the rate of said flow of fluid cannot overcome the force exerted on said piston 4 by said thrust element 5 , said piston 4 will keep occupying said first chamber 324 , thus preventing the f luid from flowing towards said outlet 323 of check valve 2 , and consequently towards said outlet 12 of hydraulic device 1 . When there is an inlet pressure "Pin" capable o f overcoming the force exerted on said piston 4 by said thrust element 5 , said piston 4 wi ll slide downwards along said axis " Z" , thus clearing said first chamber 324 and occupying said second chamber 33 , thereby allowing the fluid to flow from said inlet 321 towards said outlet 323 , and consequently from said inlet 11 to said outlet 12 of hydraulic device 1 .

[0047] In a preferred, but merely illustrative and nonlimiting, embodiment of said check valve 2 of hydraulic device 1 according to the present invention, said outlet 323 is perpendicular to an axis , e . g . said axis " Z" , along which said piston 4 slides within said first chamber 324 , said axis being the axis along which said first chamber 324 develops . The present embodiment turns out to be particularly novel in that said outlet 323 is not axial to said first chamber 324 , i . e . it is perpendicular to the direction of the flow of fluid . With such a conformation, said backpressure "Pbp" cannot be exploited to move said piston 4 for the purpose of closing said check valve 2 , since the force of said backpressure is not in axis with the direction of motion of said piston 4 .

[0048] Even more preferably, said outlet 323 of said check valve 2 is radial relative to said axis " Z" .

[0049] In one possible embodiment , said passage duct 32 comprises two or more outlets 323 . Preferably, said outlets 323 are radial and angularly equidistant from each other .

[0050] In one possible , but merely illustrative and nonlimiting, embodiment of said check valve 2 of said hydraulic device 1 according to the present invention, said inlet 321 is radial to said axis " Z" . The present embodiment makes the action of said inlet pressure "Pin" less dependent on the movement of said piston 4 , thus further increasing the importance of said thrust element 5 for the correct operation of said check valve 2 .

[0051] In another possible , but merely illustrative and nonlimiting, embodiment of said check valve 2 of said hydraulic device 1 according to the present invention, said inlet 321 is axial relative to said axis " Z" , e . g . it is aligned with said axis " Z" .

[0052] In a preferred, but merely illustrative and nonlimiting, embodiment of said check valve 2 of said hydraulic device 1 according to the present invention, said piston 4 is a monolithic element . Preferably, said piston 4 is made of plastic material .

[0053] In a preferred embodiment , said piston 4 has a substantially cyl indrical shape , matching the shape of said first chamber 324 and said second chamber 33 .

[0054] In a preferred, but merely illustrative and nonlimiting, embodiment of said check valve 2 of said hydraulic device 1 according to the present invention, said piston 4 comprises two sealing elements 6 . The present embodiment ensures that the fluid in said first chamber 324 cannot flow into said second chamber 33 , whatever the position taken by said piston 4 in said first chamber 324 .

[0055] Preferably, said two sealing elements 6 are arranged at di f ferent levels of said piston 4 relative to said axis " Z" . More preferably, a first sealing element 6 is located in proximity to said first portion 41 of said piston 4 , which faces towards said first chamber 324 ; whereas a second sealing element 6 is located in proximity to said second portion 42 , which faces towards said second chamber 324 . Even more preferably, said second sealing element 6 is arranged on said piston 4 in such a way that said sealing element 6 will never reach the level of said outlet 323 , particularly in the embodiment wherein said outlet 323 is perpendicular, preferably radial , to said axis " Z" .

[0056] Generally, said at least one sealing element 6 is a gasket , e . g . an O-ring .

[0057] Said piston 4 comprises at least one housing adapted to receive said at least one sealing element 6 .

[0058] Generally, in a preferred embodiment , said piston 4 comprises a guiding element 43 . In the present embodiment of check valve 2 of said hydraulic device 1 according to the present invention, said second chamber 33 and said thrust element 5 are , advantageously, so shaped as to allow said guiding element 43 to slide as said piston 4 moves . The present embodiment makes it possible to keep said piston 4 aligned along said axis " Z" as it moves within said first chamber 324 .

[0059] Generally, in a preferred, but merely illustrative and non-limiting, embodiment of said check valve 2 of said hydraulic device 1 according to the present invention, said thrust element 5 is a coil spring . Said coil spring may be cylindrical , conical , and / or a combination thereof . The present embodiment makes it possible to exert a thrust force on said pi ston 4 , wherein said thrust force can be varied, e . g . by replacing said coil spring 5 with another coil spring having a di f ferent elastic constant . Moreover, the use of a coil spring allows for easy assembling . The present embodiment also permits implementing said piston 4 comprising said guiding element 43 . In the present embodiment , in fact , said guiding element 43 is adapted to move within the central volume defined by said coil spring 5 , thus simpli fying the process of assembling said check valve 2 .

[0060] In a preferred, but merely illustrative and nonlimiting, embodiment of said check valve 2 of said hydraulic device 1 according to the present invention, said second chamber 33 is defined by means of a closing element 34 . In the present embodiment , said valve body 3 is not monolithic, since it comprises a main body, in which said passage duct 32 is defined, which in turn compri ses said inlet 321 , said outlet 323 , and said intermediate portion 322 in which said first chamber 324 is defined; and said closing element 34 , which defines the lower part of said second chamber 33 .

[0061] Preferably, said closing element 34 is sealingly coupled to said main body of said valve body 3 , closing the valve body 3 at the bottom, with reference to said axis " Z" , to define said second chamber 33 . The present embodiment also allows implementing said piston 4 comprising said guiding element 43 . In the present embodiment , in fact , said closing element 34 comprises a through hole along which said guiding element 43 can slide .

[0062] More generally, said guiding element 43 is a cylindrical protrusion protruding from said second portion 42 of said piston 4 .

[0063] In addition, said closing element 34 comprises at least one opening, which is adapted to keep said second chamber 33 at said atmospheric pressure .

[0064] In general , said second chamber 33 has a substantially cylindrical shape .

[0065] In a preferred, but merely illustrative and nonlimiting, embodiment of said check valve 2 of said hydraulic device 1 , valve body 3 is designed in such a way that said first chamber 324 has a cylindrical conformation . Said first chamber 324 is designed to define an abutment edge whereon said at least one sealing element 6 , associated with said piston 4 , abuts when said check valve 2 is in the closed configuration . Preferably, it is the sealing element positioned on said first portion 41 of said piston 4 that abuts on said abutment edge of said first chamber 324 .

[0066] In general , the thrust action exerted on piston 4 by said thrust element 5 causes said sealing element 6 , which is in abutment with said abutment edge , to ensure hydraulic tightness .

[0067] In one possible , and preferred, embodiment of check valve 2 of said hydraulic device 1 according to the present invention, the phases of activation and operation of the unidirectional check valve 2 can be described as follows .

[0068] Within a hydraulic device 1 according to the present invention, when fluid enters through inlet 321 of passage duct 32 of valve body 3 of check valve 2 at a known inlet pressure "Pin" and / or flow rate, said fluid starts filling said first chamber 324 in the portion thereof above said first portion 41 of piston 4, and pushes said piston 4 downwards. As it moves downwards along said axis "Z", said piston 4 lets the fluid flow towards outlet 323. This configuration is maintained until the flow of fluid through said inlet 321 stops.

[0069] If the flow of fluid through the inlet is interrupted, in fact, during a first phase, or transient phase, the fluid already present in said first chamber 324 will keep flowing, by inertia, towards outlet 323. At the same time, the flow backpressure at the outlet 323, in particular said backpressure "Pbp" that is present at said outlet 12 of hydraulic device 1, will begin to prevail.

[0070] In check valve 2, thanks to the disposition of said thrust element 5, said piston 4 will be lifted again along said axis "Z", thus obstructing the fluid passage, and the back flow of fluid generated by said backpressure "Pbp" will not be able to return upstream of check valve 2, being thus prevented from reaching said inlet 321, and hence said inlet 11 of hydraulic device 1.

[0071] Check valve 2 will operate in the above-described manner also when said outlet 323 is perpendicular to the axis of extension of said first chamber 324, e.g. radial to said axis "Z".

[0072] Check valve 2 will cause the upstream pressure, i.e. the pressure at said inlet 321, to be higher than the downstream pressure thanks to thrust element 5, preferably a coil spring, positioned in said second chamber 33. Said second chamber 33 is, in turn, outside the flow of fluid that is allowed to enter said first chamber 324, between said inlet 321 and said outlet 323. Thus, said thrust element 5 will always operate at ambient pressure, regardless of the position of said piston 4 in said first chamber 324.

[0073] When said first phase, or transient phase, is complete, since the flow of fluid through said inlet 321 has definitively stopped, the backpressure "Pbp" at said outlet 323 will not cause said piston 4 to move within said first chamber 324.

[0074] Therefore, check valve 2 of said hydraulic device 1 according to the present invention operates as a unidirectional valve due to thrust element 5, preferably a coil spring, being positioned in air. In fact, the back flow that generates said backpressure "Pbp" at said outlet 323 is not allowed to return upstream of check valve 2 and reach said inlet 321.

[0075] Generally, said hydraulic device 1 is, for example, a hydraulic valve, a valve assembly, e.g. a selector valve, and / or, simply put, a portion of a hydraulic circuit "P", e.g. a portion of a duct adapted to allow a flow of fluid to circulate in a household appliance in a desired direction only.

[0076] Said hydraulic device 1 may be a water supply and / or treatment system, such as a water conditioning system, an air break device, a water softener, a water container, and / or an assembly, or a portion thereof, comprising any combination of such devices, or a part of a household appliance "A", such as, for example, a washing device, preferably a laundry washing machine and / or a dishwasher, or a part of a circuit "P" comprised in an HVAC system. Describing now in detail one possible , but merely illustrative and non-limiting, embodiment of said hydraulic device 1 according to the present invention, Figures 1A and IB show a sectional view along a vertical plane of one possible embodiment of check valve 2 of said hydraulic device 1 according to the present invention .

[0077] In particular, Figure 1A shows check valve 2 in the closed configuration . In Figure 1A, one can see a valve body 3 defining a passage duct 32 comprising, in turn, an axial inlet 321 , whereupon an inlet pressure "Pin" acts ; an intermediate portion 322 , defining said first chamber 324 , and an outlet 323 , radial to said axis " Z" , whereupon a backpressure "Pbp" acts .

[0078] Said first chamber houses said piston 4 , which, through an O-ring-type sealing element 6 abuts on an abutment edge in said first chamber, thus closing check valve 2 under the thrust exerted by thrust element 5 , which is provided in the form of a cylindrical coil spring . Said coil spring 5 i s housed in second chamber 33 , which is defined at the bottom by said closing element 34 . Said second chamber 33 is kept at atmospheric pressure , although it is in fluidic communication with said first chamber 324 , by said piston 4 , which comprises a second sealing element 6 that prevents the fluid from flowing from said first chamber 324 to said second chamber 33 .

[0079] In the embodiment illustrated in Figure 1A, said piston 4 comprises a first portion 41 facing said first chamber 324 , and a second portion 42 facing said second chamber 33 . In the illustrative and non-limiting embodiment shown in Figure 1A, said first portion 41 of piston 4 has a domelike shape .

[0080] From said second portion 42 o f said piston 4 , a guiding element 43 extends axial to said coil spring 5 and exits said second chamber through a suitable hole formed in said closing element 34 . Said closing element comprises at least one additional opening to keep said second chamber at atmospheric pressure .

[0081] Figure IB shows check valve 2 of a hydraulic device 1 according to the present invention in the open configuration . By comparing Figure IB with said Figure 1A, one can notice that piston 4 has slid downwards along said axis " Z" , thus occupying said second chamber 33 , under the thrust exerted by an inlet pressure "Pin" , such as to overcome the thrust force of coil spring 5 , so that the fluid can flow from said axial inlet 321 towards said radial outlet 323 . Sealing elements 6 prevent the fluid from entering said second chamber 33 , thus keeping said second chamber 33 at atmospheric pressure .

[0082] In Figure IB one can also see that guiding element 43 has come out , at least partly, of said second chamber through the dedicated hole formed in the closing element 34 .

[0083] Figure IB also shows coil spring 5 compressed under the sliding action of piston 4 .

[0084] Figure 2 shows a sectional side view of check valve 2 illustrated in Figures 1A and IB of hydraulic device 1 according to the present invention in the closed configuration . In Figure 2 , one can see further construction detai ls of the embodiment shown in Figures 1A and IB . In fact , it shows that said passage duct 32 is so shaped as to comprise multiple outlets 323 , which are radial to said axis "X" . In this figure it i s also visible that under said axial inlet 321 said first chamber 324 extends , which houses piston 4 comprising two sealing elements 6 in the form o f two 0- rings .

[0085] Under piston 4 shown in Figure 2 said second chamber 33 develops , which houses said thrust element 5 , in the form of a coil spring, acting upon, i . e . pushing against, said piston 4 .

[0086] Figure 2 also shows said closing element 34 comprising a hole in which guiding element 43 is inserted .

[0087] Lastly, Figure 2 also shows additional sealing elements , in the form of 0-rings , seated in suitable housings , which will ensure tightness of check valve 2 when the latter is inserted in a hydraulic device 1 .

[0088] Figure 3 shows one possible embodiment of a hydraul ic device 1 according to the present invention in the form of a section of a hydraulic circuit "P" . Figure 3 shows hydraulic device 1 in a sectional view along a vertical plane .

[0089] Figure 3 shows check valve 2 incorporated into a structure of a circuit "P" , which comprises a radial inlet 11 whereat a fluid arrives at an inlet pressure "Pin" .

[0090] In Figure 3 , check valve 2 is in an open configuration, and arrows indicate the path followed by the fluid from said inlet 11 to said outlet 12 , whereupon a backpressure "Pbp" acts . Check valve 2 of hydraulic device 1 shown in Figure 3 is incorporated into the structure of hydraulic device 1 , and sealing elements 13 are comprised, in the form of 0- rings , to guarantee hydraulic tightness .

[0091] Check valve 2 shown in Figure 3 is the same as the one shown in the preceding figures . Therefore , it will not be described any further .

[0092] Figure 4A shows another possible embodiment of a hydraulic device 1 according to the present invention, in the form of a selector valve . Said selector valve 1 is shown in a sectional view along a vertical plane . Said selector valve 1 comprises , in addition to a check valve 2 , a rotary actuator ; a first camshaft , rotatably driven by said rotary actuator and adapted to move one or more selectors ; a second camshaft , rotatably driven by said first camshaft , said camshafts being mutually synchronous , and adapted to move one or more selectors . Said selector valve 1 comprises an inlet 11 , whereupon an inlet pressure "Pin" acts , and at least one outlet 12 , whereupon a backpressure "Pbp" acts continuously over time . Said selector valve 1 comprises sealing elements 13 allowing the fluid to circulate at the desired pressure and / or f low rate without any leakage .

[0093] Said selector valve 1 defines a section of a circuit "P" for the circulation of a flow of fluid in a household appliance "A" .

[0094] In Figure 4A one can see check valve 2 comprising an inlet 321 and an outlet 323 , both of which are radial relative to said axis " Z" . Said check valve 2 is incorporated into selector valve 1 . At inlet 321 of said check valve 2 there is an inlet pressure "Pin" ; whereas at said outlet 323 there is a continuous backpressure "Pbp" .

[0095] Figure 4B shows another possible embodiment of a hydraulic device 1 according to the present invention, in the form of a section of a hydraulic circuit " P" . Said section of hydraulic circuit "P" may be comprised in a more complex hydraulic device 1 , such as a water conditioning circuit , an air break device , a water softener, a water container, and / or an assembly comprising any combination of such devices .

[0096] Figure 4B shows hydraulic device 1 in a sectional view along a vertical plane .

[0097] In Figure 4B, check valve 2 is incorporated into a structure of a circuit "P" , which comprises a radial inlet 11 , whereat a fluid arrives at an inlet pressure "Pin" .

[0098] In Figure 4B, check valve 2 is shown in a closed configuration, and a backpressure "Pbp" is indicated at said outlet 12 .

[0099] Check valve 2 of hydraulic device 1 shown in Figure 4B is incorporated into the structure of hydraulic device 1 . Check valve 2 shown in Figure 4B is the same as the one shown in the preceding figures and will not , therefore, be described any further .

[0100] A further aspect of the present invention concerns a household appliance "A" comprising a hydraulic circuit "P" for the circulation of a flow of fluid in said household appliance "A" .

[0101] Said household appliance "A" comprises a hydraulic device 1 according to the present invention . Generally, said household appliance "A" according to the present invention is a dishwasher, a laundry washing machine , an air conditioner, etc .

[0102] Preferably, said household appliance "A" is a washing device , such as , for example , a dishwasher or a laundry washing machine , or an HVAC system for heating, ventilation and / or air conditioning, e . g . an air conditioner, a boiler, an air puri fier, or a heat pump, even mutually integrated into a single system to maximi ze ef ficiency and comfort .

[0103] Describing now some possible construction details of one possible household appliance "A" according to the present invention, Figures 5A and 5B show, by way of nonlimiting example , two household appliances "A" in which hydraulic device 1 according to the present invention may be comprised .

[0104] In particular, Figure 5A shows a dishwasher compris ing a hydraulic device 1 in the form of a water supply and conditioning system . Said water supply and conditioning system 1 is comprised in a hydraulic circuit "P" comprised in said dishwasher "A" . Said water supply and conditioning system 1 includes a check valve 2 .

[0105] On the other hand, Figure 5B shows an HVAC system comprising a hydraulic device 1 . In particular, Figure 5B shows an air conditioner comprising an outdoor unit and an indoor unit . Said outdoor unit comprises a circuit "P" for the circulation of a fluid, which circuit includes a hydraulic device 1 according to the present invention . Said hydraulic device 1 comprises , in turn, a check valve 2 .

[0106] In general , check valve 2 of hydraulic device 1 according to the present invention is unidirectional , since it prevents the fluid from flowing back from said outlet 323 to said inlet 321 , and hence from said outlet 12 to said inlet 11 . In particular, check valve 2 is still unidirectional even when said outlet 323 is perpendicular or radial to said axis " Z" , along which said first chamber 324 , where said piston 4 slides , extends .

[0107] Check valve 2 of hydraulic device 1 according to the present invention is unidirectional , allowing the f luid to flow in the desired direction from said inlet 321 to said outlet 323 in the presence of a continuous backpres sure at said outlet 12 of the hydraulic device . This is because that part which provides the returning movement of piston 4 , in particular said thrust element 5 , always operates at a pressure which is lower than that of the incoming flow .

[0108] I f the incoming flow stops , check valve 2 of hydraulic device 1 according to the present invention will still operate correctly, notwithstanding the presence of a backpressure "Pbp" acting upon outlet 323 , thanks to thrust element 5 being positioned in air . In check valve 2 of hydraulic device 1 according to the present invention, the fluid will be prevented from flowing back upstream of said check valve 2 .

[0109] Other alternative embodiments , which have not been described or illustrated in the present patent appl ication, but which can be easily inferred by a person skilled in the art in light o f the contents of the present patent application, should be considered to fall within the technical teachings of the present patent application . REFERENCE NUMERALS

[0110] Hydraulic device 1

[0111] Inlet 11

[0112] Outlet 12

[0113] Sealing elements 13

[0114] Check valve 2

[0115] Valve body 3

[0116] Passage duct 32

[0117] Inlet 321

[0118] Intermediate portion 322

[0119] Outlet 323

[0120] First chamber 324

[0121] Second chamber 33

[0122] Closing element 34

[0123] Piston 4

[0124] First portion 41

[0125] Second portion 42

[0126] Guiding element 43

[0127] Thrust element 5

[0128] Sealing element 6

[0129] Household appliance "A"

[0130] Circuit "P"

[0131] Inlet pressure "Pin"

[0132] Backpressure "Pbp"

[0133] Axis " Z"

[0134] Barzand & Zanardo S . p .A.

Claims

CLAIMS1. Hydraulic device (1) adapted to be included in a hydraulic circuit (P) for the circulation of a flow of fluid in a household appliance (A) ; said hydraulic device (1) comprising:- at least one inlet (11) , located at a first height along a vertical axis (Z) , whereat a fluid arrives at an inlet pressure (Pin) ; at least one outlet (12) , whereupon a continuous backpressure (Pbp) acts, said at least one outlet (12) being located at a second height along said vertical axis (Z) , said second height being different from said first height ; sealing elements (13) , adapted to allow the fluid to circulate in said circuit (P) at the desired pressure and / or flow rate, without any leakage;- at least one check valve (2a) , in turn comprising:- a valve body (3) defining a passage duct (32) , through which said fluid can flow, along a direction of the flow of said fluid, in turn comprising:• an inlet (321) adapted to allow said fluid to flow in at said inlet pressure (Pin) ;• at least one outlet (323) adapted to allow said fluid to flow out, and subjected to a continuous backpressure (Pbp) in operation;• an intermediate portion (322) connecting said inlet (321) and said outlet (323) , and defining a first chamber (324) ;- a piston (4) , at least partly located in said first chamber (324) , adapted to slide within said first chamber (324) to selectively allow the fluid to flow from said inlet (321) towards said outlet (323) ;- a thrust element (5) , adapted to move said piston (4) within said first chamber (324) , in order to allow the fluid to flow only in the direction from said inlet (321) to said outlet (323) ; said hydraulic device (1) being characterized in that: said check valve (2) being a vertical valve extending along said axis (Z) ;- said valve body (3) of said check valve (2) comprises a second chamber (33) , which is always at atmospheric pressure ;- said second chamber (33) being in communication with said first chamber (324) ;- said piston (4) comprising at least one sealing element (6) adapted to prevent part of the fluid in said first chamber (324) from flowing into said second chamber (33) , whatever the position taken by said piston (4) in said first chamber (324) ;- said piston (4) comprising a first portion (41) facing said first chamber (324) and a second portion (42) facing said second chamber (33) ; said thrust element (5) being located in said second chamber (33) and operating at atmospheric pressure, which pressure is lower than that of the incoming fluid, and acting upon said second portion (42) of said piston (4) .

2. Hydraulic device (1) according to claim 1, wherein said outlet (323) is radial relative to said axis (Z) .

3. Hydraulic device (1) according to claim 1 or 2, wherein said inlet (321) is:- radial relative to said axis (Z) ; or- axial relative to said axis (Z) .

4. Hydraulic device (1) according to one of the preceding claims, wherein said piston (4) comprising two sealing elements (6) arranged at two different levels of said piston (4) relative to an axis (Z) .

5. Hydraulic device (1) according to one of the preceding claims, wherein said thrust element (5) is a coil spring.

6. Hydraulic device (1) according to one of the preceding claims, wherein- said piston (4) comprising at least one guiding element (43) ; said second chamber (33) and said thrust element (5) being so shaped as to allow said guiding element (43) to slide as the piston moves (4) .

7. Hydraulic device (1) according to one of the preceding claims, wherein said second chamber (33) being defined through a closing element (34) sealingly coupled to a main body of said valve body (3) .

8. Hydraulic device (1) according to claims 5, 6 and 7, wherein :- from said second portion (42) of said piston (4) said guiding element 43 extends, which is positioned axially relative to said coil spring (5) ;- said closing element (34) comprises a through hole along which said guiding element (43) can slide.

9. Hydraulic device (1) according to one of the preceding claims, wherein said hydraulic device (1) is a hydraulic valve; a valve assembly; and / or a portion of a hydrauliccircuit "P" , adapted to allow a flow of fluid to circulate in a household appliance (A) in a desired direction only .10 . Household appliance (A) comprising a hydraulic circuit( P) for the circulation of a flow of fluid in said household appliance (A) ; said household appliance (A) comprising a hydraulic device ( 1 ) according to one of the preceding claims .11 . Household appliance (A) according to claim 10 , wherein said household appliance (A) is a washing device or an HVAC system . / EB

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