Knob for a household appliance

Abstract

The object of the present invention is a knob (1) for the switching on of a household appliance, for example a gas cooktop, and subsequent switching off. The knob (1) comprises at least one stator (20) equipped with at least first conductive sectors (23.a) which together form a plurality of capacitors (C), at least one first rotor (3) mounted so as to rotate with respect to the stator (2) and configured to interact with said first conductive sectors (23.a), one ring nut (4) configured to set and adjust at least a first operating parameter of said household appliance, one second rotor (7) configured to interact with second conductive sectors (23.b) of the stator (2) capable of detecting a change in the angular position and / or linear / longitudinal position of a ball grip (5), one actuator (8) for the automatic shut off of a gas valve (6) of the cooktop.

Description

[0001] KNOB FOR A HOUSEHOLD APPLIANCE

[0002] DESCRIPTION

[0003] The present invention relates to a knob for the activation / deactivation of a household appliance, integrating a timing function for an operation that may be performed by said household appliance.

[0004] More precisely, the object of the present invention is a knob designed for the activation of a household appliance and the subsequent automatic switching off thereof upon the expiration of an operating time previously set by a user.

[0005] The invention primarily falls within the sector of the production of household appliances, more precisely in the field of household appliances for cooking food and dishes, such as cooktops, preferably “gas”, and relative components.

[0006] Naturally, nothing prevents the possibility of extending the use of the aforementioned knob also to other sectors, for example, to that of the gas cookers and / or ovens, gas barbecues, as well as any other type of household appliance that provides for the use of a knob and / or button for the ignition / switching off thereof and / or for the programming of an operating cycle thereof.

[0007] It is known that, in the sector of gas household appliances for cooking, the aforementioned knob represents part of a user interface through which the ignition / shut off of a gas burner, e.g., of a gas cooktop, may be controlled.

[0008] In fact, the rotation of such knob allows the gas valve to be partially or completely opened or shut off, by conseauentlv controlling the gas flow that may reach the burner from the grid or a storage tank.

[0009] Possible indicators on the knob allow the burner to be set to different power values, facilitating the regulation thereof.

[0010] By now, almost all knobs used on gas cooking household appliances are usually configured to operate also as a “button”, i.e., they may be pressed to operate a piezoelectric igniter (or similar devices) and generate an electric discharge for the ignition of the gas flowing to the burner, where a flame is thus created.

[0011] The gas cooking household appliances may also integrate timers that allow the users to set the desired cooking time, improving the efficiency and safety of cooking.

[0012] For this purpose, “mechanical timers” are known, that may be manually operated and generally working through a spring mechanism without requiring electrical power, or “electronic timers”, that are more advanced and precise than the formers, generally equipped or cooperating with a digital display capable of showing the passage of the set time, facilitating the management of the cooking process.

[0013] The integration of timers into household appliances for cooking food and dishes is not free from drawbacks.

[0014] For example, such integration may increase the production cost of the household appliance, as further processing is required for the correct housing and assembly thereof; this also inevitably reflects on the sale cost of the household appliance, making it less accessible to a certain segment of consumers.

[0015] Furthermore, the presence of an integrated timer does not always ensure a correct and safe use of the household appliance.

[0016] For example, as regards the cooktops, inexperienced or distracted users may leave pots unattended on the burner while it is still ignited, even if the timer has already indicated the end of the cooking time.

[0017] This may burn the food in preparation or, in more serious cases, lead to domestic accidents.

[0018] The object of the present invention is to eliminate the above-listed drawbacks of the prior art, by providing for a knob for the activation / deactivation of a household appliance integrating a timing function for at least one of the operations that may be performed thereon.

[0019] A further object of the present invention, at least for one or more executive embodiments, is to provide for a knob for the activation of a household appliance further comprising an automatic shut off function of the same household appliance.

[0020] A further object of the present invention, at least for one or more executive embodiments, is to provide for a knob for the activation / deactivation of a household appliance that is economical to manufacture, easy to be integrated into the household appliance, safe, and reliable.

[0021] These and other objects are achieved in accordance with the invention, with the features listed in the annexed independent claim 1.

[0022] Further features of the present invention shall be better highlighted by the following description of one or more preferred embodiments, in accordance with the patent claims and illustrated, purely by way of a non-limiting example, in the annexed drawing tables, wherein:

[0023] - Figure 1 shows an exploded view of the knob for the activation / deactivation of a household appliance according to the invention;

[0024] - Figure 2 shows an overall view of part of the knob of figure 1, assembled and connected to a component of said household appliance;

[0025] - Figure 3 shows a section view of the knob of figure 1 in a first possible operating configuration;

[0026] - Figure 4 shows a section view of the knob of figure 1 in a second possible operating configuration.

[0027] The elements of the knob 1 for the activation / deactivation of a household appliance are now described, using the references described in the figures 1 to 4. With the purpose of highlighting some features instead of others, not necessarily what described in the figures is to scale.

[0028] It is also noted that any dimensional and spatial term (such as “lower”, “upper”, “inner”, “outer”, and the like) refers to the positions of the elements as shown in the attached figures, without any limiting intent relative to the possible operating conditions.

[0029] In the present description, reference shall be made, without any limiting intent, to a user interface, comprising at least one or more knobs 1, of a gas cooktop (not explicitly shown) configured for the ignition, the switching off and the regulation of at least one gas burner thereof.

[0030] Naturally, nothing prevents said user interface from being installed and used, with small adaptations within the reach of a man skilled in the art, also in other fields, for example in that of gas cookers and / or ovens and / or barbecues.

[0031] As shown in the accompanying figures, said user interface comprises a knob 1 for each burner of the cooktop.

[0032] Using the knob 1, a user may perform:

[0033] - the ignition of the burner and the shut off thereafter, at the end of the use thereof, and / or

[0034] - the setting and / or regulation of one or more operating parameters of the same burner, such as, by way of a non-limiting example, at least a first operating parameter consisting of a “cooking time” and a second operating parameter consisting of the thermal power that may be supplied.

[0035] Hereinafter, “cooking time” is to be understood as the desired operating time of the burner, set by a user in order to cook or pre-cook food and dishes or to implement a cooking step.

[0036] According to a first possible embodiment, shown by way of an example in figure 1, said knob 1 comprises at least one position sensor 2, for example an angular or linear position transducer.

[0037] According to a possible embodiment, said position sensor 2 may be of “incremental” or “absolute” type, capable, as is known, of detecting and “translating” a physical position or movement of a mechanical component into an electrical signal, subsequently acquired and processed by a control unit (not shown) to perform one or more of the aforementioned functions. It is known that such position sensor 2 may be indifferently of “capacitive” type, i.e., capable of performing the aforementioned detection, by exploiting changes in the electrical capacitance of one or more capacitors, or “inductive”, if it uses changes in the inductance generated by a metal element moving with respect to a coil, or “resistive” when it detects a change in the electrical resistance of a resistor.

[0038] For descriptive simplicity, during the present description, without any limiting intent, explicit reference shall be made to a capacitive position sensor 2.

[0039] Therefore, as shown in figure 1, the position sensor 2 of the knob 1 of the invention may comprise a stator 20 that has a first face 21, for clarity, referred to as “upper face” 21, and a second face 22, opposite to the first, herein referred to as “lower face 22”.

[0040] Preferably, the stator 20 may consist of the printed circuit board or PCB 20 of the position sensor 2, hereinafter “electronic board 20”.

[0041] A plurality of conductive tracks or sectors 23. a (hereinafter simply “conductive sectors”) are also provided on at least one face 21, 22 of the electronic board 20, which, in a known manner and according to a possible embodiment, together form the plates of a plurality of capacitors C.a arranged side by side to define a suitably designed ring or pads.

[0042] Such first conductive sectors 23. a define a first encoder of the position sensor 2 which, by cooperating, as will be seen, with other components of the knob 1, allows the setting and detection of a cooking time.

[0043] In the example of figures 1-4, said conductive sectors 23. a are preferably provided at least at the upper face 21 of the electronic board 20.

[0044] The conductive sectors 23. a are also in electrical communication with the aforementioned control unit, which is powered by a connector mounted on the electronic board 20 and connected to an electrical power supply (e.g., the electrical grid and / or a battery).

[0045] The position sensor 2 further comprises a movable element 3 consisting of a rotor 3 rotatably mounted with respect to the electronic board 20, i.e., capable of rotating around an axis perpendicular to said electronic board 20 and preferably passing through the centre O of the formed ring or pads of the conductive sectors 23. a.

[0046] According to a possible embodiment, the rotor 3, which may be operated in the manners that shall be seen by the knob 1 of the invention, may comprise one disk 30, a face 31 whereof, hereinafter referred to as “base 31” is arranged and facing the conductive sectors 23. a, with which it may interact and cooperate. Preferably, the base 31 is the lower face of the disk 30.

[0047] The disk 30 of the rotor 3 may be made of conductive or non-conductive dielectric material, in this second case, for example, a layer of metal material (not shown) of appropriate thickness and shape having to be arranged or fixed on the base 31 thereof.

[0048] Said disk 30 also have a geometric asymmetry and consequently an asymmetry of the value of its dielectric constant or coefficient; this generates a corresponding non-uniformity in the capacitance value of the capacitors C with which it interacts.

[0049] Such geometric asymmetry of the disk 30 may be obtained, for example, by means of a geometric discontinuity (not shown) of the base 31 thereof or of the metal layer possibly fixed thereon.

[0050] Without any limiting intent, said geometric discontinuity may comprise a window, a slot, or an opening designed to interface and cooperate with one of the capacitors C of the electronic board 20, in particular with the capacitor C with which it is aligned following an appropriate action on the knob 1 (which shall be discussed).

[0051] For such a purpose, said geometric discontinuity provides for dimensions compatible / similar to those of a single capacitor C.

[0052] Said rotor 3 is therefore configured so that during a rotation thereof it may cover all the capacitors C except for the one located at said geometric discontinuity.

[0053] More precisely, the disk 30 of the rotor 3 acts as a dielectric for all the capacitors C of the electronic board 20 except for the capacitor C remained “uncovered” as a result of the presence of the geometric discontinuity on the base 31 thereof or on the relative metal layer.

[0054] The control unit, electrically connected to said conductive sectors 23. a, therefore detects a different value of the capacitance of the capacitor C.a located under the geometric discontinuity of the disk 30, where the air is the dielectric, compared to the other capacitors of the electronic board 20, which are instead covered by the intact parts of the disk 30 or of the metal layer.

[0055] Based on this, the control unit may determine the angular position reached / taken by the rotor 3.

[0056] What has been seen thus far does not substantially depart from the state of the art.

[0057] However, according to the invention, the angular position of the rotor 3 is that reached by acting on a rotating ring nut 4, which is a component of a cooktop used to set and regulate, incrementally or absolutely, the cooking time of a food or dish.

[0058] The ring nut 4 is capable of being coupled integrally with the rotor 3, for example by screwing, gluing, interlocking, or any other known constraint system that prevents a reciprocal rotation between the same ring nut 4 and the rotor 3, such as for example a key or a tab.

[0059] For such purpose, the ring nut 4 may be equipped with a seat 40, for example a through hole 40, whereon a shank 32 of the rotor 3 may engage and lock.

[0060] Each capacitor C.a defined between the conductive sectors 23. a of the electronic board 20 and “intercepted” by the geometric discontinuity of the rotor 3 following the rotation of the ring 4, may correspond to a specific cooking time; in other words, any angular position taken by the rotor 3 by rotating the ring nut 4 may essentially correspond to a specific cooking time.

[0061] The capacitive electronic reading performed by the position sensor 2, representative of the position of the rotor 3, is then transmitted to the control unit of the electronic board 20 which, by means of specific and known software, may allow a direct visualisation, for example on a display of the cooktop, of the cooking time set or selected by a user.

[0062] According to the invention, a ball grip 5 of the knob 1, may also be suitably mounted on said ring nut 4, provided that said ball grip 5 and ring nut 4 may be operated autonomously and / or independently of each other.

[0063] The ball grip 5 is preferably designed both for the ignition, through the activation of an ignition mechanism (e.g., a piezoelectric), of at least one burner of the cooktop, and for the regulation of the power thereof once operational.

[0064] The ball grip 5 may therefore be connected, via a suitable kinematic mechanism, to a gas valve 6 of the cooktop, which controls the gas flow towards a burner and cooperates with the ignition mechanism to generate a spark and ignite a flame in a safe and controlled manner.

[0065] Such kinematic mechanism therefore allows, as shall be seen later, the gas valve 6 to be opened, shut off and regulated.

[0066] Since said gas valves 6 are per se well-known components, the technical and functional features thereof shall not be discussed any further. In such context, it will be simply specified how the ball grip 5 may comprise a stem 50 capable, in the ways that shall be described below, to cooperate with the shaft 60 of the gas valve 6, contributing to define said kinematic mechanism.

[0067] As shown by way of a non-limiting example in figure 2 and / or 3, the ball grip 5 and ring nut 4 may be preferably mounted coaxially, one above the other, while maintaining the possibility of rotating freely and independently of one another; preferably, a concentricity / coaxiality is provided between the ring nut 4, the stem 50 of the ball grip 5, and the shaft 60 of the gas valve 6.

[0068] In such case, the stem 50 of the ball grip 5 may be housed passing inside the hole 40 of the ring nut 4 and configured and sized to be inserted, preferably loosely, into the shank 32 of the rotor 3.

[0069] For the reasons that will be clarified hereinafter, the ball grip 5 will be free to both rotate and translate longitudinally with respect to said ring nut 4 and rotor 3, allowing a rotation of the shaft 60 of the gas valve 6 and the activation of the piezoelectric ignition mechanism, respectively. The ball grip 5 is in fact configured to be able to be pressed like a button at least for activating said piezoelectric ignition mechanism, generating a spark, and / or rotated, preferably incrementally, to regulate the flame to the burner.

[0070] According to the invention, the burner of the cooktop, when operational, is intended to automatically switch off once the cooking time set by the user and “acquired” by the control unit has elapsed, as indicated.

[0071] This means that the gas valve 6 is automatically and instantly brought / rotated to the shut off position (“OFF position”), interrupting the gas supply to the burner, as soon as the cooking time has expired.

[0072] This prevents inexperienced or distracted users from leaving pots unattended on the burner while it is still ignited, even if the set cooking time at this stage has elapsed and ended.

[0073] For such purpose, it is necessary to synchronize and / or coordinate the opening time of the gas valve 6, during which gas is supplied (“ON position”), with the cooking time set and chosen through the ring nut 4.

[0074] It is therefore desired that the gas valve 6 remains open, i.e., in ON position, only for the cooking time set by the user, however with the possibility of voluntary shut off by the user, in case an early stop or interruption of cooking is decided, or by safety devices that may intervene to force and bring the valve to the OFF position even before the cooking time has ended, in case of risks for the user and / or malfunctions of the cooktop.

[0075] For further clarity, this means that at the end of the cooking time, the gas valve 6 is intended to instantly switch from the ON position to the OFF position thereof. For such purpose, said knob 1 comprises said kinematic mechanism that connects the ball grip 5 to the gas valve 6 and at least one first actuator 8.

[0076] According to a preferred embodiment, said kinematic mechanism is further provided with one second movable element 7, also a rotor 7 made of dielectric or non-dielectric material, which is capable of interacting with second conductive sectors 23. b (not explicitly shown in the figures) of the electronic board 20 which acts as a stator 20, also electrically connected to the control unit. The second conductive sectors 23. b therefore define one second encoder of the position sensor 2 of the invention which operates to open the gas valve 6, with the ignition of the relative burner, and the subsequent shut off thereof (that shall be referred to later).

[0077] According to different embodiments, said second rotor 7 may be placed and installed on the shaft 60 of the gas valve 6 and be suitably connected to the stem 50 of the ball grip 5 to detect a change in the angular position thereof and / or in the linear / longitudinal position thereof, the latter being able to be correlated to the linear distance of said second rotor 7 from the electronic board 20.

[0078] Preferably, the second rotor 7 may be positioned so as to face the lower surface 22 of the electronic board 20, which will be therefore equipped with the aforementioned second conductive sectors 23. b, preferably arranged as a ring or configured as pads.

[0079] The possibility that the second rotor 7 may be positioned on the same side as the first rotor 3 with respect to the electronic board 20 is not excluded. In this case, both the first and the second conductive sectors 23. a, 23.b are arranged on the same face, for example, the upper face 21, of the electronic board 20.

[0080] In such case, the arrangement and the mutual spacing of the first 23. a and second 23. b conductive sectors are such as to allow the interaction thereof with the respective first 3 or second 7 rotor without interferences for the capacitive reading.

[0081] For example, the first and second conductive sectors 23. a, 23.b, as well as the respective rotors 3, 7, may be arranged concentrically with each other.

[0082] Hereinafter, for simplicity, reference will still be made to the preferred embodiment of figures 1-3, i.e., with the second rotor 7 arranged under the electronic board 20 and cooperating with the lower face 22 thereof.

[0083] As illustrated in figure 1, the second rotor 7 may be configured to cooperate and interact with the shaft 60 of the gas valve 6, said rotor 7 therefore comprising a disc-shaped element capable of:

[0084] - being crossed by said shaft 60, preferably without interference so as to be able to slide / translate, said shaft 60 protruding and cooperating / coupling with a seat 52 of the ball grip 5, preferably obtained in the stem 50 thereof,

[0085] - engaging with said shaft 60 so that a rotation of the rotor 7 may transmit to the gas valve 6, allowing an opening, the subsequent shut off, as well as a regulation thereof.

[0086] For such purpose, the rotor 7 is equipped with a through hole 70 crossed by the shaft 60 of the gas valve 6. The sections of the through hole 70 and of the shaft 60 are appropriately shaped so as to create a first shape coupling, which makes the rotor 7 integral with the shaft 60, while still allowing a translation along the latter.

[0087] For example, said sections may have a polygonal, elliptical, “D”-shape or any other geometry suitable for the purpose (e.g., see figure 1 and / or 3 and / or 4).

[0088] A second shape coupling may also be provided between said seat 52 of the ball grip 5 and the same shaft 60 of the gas valve 6 so that a rotation of the ball grip 5 corresponds to an equal rotation of said shaft 60.

[0089] Preferably, as illustrated in figures 1-4, said through hole 70 may be equipped with a shank 72, consisting of a hollow tubular body protruding from the rotor 7 and having a section substantially equival ent / similar to that of the hole 70.

[0090] A first opening 24 made on the electronic board 20, having as a centre the centre O of the conductive sectors 23. a and / or 23. b, allows the housing and the passage of said shank 72 and of the shaft 60 of the gas valve 6 and the connect! on / cooperati on thereof with the stem 50 of the ball grip 5.

[0091] For the reasons that shall be clarified shortly, the second rotor 7 may preferably include a circumferential toothing 71, acting essentially as a toothed wheel 7 with a vertical / longitudinal rotation axis.

[0092] The second rotor 7 may be operated through the ball grip 5 and the operating mode thereof is substantially similar to that widely described in detail with reference to the first rotor 3.

[0093] Even the second rotor 7, or a metal layer attached to the face thereof facing the electronic board 20, may in fact have a geometric discontinuity that causes a change in the value of the dielectric constant or coefficient. This discontinuity generates a corresponding asymmetry in the capacitance value of the capacitors C.b, with which it interacts, defined by conductive sectors 23.b.

[0094] Therefore, when a user presses the ball grip 5 in the direction of the arrow F in figure 4, the stem 50 thereof axially moves the second rotor 7, which compresses a spring 61 of the shaft 60 of the gas valve 6.

[0095] More precisely, a free end 51 of the stem 50 of the ball grip 5 acts / pushes on the shank 72 of the second rotor 7, normally protruding from the upper surface 21 of the electronic board 20, allowing the translation thereof along said shaft 60 and the compression of the spring 61 thereof.

[0096] For such purpose, in a possible executive embodiment, the free end 51 may be shaped as a plate 51, capable of interacting with the upper edge 73 of the shank 72.

[0097] The rotor 7 then moves away from the second conductive sectors 23.b, with which it was substantially in contact, creating an air gap. Such air gap varies the capacitance of the capacitors, and this is interpreted by the control unit as a linear / longitudinal stroke / displacement of the rotor 7, representing a pressure on the ball grip 5; as a consequence, the control unit gives consent to the opening of a safety solenoid valve (or similar devices) and activates the ignition mechanism, e.g., the piezoelectric, of the burner of the cooktop.

[0098] The stroke / displacement of said rotor 7 preferably depends on the vertical / longitudinal development of the shank 72 thereof and, at least for the variant of figures 1-3, is however limited by the interference of the stem 50 or of the plate 51 of the ball grip 5 with the electronic board 20 and / or of the maximum compression to which said spring 61 of the gas valve 6 may be subjected.

[0099] Once the pressure on the ball grip 5 is ceased, the compressed spring 61 of the gas valve 6 releases, returning the second rotor 7 to the initial position thereof, i.e., in substantial contact and adherence to the relative conductive sectors 23.b of the electronic board 20 and with the shank 72 thereof protruding once again from the upper surface 21 of the electronic board 20.

[0100] As mentioned, the ball grip 5 is also configured to allow and make the shaft 60 of the gas valve 6 and consequently of the second rotor 7 installed on the same shaft 60 rotate, thus allowing:

[0101] - the completion of the ignition procedure of a burner of a cooktop, and / or

[0102] - the regulation of the thermal power thereof (i.e., the intensity of the flame); it is therefore reiterated that a rotation of the ball grip 5 corresponds to an equal rotation of the second rotor 7.

[0103] In a manner completely similar to what has been seen with reference to the first rotor 3, following the rotation of the second rotor 7, the geometric discontinuity provided thereon “leaves” one of the capacitors C.b defined between the conductive sectors 23. b thereof “exposed” to the air, rather than to the dielectric of the rotor 7.

[0104] The control unit therefore detects a change in capacitance and determines the angular position of the rotor 7.

[0105] Such detection is therefore used to define an operating condition of the gas valve 6, in particular the ON position thereof.

[0106] It should be noted that the control unit is able to distinguish the change in capacitance due to the translation or rotation of the rotor 7, so as to identify the ignition or regulation steps of a burner.

[0107] At this point, a preferred method of use and operation of the knob 1 of the invention shall be described; without any limiting intent, reference shall be made to a user who intends to proceed to an operation of cooking food and dishes on a burner of a cooktop.

[0108] In such case, the user, by turning the ring nut 4, in particular by rotating it clockwise or counterclockwise, sets the cooking time, i.e., the time during which the gas valve 6 must be in the ON position so as to supply gas to the burner of the cooktop whereon a pot or pan has been placed (step a).

[0109] At the end of the rotation of the ring nut 4, the control unit of the knob 1 detects and acquires, in the manners described above, the angular position thereof corresponding to and representative of the set cooking time, possibly displayed by a user interface of the cooktop, for example, by a display thereof, or through an indicator on a relative graduated time scale.

[0110] At this point, in rapid succession, the user may ignite the burner of the cooktop chosen for the cooking operation, first by pressing the ball grip 5 of the knob 1 so as to cause, through the control unit, the opening of a safety solenoid valve and / or the spark of the piezoelectric igniter and then by rotating it so as to bring the gas valve 6, connected thereto through the specific kinematic chain, described above, from an OFF position to an ON position thereof, consequently starting the gas supply and the formation of a flame (step b).

[0111] During this step, the control unit acquires and detects, as seen, a change in the angular and / or linear / longitudinal position of said ball grip 5, namely:

[0112] - a first change in the capacitance of the capacitors C on the electronic board 20, interpreting it as a linear / longitudinal movement of the rotor 7 resulting from the pressure applied to the ball grip 5 and indicative of an attempt to ignite the burner, consequently opening the safety solenoid valve and activating the piezoelectric igniter.

[0113] - a second change in the capacitance of said capacitors C resulting from the rotation of the ball grip 5 performed to regulate the gas flow and the power of the burner, and that is acquired and interpreted as an angular position of said rotor 7 indicative of an ON position of the gas valve 6.

[0114] Once the burner is ignited:

[0115] - the user releases and / or interrupts the pressure on ball grip so as to suspend the action of the piezoelectric igniter,

[0116] - the user interface of the cooktop begins to display the elapsed cooking time; preferably, it shows a countdown.

[0117] When the cooking time has totally elapsed, the same control unit detects the conclusion thereof and activates a first actuator 8, preferably an electric motor 8 (or similar device), integrated into the knob 1 of the invention, which proceeds with the immediate and automatic shut off of the gas valve 6, moving it from an ON position to an OFF position thereof, thereby interrupting the gas supply to the burner (step c).

[0118] For such purpose, the first actuator 8 is configured to operate, preferably by making it rotate, a toothed wheel 80 capable of engaging the circumferential toothing 71 of the second rotor 7, and making it rotate.

[0119] Since the rotor 7 is suitably constrained, in the manners described above, to the shaft 60 of the gas valve 6, a rotation thereof causes an equal rotation of said shaft 60 and the consequent shut off of the gas valve 6.

[0120] Preferably, the toothed wheel 80 and the second rotor 7 are always suitably meshed / engaged with each other so as to:

[0121] - allow a linear stroke / displacement of said rotor 7 without interference, with respect to the thickness of said toothed wheel 80, and, at the same time,

[0122] - ensure continuity of the mutual coupling / engagement thereof necessary for the subsequent shut off of the gas valve 6.

[0123] For such purpose, the thickness S of the toothed wheel 80 (see figures 1-2-3) is preferably at least equal to the linear stroke / displacement of the second rotor 7.

[0124] In such case, in fact, when the second rotor 7 is translated under the action of the ball grip 5 or of the spring 61 of the gas valve 6, it may slide without interference along the thickness of the toothed wheel 80, maintaining and ensuring the cooperation and engagement between the parts necessary for the subsequent shut off of the same gas valve 6.

[0125] It should also be noted that said actuator 8 is preferably equipped with known releasing systems to avoid, when not in operation, opposing resistance to the rotation of the ball grip 5 and of the related rotor 7 required to open the gas valve 6 and consequently ignite the selected burner on the cooktop.

[0126] In other words, during the opening of the gas valve 6, such releasing systems intervene so that the toothed wheel 80 of the actuator 8 does not oppose resistance to the rotation of the rotor 7, effectively acting as an idler wheel.

[0127] Conversely, during the shut off of the gas valve 6, the actuator 8 activates and said toothed wheel 80 acts as a drive wheel engaging and making the rotor 7 rotate, as seen.

[0128] The extent and the duration of the rotation of the toothed wheel 80 of actuator 8 are therefore those necessary to bring the gas valve 6 to the OFF position and are a function of the angular position taken by ball grip 5 of the knob 1 when the burner is ignited and detected by the control unit.

[0129] For clarity, it should be further noted that the actuator 8 is configured only for the shut off of the gas valve 6 and that, for safety reasons, it is generally not suitable for a motorised opening thereof.

[0130] According to a possible executive embodiment, shown by way of a non-limiting example in figure 2 and / or 3, a second opening 25 (not explicitly shown) on the electronic board 20 allows the housing and the passage, without substantial interference, of the shaft 81 of the actuator 8, ensuring a correct transmission of the rotation to the toothed wheel 80 keyed thereon.

[0131] It is finally clear that several embodiments of the knob 1 according to the invention are possible to the man skilled in the art, without departing from the novelty scopes of the inventive idea, as well as it is clear that in the practical embodiment of the invention the various components of said knob 1, described above, may be replaced with technically equivalent elements.

[0132] For example, nothing prevents the ring nut 4 and the ball grip 5, together with the respective rotors 3 and 7 and kinematic chains, from being separate and independent elements, rather than components mounted one on top of the other in the ways seen above.

[0133] Furthermore, although during the description reference has been primarily made to incremental-type ring nuts 4, nothing prevents the possibility, especially for more economical cooktops, of using ring nuts 4 of the absolute type.

[0134] While with an incremental ring nut 4, the elapsing of the cooking time, and the conclusion thereof, may be viewed and controlled on the user interface display, a ring nut 4 of the absolute type may require the use of a second actuator or known mechanism (not shown) adapted to return a cooking time indicator from the set value thereof back to “time 0”. In both cases, an acoustic or visual warning may indicate the end of the cooking time.

[0135] Naturally, nothing prevents, according to an even more simplified variant, said ring nut 4 of the absolute type from being manually returned to “time 0” at the end of a cooking operation.

[0136] Furthermore, nothing prevents the aforementioned conductive sectors 23. a, 23.b from being alternatively arranged in a linear sequence along an axis parallel to the surface of the electronic board 20.

[0137] In such case, the respective rotors 3, 7 may comprise sliders capable of sliding linearly on said conductive sectors 23. a, 23. b, and equipped with a surface discontinuity that acts as a selector to leave exposed only one of the capacitors C.a, C.b defined between the conductive sectors 23. a, 23.b (variant not shown). For further details on such type of knob 1, reference shall be made to patent no. 102015000057386 in the name of the same Applicant. In such context, it is noted that, according to such executive variant, the actuator 8 is of the type suitable for dragging the slider.

[0138] As for the operating mode of the knob 1, it makes no difference, for the purposes of the invention, whether the cooking time may be set before the ignition of the burner (as described so far by way of a non-limiting example) or when the burner is already ignited and operational.

[0139] As already partially anticipated, it is further reiterated that the knob 1 of the invention, described above, is entirely compatible, from a functional and operational point of view, with the various safety systems normally provided on a cooktop, for example, with the safety solenoid valves thereof for the shut off the gas supply and / or with the thermocouples designed for the immediate reignition of the burner in case of an unintentional or accidental flame extinguishment.

[0140] Finally, although during the present description, without any limiting intent, reference has been explicitly made to a position sensor 2 and relative capacitive encoders, i.e., able to detect a change in the capacitance between the conductive sectors 23. a and / or 23.b and the respective rotors 3, 7, nothing prevents the possibility of detecting changes in the inductance or resistance of a sliding contact also present on said rotors 3, 7.

[0141] It is clear that with the knob 1 of the invention the stated objects are achieved; in particular, the possibility of providing an automatic switching-off function for the same household appliance, increasing the safety thereof.

[0142] Said knob 1 is also economical to make, reliable, and may be easily integrated into the household appliance.

Claims

CLAIMS1. Knob (1) for the ignition, shut off and / or regulation of one or more operating parameters of a gas cooking household appliance comprising at least one burner and a relative gas valve (6), said knob (1) being coupled to said gas valve (6) and comprising at least:- one position sensor (2), in turn comprising:- a stator (20),- at least first conductive sectors (23. a) of said stator (20), which together form a plurality of capacitors (C.a),- at least one first movable element (3) comprising a rotor (3) rotatably mounted with respect to said stator (20) and configured to interact with said first conductive sectors (23. a) and detect a change in the angular position of a ring nut (4),- said ring nut (4) configured to set and regulate at least one first operating parameter of said gas cooking household appliance, said ring nut (4) being integrally coupled with said movable element (3) and said first operating parameter comprising a cooking time,- a control unit electrically connected to at least said first conductive sectors (23. a) and configured to acquire and process at least one electrical signal representative of said angular position of said ring nut (4),- a ball grip (5) designed for the ignition of said household appliance and the regulation of at least one second operating parameter thereof, said ball grip (5) being configured to be pressed as a button and / or rotated and said second parameter comprising a thermal power that may be supplied by said burner, characterised in that said knob (1) further comprises a second movable element (7) comprising a second rotor (7) configured to interact with second conductive sectors (23. b) of said stator (20), said second rotor (7) being connected to said ball grip (5) and configured to at least detect a change:- in the angular position thereof indicative of an opening position of saidgas valve (6), and / or- in the linear / longitudinal position thereof indicative of an ignition attempt, said changes in the angular and / or linear / longitudinal position being acquired and processed by said control unit, and in that it further comprises an actuator (8) configured to shut off said gas valve (6) once said cooking time is elapsed.

2. Knob (1) according to the previous claim, characterised in that:- said second rotor (7) comprises a circumferential toothing (71) and is placed and installed on the shaft (60) of said gas valve (6),- said actuator (8) comprises a toothed wheel (80) capable of engaging on said circumferential toothing (71) of said second rotor (7) and causing it to rotate, said rotation of the rotor (7) resulting in the shut off of said gas valve (6).

3. Knob (1) according to at least claim 1, characterised in that said position sensor (2) is of the capacitive type, said first and second rotor (3; 7) both comprising a geometric discontinuity capable of interfacing and cooperating with one of the capacitors (C.a; C.b) defined by the respective first and second conductive sectors (23. a; 23.b).

4. Knob (1) according to claim 3, characterised in that said first and second rotor (3; 7) are made of conductive dielectric material.

5. Knob (1) according to claim 3, characterised in that said first and second rotors (3; 7) are made of non-conductive dielectric material, said geometric discontinuity being obtained in a layer of metallic material arranged or fixed on said first and second rotor (3; 7).

6. Knob (1) according to claims 4 and / or 5, characterised in that said geometric discontinuity comprises a slot, a window, an opening, or the like.

7. Knob (1) according to one or more of the previous claims, characterised in that said ring nut (4) and said ball grip (5) are mounted one on the other in a coaxial manner, said ball grip (5) maintaining the possibility of rotating andtranslating freely and independently with respect to said ring nut (4).

8. Knob (1) according to claim 7, characterised in that a stem (50) of said ball grip (5) is housed passing inside a hole (40) of said ring nut (4), said stem (50) being configured and sized to be inserted into a shank (32) of said first rotor (3).

9. Knob (1) according to one or more of the previous claims, characterised in that said second rotor (7) is configured to:- be crossed without interference by said shaft (60) of said gas valve (6) so as to be able to slide / translate therein, said shaft (60) coupling / cooperating with said ball grip (5),- engage with said shaft (60) so that a rotation of said rotor (7) may be transmitted to said gas valve (6), said second rotor (7) being equipped with a through hole (70) wherethrough said shaft (60) passes, the sections of said hole (70) and said shaft (60) being shaped so as to create a first shape coupling that makes said second rotor (7) integral with said shaft (60), while still allowing the translation thereof along the latter.

10. Knob (1) according to the previous claim, characterised in that said through hole (70) is provided with a shank (72) consisting of a hollow tubular body protruding from said second rotor (7) and of equivalent / similar section to that of said hole (70).

11. Knob (1) according to one or more of the previous claims, characterised in that said stem (50) of said ball grip (5) comprises:- a free end (51) capable of acting on said shank (72) of said second rotor (7), allowing the translation thereof along said shaft (60) of said gas valve (6),- a seat (52) whereon said shaft (60) couples, a second shape coupling being provided between said seat and said shaft (60) so that a rotation of said ball grip (5) corresponds to a rotation of said shaft (60).

12. Knob (1) according to one or more of the previous claims, characterised inthat said first and second conductive sectors (23. a; 23. b) are made respectively on a first face (21) and on a second face (22), opposed to the first, of said stator (20), said first rotor (3) and said second rotor (7) facing respectively said first (21) and second (22) face of said stator (20).

13. Knob (1) according to one or more of the previous claims 1 to 11, characterised in that said first and second conductive sectors (23. a; 23. b) are both made on a same face (21; 22) of said stator (20), said first and second conductive sectors (23. a; 23. b), as well as said respective first and second rotors (3; 7) being able to be arranged concentrically with each other.

14. Knob (1) according to one or more of the previous claims, characterised in that said stator (20) comprises at least:- one first opening (24) for the passage of at least said shaft (60) of said gas valve (6) and of said shank (72) of said second rotor (7),- one second opening (25) for the passage of at least one shaft (81) of said actuator (8).

15. Knob (1) according to one or more of the previous claims, characterised in that said stator (20) is an electronic board (20) of said knob (1).

16. Household appliance for food and dishes gas cooking, comprising:- at least one burner- at least one gas valve (6) configured to supply gas to said at least one burner,- at least one flame ignition mechanism on said burner,- one user interface, characterised in that said user interface comprises at least one knob (1) according to one or more of claims 1 to 15, said knob (1) comprising at least:- one ring nut (4) configured to set a cooking time for a food or dish,- one ball grip (5) configured to be pressed as a button to activate said ignition mechanism of said burner and / or to be rotated to regulate the thermal power thereof that may be supplied,- one actuator (8) configured to shut off said gas valve (6) once said cooking time is elapsed.

17. Household appliance for food and dishes gas cooking according to claim 16, characterised in that it is a gas cooktop and / or a gas barbecue and / or a gas cooker, or the like.

18. Use and operation method of a knob (1) according to one or more of claims 1 to 15 and configured to be installed on at least one gas household appliance for cooking food and dishes according to claim 16 and / or 17, characterised in that it comprises, in succession, at least the following steps of- rotating said ring nut (4) by setting a cooking time for said food and dish, the control unit of said knob (1) detecting and acquiring the angular position of the first rotor (3), integrally coupled with said ring nut (4), corresponding to and representative of said set cooking time,- pressing the ball grip (5) of said knob (1) to activate the ignition mechanism of said burner of said gas household appliance, the control unit detecting and acquiring the linear / longitudinal movement of said second rotor (7) connected to said ball grip (5),- rotating said ball grip (5) to bring said gas valve (6) of said gas household appliance from an OFF position to an ON position thereof when it may supply and regulate the gas flow to the burner of said gas household appliance, the control unit detecting and acquiring the angular position of said second rotor (7),- displaying the elapsing of the set cooking time and the conclusion thereof,- activating said actuator (8) of said knob (1) for the automatic shut off of said gas valve (6), by interrupting the gas supply to the burner, and in that said gas valve (6) remains in said ON position only for a time equal to said cooking time set via said ring nut (4).

19. Use and operation method of a knob (1) according to claim 17,characterised in that said angular position of said first (3) and second rotor (7) respectively of said ring nut (4) and ball grip (5) and / or the linear / longitudinal movement of said rotor (7) of said ball grip (5) are detected as a function of a change in the capacity of the capacitors (C.a; C.b) defined by the conductive sectors (23. a; 23.b) of said stator (20) whereon said first (3) and second rotor (7) face and cooperate.

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