Device for detecting the presence of a recipient in a gas cooker and associated cooker

Abstract

Device (100) for detecting the presence of a vessel (2) on a gas cooker comprising a grid (3) configured to support the vessel (2) on the gas burner (1) and an electrical circuit with two terminals, the vessel (2) being detected when said electrical circuit is closed. The grid (3) comprises a first rib (3a) and a second rib (3b) of conductive material which are electrically insulated from each other when no vessel (2) is on the grid (3). Each terminal of the electrical circuit is connected to one of said ribs (3a, 3b), so that, when a vessel (2) of conductive material is placed on the grid (3), said vessel (2) electrically connects both ribs (3a, 3b), thus closing the electrical circuit.

Description

TECHNICAL FIELD

[0001] The present invention relates to devices that detect the presence of vessels in gas cookers comprising grids for supporting the vessels during the cooking process.PRIOR ART

[0002] Cookers with induction or glass ceramic hobs are known to include means for detecting the presence of vessels, e.g. a sensor, and means for automatically switching on and off the heating elements of the hotplates to activate or deactivate the heating of the hotplates. Gas cookers with said detection means are also known.

[0003] In this regard, document EP2187131A1 describes a gas cooker with several gas burners. The gas cooker comprises a common grid associated with all the burners. The grid is made of an electrically conductive material and supports the vessels arranged on each gas burner. The gas cooker also comprises a device for detecting the presence of vessels arranged on a gas burner. Said detection device comprises an electrical circuit with two terminals, one terminal of the circuit being connected to the conductive grid which is in contact with the vessel through a rib of the grid and the other connector to an electrode arranged in the centre of the burner. When the vessel of conductive material is placed on the burner, the vessel closes the electrical circuit and the vessel is detected, and when the vessel is removed, the electrical circuit is open and the vessel is no longer detected.DISCLOSURE OF THE INVENTION

[0004] The object of the invention is to provide a device for detecting the presence of a vessel in a gas cooker comprising at least one gas burner, and an associated gas cooker, as defined in the claims.

[0005] The device of the invention comprises a grid configured to support the vessel over the gas burner and an electrical circuit with two terminals, the vessel being detected when the electrical circuit is closed.

[0006] The grid comprises a first rib and a second rib of conductive material which are electrically isolated from each other when no container is placed on the grid. Each terminal of the electrical circuit is connected to one of these ribs, so that when a vessel of conductive material is placed on the grid, said vessel electrically connects the two ribs, closing the electrical circuit.

[0007] The device of the invention makes it possible to detect the presence of a vessel of conductive material on a gas burner automatically and efficiently, and without adding additional components, such as sensors, probes or electrodes, which can be damaged over time or by misuse, so that the device of the invention is more robust and reliable. Moreover, the fact of detecting the presence of vessels automatically makes it possible to automate other operations, such as for example the switching on and off of the burner, thus contributing to improve energy saving as it is possible to optimise the ignition time of the burner flame.

[0008] These and other advantages and features of the invention will become apparent in view of the figures and the detailed description of the invention.DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 shows a perspective view of an embodiment of the gas cooker according to the invention. Figure 2 shows a detail of one of the gas burners of the cooker of figure 1 incorporating an embodiment of the device according to the invention. Figure 3 shows a cross section of part of the gas cooker of figure 1. Figure 4 shows a schematic representation of an embodiment of the device according to the invention, depicted on one of the burners of the cooker of figure 1, wherein the vessel arranged on said burner is also shown. Figure 5 shows a detail of the device shown in figure 4. DETAILED DISCLOSURE OF THE INVENTION

[0010] Figure 4 shows a schematic of a first embodiment of the device 100 for detecting the presence of a vessel 2 of conductive material, preferably metallic, in a gas cooker 200 according to the invention, and figure 1 shows a perspective view of the gas cooker 200 of the invention with the device 100 mounted on said cooker 200.

[0011] The device 100 of the invention comprises a grid 3 configured to support the vessel 2 on the corresponding gas burner 1 and an electrical circuit with two terminals, the vessel 2 of conductive material being detected when said electrical circuit is closed.

[0012] The grid 3, according to the preferred embodiment of the invention, comprises a first rib 3a and a second rib 3b of conductive material which are electrically isolated from each other when no vessel 2 is arranged on the grid 3, as shown in figure 3. The first rib 3a and the second rib 3b are configured to support the vessel 2 on the burner 1 during the cooking process, as shown in figure 4. Each terminal of the electrical circuit is connected to one of said ribs 3a or 3b, so that, when a vessel 2 of conductive material is arranged on the grid 3, said vessel 2 electrically connects both ribs 3a and 3b, closing the electrical circuit.

[0013] The device 100 of the invention makes it possible to detect the presence of a vessel 2 of conductive material on a gas burner 1 in an automatic and efficient manner, and without adding additional components, such as sensors, probes or electrodes, which may be damaged over time or by misuse, so that the device 100 of the invention is more robust. Furthermore, the fact of detecting the presence of vessels 2 in an automatic manner makes it possible to automate other operations, such as for example the switching on and off of the burner 1, as will be detailed below, thus contributing to saving energy as it is possible to optimise the ignition time of the flame of the burner 1.

[0014] The cooker 200 of the invention comprises a cooktop 10, preferably bowl-shaped and preferably metallic, for example of stainless steel, so that the gas burners 1 protrude from the bottom of said cooktop 10, as can be seen in figure 3. The grid 3 when it is in use is supported on said cooktop 10. Each burner 1 may have its own cooktop 10 or they may share the cooktop 10.

[0015] The grid 3 according to the preferred embodiment of the invention, comprises a perimeter frame 3', the first rib 3a and the second rib 3b being attached to said perimetral frame 3', as can be seen in figure 2. The grid 3 of the invention also comprises at least one additional rib 3c or 3d attached to the perimetral frame 3' to improve the stability of the vessel 2, preferably comprising two additional ribs 3c and 3d to further improve the stability of the vessel 2, so that in the preferred embodiment of the invention the vessel 2 is supported by the additional rib or ribs 3c and / or 3d of the grid 3, and the first rib 3a and the second rib 3b of the device 100 of the invention. In the preferred embodiment of the invention the additional ribs 3c and 3d form a single piece with the perimetral frame 3', therefore, they may be of the same material, and the first rib 3a and second rib 3b, although they are attached to the perimetral frame 3', do not form a single piece with the perimetral frame 3'. However, in a variant of the invention, the second rib 3b could also form a single piece with the perimetral frame 3', but not so the first rib 3a as both ribs 3a and 3b have to be electrically isolated.

[0016] In the preferred embodiment of the invention the perimetral frame 3' and the additional ribs 3c and 3b are metallic, preferably of steel or stainless steel, and are varnished with an electrically insulating material, on the one hand, to improve the aesthetic appearance of the grid 3, and on the other hand to prevent oxidation. However, although the first rib 3a and the second rib 3b of the device 100 of the invention are also metallic, preferably of stainless steel, they do not comprise the external varnishing, precisely in order to maintain the conductive property. However, in the case where the second rib 3b forms a single piece with the perimetral frame 3', the end of said second rib 3b which is in contact with the vessel 2 must dispense with the insulating varnish in order to ensure that the electrical circuit of the device 100 of the invention is closed when the vessel 2 is placed on the grid 3.

[0017] In the preferred embodiment of the invention wherein both the first rib 3a and the second rib 3b are attached to the perimetral frame 3' but do not form a single piece, each rib 3a and 3b comprises a main arm 4 on which the vessel 2 is supported, and a secondary arm 5 following the main arm 4 which is housed in a housing of the perimetral frame 3' through a bushing 6 of electrically insulating material, for example plastic or ceramic, the secondary arm 5 protruding beyond the bushing 6 so that it can be connected to a terminal of the electrical circuit, as shown in figure 5. The secondary arm 5 of the first rib 3a and the second rib 3b comprises a threaded section 7 protruding from the bushing 6, so that the ribs 3a and 3b are fixed to the perimetral frame 3' by a nut 8 threaded to said threaded section 7, as shown in the detail of figure 5.

[0018] The bushing 6 comprises a main body 6', preferably rectangular, which is housed in a housing of the perimetral frame 3' as shown in Figure 5, and at the top comprises a perimetral flange 6" disposed at one end of said main body 6' which extends beyond the outer dimensions of the main body 6', said perimetral flange 6" being supported on an outer surface of the perimetral frame 3' of the grid 3 when the bushing 6 is inserted into the housing of the perimetral frame 3', and fixed to the grid 3 by fastening means such as screws, rivets or similar elements.

[0019] The secondary arm 5 of the first rib 3a and / or of the second rib 3b is inserted and housed in an inner housing of the main body 6' of the corresponding bushing 6 according to an insertion direction Z 1 which corresponds with the direction of insertion of the corresponding rib in the perimetral frame 3', as shown in the detail of figure 5. As already mentioned, the threaded section 7 protrudes from the bushing 6, so that when the nut 8 is screwed onto said threaded section 7, the nut 8 generates a tightening force against the bushing 6 (in the direction opposite to the insertion direction Z 1 ), This force is counteracted by the fastening means of the perimetral flange 6" which generates another tightening force against the perimetral frame 3' of the grid 3 (in the insertion direction Z 1 ), the secondary arm 5 being fixed to the perimetral frame 3' by means of the bushing 6 (which is fixed to the perimetral frame 3') and the nut 8 (which holds the secondary arm 5 against the bushing 6).

[0020] In the preferred embodiment of the invention, the threaded section 7 of the secondary arm 5 of the first rib 3a and / or of the second rib 3b comprises an axial groove 12, i.e. in a direction parallel to the insertion direction Z 1 . On the other hand, the device 100 comprises a contact element 13 housed in the groove 12 of a respective threaded section 7, such that the free end of the contact element 13 protrudes from the corresponding threaded section 7 and the corresponding nut 8 in the insertion direction Z 1 , the corresponding contact element 13 being fixed through the respective nut 8 but in such a way that it can move freely in the corresponding groove 12, thereby ensuring electrical contact with the corresponding terminal of the electrical circuit of the device 100 of the invention. When the grid 3 is in the position of use, i.e. on the cooktop 10, the contact elements 13 absorb any height difference that may exist between the cooktop 10 and the grid 3, by moving into or away from the corresponding threaded section 7, thereby ensuring electrical contact with the respective terminal.

[0021] The contact element 13 of the first rib 3a is in electrical contact with one of the terminals of the electrical circuit of the device 100 of the invention, as will be detailed below, and the contact element 13 of the second rib 3b is in electrical contact with the second terminal of the electrical circuit, as will also be detailed below.

[0022] The corresponding contact element 13 is metallic, i.e. of conductive material, and in the preferred embodiment of the invention comprises a T-shape, although other shapes, e.g. a cylindrical pin, are not ruled out.

[0023] To allow axial displacement of the corresponding contact element 13, optionally, the respective bushing 6 may also comprise an axial groove (not shown in the drawings), thus increasing the axial stroke of the contact element 13 as the lateral ends of the T-shaped contact element 13 are prevented from colliding with the bushing 6.

[0024] The first rib 3a is configured to be electrically connected to a terminal of the electrical circuit of the device 100 of the invention, said terminal being connected to an electronic module 11 which in use of the gas cooker 200 is electrically powered. In the preferred embodiment of the invention, the contact element 13 of the first rib 3a is the one which is in electrical contact with said terminal of the corresponding electrical circuit. However, in a variant of the invention, and in the absence of said contact element 13, it is the threaded section 7, with or without groove 12, which is in electrical contact with the terminal of the corresponding electrical circuit.

[0025] The device 100 of the invention also comprises a connector 9 for ensuring electrical contact with the first rib 3a, said connector 9 being fixed to the cooktop 10 of the gas cooker 200 but so as to be electrically isolated from the cooktop 10. The connector 9 comprises an electrode 9a of conductive material which is in electrical contact with the first rib 3a, via the contact element 13 housed in the threaded section 7 of the secondary arm 5 of the first rib 3a, when the grid 3 is arranged on the cooktop 10, and a bushing 9b of electrically insulating material, for example plastic or ceramic, the electrode 9a being inserted inside the bushing 9b so that a portion of the electrode 9a protrudes from the bushing 9b to ensure electrical contact with the contact element 13 of the first rib 3a when the grid 3 is arranged on the cooktop 10, as shown in figure 5. The bushing 9b therefore makes it possible to electrically isolate the electrode 9a from the cooktop 10. Likewise, the electrode 9a comprises an electrical connection to allow electrical connection with the electronic module 11, the electrode 9a being therefore one of the terminals of the electrical circuit of the device 100 of the invention. In the preferred embodiment of the invention the connector 9 is a spark plug, thus avoiding having to manufacture a specific connector 9 and having to provide the electrical connection at the electrode 9a.

[0026] The second rib 3b is configured to be earthed through the mass m of the gas cooker 200. In this regard, the secondary arm 5 of the second rib 3b is configured to make electrical contact with a conductive element of the gas cooker 200, for example, the cooktop 10 of the cooker 200, which is earthed. In the preferred embodiment of the invention the second terminal of the device 100 is electrically connected to the cooktop 10, or it could be said that the cooktop 10 itself is the second terminal. In order to ensure electrical contact between the second rib 3b and the cooktop 10, the second rib 3b is fixed to the perimetral frame 3' of the grid 3 in the same way as the first rib 3a is fixed, i.e. via a respective insulating bushing 6 and a respective contact element 13, so that the contact element 13 housed in the threaded section 7 of the secondary arm 5 of the second rib 3b is supported by, and thus is in electrical contact with, the cooktop 10. However, in a variant of the invention where the perimetral frame 3' of the grid 3 is made of a conductive material, the second rib 3b is fixed to the perimetral frame 3' without the insulating bushing 6, since it is not necessary to electrically insulate the second rib 3b of the grid 3, or even the second rib 3b could be an integral part of the perimetral frame 3', in which case the corresponding contact element 13 would not be necessary either, provided that an electrical contact between the cooktop 10 and the second rib 3b is ensured, for example by dispensing with the insulating varnish in the area of contact with the cooktop 10.

[0027] The gas cooker 200 according to the invention comprises at least one gas burner 1 wherein the gas passage to said burner 1 is regulated by an electrovalve, not shown in the drawings, and also comprises the device 100 of the invention associated with a respective gas burner 1 and a control unit adapted to process the signal of the corresponding electrical circuit, said control unit being arranged for example in the electronic module 11. In the non-limiting example of figure 1, the cooker 200 comprises four gas burners 1, each gas burner 1 being associated with a corresponding cooktop 10, a corresponding grid 3 and a corresponding electrical circuit. In a variant of the invention, the cooktop 10 may be common to all the burners 1, as the grid 3, wherein in this case, the ribs 3a, 3b, 3c and 3d associated with each gas burner 1 for supporting the cooking vessel 2 are attached to a common frame 3' of the grid 3, directly or indirectly, while maintaining the requirement of electrical conductivity or insulation of the corresponding ribs.

[0028] The gas cooker 200 of the invention also comprises ignition means associated with each gas burner 1 (for example, a spark plug) and an electrovalve associated with each gas burner 1. The control unit of the electronic module 11 is configured to open the corresponding electrovalve and to activate the corresponding ignition means when it detects a vessel 2 on the grid 3, igniting the flame on the corresponding gas burner 1. The control unit is also configured to close the corresponding electrovalve when it detects that vessel 2 has been removed from the grid 3, extinguishing the flame in the corresponding gas burner 1.

[0029] In the preferred embodiment of the invention the control unit is configured to wait for a predetermined time before closing the corresponding electrovalve when it detects that the vessel 2 has been removed from the grid 3, to prevent the flame from being extinguished unnecessarily.

[0030] The ignition means and the device 100 of the invention allow the gas burner 1 of the gas cooker 200 of the invention to be switched on and off automatically by simply placing the vessel 2 on the corresponding burner 1, or by removing it. In this way, it is possible to save energy since when removing the vessel 2 it is not necessary for the flame of the burner 1 to remain lit, avoiding unnecessary waiting times, thus optimising the ignition time of the flame. On the other hand, the ignition of the burner 1 is also optimised, as it no longer depends on the ability of the user, thus minimising the leakage of unburned gas, while avoiding the use of other tools such as matches or lighters.

Claims

1. Device for detecting the presence of a vessel (2) in a gas cooker (200) comprising at least one gas burner (1), the device (100) comprising - a grid (3) configured to support the vessel (2) over the gas burner (1), and - an electrical circuit with two terminals, the vessel (2) being detected when the electrical circuit is closed, characterised in that the grid (3) comprises a first rib (3a) and a second rib (3b) of conductive material which are electrically isolated from each other when no vessel (2) is placed on the grid (3), each terminal of the electrical circuit being connected to one of said ribs (3a, 3b), so that, when a vessel (2) of conductive material is placed on the grid (3), said vessel (2) electrically connects both ribs (3a, 3b), closing the electrical circuit.

2. Device according to claim 1, wherein the grid (3) comprises a perimetral frame (3'), the first rib (3a) and the second rib (3b) being attached to said perimetral frame (3') and the grid (3) comprising at least one additional rib (3c, 3d) attached to said perimetral frame (3').

3. Device according to claim 2, wherein the grid (3) comprises two additional ribs (3c, 3d) attached to the perimetral frame (3').

4. Device according to claim 2 or 3, wherein the at least one additional rib (3c, 3d) forms a single piece with the perimetral frame (3').

5. Device according to any of claims 2 to 4, wherein the first rib (3a) and / or the second rib (3b) comprises a main arm (4) on which the vessel (2) is supported, and a secondary arm (5) following the main arm (4) which is housed in the perimetral frame (3') through a bushing (6) of electrically insulating material of the device (100), the secondary arm (5) protruding beyond the bushing (6) to connect to a terminal of the electrical circuit.

6. Device according to claim 5, wherein the secondary arm (5) of the first rib (3a) and / or of the second rib (3b) comprises a threaded section (7) protruding from the corresponding bushing (6), so that the corresponding rib (3a, 3b) is fixed to the perimetral frame (3') by means of a nut (8) threaded to the threaded section (7).

7. Device according to claim 6, wherein the corresponding threaded section (7) comprises a groove (12) and wherein the device (100) comprises a contact element (13) housed in a respective groove (12) to be electrically connected to the corresponding terminal of the electrical circuit, the contact element (13) being fixed by the respective nut (8) but in such a way that it can move in said groove (12).

8. Device according to claim 6 or 7, wherein the bushing (6) comprises a main body (6') which is housed in a housing of the perimetral frame (3') and a perimetral flange (6") disposed at one end of said main body (6') which is supported on an outer surface of the perimetral frame (3'), so that the bushing (6) can be attached to the perimetral frame (3') by attaching the perimetral flange (6") to said perimetral frame (3'), preferably by screwing the perimetral flange (6") to the perimetral frame (3').'9. Device according to any of claims 6 to 8, wherein the first rib (3a) is configured to connect to a terminal of the electrical circuit, said terminal being connected to an electronic module (11), and the second rib (3b) is configured to connect to a second terminal of the electrical circuit which is earthed.

10. Device according to claim 9, further comprising a connector (9) comprising an electrode (9a) of conductive material configured to make contact with the first rib (3a) and a bushing (9b) of electrically insulating material, the electrode (9a) being inserted inside the bushing (9b) so that a portion of the electrode (9a) protrudes from the bushing (9b) to ensure contact with the first rib (3a) of the grid (3), the opposite end of the electrode (9a) being electrically connected to the electronic module (11), so that said electrode (9a) is one of the terminals of the electrical circuit of the device (100).

11. Device according to claim 10, wherein the connector (9) is configured to connect to a cooktop (10) of the gas cooker (200) so that it is electrically isolated from the gas cooktop (10).

12. Device according to claim 10 or 11, wherein the connector (9) is a spark plug.

13. Gas cooker characterised in that it comprises at least one gas burner (1), a device (100) according to any of the preceding claims associated with a respective gas burner (1) and a control unit processing the signal from the corresponding electrical circuit.

14. Gas cooker according to claim 13, comprising ignition means associated with each gas burner (1) and a electrovalve associated with each gas burner (1), the control unit being configured to open the electrovalve and to activate the corresponding ignition means when it detects a vessel (2) on the grid (3), igniting the flame on the corresponding gas burner (1), and to close the corresponding electrovalve when it detects that the vessel (2) has been removed from the grid (3), extinguishing the flame on the corresponding gas burner (1).

15. Gas cooker according to claim 14, wherein the control unit is configured to wait for a predetermined time before closing the corresponding electrovalve when it detects that the vessel (2) has been removed from the grid (3).

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