EP4639309A1

EP4639309A1 - Manual control system, control knob and household appliance

Info

Publication number: EP4639309A1
Application number: EP23822341.6A
Authority: EP
Inventors: Alvaro Martinez Diez; Alberto GAIPO DUQUE; Alfonso Herrera Ruiz; Emilio Placer Maruri; Luis Alberto Abascal Carrera; Roberto Carballo Fernandez; Lara FERNANDEZ GUTIERREZ; Alicia FERNANDEZ SANZ; Eduardo Borbolla Jimenez
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2022-12-19
Filing date: 2023-12-11
Publication date: 2025-10-29
Also published as: WO2024132651A1

Abstract

Manual control system, control knob and household appliance A manual control system for a household appliance, in particular for a cooking hob, comprising: an electronic board; and a control knob for rotating a shaft in the household appliance, in particular for operating a valve shaft in a gas valve of a cooking hob, the control knob comprising a rotatable part for coupling to the shaft and a spring that is attached to the rotatable part; wherein in a released state of the spring, the spring pushes the rotatable part onto the electronic board for physical connection therewith; and wherein in a compressed state of the spring, the rotatable part is physically and electrically separated from the electronic board.

Description

Manual control system, control knob and household appliance

The present invention relates to a manual control system for a household appliance, in particular for a cooking hob. The present invention further relates to a control knob provided in such a manual control system, as well as to the entire household appliance.

Control knobs can be manually rotated by an operator such as to rotate a shaft connected to the control knob and accordingly modify an operational state of a household appliance. Such control knobs are for example used on gas cooking hobs to modify the flame size by tuning a gas valve connected to the shaft.

To achieve certain functionalities of the household appliance, such as ignition in the case of a gas cooking hob, the control knob needs to be pushed inwards, thereby physically separating a rotatable part (rotor) of the control knob from an electronic board. To restore the rotatable part into its initial position when the control knob is released, a spring can be provided.

This spring can be positioned between the rotatable part and the gas valve, where there is limited space.

It is one object of the present invention to provide an improved control system which requires less space and can be used flexibly.

According to a first aspect, a manual control system for a household appliance, in particular for a cooking hob, is provided. The manual control system comprises: an electronic board; and a control knob for rotating a shaft in the household appliance, in particular for operating a valve shaft in a gas valve of a cooking hob, the control knob comprising a rotatable part for coupling to the shaft and a spring that is attached to the rotatable part; wherein in a released state of the spring, the spring pushes the rotatable part onto the electronic board for physical connection therewith; and wherein in a compressed state of the spring, the rotatable part is physically and electrically separated from the electronic board. i Attaching the spring to the rotatable part is advantageous because the spring and the rotatable part form a single unit, that is displaceable and mountable as a whole. This facilitates mounting and positioning of the spring and the rotatable part, in particular because the spring does not need to be mounted separately.

The control knob may be a rotatable control knob. It can be used on any type of household appliance, in particular gas cooking hobs, ovens, dishwashers, washing machines and the like. The control knob can be engaged with a shaft in a rotationally fixed manner such that the shaft rotates upon rotation of the control knob. Rotation of the shaft can modify a setting of the household appliance. For example, the shaft can be a valve shaft in a cooking hob, the valve shaft being connected to a gas valve and allowing selection of the amount of gas to be output (and hence modification of a flame size).

The electronic board can be a printed circuit board or any component having an electrically guiding portion (made of metal, for example) for connection with the rotatable part. The electronic board can initiate some functionalities of the household appliance upon electrical connection and/or disconnection with the rotatable part. Such functionalities can include ignition of the gas cooking hob, control of the display of a current mode of the household appliance or the like. The electronic board can have a board or plate shape, in particular with at least one flat surface. The electronic board can include a capacitive sensor that for example senses variations in the capacity of the rotatable part as it rotates or is pushed away/onto the electronic board. The electronic board may include or be connected to a display unit for displaying the current mode of the household appliance.

The rotatable part of the control knob may be designated as a "rotor". It can be rotated directly by a user or connected to a manual part that gets rotated by a user. Upon rotation of the rotatable part, the shaft may rotate, thereby modifying a setting of the household appliance, as indicated above. The rotatable part may include a disc-shaped part centered around a rotation axis. The rotatable part may further include a connection part for connection with the shaft in a rotational fixed manner. The connection part may extend perpendicularly to the disc-shaped part of the rotatable part. The connection part can have a cylindrical shape (in particular, a tubular shape) centered around the rotation axis. In a mounted state, the rotation axis corresponds to an axial axis of the shaft. The disc-shaped part of the rotatable part can be arranged in parallel to the electronic board, in particular such as to come in planar contact with one another.

The coupling between the shaft and the rotatable part may be a rotational fixed coupling. That is, when the rotatable part rotates, so does the shaft. This is achieved, for example, by a shaft having a D-shaped, a plus-shaped or a star-shaped cross section and the rotatable part having a corresponding connection part cross-section.

The rotatable part in particular forms a single element. It may be constructed as one piece. It can be made of plastic and/or metal.

The spring can be any type of elastic element. It can be made of metal or plastic. The spring being attached to the rotatable part means that there is a physical connection between the spring and the rotatable part holding them together. As a result, the spring and the rotatable part form a single element that is displaceable as a whole. This facilitates the mounting of the manual control system as the spring does not need to be positioned with respect to the rotatable part, as they are fixed to one another.

The released state of the spring is a state in which the spring is either fully extended or extended until the rotatable part abuts against the electronic board. In other words, the released state is a default state (rest state) of the spring in which no manual pressure is applied onto the control knob by a user.

In the released state, the rotatable part is in contact with the electronic board, meaning that there is a physical contact between the rotatable part and the electronic board, preferably along a plane that is perpendicular to the rotation axis of the control knob. In the released state, the spring may push the rotatable part onto the electronic board for electric connection therewith, namely such that electric currents can pass between the rotatable part and the electronic board.

The compressed state can be a state in which an additional force is applied onto the control knob, for example by a user. This additional force can be applied along the rotation direction and/or by pressing the control knob towards and/or into the household appliance. In this compressed state, the rotatable part is physically and electrically separated from the electronic board, meaning that there is no physical or electrical connection between the rotatable part and the electronic board. In the compressed state, a physical gap may be formed between the rotatable part and the electronic board.

According to an embodiment, the spring is a compression coil spring.

This is advantageous because compression coil springs a widely available. The force of the compression spring can act outward along its axial axis.

According to another embodiment, the spring has a conical shape, and wherein in particular, a base of the conical shaped spring is attached to the rotatable part.

Providing the spring with a conical shape is advantageous because in the compressed state, it takes less space along the rotation axis than a spring with a cylindrical shape. Indeed, in the compressed state, a portion of the conical spring with a smaller diameter folds into a portion of the conical spring with a larger diameter. On the other hand, all windings of a cylindrical shape lie on top of one another, leading to a larger compressed spring.

Advantageously, the compressed conical spring is smaller. This means that the control knob can be pressed down further without having to increase a size of an empty space under the control knob. This ensures proper separation of the rotatable part from the electronic board, for example.

According to another embodiment, an end of the spring is attached to the rotatable part.

In particular, only an end portion and/or a portion of the first winding of the spring are attached to the rotatable part.

According to another embodiment, the spring is attached to the rotatable part through clipping, gluing and/or welding. Alternatively, the spring can also be attached by inserting its end into a specific opening in the rotatable part. Any other attachment means than the ones above are also possible, such as screwing, pinning, stapling or the like. The spring can also be constructed as a single element together with the rotatable element.

According to another embodiment, the control knob is rotatable around a rotation axis that is perpendicular to the electronic board, and wherein in particular, in the released state, the spring is configured to push the rotatable part onto the electronic board along a direction of the rotation axis.

According to another embodiment, the rotatable part is arranged between the electronic board and the spring.

According to another embodiment, the electronic board is configured to initiate an ignition of a gas burner of the cooking hob and/or to control a display indicating an operation mode of the household appliance as a function of an orientation of the rotatable part with respect to the electronic board.

The electronic board can initiate some functionalities of the household appliance upon electrical connection and/or disconnection with the rotatable part. Such functionalities can include ignition of the gas cooking hob, control of the display of a current mode of the household appliance or the like. The electronic board can include a capacitive sensor that for example senses variations in the capacity of the rotatable part as it rotates or is pushed away/onto the electronic board, the capacitive sensor initiating the above functionalities.

According to another embodiment, the rotatable part includes multiple electric connection parts for connecting electrically with the electronic board in the released state of the spring, wherein a different electric connection part is connected electrically to the electronic board upon rotation of the rotatable part.

Upon rotating the rotatable part, the electric connection parts provided thereon are also rotated. This brings different electric connection parts to face a sensor part of the electronic board. Based on the electric connection part currently facing the sensor part (which is identified by the sensor part), the electronic board can determine an orientation of the rotatable part and/or initiate some of the above functionalities based thereon.

According to another embodiment, the control knob comprises a manual part coupled to the rotatable part in a rotationally fixed manner, wherein the manual part is configured to be manually rotated around the rotation axis, wherein the electronic board is at least partly arranged between the manual part and the rotatable part.

The manual part can be for manual operation by an operator (or equivalently, user). Manual operation means that the operator rotates the knob element by hand. Rotationally fixed means that the rotation of the manual part leads to a corresponding rotation of the rotatable part.

According to a second aspect, a control knob for the manual control system according to the first aspect or any embodiment thereof is provided. The control knob is configured for rotating a shaft in a household appliance, in particular for operating a valve shaft in a gas valve of a cooking hob. The control knob comprises a rotatable part for coupling to the shaft and a spring that is attached to the rotatable part.

The embodiments and features described with reference to the manual control system of the first aspect or an embodiment thereof apply mutatis mutandis to the control knob of the second aspect.

According to a third aspect, a household appliance, in particular a cooking hob, is provided. The household appliance comprises: the manual control system according to the first aspect or any embodiment thereof; and a rotatable shaft, in particular a valve shaft of a gas valve, coupled to the rotatable part in a rotationally fixed manner; wherein the electronic board comprises an opening through which the shaft passes.

The opening in the electronic board can be an through hole. In parallel to the electronic board and towards an exterior of the household appliance, an external wall of the household appliance, such as a top sheet of a gas cooking hob can be provided. The electronic board can be located between the external wall and the spring.

According to an embodiment, the shaft axially traverses the rotatable part and the spring in a centered manner.

In other words, the spring and the rotatable part are centered around the shaft, which can be aligned with the rotation axis.

According to a further embodiment, the spring comprises two ends, one of which is attached to the rotatable part, and wherein the household appliance further comprises an abutting portion for maintaining the end of the spring that is opposite to the end of the spring that is attached to the spring into place.

The abutting portion can be part of the gas valve. The abutting portion can form a support for the spring, in particular against which the spring is compressed in its compressed state. The end of the spring that is maintained by the abutting portion in particular does not change position upon changing from the released state and the compressed state of the spring. "Maintaining" in particular means attaching, inserting and/or being placed onto.

According to a further embodiment, the abutting portion is a flat surface, and in particular, the abutting portion is a notch plate of the gas valve.

The notch plate allows selecting the different settings of the household appliance. In particular, the notch plate allows selecting the different settings in increments (stepwise).

The embodiments and features described with reference to the manual control system of the first aspect or an embodiment thereof as well as with respect to the control knob of the second aspect or an embodiment thereof apply mutatis mutandis to the household appliance of the third aspect.

Further possible implementations or alternative solutions of the invention also encompass combinations - that are not explicitly mentioned herein - of features described above or below with regard to the embodiments. The person skilled in the art may also add individual or isolated aspects and features to the most basic form of the invention.

Further embodiments, features and advantages of the present invention will become apparent from the subsequent description and dependent claims, taken in conjunction with the accompanying drawings, in which:

Fig. 1 shows a top view of an example of a gas cooking hob;

Fig. 2 shows a perspective view of the gas cooking hob according to Fig. 1 ;

Fig. 3 shows a manual control system with a spring in a released state;

Fig. 4 shows another embodiment of a manual control system with a spring in a released state;

Fig. 5 shows the manual control system of Fig. 4 with the spring in a compressed state;

Fig. 6 shows a control knob;

Fig. 7 shows a side view of the control knob of Fig. 6;

Fig. 8 shows a cross-sectional view of the control knob of Fig. 7;

Fig. 9 shows a perspective view of the control knob of Fig. 8; and

Fig. 10 shows a bottom view of the control knob of Fig. 9.

In the Figures, like reference numerals designate like or functionally equivalent elements, unless otherwise indicated.

Fig. 1 shows a schematic top view of an embodiment of a gas cooking hob or gas stove 1. Fig. 2 shows a schematic perspective view of the gas stove 1. In the following, Figs. 1 and

2 are referred to at the same time. The gas stove 1 can be a household appliance or part of a household appliance. The gas stove 1 comprises a cooking trough 2. The cooking trough 2 is a deep-drawn metal sheet. The gas stove 1 further has at least one gas burner arrangement 3. The number of gas burner arrangements 3 is arbitrary. As Fig. 1 shows, there can be provided five gas burner arrangements 3.

Each gas burner arrangement 3 comprises a gas valve 4 which is attached to a main gas pipe 5, a gas burner 6 and a gas conduit 7 which connects the gas valve 4 to the associated gas burner 6. The gas valve 4 preferably is a gas regulating valve. The gas valve 4 is suitable for regulating a stream of combustion gas from the main gas pipe 5 to the gas burner 6 continuously or stepwise. In particular, the gas valve 4 is a so-called step valve. The gas valve 4 is preferably clamped to the main gas pipe 5.

The cooking trough 2 is covered by means of a cover plate or top sheet 8. The plate 8 covers the cooking trough 2. The plate 8 is a glass plate or a glass-ceramic plate. The plate 8 can also be made of metal, in particular stainless steel. The plate 8 has a front side (upper surface) and a back side (bottom surface). The front side faces to a potential user of the cooking hob 1. The back side is facing the cooking trough 2. The plate 8 comprises a number of apertures (breakthroughs or openings) 11. The number of openings 11 is the same as the number of gas valves 4. Each gas valve 4 has its own aperture 11. The openings 11 are cylindrical bores. In the following only one opening and only one gas valve 4 will be referred to.

The gas valve 4 is arranged below the plate 8. That means, the gas valve 4 faces the back side of the plate 8. The gas valve 4 has a rotational shaft (actuation stem) 12 which is guided through the opening 11. In particular, the shaft 12 can be guided from the back side 10 to the front side 9 of the plate 8. However, the shaft 12 can end before the plate 8 so that it is not guided through the opening 11. The shaft 12 can be rotated around an axis of rotation A to adjust the flow of combustion gas from the main gas pipe 5 to the gas burner 6. Depending on an angle of rotation of the shaft 12, the flow of combustion gas from the main gas pipe 5 to the gas burner 6 can be increased, decreased or completely blocked. An electronic board or circuit board 9 (see Fig. 3) is arranged between the gas valve 4 and the plate 8. The shaft 12 can be guided through the circuit board 9. Each gas valve 4 has a control knob 13 for actuating the shaft 12. "Actuating" in this context, means rotating, in particular around the shaft rotation axis A. The control knob 13 comprises a knob element 15, which is manually operable (rotatable) from the outside by an operator. The knob element 15 is preferably made of plastic. The knob element 15 can be made of acrylonitrile butadiene styrene (ABS), polypropylene (PP), polyethylene (PE) or any other suitable opaque plastic material. In embodiments, the knob element 15 is made of a metal material. The knob element 15 can be made by injection molding.

Fig. 3 shows a manual control system 10 including the control knob 13 and an electronic board 9. As shown in Fig. 3, the control knob 13 includes a rotor (rotatable part) 16 located under the knob element 15 and connected therewith in a rotatably fixed manner through the shaft 12.

The control knob 13 further includes a spring 17 surrounding the shaft 12 which is fixed by glue to the rotatable part 16. This facilitates the positioning of the spring 17 as it is attached to the rotatable part 16. In the example of Fig. 3 and 4, the spring 17 is in its released state (rest state). Namely, it holds (pushes) the rotatable part 16 against the electronic board 8 by means of a spring force directed along the rotation axis A. The rotatable part 16 is pushed vertically upwards in the orientation of Fig. 3 - 5.

On the lower end of the spring 17 in the orientation of Fig. 3 - 5, the spring abuts against an abutting portion 18. The abutting portion 18 is part of the gas valve 4, with the remaining of the gas valve 4 being located right below the abutting portion 18 (not shown in Fig. 3 - 5). The abutting portion 18 serves as a support for the spring 17. In particular, a loose end 24 of the spring 17 abuts against the abutting portion 18.

The function of the rotatable part 16 is to transmit its position (orientation) to the electronic board 9. In the example of Fig. 3, the rotatable part 16 transmits its position to the electronic board 9, thereby indicating the number indicating the operation mode that seven segments display included in the electronic board 9 must show. To be able to display these segments through the top plate 8, the top plate 8 can be made of a transparent material. The logic functions of the rotatable part 16 are as follow. When the gas hob 1 is switched off, the spring 17 is in its released state. This released state is shown in Fig. 4. The spring 17 is pushing the rotatable part 16 against the electronic board 9 and the rotatable part 16 is aligned with the "0 position". The rotatable part 16 is in physical contact with the electronic board 9 along a planar contact surface 26. In the released state, a length of the spring 17 along the rotation axis A is hi .

In order to turn the gas hob 1 on, the rotatable part 16 is pushed downwards. This is achieved by pressing the knob element (manual part) 15 downwards along the rotation axis A. This puts the spring 17 in a compressed state (see Fig. 5). The length of the spring 17 in the compressed state is h2, which is smaller than hi. As shown in Fig. 5, pressing the rotatable part 16 downwards, a physical gap 19 is created between the rotatable part 16 and the electronic board 9. In this state, the electronic board 9 gives the signal to produce ignition sparks and to switch on the gas hobs.

When the rotatable part 16 is pushed and rotated at the same time using the knob element 15, a gas flow is activated in addition to the sparks. By the combination of sparks and gas, flames are obtained at the corresponding burner 6.

When the knob element 15 and consequently the rotatable part 16 are turned but not pushed, the spring 17 is again in the released state described above (Fig. 4). Spark production is stopped and the rotatable part 16 is now merely indicative of the orientation thereof and of the shaft 14 to the electronic board. Namely, in the present example, depending on the orientation of the rotatable part 16, the electronic board 9 displays the specific position of the rotatable part 16 using the seven segments display of the electronic board 9.

The control knob 13, in particular the rotatable part 16 and the spring 17 attached thereto are shown in greater detail in Fig. 6 to 10.

In detail, as shown in Fig. 6, the rotatable part 16 includes a connection part 20 and a disc-shaped part 21. The connection part 20 has a tubular shape with an opening 22 having a D-shaped cross section. The opening 22 is for insertion of the shaft 12, which also has a D-shaped cross section. This allows connecting the shaft 12 to the connection part 20 such that a rotation of the rotatable part 16 also rotates the shaft 12.

Extending radially outwards from a lower end of the connection part 20, the rotatable part 16 further includes the disc-shaped part 21. An upper surface 27 of the disc-shaped part 21 is the surface that connects physically and electrically with the electronic board 9 in the released state.

As shown in Fig. 7, the spring 17 is a compression coil spring that has a conical shape. A base 23 of the spring 17 is attached to the disc-shaped part 21 at an attachment point 25. Due to the conical shape of the spring 17, when the spring 17 is compressed, it is very flat because the smaller windings are folded in the center of the larger windings (see Fig. 5). This is advantageous when space is limited under the control knob 13.

Fig. 8 shows a cross-sectional view of the control knob 13. The spring 17 is, at its base 23, partly arranged within an enclosure inside the disc-shaped part 21. The spring thus extends partly inside the rotatable part in a vertical direction along the rotation axis A.

Although the present invention has been described in accordance with preferred embodiments, it is obvious for the person skilled in the art that modifications are possible in all embodiments. For example, the electronic board 9 and the top plate 8 can be constructed as a single element.

Reference Numerals:

1 gas stove

2 cooking trough

3 gas burner arrangement

4 gas valve

5 main gas pipe

6 gas burner

7 gas conduit

8 top plate

9 electronic board 10 manual control system

11 aperture

12 shaft

13 control knob

14 lateral wall

15 knob element

16 rotatable part

17 spring

18 abutting portion

19 gap

20 connection part

21 disc-shaped part

22 opening

23 spring base

24 loose end

25 attachment point

26 contact surface

27 upper surface

A rotation axis hi length h2 length

Claims

1. A manual control system (10) for a household appliance (1), in particular for a cooking hob, comprising: an electronic board (9); and a control knob (13) for rotating a shaft (12) in the household appliance (1), in particular for operating a valve shaft (12) in a gas valve (4) of a cooking hob, the control knob (13) comprising a rotatable part (16) for coupling to the shaft (12) and a spring (17) that is attached to the rotatable part (16); wherein in a released state of the spring (17), the spring (17) pushes the rotatable part (16) onto the electronic board (9) for physical connection therewith; and wherein in a compressed state of the spring (17), the rotatable part (16) is physically and electrically separated from the electronic board (9).

2. The manual control system according to claim 1 , wherein the spring (17) is a compression coil spring.

3. The manual control system according to claim 1 or 2, wherein the spring (17) has a conical shape, and wherein in particular, a base of the conical shaped spring (17) is attached to the rotatable part (16).

4. The manual control system according to any one of claims 1 to 3, wherein an end of the spring (17) is attached to the rotatable part (16).

5. The manual control system according to any one of claims 1 to 4, wherein the spring (17) is attached to the rotatable part (16) through clipping, gluing and/or welding.

6. The manual control system according to any one of claims 1 to 5, wherein the control knob (13) is rotatable around a rotation axis (A) that is perpendicular to the electronic board (9), and wherein in particular, in the released state, the spring (17) is configured to push the rotatable part (16) onto the electronic board (9) along a direction of the rotation axis (A).

7. The manual control system according to any one of claims 1 to 6, wherein the rotatable part (16) is arranged between the electronic board (9) and the spring (17).

8. The manual control system according to any one of claims 1 to 7, wherein the electronic board (9) is configured to initiate an ignition of a gas burner (6) of the cooking hob and/or to control a display indicating an operation mode of the household appliance (1) as a function of an orientation of the rotatable part (16) with respect to the electronic board (9).

9. The manual control system according to any one of claims 1 to 8, wherein the rotatable part (16) includes multiple electric connection parts for connecting electrically with the electronic board (9) in the released state of the spring (17), wherein a different electric connection part is connected electrically to the electronic board (9) upon rotation of the rotatable part (16).

10. The manual control system according to any one of claims 1 to 9, wherein the control knob (13) comprises a manual part (15) coupled to the rotatable part (16) in a rotationally fixed manner, wherein the manual part (15) is configured to be manually rotated around the rotation axis, wherein the electronic board (9) is at least partly arranged between the manual part (15) and the rotatable part (16).

11. A control knob (13) for the manual control system (10) according to any one of claims 1 to 10, the control knob (13) being configured for rotating a shaft (12) in a household appliance (1), in particular for operating a valve shaft (12) in a gas valve (4) of a cooking hob, the control knob (13) comprising a rotatable part (16) for coupling to the shaft (12) and a spring (17) that is attached to the rotatable part (16).

12. A household appliance (1), in particular a cooking hob, comprising: the manual control system (10) according to any one of claims 1 to 10; and a rotatable shaft (12), in particular a valve shaft (12) of a gas valve (4), coupled to the rotatable part (16) in a rotationally fixed manner; wherein the electronic board (9) comprises an opening (11) through which the shaft (12) passes.

13. The household appliance according to claim 12, wherein the shaft (12) axially traverses the rotatable part (16) and the spring (17) in a centered manner.

14. The household appliance according to claim 12 or 13, wherein the spring (17) comprises two ends, one of which is attached to the rotatable part (16), and wherein the household appliance further comprises an abutting portion for maintaining the end of the spring (17) that is opposite to the end of the spring (17) that is attached to the spring (17) into place.

15. The household appliance according to claim 14, wherein the abutting portion is a flat surface, and in particular, the abutting portion is a notch plate of the gas valve (4).