GB2385947A

GB2385947A - Controller for a domestic appliance with time switch to prevent accidental adjustment

Info

Publication number: GB2385947A
Application number: GB0302097A
Authority: GB
Inventors: Walter Gramlich; Bernhard Goetz; Jochen Herbolsheimer
Original assignee: BSH Bosch und Siemens Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2002-01-30
Filing date: 2003-01-29
Publication date: 2003-09-03
Anticipated expiration: 2023-01-29
Also published as: DE10203614B4; GB0302097D0; GB2385947B; DE10203614A1

Abstract

A controller for a domestic appliance includes control means 38 with a time switch and setting devices 16, 18, 20, 24, 26, 30. The time switch is responsive to actuation of the setting devices 16, 18, 20, 24, 26, 30, and the control means 38 is able to inhibit actuation of some of the setting elements upon deactivation of the time switch. The time switch may be activated to provide a time window of approximately 2-8 seconds during which operating modes may be set. Deactivation of the time switch, at the close of the time window, may then restrict the number setting possibilities available, such that accidental adjustment of the operating mode, e.g. during cleaning, may be avoided. The controller may be a controller for an oven, and audio-visual indicators may be used to give notification of the opening and closing of the time window.

Description

CONTROL OF SETTING SELECTION IN A DOMESTIC APPLIANCE

The present invention relates to a method of operating a domestic appliance for example a baking oven and an appliance in which the method can be carried out.

A control system for an electrical baking oven is described in German Utility Model DE 200 02 948 U1, in which setting devices have dual functions, between which it is possible to switch over by actuation of further setting devices. However, there is no safeguard present that due to erroneous contact, for example, during cleaning or by playing children, an adjustment of the set functions takes place, such as, for example the operating mode of grilling or a supplementary operating parameter such as temperature or operating time.

Moreover, glass-ceramic cookirfg bobs are known in which an on/off switch setting device in the form of a pushbutton effects switching-on only after actuation maintained over a time period of a few seconds. This safeguard is not particularly user-friendly and is therefore used only for the main switch. The remaining switches for the modes of operation for, for example, selection of the heated cooking zones or for further functions such as setting of a heating power or a time control are not safeguarded, so that unintended adjustments can take place. This brings the risk that food is ruined, for example scorched, over-cooked or even set on fire and a safety risk exists.

Furthermore, glass-ceramic cooking bobs are known in which, for security against unauthorized operation, a control knob is removed from the appliance. With the removal of the control knob, however, the entire appliance is completely switched off. The different setting devices for setting different appliance functions are not secured against adjustment. There is thus a need for a method and an appliance in which the disadvantages of the known methods and appliances are avoided and, in particular, the operational safety of the appliance is increased with a more user-friendly control capability.

According to the first aspect of the invention there is provided a method of operating a domestic appliance, particularly a baking oven, with a control device and setting devices, which co-operate therewith, for setting different appliance functions inclusive of different operating modes, characterized in that with the setting of a mode of operation by actuation

of an operating mode setting device a time switching device of the control device is set in motion, the user during the time window determined by the running period of the time switching device can undertake a supplementary setting or set a different operating mode and at the end of the running period of the time switching device the control device renders at least a part of the setting possibilities of the setting devices ineffective.

According to a second aspect of the invention there is provided an operating device for carrying out the method according to the first aspect of the invention for a domestic appliance, particularly a baking oven, with a control device and setting devices, which co-

operate therewith, for setting different appliance functions inclusive of different modes of operation, characterized in that the control device comprises a time switching device which, with the setting of a mode of operation by actuation of the operating mode setting devices, can be set in motion and that the control device at the end of the running period of the time switching device renders ineffective at least a part of the setting possibilities of the setting devices.

Such a method and such a device have the advantage of not obstructing the user in the case of normal control, for example, by a longer response delay. This does not exclude a short response delay of a few milliseconds up to at most approximately two seconds of response of the control device on actuation of a function setting device or element. The user also does not have to wait for expiry of the time window opened by the setting of a mode of operation, i.e. running down of the time switching device or time switch. A safety blocking of the setting devices automatically comes into being at the end of a relatively long time window. These solutions have the further advantage in the case of control devices with a microcontroller, which is programmable by software, of being able to be realised almost without additional outlay Advantageously, the control device at the end of the running period of the time switch device renders ineffective at least a part of the operating mode setting possibilities of the setting devices with the exception of the set operating mode setting, wherein the time switching device can be set in motion again by renewed actuation of the set operating mode setting and the setting possibilities rendered ineffective are reactivated and a time window is opened for new settings. In that case, a certain degree of safety resides in the fact that, with an erroneous new actuation of the selected mode, initially a resetting does not take place, but this mode of operation is simply reselected. For resetting, a further

operating mode setting possibility must first be actuated within the thusopened time window, for example by a further pushbutton. This mode of operation is user-friendly for a desired resetting, since it acts as a switching-off of the previously set mode of operation and thus, for the user, logically fits in with a resetting process.

Alternatively, or additionally, at least the operating mode setting possibilities rendered ineffective can be reactivated by actuation of a resetting device. This has the advantage that a user, who does not know the appliance, can gain assistance in this manner, although the user possibly has to take into account a certain degree of operating inconvenience which resides in a safeguarding of the on/off switch, for example by a response time threshold. In that case, function setting possibilities other than just the operating mode setting possibilities can be reactivated, however, certain setting possibilities, for example for the temperature, can be kept ineffective as before by the control device until the time window for further settings is opened by setting of an operating mode.

Further setting devices for supplementary operating parameters can serve for the setting of a time switching clock and are preferably rendered ineffective by the control device at the end of the running period of the time switching device when they result in a set operating period. If, for example, a cooking time end is selected, the appliance clock time cannot change since the cooking time would also change therewith and introduce a risk of, for example, scorching or burning food.

Expediently, with each actuation of a function setting device during the running period of the time switching device the latter is newly set in motion, since this actuation at the appliance indicates that the user is still in the process of setting and possibly needs more time. The operation of the appliance preferably starts only at the end of the running period of the time switching device, whereby unnecessary switching actions during the control procedure are avoided.

An optical and/or acoustic signal can be issued, for indication of the time window determined by the running period of the time switching device, during the entire period thereof and/or at the end thereof. In that case, for example during the entire time window

an indication can flash and at the end of the time window a signal tone can be issued in order to draw to the attention of the user to the setting possibility which exists and to the expiry thereof. Such an indication can be realised with low cost if an optical signal device already provided for other purposes, for example a temperature indication or the indication of a selected mode of operation, gives a signal by a suitable signal form for example flashing, and possibly indicates the next operating step.

The operating mode setting devices can comprise an own operating mode setting device for each mode of operation, for example a pushbutton. They can, however, also have common setting devices for several operating mode setting possibilities, such as, for example, rotary switches which, for example, are initially turned to the desired mode of operation this mode of operation then being set or switched on by pressing. The further setting devices for, for example, temperature and time, can also be realised by pushbuttons or rotary switches or other setting devices. Such pushbuttons can be movable, mechanical-buttons or by sensors responding to touch.

The appliance is not limited to being an electrically heated appliance, but can be an appliance heated by gas, for example by means of electromagnetic valves and automatic ignition and safety devices.

Embodiments of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a front view of a control panel of a baking oven embodying the invention; Fig. 2 is an inverted plan view of the control panel of Fig. 1, in conjunction with a control device, depicted as a signal flow diagram; and Fig. 3 is a view similar to that of Fig. 1, but showing a control panel of a baking oven in a modified embodiment of the invention.

Referring now to the drawings there is shown in Figs. 1 and 2 a control panel 12 of an electric domestic baking oven, the panel including a glass plate 14. Arranged at this at the left are three operating mode setting devices or elements in the form of pushbuttons 16, 18 and 20 for the operating modes of upper and lower heat, lower heat alone and grill. These

pushbuttons each have on the front face of the plate a respective symbol of the corresponding mode of operation and for characterization of the corresponding button field. Also associated with each of the pushbuttons is a respective touch sensor which is

arranged behind the plate 14 and which embraces a light source for illumination of the symbol. In addition, the glass plate 14 includes a luminescent indicator 22 for temperatures, the indicator being in the form of a seven-segment display. Arranged alongside that are two pushbuttons 24 and 26 for decreasing or increasing the temperature setting. Moreover, the glass plate 12 includes a luminescent display 28 in the form of a clock and, adjacent thereto, a control device 30 with six pushbuttons for setting clock time, operating start and end, cooking time and short alarm time. Finally, the glass plate 14 includes an on/off pushbutton 32.

The operating device according to Figs. 1 and 2 additionally comprises a control device 38, which is illustrated in Fig. 2 outlined by a dashed line and which comprises an evaluating logic 40 and, co-operating therewith, a memory 44 and a time switching device or time switch 42. The evaluating logic 40 receives signals from the operating mode pushbuttons 16, 18 and 20, the further function pushbuttons 24, 26 and 30 for temperature and time and the on/off pushbutton 32. It sends signals for the actuation of the indicating lamps in the operating mode pushbuttons 16, 18 and 20 and the on/off pushbutton 32.

Moreover, the evaluating logic 40 issues signals to the luminescent displays 22 and 28 and setting signals to power switches 48, 50 and 52, which set the heating power for an upper-heat heating body, a lower-heat heating body and a grill heating body, respectively (not illustrated). The voltage supply for the control device 38 and the power switches 48, 50 and 52 has, for simplification, been omitted from the drawings. The evaluating logic 40 is always disposed in the readiness mode as soon as the oven is connected with the mains, wherein the clock is also permanently supplied with current and the on/off pushbutton can be constructed as a contact sensor switch.

For setting the appliance in operation the user actuates the on/off pushbutton 32, which resets the control device 38, preferably with a response delay of a half a second, from the readiness mode into the operating mode. The luminescent display 22 for the temperature initially displays "000". The user then actuates one of the three operating mode pushbuttons 16, 18 or 20 in order to set the desired mode of operation. In that case the

evaluating logic immediately switches on or activates the time switching device 42 and the illumination of the actuated one of the operating mode pushbuttons 16, 18 or 20. In addition, the control device 38 indicates by way of the luminescent display 22 a temperature recommended for the set mode of operation. During the running period of the time switching device 42 the control device 38 causes the indication provided by the temperature luminescent display 22 to flash in order to indicate to the user that a time window, which is preset by the time switching device 42 and lasts for, for example, four seconds, for supplementary settings of, for example, the cooking time, another temperature or resetting to another mode of operation is open. If the user actuates one of the function pushbuttons, inclusive of the operating mode pushbuttons, during this time window the time switching device 42 is reset, i.e. newly set in motion. With expiry of the running time of the time switching device 42 the control device 38 renders all function pushbuttons, with the exception of the last-actuated one of the operating mode pushbuttons 16, 18 or 20, ineffective or blocks this and starts, through actuation of the power switch 48 and/or 50 and/or 52, the operation of the appliance in the set operation mode. If the user wishes to undertake yet another setting, he can do this by actuating again the last-actuated, illuminated one of the operating mode pushbuttons 16, 18 or 20, whereby the time switching device 42 is set back into motion or reactivated by way of the evaluating logic 40, the blocking or ineffectiveness of the remaining function pushbuttons is cancelled and the power switches 48, 50 and 52 are switched off. During the thus-opened time window a new setting is possible until expiry again of the time window set by the switching device 42.

An alternative possibility of changing the settings after expiry of the time window or running down or deactivation of the time switching device 42 is actuation of the on/off pushbutton 32, which serves as a resetting button.

In a modification of the described embodiment, those pushbuttons of the operating device 30 for setting of the clock which have an effect on a set cooking time can be rendered ineffective on expiry of the time window, whilst the other clock setting pushbuttons remain effective. The pushbuttons 24 and 26 for changing the temperature setting are active only during the running period of the time switching device 42. The evaluating logic 40 is preferably a microcontroller programmable with software.

In the case of the modification illustrated in Fig. 3, there is shown a control panel 312 of an electric domestic baking oven. The panel again comprises a glass plate 314. An operating mode setting device 315 with a rotary switch 317 is arranged thereat. shaft (not illustrated) of the rotary switch 317 extends through the glass plate 314 in order to actuate, by axial displacement, a switching device which is arranged therebehind and which co-operates with a control device (not illustrated) corresponding with the control device 38 of the embodiment of Figs. 1 and 2. The rotary switch 317 has a zero setting as well as three rotational settings selecting three modes of operation, the rotational settings being indicated by operating mode symbols 316, 318 and 320 printed on the front side of the glass plate 314. A respective indicating lamp arranged at the rear side of the plate 314 and actuated by the control device is associated with each of the symbols 316 to 320. In addition, the plate 314 has in its centre region a luminescent display 322 for indication of a set or measured temperature. Arranged adjacent thereto is a rotary switch 330 by which the set temperature can be increased or decreased and which acts on the control device by way of a switching device. Moreover, the plate 314 includes an on/off pushbutton 332 which can include a movable button.

In order to set an appliance with a control panel according to Fig. 3 into operation, the user initially presses the on/off pushbutton 332, whereby the control device is reset from a readiness mode into an operating mode with a response delay of, for examples. two seconds. The user then sets the operating mode rotary switch 317 to the corresponding operating mode symbol 316, 318 or 320 as indicated by a setting mark 319, wherein the user then switches on this operating mode by pressing on the rotary switch 317 and slight axial displacement of this switch. A time switching device (not illustrated) of the control device is thereby simultaneously set in motion, the corresponding operating mode symbol is lit and a proposed temperature is indicated in the luminescent display 322. The luminescent display 322 flashes in order to make noticeable to the user the opened time window for further settings or resettings. For example, the proposed temperature can be increased or decreased by means of the rotary switch 330 to a value departing from the proposal. The rotary switch 330 is biassed into its middle setting and, in the case of small rotations to the right or the left, allows the values in the temperature luminescent display 322 to run upwardly or downwardly. At the end of the running period of the time switching device all setting possibilities of the function setting devices 317 and 330 with the exception of the switch of the set operating mode setting are rendered ineffective and the

appliance is set by the control device into operation in the set operating mode by way of power switches (not illustrated).

Thereafter, on renewed actuation of the corresponding operating mode setting by way of the rotary switch 317 through rotation to the corresponding operating mode symbol and pressure actuation of the rotary switch 317 the time switching device can be set back into motion, whereby the time window is reopened for performance of settings or resettings.

As long as the time window is still open, each actuation of the operating mode setting device 315 or the rotary switch 330 resets the time switching device, i.e. sets it back into motion. The time window of, for example, four or six seconds is opened in each instance from the last actuation of a function setting device.

In a further modified embodiment the running duration of the time switching device can also be indicated by a flashing of the illuminated operating mode symbol of the selected operating mode.

Claims

PATENT CLAIMS

1. A method of operating a domestic appliance equipped with control means including a time switch and with setting elements actuable to set different functions inclusive of different operating modes of the appliance, the method comprising the steps of opening a time window by way of activation of the time switch in response to actuation of one of the setting elements to set an operating mode, the time window allowing actuation of the setting cements at least to set a different operating mode, and on closure of the time window inhibiting at least part of the range of setting actuations possible by the setting elements.

2. A method as claimed in claim 1, wherein the inhibited part of the range of setting possibilities excludes resetting of the respective set operating mode and the method comprises the further step of reopening the time window by way of reactivation of the time switch in response to reactuation of the setting element previously actuated to set that mode, the reopened time window allowing actuation of the setting elements at least to set a different operating mode.

3. A method as claimed in claim 1 or claim 2, wherein the inhibited part of the range of the setting possibilities includes the setting of different operating modes and the method comprises the step of removing, by actuation of resetting means, the inhibition with respect to at least the setting of different operating modes.

4. A method as claimed in any one of the preceding claims, wherein the appliance is equipped with further setting elements actuable to set operating parameters of the appliance and the method comprises the step, on closure of the time window, of inhibiting at least part of the range of setting actuations possible by the further setting elements.

5. A method as claimed in claim 4, comprising the step of controlling at least one of the further setting elements by way of the control means to be actuable when and only when the time window is open.

6 A method as claimed in claim 4 or claim 5, wherein the inhibited part of the range of setting possibilities of the further setting elements comprises the setting of an operating time of the appliance.

7 A method as claimed in any one of the preceding claims, comprising the steps of extending the time window, while open, by reactivation of the time switch in response to each actuation of one or more of the setting elements.

8. A method as claimed in any one of the preceding claims, comprising the step of starting operation of the appliance to perform a set operating mode on closure of the time window.

9. A method as claimed in any one of the preceding claims, wherein the window is substantially 2 to 8 seconds.

10 A method as claimed in claim 9, wherein the window is substantially 3 to 6 seconds.

1 1. A method as claimed in claim 10, wherein the window is substantially 4 seconds.

12. A method as claimed in any one of the preceding claims, comprising the step of providing at least one of an optical indication and an acoustic indication at the appliance that the time window is open and/or that the time window has closed.

13. A method as claimed in any one of the preceding claims, wherein the appliance is an oven.

14. A domestic appliance comprising control means with a time switch, and setting elements actuable to set different functions inclusive of different operating modes of the appliance, the time switch being activatable in response to actuation of one of the setting elements to set an operating mode. and the control means being operable in response to deactivation of the time switch to inhibit at least part of the range of setting actuations possible by the setting elements.

15. An appliance as claimed in claim 14, wherein the inhibited part of the range of setting possibilities excludes resetting of the respective set operating mode and the time switch is reactivatable in response to reactuation of the setting element previously actuated to set that mode, the reactivated time switch allowing actuation of the setting elements at least to set a different operating mode.

16. An appliance as claimed in claim 14 or claim 15, wherein the inhibited part of the range of setting possibilities includes the setting of different operating modes and the appliance comprises resetting means actuable to remove the inhibition with respect to at least the setting of different operating modes.

17. An appliance as claimed in any one of claims 11 to 16, comprising further setting elements actuable to set operating parameters of the appliance, the control means being operable in response to deactivation of the time switch to inhibit at least part of the range of setting actuations possible by the further setting elements.

18. An appliance as claimed in claim 17, wherein the control means is operable to control at least one of the further setting elements to be actuable when and only when the time window is open.

19. An appliance as claimed in claim 17 or claim 18, wherein the inhibited pad of the range of setting possibilities of the further setting elements comprises the setting of an operating time of the appliance.

20 An appliance as claimed in any one of claims 11 to 19, wherein the control means is operable to reactivate the time switch in response to each actuation of one or more of the setting elements.

21. An appliance as claimed in any one of claims 11 to 20, wherein the control means is operable in response to deactivation of the time switch to start operation of the appliance to perform a set operating mode on closure of the time window.

22. An appliance as claimed in any one of claims 11 to 21, wherein the time switch is activatable to run for a period of substantially 2 to 8 seconds.

23. An appliance as claimed in claim 22, wherein the period is substantially 3 to 6 seconds.

24. An appliance as claimed in claim 23, wherein the period is substantially 4 seconds.

25. An appliance as claimed in any one of claims 11 to 24, comprising at least one of optical indicating means and acoustic indicating means to provide an indication that the time switch is activated and/or that the time switch is deactivated.

26. An appliance as claimed in claim 25, comprising luminescent display means for displaying temperature indications, the display means also serving as the optical indicating means and being arranged to cause the indication to flash while the time switch is activated.

27 An appliance as claimed in claim 25, comprising luminescent display means for displaying an indication of an operating mode set by one of the setting elements, the display means also serving as the optical indicating means and being arranged to cause the indication to flash while the time switch is activated.

28 An appliance as claimed in any one of claims 11 to 17, wherein the setting elements for the operating modes comprise a respective setting device for each mode.

29. An appliance as claimed in claim 27, wherein each setting device comprises a pushbutton.

30. An appliance as claimed in any one of claims 11 to 29, comprising a time clock controllable by actuation of one of the setting elements and an on/off resetting device for the full range of setting actuations except for time control of the clock.