EP2174065B1 - Heating device with watchdog timer - Google Patents

Description

The invention relates to a heater with a plurality of heating / hobs, the respective heat source for safety reasons after activation by means of a timer switching device is automatically switched off after a predetermined heating time.

A method is known for preventing the unintentional and therefore undesired heating operation of an electric range ( DE 37 37 712 A1 ), in which after switching on a heat source of the electric range and after a predetermined, uninterrupted by another circuit of one or more heat sources, an automatic shut-off takes place, and after the predetermined time since the last circuit of a heat source is also an automatic shut-off , In practice, when using such a method in electric stoves, in so-called security or holiday circuits, depending on the set cooking or heating level (electric power level) the heater a heating time until the automatic shutdown of the heating energy of one to 10 hours firmly impressed , ie predetermined. In this case, after the safety shutdown caused by a further circuit, the time switching device initially reset to zero is again set to a safety heating duration corresponding to the selected power level. Practice has shown that the predetermined safety times are very long and thus represent a significant security risk, especially at careless operation of the heater.

DE 38 15 984 A1 discloses a safety circuit for an electric cooker and allows the automatic shutdown of the cooker when one or more cooking zones of the cooker are in operation for more than a predetermined time. For this purpose, one or more counters are provided which begin to count to zero after switching on one of the power controllers after resetting and switch off the oven after reaching the preset counter reading if the corresponding power controller has not previously been set to zero.

DE 199 59 114 A1 discloses a method for monitoring and switching off hotplates on electric stoves. By a power-on limit is a Supervision of every single hotplate guaranteed. The limitation period for the cooking zones can therefore be chosen to be short in time, because in a change of setting on a control knob of the stove from a monitoring by a person can be assumed. Now the monitoring time begins again. Through this constellation, the duty cycle can be reduced to a time that protects pots, pans or the stove itself meaningful, without affecting the cooking process negative. If the specified maximum switch-on duration is exceeded, a forced switch-off of individual hotplates or of the entire appliance occurs. Warning signals indicate the end of the allowed switch-on duration and the forced switch-off that has occurred.
US 6,140,620 A discloses an apparatus for disconnecting an electrical device or component thereof from a source of electricity, including circuitry that connects the device or a component thereof to a power source via a relay or other component to open the circuit; and a timer circuit connected to the relay. The timer circuit includes a processor for setting the timer circuit and a manually operated switch in communication with the processor. The timer circuit is activated for a predetermined time increment by closing the switch, and the relay is closed while the timer circuit is activated. When the switch is closed again while the timer circuit is activated, an additional time step is added to the activation period.
CA 2 498 227 A1 discloses a safety circuit interposed between a heater and a power supply, which disconnects a connection between the heater and the power supply when a predetermined period of time has elapsed after activation of the safety circuit. By operating the safety circuit before the expiration of the predetermined period of time, this period can be extended. The safety circuit is operated via a remote control.

The present invention is based on the object to provide a heater of the type mentioned, which is suitable without special expertise or without special attention of the device user to a significant Improvement of the safety issue with regard to the limitation of heating time while achieving a high degree of user-friendliness.

This object is achieved by a heater according to claim 1.

In the heater, with a circuit, in particular the switching, the at least one heat source, the timer is set to a predetermined short rule heating time and dependent deactivation of the heat source, and preferably, the predetermined control heating time by manual operation to another safety heating period variable. Thus, the user is given a security-determined, short rule heating duration of between about 10 minutes to 1 hour, in particular in the range of 30 minutes, and proposed automatically executed without further action and, if necessary, can only be changed by a deliberately performed manipulation. It is in the foreground often desired by older users, community kitchens and the like safety aspect in which the user is offered as a default value and permanently installed and functioning without additional operation in the heating system rule heating time and thus a security measure is given, which is independent of individual each selected and entered cooking or power levels with z. B. very long Sicherheitsheizdauer of up to 10 hours in the lowest power level and thus also on the one hand is independent of the more or less fast-burning food and on the other hand is independent of a more or less attentive, the heater user.

For this purpose, the heater has a plurality of heating / cooking areas, the respective heat source for safety reasons by switching means of a - respective or common - time switching device automatically switched off after a predetermined heating time, with the circuit - in particular a switch, but also a switch - a any of the heat sources, the timing device for all heat sources is set equal to the predetermined short heating period and a dependent simultaneous shutdown of all heat sources. This results for all heat sources compared to the running of several shutdown simultaneously that better clarity is given, especially for people who are less experienced in dealing with electronic devices. This is a shutdown time preferably always visible and thus shows at a glance when the device is turned off. In addition, the device can be made simpler, since only one timer is needed for all heat sources.

Further, a button is provided by the operation of the rule heating duration is automatically extended by a simple operation only by a predetermined value of the same for all heating / cooking safety heating duration.

In addition, an acoustic and / or an optical signal generator is activated within a predetermined period of time before the end of the control / safety heating period.

In addition, a display device for the display of the predetermined, or changed control / Sicherheitsheizdauer is provided.

The type of circuit is not limited and may include any circuit on the heater or only defined switching options. Thus, the respective Regelheizdauer be activated or adjusted by any circuit of the hotplate or even the heater except a shutdown of the hob or the heater. It is assumed that an operation of the heater is performed by an attentive operator who would recognize an unintentionally turned on cooking and automatically turn off. Alternatively, the Regelheizdauer a cooking area is set only by switching on and / or switching this hotplate and / or by pressing an operator to set this Regelheizdauer. In a further alternative, the Regelheizdauer a cooking point is also set by switching on other hobs or set to the original value, if the remaining heating time is below the standard heating time. There are also other switching options conceivable, which are not detailed here for reasons of clarity.

The setting of the common safety heating period can also be activated or set here, for example, by any circuit of the hotplate or the heater except a shutdown of the hob or the heater. Alternatively, the Regelheizdauer a cooking only by switching on and / or Switching an arbitrary hotplate and / or be set by an operator control to set this Regelheizdauer, especially if the remaining heating time is below the standard heating time. In a further alternative, the Regelheizdauer a cooking place is set only by switching on a first active cooking or set to the original value and not changed by switching more hotplates. There are also other switching options conceivable, which are not detailed here for reasons of clarity.

A preferably change of the predetermined control heating time requires a purposeful manipulation of the control unit of the heater. The standard heating time, d. h., The aforementioned default value is clearly displayed in the display of the heater, and thus the user is forced to make a desired change in the displayed control heating period on the control unit, a tampering or not.

For safety reasons, it is proposed according to an embodiment of the invention that the control heating duration for all operating modes and / or heating levels of the heater is the same, with a short rule heating time of about 10 minutes to 1 hour, especially in the range of 30 minutes, as a guide seems appropriate. Furthermore, it is advantageous for safety reasons if the time switching device is set to the same safety heating duration for all heating stages of the at least one heating hob.

Of course, the inventive method is applicable to heaters of different design and determination, as in hobs, ovens, grills and the like.

In a device for carrying out the method, among other things according to the invention, it is provided that the device has an operating element for changing the standard heating duration.

Starting from the fundamental and safety-relevant predetermination of a very short rule heating duration in comparison with known methods, it can be done by conscious Manipulation on the device a z. B. arbitrarily selectable other heating time can be set; without such a change, the heating operation is automatically switched off after the short heating period has ended.
In the context of the present invention, there are various variants in order to overcome the security problem addressed. Thus, it can be specified that the control heating duration is the same for all operating modes of the heater and is displayed perceptibly on the heater. The same applies not only to the device operating modes in the form of power levels, but also for the heating, z. B. in the form of several hotplates of a hob.
Not least, according to a development of the invention, a change in the control or safety heating time down (decrement) or above (increment) can be simplified in terms of operation by providing an operating element with which the control heating time is automatically triggered by a simple switch actuation , in particular by tapping a button, z. B. a touch-sensitive sensor button to a predetermined value changeable, preferably extendable, is. It is also the adjustment of the switch-off by means of other control elements, z. Turning knob, increment / '+' key and decrement / '-' key, possible, possibly with different time periods. In particular, it is advantageous to increment the safety heating duration by tapping on a "+" key: by 1 min and decrementing the safety heating duration by tapping a "-" key: by 1 min. Such an embodiment is advantageous for heaters with separate Sicherheitsheizdauern for each hob as well as heaters with only a common Sicherheitsheizdauer. Alternatively, it may be preferred that the operating element comprises a switch, in particular a button, by the actuation of which the safety heating duration can only be increased by the predetermined value. A practical embodiment may be such that the user must press a key every 10 minutes (from a preferred range of about 10 minutes to about 30 minutes) after the end of the control or safety heating time, otherwise the hob automatically switches off (principle 'Dead man's switch "). In this case, an extension of the heating time on any button of the heater (except the ON / OFF button) happen, or there may be one or more specially designated buttons, z. For example, the timer button. Such a configuration is particularly advantageous for heaters with only a common Sicherheitsheizdauer.

It is advantageous if, within a predetermined period of time, for. B. about one minute, before the end of the safety heating period, the user is prompted by a beep and / or an optical signal to press a (eg., Any) button. If this is not the case, the cooking zones are switched off. Preferably, the time should always be counted only after the last operation on the hob, as each operation shows that a person is present on the device.

In one possible device, with any circuit of the heater, the timer is set to the predetermined short heating period and a dependent shutdown of all heat sources. The arbitrary circuit may be an activation of a hotplate, or switching a hotplate, z. As an adjustment of the cooking level, or other operation for operating the heater, z. B. an operation of a menu or lighting button, or an operation of a dedicated button or buttons, etc.

Preference is given to a device in which, with a specific circuit of the heater, the timer is set to the predetermined short heating period and a dependent shutdown of all heat sources. The particular circuit may be an activation of a hotplate or the actuation of a special "snooze" button, e.g. As a 'timer' button. Switching on another cooking zone can reset the standard heating time to its original value (especially if the remaining heating time is shorter than the standard heating time), but alternatively the remaining heating time will not be changed.

The invention will be explained below with reference to the figures shown in the drawing.

FIG 1

ein Funktionsschaubild, das die Bedienung eines Heizgerätes und die Aktivierung, bzw. Veränderung einer vorbestimmten Regel-Heizdauer verdeutlicht,

FIG 2

ein Bedienpaneel eines nicht weiter dargestellten Heizgerätes.

It shows:

FIG. 1

a functional diagram illustrating the operation of a heater and the activation or change of a predetermined control heating duration,

FIG. 2

an operating panel of a heater, not shown.

• Kasten 1: Das Heizgerät wird z. B. durch Betätigen eines Hauptschalters, zum Beispiel des Bedienorgans 8 gemäß FIG 2 eingeschaltet.
• Kasten 2: Die gewünschte Kochstelle, z. B. eines mehrere Kochstellen enthaltenden Kochfeldes wird aktiviert.
• Kasten 3: Die gewünschte Kochstufe, bzw. Leistungsstufe wird durch Betätigen der Bedienorgane 9 mit optischer Anzeige an den Anzeigeorganen 10 gemäß FIG 2 eingestellt oder umgeschaltet.
• Kasten 4: Eine vorbestimmte Regel- bzw. Sicherheits-Heizdauer bzw. deren Abschaltzeit wird automatisch aktiviert, kenntlich gemacht durch ein digitales Anzeigeorgan 11 gemäß FIG 2.
• Kasten 5: Der Benutzer entscheidet sich zwischen "Abschaltzeit ändern" (waagerechte Verbindungslinie) und "Abschaltzeit nicht ändern" (senkrechte Verbindungslinie).
• Kasten 6: Wird auf Nicht-Änderung entschieden, wird nach der vorbestimmten und vorprogrammierten Sicherheits-Heizdauer von z. B. 30 Minuten die Heizquelle, bzw. Kochstelle automatisch ausgeschaltet.
• Kasten 5.1: Wird in Position 5 auf Änderung entschieden, so kann mittels der Bedienorgane 12 FIG 2 eine andere Heizdauer bzw. Abschaltzeit manuell eingestellt werden, die wiederum am Display 11 angezeigt wird.
• Kasten 5.2: Der Benutzer trifft die Entscheidung, ob bedarfsweise keine weitere Heizdauer gewollt wird und zumindest die eingestellte Kochstelle bei Position 7 manuell abgeschaltet wird oder ob die veränderte Heizdauer bzw. Abschaltzeit bestehen bleiben soll, was wiederum zur automatischen Ausschaltung des Heizgerätes oder der Kochstelle bei Position 6 führt.

In the diagram in FIG. 1 are in temporal succession from top to bottom, or laterally, the necessary to turn on the heater until the determination of the safety heating time operations, or functional steps in rectangular and diamond-shaped box illustrates, the indicated in diamonds function steps each require a decision of the user , "yes" for horizontal, and "no" for vertical connecting line to the next box. The operating and decision steps are listed below:

• Box 1: The heater is z. B. by pressing a main switch, for example, the control element 8 according to FIG. 2 switched on.
• Box 2: The desired hotplate, z. B. a cooking hob containing several cooking zones is activated.
• Box 3: The desired cooking level, or power level is by pressing the controls 9 with optical display on the display elements 10 according to FIG. 2 set or switched.
• Box 4: A predetermined control or safety heating time or their turn-off time is automatically activated, indicated by a digital display element 11 according to FIG. 2 ,
• Box 5: The user decides between "change switch-off time" (horizontal connection line) and "do not change switch-off time" (vertical connection line).
• Box 6: If it is decided not to change, after the predetermined and pre-programmed safety heating time of z. B. 30 minutes, the heating source, or hotplate off automatically.
• Box 5.1: If a decision is made in position 5, then by means of the controls 12 FIG. 2 another heating time or shutdown time can be set manually, which in turn is displayed on the display 11.
• Box 5.2: The user makes the decision as to whether no further heating time is required and at least the set cooking position is switched off manually at position 7 or whether the changed heating time or shutdown time should remain, which in turn to automatically switch off the heater or the hotplate at Position 6 leads.

For the sake of better clarity, the above flow chart includes the actuation (in particular a switch-on) of only one hotplate. When two or more cooking zones are operated, the same procedure is carried out for each cooking zone, with only one timer (not shown) for all cooking zones being present here. Therefore, an actuation of a hotplate, the shutdown time for the other - possibly set previously - cooking units reset ('override'). The above procedure may be followed each time a hotplate or even the cooking appliance is operated (except for the switch-off) or only during certain operations such as switching on a hotplate, adjusting a hotplate parameter (eg a heat setting) and an actuation of the operating element of the time switching device, or as only when switching on a cooking position and an operation of the operating element of the timer device. Alternatively, the timer can be designed so that the actuation of other hotplates the already activated shutdown time (activated by switching on the first hotplate) is not changed. The turn-off time is then only by a purposeful operation of the controls 12, 14,15 (see FIG. 2 ) of the timer.

In FIG. 2 illustrate the characters 13, the position of the example in the four cooking zones of a hob, each of which the display elements 10 for the set cooking levels and the Setting members 9, z. B. are assigned in the form of sensor buttons for selecting the cooking levels.

The control element 12, 14, 15 for the automatic shutdown of the cooking zones over the safety heating period comprises three sensor buttons 12, 14, 15, (eg with a capacitive, infrared-sensoric, piezoelectric element), by their repeated operation, the safety heating time a corresponding multiple of the predetermined value is variable, preferably extendable, which is displayed in the associated display 11. The turn-off time can be incremented by means of a "timer" / "clock" key 12, e.g. B. by tapping the button each by a fixed value, eg. Eg 5 min: press "clock" button once = extension of 5 min, tap twice "clock" button = extension by 10 min, and so on. Alternatively, the turn-off time can be incremented by means of an increment / '+' key 14 and decremented by means of a decrement / '-' key 15, e.g. B. by tapping the keys 14, 15 each by a further fixed value, for. Eg 1 min: press the '+' key 1 time = tap extension for 1 min, 2 times '+' key = extension for 2 min, and so on. In addition, however, is still the adjustment of the shutdown by other control elements, eg. B. rotary knob (not shown), possible. Alternatively, the turn-off time is only increased, which - depending on the device design - the decrement button 15 can be omitted. The increment / decrement times may also include other values, e.g. Example, a range of 1 min to the rule heating time, in particular a range of 1 to 30 min.

Alternatively, by operating the operating member 12, 14, 15 (or optionally also another switch 9), the safety heating duration can only be extended by a predetermined value (deadman circuit), wherein within a predetermined signaling interval, in particular a length of approx. one minute, before the end of the safety heating period an acoustic and / or optical signal is output. This z. B. the increment and decrement keys 14, 15 are omitted for setting the Sicherheitsheizdauer or switched inactive. In the dead man's circuit, it can be advantageous if extension of the safety heating duration comprises 10 minutes to 30 minutes, in particular 10 minutes. Here is z. B. the Regelheizdauer also only 10 min. In particular, in the deadman circuit, it may also be advantageous if they are set to their maximum value with each actuation of the heater becomes. Particularly advantageous is an embodiment in which an extension of the Sicherheitsheizdauer only by means of the timer button 12 is feasible

Of course, the hotplates can also be switched off manually.
Preferably, the Regelheizdauer and the time steps for setting or adjusting the Regelheizdauer to another Sicherheitsheizdauer in the heater factory preset, but reprogrammed by the operator to other values. Also, an operator may preferentially switch the control or safety heating duration function on or off, for. B. via a basic function menu.

Claims (8)

1. Heating device with a number of heating elements/hotplates, the respective heat source of which, for safety reasons, is automatically switched off after activation by means of a watchdog timer upon completion of a predetermined heating duration, wherein

   - with a switching of the at least one heat source, the watchdog timer can be set to a predetermined short controlled heating duration of between approximately 10 minutes to 1 hour and a switch-off of the heat source which is dependent thereupon,

   - with the switching of a heat source, the watchdog timer is set to the predetermined short controlled heating duration and a switch-off of all heat sources which is dependent thereupon,

   characterised in that

   - a button (12, 14, 15) is provided, by the actuation of which the controlled heating duration can be extended automatically by a simple actuation only by a predetermined value of a safety heating duration which is the same for all heating elements/hotplates,

   - an acoustic and/or a visual signal sensor is activated within a predetermined period before completion of the controlled/safety heating duration and

   - a display element (11) is provided to display the predetermined or modified controlled/safety heating duration.
2. Heating device according to claim 1, characterised in that the controlled heating duration is the same for all modes of operation and/or heating levels of the heating device and is indicated clearly on the heating device.
3. Heating device according to claim 2, characterised in that the controlled heating duration amounts to approximately 30 minutes.
4. Heating device according to one of the preceding claims, characterised in that the change in the safety heating duration can be adjusted by a single actuation of a control element (12, 14, 15) in a range between 1 min and the controlled heating duration, preferably between 1 min and 15 min, more preferably between 5 min and 10 min.
5. Heating device according to one of the preceding claims, characterised in that the watchdog timer is set to the predetermined short controlled heating duration and a switch-off of all heat sources which is dependent thereon with any switching of the heating device aside from a switch-off of a heating element/hotplate or the heating device.
6. Heating device according to one of claims 1 to 4, characterised in that the watchdog timer is set to the predetermined short controlled heating duration and a switch-off of all heat sources which is dependent thereon with a switch-on of a hotplate or a switch provided specially therefor.
7. Heating device according to claim 6, characterised in that the watchdog timer is set to the predetermined short controlled heating duration and a switch-off of all heat sources which is dependent thereupon only with a first switch-on of a hotplate or a switch provided specially therefore.
8. Heating device according to one of the preceding claims, characterised in that the heating device is a cooking stove.

Images