DE2004473A1 - - Google Patents

Description

The invention relates to an electric oven whose cleaning by means of combustion on the Walls existing deposits is feasible.

Furnaces of this type are designed to that automatic cleaning takes place at regular intervals, namely by raising the oven temperature to a height that is well above the temperatures required for baking, with this elevated temperature is maintained until the combustion of those present on the walls Deposition is actually complete.

This goal is achieved in that the electrical Heating resistors of the furnace are switched on as well as an in the immediate vicinity of the oven door

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bath

neter additional resistor is switched to also ensure that the inner surface of the door is heated.

Suitable sealing means are also placed around the door to prevent any heat loss to be avoided outside, and an outlet channel through which the released combustion gases or freely floating Combustion residues can escape using an associated extraction system.

Wk In addition, a locking system is provided which is intended to ensure that the! Dur remains in the closed state and cannot be opened in any way during the duration of the disconnection process.

In view of the diverse demands and different safety requirements that electrical Furnaces of this type must be established become that the arrangements used heretofore are relatively complicated. That also applies to the electrical circuits of these ovens and inevitably leads to high prime costs.

™ The object of the invention is therefore, for a Oven of the type provided above to be designed to the effect that he compared to conventional Circuits shows a greatly simplified structure.

The invention relates to a furnace in whose circuit two thermostats are arranged, welohe serve to regulate the heat, one for normal operation of the oven and the other for the two

009838/0117 BAD ORIO ₁ NAL

the first thermostat as well is switched in such a way that the device or device used to control or block the door bolt is activated. regulates the circuit assigned to it to the effect that there is the device until the end of the cleaning process in the position "remains in which the blocking of the Riegel is required.

The one used to control the furnace according to the invention Main switch shows in addition to the settings that are for Control of the different modes of operation of the oven are used to set a setting that is used to control the Cleaning process is used, so a setting in which the circuit, which the bolt blocking device is assigned, after the closure of a designated, manually operated contact can be energized,

In this position, however, the power supply to the heating elements of the furnace is controlled by a contact, which can only be closed after the The door is closed. As a result, the oven can be heated intensively for cleaning can only be made after this interlocking, which provides an essential security before the execution of the Cleaning process is guaranteed.

The idea of the invention allows the most diverse implementation possibilities to, some of which are shown in the attached drawings, which show: Pig. 1 The Sehaltschema of the furnace according to the invention during normal operation of the furnace,

Fig. 2 and 3 the Sehaltschema according to Fig. 1, respectively at the beginning of the cleaning process or during its course.

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"..: .. BADORLGiNAL

The furnace according to the invention has a main control switch which is operated via a rotary handle 1 will. Two pure contacts are assigned to this switch, on the one hand the contacts a, b, c ..., h and on the other hand the contacts i, ^, ... n.

These contacts sit in the circuits of various electrical apparatus and components of the furnace, whereby the mode of operation of the rotary switch is designed in such a way that the necessary connections are made for each setting getting produced.

A changeover device 2 is provided, among other things, due to which the furnace can be operated either by manual control or by means of a programming device controls. The circuit also has two switch-off devices 3> a and Jb, which are suitable are to be controlled with the aid of the motor 4 of the programming device.

The entire circuit is connected to the two phases I and II of the power grid. The first of the two

■ Phases is connected to contact i, phase II, on the other hand, is connected to contact g of the main control switch.

P closed. Additional auxiliary connections can be made on the second phase of the power grid. The motor 4 of the programming device is, however, connected to both phases and therefore remains in constant operation.

The oven has two heating resistors 5a and a third resistor i? B, which is to be switched on when the oven is to serve as a "grill" .

0 0 9 8 3 8/0117 ^BAD

Together with these three resistors in series A heating resistor 6 of a catalytic converter is switchable provided, which is intended to prevent the occurrence of Äauch. In this context, let mentions that due to the intended connection this device serving to remove smoke constantly is in operation, i.e. not only while the oven is being cleaned, but also during normal oven use. ■

The circuit is a fourth additional heating resistor 7 assigned, which is around the one for the oven door provided names is arranged to ensure that the inner surface of the oven door is heated during the cleaning process. This resistance gets so only electricity while the oven is being cleaned.

An essential feature of the furnace according to the invention is that two thermostats 8a and 8b are provided for heat regulation, one of which comes into operation during normal oven operation, while the other is dedicated to the cleaning process.

. Consequently, the first thermostat 8a is relevant coordinated that it ensures the opening of the circuit for an oven temperature of e.g. 300 °, but it is also adjustable so that the user of the oven can set the maximum temperature inside the oven as desired can adjust. The control of the thermostat follows by turning axis 1a of the main switch, by actuating the rotary knob 1.

The second thermostat is designed to automatically interrupt the associated Circuit causes as soon as the internal temperature of the

009838/0117

Oven reached e.g. 500 °. However, in contrast to thermostat öa, this thermostat cannot be regulated.

In this embodiment, the circuit also has a motor 9 _f which is used to set up a skewer for poultry, pieces of meat or the like. to put in rotation. You could of course do without this engine.

As in previously known ovens with a no-control system, that works by burning residues, the oven door is manually operated Bolt provided. üJine electrically functioning blocking device is suitable to ensure that the bolt remains in the closed state for the period required for the cleaning process.

This bio-storage device can consist of a locking component, which by means of a Electromagnet 10 is actuated, which in turn is set in action by means of a push button 11 can be.

Furthermore, a contactor 16 is provided, which fulfills the function of a safety device target. This contactor is only switched on when the oven door is locked in the closed state has been.

A lamp 13 is also assigned to the circuit, which provides lighting inside the furnace as well as three control lamps 14a, Hb and Ho. The lamp Ha should light up during normal furnace operation.

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th, the second 14b is the one to block the Door bolt serving device assigned, while the lamp 14c in the cleaning process of the oven should light up.

lalls the oven or stove according to the invention with electric Heating plates is equipped, as in the embodiment shown, so are the Circuits 15 of these heating plates also have contacts

assigned o, g, £ as well as the contacts r, s, t / j * sera connections also made with the help of the main control switch will. The main control switch is designed so that these contacts close continuously and can only be interrupted when cleaning the oven.

During this process, the electrical heating plates are switched off, so that all the electricity is only available to the heating resistors of the furnace.

The main control switch has a setting that is specifically intended for the heating process, and next to it several settings that are for the various Possibilities of normal furnace operation are provided.

The main switch has the following setting options »
. 1 ° - switching off the oven ι In this position only the contacts ο , g, cj and r, s, t are closed, so that the

Circuits 15 angesohlossenen heating or cooking · \ can be benutst plates.

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However, the programmer's motor 4 is also energized because it is constantly in operation.

- Switching on the oven lighting By turning knob 1 in a certain direction, contacts b and i are initially closed and contacts g and n are closed.

In this way, the lighting lamp 13 enters before the heating resistors are put into operation Task.

- Normal baking in the oven

By further turning the knob 1, the two heating resistors 5a are switched on and the The furnace can perform its normal function. As can be seen from "Pig. 1, the both contacts a and b are then connected to contact i, while contact ο is connected to the Contact k is connected. In addition, contact e is connected to contact 1, the contact g but with the contacts m and n. Bs should be noted that the power supply of the heating resistors 5a then from the first Thermostat 8a is controlled so that the heating temperature rises to a maximum of e.g. 300 ° is determined by the thermostat, the control of the thermostat respectively takes place by turning the knob 1 by one or more steps.

It should also be pointed out that when the furnace is in operation, the smoke extraction device is in operation, since the associated resistor 6 is switched on.

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The control lamp 14a receives power and indicates that the stove is working well «■

The furnace works immediately, of course, if the changeover device 2 is previously in the manual control position has been brought:

whereby the two associated switches in turn ^{assume the position shown in I 1} Xg. 1 has been fully drawn. If the two switches assume the position shown in broken lines according to FIG. 1, the switching on of the oven, as described above, is automatically ensured at the moment of the closure of the breakers 3a and Jb, which are closed with the aid of the programming device. '■ · ■■ _
- Using the oven as a "grill" the main control knob 1 becomes even further. turned around, a setting is achieved at which the oven can be used as a grill.

The characteristic of this setting is that contacts be connected differently, i.e. that from there, at which contact k is assigned to contact d and no longer to contact o.

In this way the two heat resistance | de 5a switched off, while the resistance provided for grilling 5b is switched on. From this point in time on, the first thermostat Qa is set in such a way that the intended maximum temperature of, for example, JQQ ⁰ occurs. As on the setting level mentioned above, this setting can either be done using Dianuel- _; by the control system or automatically by the programmer.

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- use; of the oven as a "roaster"

In a later setting of button 1, the switch ensures that the Oven can work as a roaster. The connections are at this setting level the same between the contacts as on the ü-rill level, only with the difference that the contact m is connected to the contact g and to the contact f at the same time. In this way the motor 9 is switched on, the function of which is to do so β to ensure that a skewer with the sitting on it

Piece of meat is rotated.

As above can manual control, but auoh the automatic control by means of the programmer 4 thereby enter the puncture.

- Automatic oven cleaning

In the last setting of the button, the oven walls are cleaned using Incineration of the residues on them. This process consists of the following work phases.

a) - Control of the process (cf., ffig. 2) ^ The main switch is in a

Position in which the circuits 15 of the heating plates are switched on.

Furthermore, contacts a and b are connected to contact i, while contact ο is connected to the two contacts ^ and k. In addition, contacts g and h are an dit both contact m and η connected due to the contact base i to the contact a and b as well as the connection of the contacts

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η and h can the device provided for blocking the door bolt-.TO-when the Push button 11 come into operation. The control lamp T4b receives power and shows • In this way, that this puncture is possible is. The blocking device 10 can therefore be operated to the effect that an immediate Neutralization of the device takes place, which gives the option of manual the operable door bolt into the closed position of the door.

As already stated, the interlocking ™ has an effect

ment of the door in such a way that the contact is closed, which in turn the control lamp 14c lights up, indicating that the door is properly closed and that the! cleaning process begins immediately.

The contact 16 also ensures that the Current phase I is connected to one of the terminals of the interrupter 3a of the programmer. After this adjusted accordingly that the cleaning process lasts long enough, the two switches or | are located

Interrupter 3a and 3b in the switched-on state, whereby the cleaning process is effectively initiated, since from that moment on the two heating resistors 5a of the furnace and the additional resistor 7 », which is located in the area of the oven door surround, is switched on will or will. j

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The resistor 6 of the smoke extraction gate device remains switched on, as before .

It should be noted in this context, that the UmscäraltTorrichtung 2 then switched off is. As a result, it can be placed in any of the two parts of the gate.

b) - Main phase of the cleaning table (Tgl. Pig. 3) When the resistances 5a and 7 are switched on for a certain time, the oven temperature has exceeded the maximum temperature intended for baking.

fe steps that up to a temperature level τοη

eg 500 ° is enough and
6a is controlled.

E.g. 500 ° is enough and τοη the first thermostat

At this temperature the thermostat switches off so that it interrupts the associated circuit and thereby prevents the gate direction seen to block the door bolt 10 comes into operation. The handle remains blocked and it is impossible at this moment, to open the door. This can be seen from the fact that the control lamp 14b is no longer lights up as soon as the thermostat 8a is switched off.

Tone at the moment when the internal temperature of the oven is that intended for the cleaning process The second takes care of the limit value, e.g. §00 ° Thermostat 8b for heating regulation,

The heating regulation is maintained until the combustion on the stove walls deposited residues uni. Jette in front of $ «- senene be trust has elapsed, whereby auoh the to the inside of the for existing debris

to be burned. .

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BATH ORIGrNAL

c) - Shutdown of the cleaning process:

The shutdown of the cleaning process is controlled by the program device 4, which the Breakers 3a and 3b open. The opening of the Interrupter 3a leads to the deactivation of the "" "Heating resistors 5a and 7 ·

The control lamp 14a is also switched off, while the control lamp 14o continues to light to indicate that the temperature inside of the oven is still very high.

At this moment it is not yet possible -

to open the oven door or flap, because the manually operated latch the door will always be still blocked by means of the device 10, which can not yet be operated to the effect that she releases the bolt *

d) - End of the cleaning process

üJin a certain time after switching off the resistors 5a and 7, the temperature falls inside of the furnace to the one for the first thermostat 8a intended limit value, e.g. 300-. Then comes it switches on the thermostat and thereby, | to power the associated circuit. !

The control lamp · 14b lights up and picks up daduroh that the door bolt that can be used to block the manu # 11 is in front of · direction 10 can be operated again, the oven door alao be opened know. The device 10 can be operated in the manner that is applied to the 11th.

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The oven door or oven flap can then be opened. The cleaning process is complete. The button 1 only needs to be turned back to its original position.

The first! Thermostat 8a of the furnace fulfills two functions, namely:

- on the one hand, its usual function as a control organ to regulate the oven temperature during normal oven use}

- on the other hand, the function of a security body, * which automatically prevents the oven door or flap from being opened as soon as

the oven temperature has reached an increased value in the course of the cleaning process. As already described above, the first i'hermostat 8a has the task of to ensure that the oven door or flap opens by the end of the cleaning process cannot be opened under any circumstances, i.e. until the moment when the oven temperature has reached a value falls, which is identical to the maximum Baok temperature.

The use of this thermostat for the two functions described above is to be rated as a considerable advantage and, in particular, makes the installation of various control devices and a relatively complicated electrical circuit superfluous.

Despite its simplicity, the circuit according to the invention guarantees all the necessary safeguards. In this context it was dependent on -

009838/0117

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Claims (5)

Patent claims » j 1 J Elektriseher Baokofen whose inner walls can be cleaned by the at Ky them existing deposits by combustion with a during combustion electrical device effective to block the manually operable door or flap bolt, characterized in that the circuit of the furnace two thermostats (8a, 8b) are assigned, which are used to regulate the hit, namely one for normal operation dts oven and fc the other for the cleaning process, the first thermostat (8a) is also switched so that it is used to control or block the The device (10) serving as a door bolt or the circuit associated with it controls the device 110) from the beginning to the end of the cleaning process in the blocked position when the thermostat is switched off, i.e. until the moment when the temperature drops inside the oven the activation of the thermostat causes and thus from then on the neutralization of the to r blocking of the bolt serving device is guaranteed. 2. Oven according to claim 1, characterized in that a main control so-holder (1) is provided is the one next to the! settings that control the various modes of operation of the oven serve, has a setting that is intended for the cleaning process, i.e. an 009838/0117 position in which the circuit, which of the ' Hiegelblockiervorrichtung (10) is assigned, after closing a designated, manually actuated contact (11) energized will. . " 3. Baokofen naoh claim 2, characterized in that that when the main switch (1) is set to "oven cleaning", the power supply to the heating resistors (5a, 5b) is controlled by a contact (16) is, whose activation or closure only naoh g The oven door or flap is locked in the closed state. 4. Baokofen naoh Anspruoh 3 »daduroh marked, that in the same setting of the main switch (1) the current supply of the resistors of the furnace also by means of one or two contacts (3a, 3b), it is checked which by means of an adjustment system or a programming device (4) be controlled, the or the ultimately the The cleaning process is correct. 5. Baokofen naoh Anspruoh 1-4 »daduroh marked," dafi, fall d · «oven assigned to heating or hot plates The circuits (15) can be switched on from the main switch (1), the strokes (15) being arranged in such a way that, when they are set to ^M frequency, they can generate a current; ; ....; '. ■.' ■ '., V. ■' ..-.. '■■ ... BATH 00 9 8 3a / 0 : H% Blank page