FI68141C - KOKENHET MED MINST TVAO ELEKTRISKA KOKPLATTOR - Google Patents

Description

| «2ντ7 | advertisement publication ^ 8141 ™ 11 UTLAGGNI NGSSKRIFT °° • c (45); ; ·. ·: ':: --7 y-5 (51) Kv.ik. * / Int.a.4 H 05 B 1/02, 3/68 FINLAND - FINLAND (2.1) Patent application - Patent appeal 791036 (22) ) Application date - Ans & kningsdig 28.03 · 79 (EN) (23) Starting date - Glltighetidag 28.03-79 (41) Become Public - Bllvlt offentlig 29.09-80

National Board of Patents and Registration (44) Date of publication and hearing. -

Patent * och registerstyrelsen '' Ansökan utiagd och ud.sicriften publicerad 29.O3.85 (32) (33) (31) Privilege claimed - Begärd priority (71) (72) Karl Fischer, Am Gaensberg, 7519 Oberderdingen, Federal Republic of Germany Republic-Förbundsrepubliken Tyskland (DE) (7 * 0 Oy Kolster Ab (5 * 0 Cooking unit with at least two electric hotplates -

Experienced with the electric electric platform

Cooking units, such as flush-mounted cooking trays or pans, hobs, portable cookers, etc., are most often equipped with 2-4 electric hotplates, each with an installation power of between 1000 W and 2000 W, in order to achieve a relatively fast boiling state. The four-plate hob can therefore have a connection power of 7-8 kW. This is often too much for a normal household-electric power grid, especially if the mains voltage is only 120 V.

Besides, it cannot be plugged into a normally protected electrical outlet. Previously, cooking units with one high-power so-called a quick or flash plate and three ordinary hotplates, the former having a high connection power and the latter a rather small one, the latter being intended for further cooking. The hostess must then carry out all the pre-cooking or preheating steps in succession on a high-power plate and, for further cooking, she must transfer the cooking vessels to three lower-power plates. This complicates the work and requires special attention.

68141

It is an object of the invention to provide a cooking unit with at least two electric hotplates, at least one of which is preferred over at least one subsequent plate and is synchronously adjusted or controlled by a switching device actuated by a temperature sensor.

According to the invention, this object is solved by including a privilege circuit known per se and that the switchgear of the privileged electric hob has two toggle switches, each of which switches the power supply between the heating element in the preferred hob and the next hob depending on the temperature detected by the temperature sensor.

Thus, a certain order of values is determined (which, however, can also be changed or removed by means of toggle or selection switches), so that power is supplied to the hobs connected to the rear when the first hob at least partially switches off the power due to its adjustment or control event. Since the high-cooking hob undergoes an initial cooking step and during further cooking the powers hardly exceed 10 or 15% of the connection value, a sufficiently long time remains to be used, for which times the following hotplates are switched on. Especially when the Intervals, i.e. the switching times (i.e. the closing and switching times) are dimensioned to be very short, the cooking events following the hotplates are hardly disturbed and the user hardly notices the mandatory de-energized times of these subsequent hot plates. This is especially the case when the hobs in their priority step are arranged in the cooking unit in such a way that the hobs most frequently used under this arrangement are the first in the priority step. In privileged electric hotplates, the synchronizing mode of operation of the switching device is important, but a rear-mounted hotplate could also have another method of adjustment, e.g. seven-stroke switching. The temperature controller (thermostat) could preferably be a so-called an automatic regulator that works with a hydraulic sensor box located in the center of the hob and pressed against the bottom of the cooking pot. In this case, the hob has two heating resistors and the controller has two corresponding contacts, which open the circuit at successive temperature values. While the partial power of the first hob is switched off, the total or partial power is started to be fed to the next hob.

3 68141

In addition, a very advantageous and not only low-value but also energy-saving implementation is proposed, in which the switching device is a state controller which reacts to the steam generated in the cooking vessel. When this state controller, described in DE-PS 1 029 502, is provided for a privileged electric hob, it is possible, when several hobs are placed on top of this hob, the lower of which heats the upper one, to prepare a meal consisting of several separate dishes and one another hob connected to the back, for example for frying.

Embodiments of the invention will now be described in more detail with reference to the drawings, in which Figures 1 to 3 show wiring diagrams of different variants of cooking units, Figure 4 shows a detail of one variant, Figure 5 shows a side view of the cooking unit and Figure 6 shows the wiring diagram of Figure 4.

Similar parts are marked with the same reference numerals.

The circuit diagram shown in Fig. 1 shows a cooking unit 11 with four electric hobs 12, 13, 14, 15, which can be connected to the socket 17 of the household electrical network with a plug 16. The cooking unit can be an electric stove, a flush-mounted or portable cooker or a portable cooker. Each electric hob can be a standard casting hob with two heating conductors, i.e. resistors 18, 19, which can be connected individually or together by two contact arms 20, 21 or a coupling spring of the switching device 22. The switching device 22 is a temperature controller, i.e. a thermostat, which can be set to the desired temperature by hand from the control or setting knob 23. Each thermostat includes a sensor box 24 which is resiliently mounted in the center of the hob in a conventional manner, not shown here, and may be limited to the bottom of the hob in order to know the temperature of the hob. It is mainly arranged for a built-in heating conductor 19. The sensor box 24 is filled with expansion fluid and connected by a capillary tube 25 to the expansion box 26, which acts on the switching contacts 20, 21 depending on the temperature and manual setting of the sensor box. The contacts 20, 21 are so tuned relative to each other that they switch in succession as the temperature 68141 4 rises, the contact arm 20 a few degrees before the contact 21. This largely prevents the set or reference temperature from being exceeded.

The thermostat can be constructed according to either DE-OS 2,058,512 or DE patent 2,414,813. The contact arms 20, 21 are also electrically separated on the inlet side and may have two separated coupling springs. Adjacent to the fixed contacts 27, 28 of the switching device 22 leading to the heating resistors 18, 19, a fixed changeover contact 29, 31 is arranged, which cooperates with the respective switching springs when the the heating element is switched off.

The heating resistors of all the hobs are connected by a return line 36 to one terminal of the household electrical network and to the contact arms 20, 21 of the switchgear at its other terminal. The changeover contact 29 and 31, respectively, are connected to the contact arm 21 and 20, respectively, of the next switching device, so that the changeover contact of the (e.g., inner) heating resistor is provided for the second (e.g., outer) heating resistor of the next hob. As a result of this cross-connection, the heating resistor which controls the temperature sensor 24 is switched on in each case. The cooking unit according to Fig. 1 operates as follows:

The plug 16 is connected to a socket whose fuse corresponds to the maximum power of the strongest hob, eg 2000 W.

Figure 1 shows a state in which the hobs 12, 13 and 14 are connected by a control knob 23. The hob 12 has an initial cooking step in which both heating resistors were switched on, has already ended and the switching device 22 has received a message from the temperature sensor 24 that the set temperature has been reached. For further cooking, only average powers up to approx. 500 W are required, which partial power is supplied by switching on and off the heating resistor 19 (contact arm 21) and then switching takes place between contacts 28 and 31. In the hob 12, both contacts 27, 28 are de-energized, so that both contact arms 20, 21 are limited to changeover contacts 29, 31 connected to the contact arms 20, 21 of the next hob 13.

The hob 13 has also completed the initial cooking step. This plate 13 shows a state in which the inner heating resistor 19 receives 68141 currents (shaded dark) and the heating of which mainly affects the temperature sensor. The changeover contact 31 is free and the heating resistor 18 of the hob 14 does not receive current, although it, like the heating resistor 19, is connected by the switching device 22 and this hob has not yet reached the set temperature.

However, the situation shown does not last long, because after a short time the contact 21 switches off the current from the hob 13 again, whereby both heating resistors 18, 19 of the hob 14 receive current.

Since the hob 13 has the current cut off from the heating resistor 18 and the contact arm 20 is limited to the changeover contact 29, the contact arm 21 of the plate 14 and its heating resistor 19 receive current. Thus, during the time that the hob 13 acquires its cooking power, the initial cooking time of the hob 14 slows down slightly. But when the power is disconnected from the disc 13 shortly thereafter, the disc 14 receives full power. The coupling events in the plate 12 affect the plate 13 and the subsequent plates, respectively. The hobs 12-15 are thus privileged relative to one another in their order of connection. Although three hobs are in operation, the maximum connection power is not greater than just one hob.

Due to the low relative power supply times, the last hob also has a sufficient power supply or on-time.

The cooking unit 11 'according to Figure 2 also has four hotplates, of which the hotplates 12' and 15 'have a smaller diameter and 1500 W power and the other hotplates 13', 14 'have a larger diameter and 1500 or 2000 W power. The thermostats 22 'differ from the thermostats according to Fig. 1 only in a particularly simple quick-switch design. It has a movable quick-moving spring 37. This consists of two spring-loaded contact halves 20 ', 21' from which spring tongues are bent, which are supported on fixed support bearings 38, 39, through which current is supplied. The spring-side housings are partially embedded in the central special body 55, which is affected by the expansion housing 26. The contacts 27, 28, 29, 31 co-operate with the contacts at the end of the spring halves 2Q1, 21 '. This double spring quick switch 37 is so tuned that the contact half 21 'cuts off the current at a lower temperature than the half 20'.

Power is supplied from the plug 16 by a manually operated switch 56 having two contact arms which in the first position switch on the hobs, in the second position switch on additional sockets 57 for the mixer, in the third position separate the hobs from both household mains. In Figure 2, the thermostats 22 'of both privileged hobs 12', 14 ', preferably located at the front of the cooking unit 11, are connected to the other terminal of the network, while the hobs 13', 15 'are connected to the changeover contacts 29, 31 of these thermostats. Here again, in the preferred hotplates 12 ', 14', the power supplies 38, 39 to the contact arms 20 ', 21' are electrically connected so that a normal double quick coupler can be used here without electrically isolating both contact halves 20 ', 21' from each other, while in subsequent hotplates 13 ', 15 the electrical separation of the chain arms is important, but the exchange contacts could be omitted.

In the state shown in Figure 2, it is assumed that all hotplates are connected. The hobs 12 ', 14' have already reached their set or guide temperature range; the cooking power 18 is currently fed to the plate 12 ', while the power 14 is completely cut off from the plate 14'.

According to this, even in the plate 13 'connected after the plate 12', only the heating resistor 18 is energized, while in the plate 15 both heating resistors receive current because it is still at the initial heating.

Although the cooking unit 11 'has two privileged hotplates 12', 14 'that are always fully utilized, and although both trailing ones are almost always fully available outside the initial heating time of the privileged hotplates, all heating resistors 18, 19 are equivalent, only 3500 W , i.e. less than 16 A at a voltage of 200 V. The division into two branches 12 ', 13' and 14 ', 15' thus increases the usability.

The switch 56 ensures a two-pole disconnection and that the socket 57 is used only when the hobs are not connected. It could also be connected to the free changeover contacts of the hobs 13 ', 15' and thus be included in the priority connection.

Fig. 3 shows a cooking unit with a manual switch 56, a socket 57 according to Fig. 2 7 681 41 and a hob 12 and a thermostat 22 according to Fig. 1. Here is a manual seven-switch 13a, 14a three heating resistors. Thus, in this embodiment, the hob 13a is put into full operation only after the power is turned off by the heating resistor 19 of the hob 12 and the hob 14a is also turned off by its heating resistor 18. The maximum connection power is 2500 W, although the total power of the hobs is 4500 W.

Figure 4 shows a modified switching device 22 "having only one heating conductor 18 'in the hob 12b for the total installed power. The expansion box 26 acts on a bimetallic metal 33 heated by a lower power control heating resistor 34 connected in parallel with the heating resistor 18'. the heating resistors 18 'and 34 are controlled by a quick switch 35 which, in its "closed position" shown, supplies both heating resistors and which in its second or "open position" communicates with a changeover contact 29' connected by a supply line 30 'to the next hob switch device. The embodiment according to Fig. 4 works as follows: This is a synchronizing thermostat which can be set to the desired temperature value from the setting knob 23 'The synchronous heating, i.e. power switching and disconnection from one heating resistor 18', takes place together with the heating plate heating, relative presence time changes according to the temperature setting (knob 23 ') and the current temperature of the cookware. This relative on-time decreases from almost 100% during the initial cooking step to about 10-20% during the further cooking step. In the meantime, i.e. during the further cooking phase, which is 80-90% of the time, full power is available for the following Hobs.

When the temperature control 24, 25, 26 shown in broken lines is omitted, a steplessly synchronizing power control device is created, which, while keeping the power from the cut-off plate 12, feeds to the next hob.

Figures 5 and 6 show a cooking unit 11a formed as a movable unit and having two hotplates 12a 8 68141 and 13a. For the hob 12a, a presence controller 40 is provided, which is connected to the cooking unit 11a by a flexible supply line 41 and is adapted to be placed on the cookware lid 42 with a steam flow opening 47. The hob 12a is provided with three stacked and in each case the lowest boiler heats the upper ones. With this "tower cooking", several different dishes can be cooked in different cooking pots on a single hob.

The steam coming out of the lid 42 of the top cooking pot indicates that the cooking temperature prevails in all cookware. The steam acts on a pressure vessel 43 which is filled with a liquid which boils slightly below the boiling point of water. The outflowing steam thus causes rapid evaporation in the box 43, the membrane of which controls the switch 44 of the presence controller 40, which is constructed as a quick switch and switches between the contacts 45 and 46.

The toggle switch (selector switch) 48 is arranged to be able to completely separate the presence controller 40 and thus the hob 12a from the circuit. In the position shown in this switch 48, the electric hob 12a with only one heating resistor 18a is connected or energized through the switch 44 and the control switch 49 and the temperature protection switch 50. The control switch 49 can be either a simple on-off switch, a seven-stroke switch or also a stepless power control device. The purpose of the temperature protection switch (temperature limiter) is to protect the hob and cookware when the presence control has not been put in place or the cooking medium has been placed on the hob without water.

The hob 13a has a switching device 22 according to Fig. 1. The common supply line 30 of the switching device 22 is connected to the changeover contact 46 of the presence controller 40 and to the contact of the selector switch 48.

Other hobs, sockets or appliances may be connected after the hob 13a.

The cooking unit 11a operates as follows.

To prepare a complete meal, e.g., a variety of dishes, three cooked foods are placed in three cooking vessels 50, which are stacked and closed with a lid 42. After being placed on the hob 12a and on the lid 42 of the presence control 40, the hob 12a is turned on. or control knob 51. The heating resistor 18a heats three cookware with a total power until the uppermost cookware 50 has a cooking temperature, whereby the steam coming out of the opening 47 heats the pressure box 43 and switches the switch 44 from contact 45 to contact 46. one more cooking or frying can be performed. After initial cooking, the cooking power is still quite low, so that the hob 13a is available more than 80% of the time. The state controller 40 works in cooperation with the hob 12a quite quickly, so that it switches off again a few seconds after it is switched on again. Such a short power supply is sufficient to re-generate steam. In fact, it is therefore a matter of regulating the state of "cooking" and not just inaccurately the temperature to be understood. Short interruptions in the power supply are hardly noticeable in the hob 13a. This implementation makes it possible to cook a meal comprising four or more different dishes at the same time on a two-plate hob with only one hob connection value.

The selector switch 48 provides the privilege normally present on the hob 12a over the hob 13a to the latter and thus disconnect the hob 12a from the mains.

It is also possible to change the privilege. Instead of a presence controller 40 connected to the cooking unit 11a by a flexible supply line 41, a presence controller can also be used, which transmits its switching on and off signals wirelessly to the cooking unit (see DE-AS 21 61 371).

Numerous variations of the described and illustrated embodiments are possible within the scope of the invention. Thus, the described hotplates are particularly advantageous in connection with the invention due to their temperature equalizing properties, but other cooking plates can also be used, e.g. each electric hotplate can be formed by placing a heating unit below a glass-ceramic plate or electric hotplates can be formed of tubular heating elements. It is also possible to connect one or more independent hotplates in parallel with the cascaded Hobs.

Claims (13)

A cooking unit with at least two electric hobs (12 ... 15, 12 '... 15'), at least one of which is preferred over at least one subsequent plate (13 ... 15, 13 '... 15') and synchronously adjusted or controlled by a switching device (22, 22 ') actuated by a temperature sensor, characterized in that it includes a priority circuit known per se and in that the switching device (22, 22') of the preferred electric hob (12, 12 ', 14') has two changeover switches ( 20, 21,20 ', 21'), each of which, depending on the temperature detected by the temperature sensor, switches the power supply between the heating element (18,19) on the preferred hob and the next hob switching device (22,22 ', 58,59). Cooking unit according to Claim 1, characterized in that the temperature sensor is connected to a temperature controller with two contact arms (20, 21) which are connected to one another at successive temperature values and which are in each case designed to switch between two fixed contacts (27, 28 , 29, 31) connected to the heating element (18, 19) on the preferred hob and one of the following hobs. Cooking unit according to Claim 1 or 2, characterized in that it comprises a plurality of electric hotplates (12, 13, 14, 15), one of which in each case has priority over the next. Cooking unit according to one of the preceding claims, characterized in that the switching device (22, 22 ', 22 ") is a temperature controller. Cooking unit according to Claim 4, characterized in that the temperature controller (22, 22 ') has two switching contacts (20, 21') which switch in successive temperature values, each of which connects one of the at least two heating elements (18, 19) of the hob. ), and that both, in any case at least the higher temperature-responsive switching contact (20), have a changeover circuit (29) connected to a rear-connected electric hob (13, 14, 15). Cooking unit according to claim 5, characterized in that the temperature controller has a quick-release switch with a snap spring, which in turn has two electrically separated supply lines 11 68141 and also has two contacts (27,29) adjacent to the pole suction spring contact next to the municipal end. and 28.31). Cooking unit according to one of the preceding claims, characterized in that the switching device (22 ") has at least one switching contact (35) under the influence of a quantization element which, in its second switching position, supplies power to the electric cooking plate (12 ') synchronously, in particular with a temperature-dependent relative switching time, in its second switch position, supplies power to the next electric hob. Cooking unit according to one of the preceding claims, characterized in that the switching device is a presence controller (40) which reacts to the steam generated in the cooking vessel and in particular controls the privileged cooking plate (12a). Cooking unit according to Claim 7 or 8, characterized in that the presence controller (40) and the cooking plate (12a) adjusted by it are intended for setting up the placed cooking utensils (50) (tower cooking). Cooking unit according to one of the preceding claims, characterized in that the switchgear has short switches. 10,681 41 Cooking unit according to one of the preceding claims, characterized in that it has a plurality of privileged electric hotplates, each of which has at least one rear-mounted electric hotplate. Cooking unit according to one of the preceding claims, characterized in that it has a manually operated switch (56) which, in one switching position, can open, preferably bipolar, the circuit of electric hobs and at the same time provide connection to other electric hobs (e.g. socket 57). Cooking unit according to Claim 5 or 6, characterized in that current is supplied to the heating element (9) of the cooking plate (13) closer to the temperature sensor from the changeover contact (29) of the switch device (22) of the preferred cooking plate (12). 12) a heating element (18) located further away from the temperature sensor. 12 Patentkrav 681 41