DE1615222A1 - Bimetal switch for setting and regulating the power consumption of electric hotplates - Google Patents

Description

Sehro-ITr. D 256/237

DIEHL company, Nuremberg, Stephanstrasse »49

Bimetal switch for setting and regulating the power consumption of electric hotplates

The invention relates to a bimetal switch for setting and regulating the power consumption of electric hotplates, with a working bimetal carrying a heating coil, which .steuert a snap contact, the latter the circuit for this heating winding and the heating resistor in series with it periodically interrupts for the hotplate, furthermore with a parallel to the heating coil of the working bimetal Series connection of a temperature-dependent resistor built into the hotplate and one through a switch bypassable detuning resistor, as well as with a compensation bimetal that can be adjusted manually using a curve, which is rigidly connected to the working bimetal via a pivotable lever.

In the case of bimetal switches of the aforementioned type, the hotplate during the boiling-up time, within a period that always remains constant, this is a multiple compared to the JPortcoeh level increased power supplied «Such a bimetal holder is for example in the German ßebrauahsuraster 1 908 042 "It has been shown, however, that such species

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parboiling is not the optimal solution, as this does not take sufficient account of the type and quantity of the food to be cooked can be. The parboiling time and parboiling power can can only be placed on "medium" items. Small amounts of food are therefore too fast, larger amounts of food 'On the other hand, cooked too slowly. Thus, the previously known arrangements for regulating the parboiling process meet .The hotplates are not sufficient for such an "automatic parboil" A requirement to be made is that each item to be cooked must be brought to a predetermined temperature in a short time.

The object of the invention is to improve a bimetal switch of the type mentioned in such a way that the parboiling time depends on the food to be cooked and on the power level set for subsequent continued cooking. Another task of the The invention is to propose a solution that is simple and much cheaper in structure than the previous arrangements.

According to the invention it is therefore proposed that the compensation bimetal also carries a heating coil and that a -'.....- · Changeover switch is available through which the compensation winding paiäLlel to the temperature-dependent one at the beginning of parboiling Resistance switchable .is, whereby at the same time the working bimetal winding de-energized and the working bimetal becomes effective as a compensation bimetal, and through which switch at the beginning of the continued boiling, the working bimetal winding can be switched in parallel to the temperature-dependent resistor, whereby the compensation bimetallic winding is de-energized and the compensation bimetal becomes effective in a manner known per se.

For the invention, the recognition is therefore essential that in the parboiling area the compensation bimetal has the function of a Working bimetal, which determines the boiling time, while the actual working bimetal in the boiling area only has the function has a Kompenaationsbimetalls, because namely during this Time the winding of the working bimetal is de-energized and the latter only serves, -the on the compensation bimetal and the

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Compensate for the ambient temperature acting on the working bimetal. When switching from the parboiling area to the continued boiling area, on the other hand, the winding of the compensation bimetal is de-energized, while the winding of the working bimetal is in the heating circuit is switched on. These two bimetals then become effective in the usual way. The dependence of the boiling time of the food used is determined by the parallel connection of the temperature-dependent resistor and the compensation bimetallic winding causes. As long as the temperature-dependent resistor built into the hotplate is cold, it has an essential one lower resistance than the winding of the compensation bimetal. When it is warm, however, its resistance value is about the same size as the winding of the compensation bimetal. Due to the resulting different power distribution in the two elements in their cold and warm state, the compensation bimetal is only then punctured occur when its winding receives a correspondingly large current, d. H. only when the temperature-dependent resistance corresponds to one de temperature has reached.

According to a further invention it is proposed that a switch in the vicinity of the compensation bimetallic winding, each of which is operated at the same time with the changeover switch and which at the beginning of parboiling the snap contact and the detuning resistor bridged, whereby the hotplate in the parboiling area depends on the type and quantity of the food Continuous full load.

In contrast to the previously known arrangements, the hotplate receives constant power and no pulse power in the parboiling area. This results in a reduction in price, since the corresponding elements for the clocking in the parboiling area, the are different from those of the port cooking area. The hotplate is thus given for the parboiling area and the port cooking area the same current in each case, the latter being clocked in the port cooking area, since here the clocking is compared to the constant supply of a changing power has the known advantages.

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According to a first development of the invention, it is proposed that that the curve for setting the bimetal is adjustable by hand by a toggle and that before Beginning of parboiling the compensation bimetal at each ' Toggle position on the curve, but not the working bimetal. This training makes it possible to reduce the boiling time also to make dependent on the toggle position for the set power level.

According to a second development of the invention, however, it is proposed that the curve be adjusted by hand using a toggle is, and that before the start of parboiling, the working bimetal rests against the curve in every toggle position, the compensation bimetal however not, and that the deflection of the two bimetals takes place in the direction of the curve.

These two developments of the invention thus differ in that the direction of deflection r " ⁿ r bimetals is different, and that the working bimetal in one case interacts with the snap contact, in the other case with the switch and the changeover switch exactly the opposite =

In the following, these and further features of the invention will be described in two exemplary embodiments with reference to the drawing will be explained in more detail.

Show it:

1 shows an electrical circuit diagram of the bimetal switch according to the invention;

Fig. 2 shows the bimetal switch in a first embodiment in a highly schematic representation in a view from above;

Fig. 3 is a diagram showing the dependency of the boiling time represents from the toggle position for the set power level;

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Pig. 4 shows the bimetal switch in a second exemplary embodiment in the same representation as in FIG. 2.

In Figure 1, 1 and 1 'denote the two power terminals for the bimetal switch. It can be connected to the Fetz by two isolating switches 2 and 2 '. A snap contact 3 and a detuning resistor 4, which can be bridged by a switch 5, are located between these two disconnectors. This switch, 5 is in the toggle positions for the power levels 1-7 in the open state, while in the toggle positions 8-12 it is in the closed state. The detuning resistor 4 is only used to easily subdivide the 12 power levels into two large control ranges.

At the upset resistance to a temperature-dependent resistor 6 connects with a positive temperature coefficient. This is built into the hotplate and is used there to sense the actual temperature. It is therefore also referred to as the sensor resistance. This is followed by the actual heating resistor 7 of the hotplate. The winding 8 of a working bimetal and a changeover switch 9 are parallel to the detuning resistor 4 and the sensor resistor 6.

In parallel with the snap contact 3 and with the working bimetal winding 8 and the switch 9 are finally a switch 10 for short-circuiting the snap contact 3 and the Detuning resistor 4 and the winding 11 of a compensation bimetal, which can be switched in parallel to the sensor resistor 6 by means of the changeover switch 9 the winding 8 of the working bimetal is de-energized.

The mechanical structure of the arrangement will be explained in more detail with reference to FIG. 2. The winding 8 is on a working bimetal 12, which has one end to his Center 13 pivotable two-armed lever 14 is attached. The latter is under the straightening force of a tension spring 15. On the other

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A compensation bimetal, which carries the winding 11, is attached to the end of this two-armed lever. A cam 17, which is arranged on the axis of the adjustment knob for the different power levels, is designed so that you The radius decreases continuously with a counterclockwise rotation, i.e. in the direction of higher power. To this cam the working bimetal and the compensation bimetal can apply by means of not shown stops. This is in 2 indicated schematically by the lines of action 18 and 19. In the idle state, only the compensation bimetal is on this Curve on, but the working bimetal does not. In the deflection area of the working bimetal 12 is a pawl 20 with a switching nose 20 'arranged, the former being pivotable about an axis 21 and under the restoring force of a Spring 22 stands »This pawl carries a switch nose 25 which interacts when the pawl 20 is deflected with the stationary base 24 switches the snap contact 3 by means of its switching arm 25.

In the deflection area of the compensation bimetal 16 there is a pawl 26 which can be pivoted about an axis 27 is. This pawl carries switching noses and 29 at both ends, one of which with the compensation bimetal and the other interacts with a switching cam 30 of a switching rod 31. This shift rod 31 carries at one end a button 32, with which the automatic parboiling process can be triggered by pressing. This state is in Fig. 2, however, relates only to the first moment in which the two bimetals 12 and 16 are still at rest are located. In addition, the shift rod 31 is under the restoring force of a tension spring 33 and contributes to its second end Actuator 34, the buttons 35 and 35 'of the switch 9 and the switch 10 by pressing the button 32 close ».

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In Figure 3, finally, the heat-up time as a function of the set toggle position and in dependence on the quantity of the cooking material is shown "It is readily apparent that the heat-up time can be varied by more or less strong deflection of the compensation bimetal because of the different radius ¹ of the curve 17 can. Due to different amounts of food or types of food, the boiling time also changes, since the sensor resistor 6 takes on the corresponding temperature value more slowly or more quickly, and as a result, the compensation bimetal also switches later. For the toggle positions 8-12 there is a different set of curves than for the toggle positions 1-7, since the bypass switch 5 for the detuning resistor 4 is closed and thus a second control range is created »

It is assumed that the cam 17 is set by hand to the desired power level by the toggle, not shown. As a result, the compensation bimetal, which lies under spring tension on the lateral surface of the cam disk, is changed in its distance from the switching nose 28 of the pawl 26 in relation to its rest position. If now the key 32 printed, to trigger the parboiling _s so wird'der switching cam 30 with its inclined rising surface of first the S - rklinke ^ 26 pivot counterclockwise * At the same time, the actuator 34 closes by means of its buttons 35 to switch 9 for the circuit of the Kompensationabimetallwickel 11 as well as the switch 10 for short-circuiting the snap contact 3 and the detuning resistor 5 »When the button 32 has reached its end position, the switching cam 30 has passed the switching nose 29 of the pawl and the latter returns to the rest position shown in the drawing. As a result, the switching rod 31, which is under the restoring force of the spring 33, is locked in this position. Now the full power flows between the terminals 1 and 1 'via the switch 10 and via the parallel connection from the sensor resistor 6 and the winding 11 of the compensation bimetal 16 and

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the changeover switch 9 to the heating resistor 7. Since the sensor resistor 6 has a much lower resistance value than the winding 11 in the cold state, the heating current initially flows essentially only through the sensor resistor 6. The hotplate heats up. As the hotplate heats up, the resistance value of the sensor resistor 6 also increases and the winding 11 takes on an ever-increasing proportion of the heating current. As a result, the compensation bimetal 16 is heated and continues to bend. By the spring 15, the compensation bimetal 16 is held with its stop on the curve 17, which means that the bending of the compensation bimetal, a torque is exerted on the two-armed lever 14, which rotates it clockwise. Because of this, with increasing deflection of the compensation bimetal 16, the working bimetal 12 through which no current flows and which has only experienced a slight deflection due to the ambient temperature, is moved towards the curve 17 until it rests there with its stop, Now can the two-armed lever 14 can no longer be moved further by the spring and the compensation bimetal 16 bends further and further in the direction of the switching nose 28 away from the curve 17 due to the increasing current in the winding 11. The deflection eventually becomes so great that the pawl 26 is pivoted in the G-egenuhrzeigersinn and the switching lug 29 releases the lock of the shift rod 31 "Due to the restoring force ^v ewegt the latter back to the left in the rest position. At the same time, the actuator 34 switches the changeover switch 9 and the switch 10 to the other working position or opens it, while the winding 11 of the compensation bimetal 16 is de-energized, whereas the winding 8 of the working bimetal 12 is switched on in the heating circuit. This ends the parboiling and now begins the continued boiling, which is characterized by the pulsed, "cetaktete" supply of full power to the heating resistor 7 as a function of the closing and opening of the snap contact 3 due to the periodic deflection movement of the working bimetal 12; the latter in turn depends on the actual temperature of the hotplate due to the parallel connection of the winding 8 to the sensor resistor 6.

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When the parboiling is complete, the working bimetal begins to bend downward due to the current flowing through its winding 8, however, is through'die spring 15 and the two-armed lever 14 still held on the curve 17. At the same time, the compensation bimetal 16 begins to cool and to move back into its non-bent position Movement is supported by the clockwise torque exerted on the spring 15 on the two-armed lever 14, due to the increasing deflection of the working bimetal. As soon the compensation bimetal rests against the curve with its stop, the working bimetal can move away from the curve 17 and move the pawl 20 in the direction of the cam 20 '. This movement is now supported by the further bending back of the compensation bimetal in its starting position, which now applies a torque in the G-e counterclockwise direction two-armed lever 14 and thus on das_Arbeitsbimetall 12 exerts.

Has the working bimetal the switching nose 20 'of the pawl reached, it is deflected and thus the snap contact is switched over, d. H. opened. Now the current flow is through the parallel connection of detuning resistor and sensor resistor 6 on the one hand and working bimetallic winding 8 and changeover switch on the other hand and interrupted by the heating resistor 7. That Parboiling has now ended. The continued cooking operation now begins.

The work bimetal now begins to cool down and slowly to detach itself from the switching nose 20 '. Once this has happened, the snap contact 3 is switched over again and the current flow begins again. The working bimetal begins to bend again. This process continues until the arrangement is switched off by opening switches 2 and 2 ¹ .

As already mentioned, the compensation bimetal has during the continued cooking stage only the task of equalizing the ambient temperature in the area of the working bimetal and Kompenaaiionabimetall. This is done in such a way that the

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Compensation bimetal more depending on the prevailing temperature . or less bends and thus swings the two-armed lever more or less clockwise ο This in turn means however, that the working bimetal is also more or less close to the switching nose 20 'and thus in a corresponding manner shorter or longer time intervals.

Finally, FIG. 4 shows the second exemplary embodiment of the bimetal switch according to the invention. Compared to the first it differs in that the two bimetals 16 and 16 together with their associated windings 8 and 11 in their Arrangement on the two-armed lever 14 are interchanged and that on each bimetal itself the active and the passive side are also interchanged, so that a deflection of the bimetals in the opposite direction as before, so after above, results. Now the working bimetal is constantly on the curve in the idle state, whereas the compensation bimetal is against it is not there.

For the sake of clarity, all components in FIG. 4 are provided with the same reference numerals as in FIG. 2. The operation of this second embodiment is similar to that of the first. If the button 32 is pressed, the Actuator 34 of the switch 9 switched and the winding 11 of the compensation bimetal connected in series with the heating resistor 7. At the same time the switch 10 is closed »ITunmore current begins to flow through the winding 11, whereupon the Compensation bimetal 16 upwards in the direction of curve 17 sags until it rests against this curve. Due to the increasing warming of this bimetal and the with it associated deflection, a counterclockwise torque is now exerted on the two-armed lever, which causes that the Arbeitsabimetall 12 moves slowly downward in the direction of the nose 28 of the pawl 26. As with increasing As the hotplate heats up, the resistance value of the sensor resistor 6 increases steadily, which is caused by the winding 11 of the Kompenaationsbimetalle flowing current always bigger and the

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The heating of this bimetal increases disproportionately. The working bimetal 12 finally reaches the switching nose 28 and deflects the switching pawl 26 in such a way that the switching nose releases the switching cam 30 of the switching rod 31 and the latter returns to its starting position to the left. As a result, the changeover switch 9 is switched over and, at the same time, the switch 10 'is opened. The working bimetal 12 begins to bend upwards, that is to say away from the switching nose 28. At the same time, the compensation bimetal 16 cools down and begins to bend back into its rest position. Since the KompensationsMmetall is constantly held on the curve 17 by the spring 15, a clockwise torque is now exerted on the two-armed lever 14, whereby the upward movement of the working bimetal is accelerated. Finally, the working bimetal 12 rests on the curve 17, where it constantly bends further upwards, while at the same time the compensation bimetal 16 loses its deflection more and more and moves away from the curve. Now the working bimetal 12 rests against the curve 17 under the spring tension 15 and, through its further bending, causes a counterclockwise torque to be exerted on the two-armed lever 14, which in turn causes the compensation bimetal 16 to move in the direction of the Switching nose 20 · of the switching pawl 20 moved. Finally, the compensation bimetal will reach this switching nose 20 'and the snap contact 3 will open. So that the current flow to the heating resistor 7 is interrupted by the winding 8 of the working bimetal and the latter begins to cool down again. The compensation bimetal moves away from the switching nose 20 'again and finally releases the snap contact 3 again, whereupon it jumps back into its closed switching position. This process is now repeated periodically during the entire continued cooking time.

It is also possible at any time within the meaning of the invention to continue cooking interrupt by pressing key 32 and again

to begin parboiling. " _ATO

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Claims (1)

Claim ) Bimetal switch for setting and regulating the power consumption of electric hotplates, with a working bimetal carrying a heating coil, which has a snap contact controls, where the latter controls the circuit for this heating coil and the heating resistor for the hotplate in series with this periodically interrupted, furthermore with a series connection lying parallel to the ■ heating winding of the working bimetal from a temperature-dependent resistor built into the hotplate and one that can be bridged by a switch Detuning resistor, as well as with a compensation bimetal that can be adjusted manually by means of a curve, soft via a pivotable lever is rigidly connected to the working bimetal, characterized in that the compensation bimetal (16) also carries a heating winding (11) and that a changeover switch (9) is present, through which the compensation bimetallic winding at the beginning of parboiling (11) can be switched in parallel to the temperature-dependent resistor (6), whereby the working bimetallic winding at the same time (8) de-energized and the working bimetallic element (12) becomes effective as a compensation bimetal, and through which switch (9) at the beginning of the continued cooking, the working bimetal winding (8) can be switched in parallel to the temperature-dependent resistor (6), whereby the compensation bimetal winding (11) without current and the compensation bimetal (16) takes effect in a manner known per se. l) bimetal switch according to claim 1, characterized in that a switch (10) is in series with the compensation bimetal winding (11), which is operated simultaneously with the changeover switch (9) and which at. Beginning of parboiling, the snap contact (3 ") and the tuning resistor (14) are bridged, whereby the hotplate in the parboiling area receives uninterrupted full load for a period of time depending on the type and amount of food to be cooked. · ORIGINAL SNSPECTEO 00a8227068ff 3) bimetal switch according to claim 1 or 2, characterized in that the curve. (17) can be adjusted by hand with a toggle and that the compensation bimetal (16) rests against the curve (17) at each knuckle division before the start of parboiling, the working bimetal (12). however not, and that the bending of the two bimetals (12, 16) takes place in the direction away from the curve (17). 4) bimetal switch according to claims 1 to 3, characterized characterized in that there is a loop (31) displaceable by a button (32) against a restoring force (33) is through which, when you press Ta-s -.7-2), the toggle switch (9) ■ and the switch (10) are operated. 5) bimetal switch according to claims 3 and 4, characterized in that that there is a pawl (26) which locks the switch rod (31) when the button (32) is pressed • and which due to their deflection by the compensation · bimetal (16) releases this locking mechanism at the end of the boiling time. 6) bimetal switch according to claims 1 and 3, characterized in that that the snap contact (3) is arranged in the deflection area of the 3 working bimetal (12) * 7) bimetal switch according to claim 6, characterized in that that in the deflection area of the working bimetal (12) a pawl (20) under a restoring force (22) which actuates the snap contact (3) » 8) bimetallic switch according to claim 1 or 2, characterized in that the _r Kurve- (17) is adjustable by a knob by hand, and that the Arbeitsbimetall (12) rests at each toggle position on the curve (17) before the start of parboiling ,, the Kompen, - sationebimetali, however, not, and that the curvature of the - ~; A _: both bimetals CT ^ W 16J itt direction to the curve CT7l success-tr- '' / ^ -;. __. _ ORIGINAL BATHROOM 9) bimetal switch according to claims 4 and 8, characterized in that a pawl (26) is present, which locks the switching rod (31) when the button (32) is pressed, and which in the deflection area of the working bimetal (12) is in such a way that it releases the lock at the end of the boiling time. 10) bimetal switch according to claims 1 and 8, characterized in, that the snap contact (3) in the deflection range of the Compensation bimetal (16) is arranged. 009822/0668 Blank page