DE2359581A1 - THERMOMAGNETICALLY CONTROLLED SWITCH - Google Patents

Description

Thermomagnetically controlled switch

The invention relates to a thermomagnetically controlled switch ' using a reed switch where in a closed Housing two contacts designed as leaf springs (reed contacts) made of ferromagnetic material, the free ends of which are overlap, are provided, the reed contacts by the arrangement of a permanent magnet and a further magnetic "· ■ Substance near the reed switch depending on the Temperature are drawn against each other and thus closed, can.

Such switches are known (FR-PS 1 549 349, US patent 3 29 5 081). They are used to run the operation of somebody Devices as a function of a predetermined temperature

_l ι

to control ; they are mechanically and thermally stable and resilient, stable in operation even after a long service life and have a long service life.

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However, these known switches have only one switching point, that is, there is only one temperature along the temperature axis at which switching of the switch occurs. So far its scope is limited.

In certain areas of application of the automatic control however, there is very often the need to have a specific device operate within a temperature range determined by two different temperatures. The operation should be at start at a certain temperature and stop at a certain further temperature.

There are thermomagnetically controlled switches that do this it not. It is true that you can choose from switches each with a different one Switching temperature set up a corresponding circuit; ■ man however, it requires larger installation space than for just one switch and requires a certain amount of effort for the circuitry Linking the switch drive.

It is the object of the invention to provide a thermomagnetically controlled To create a switch which has two switching temperatures, i.e. two switching points along the temperature axis, so that it is below the lower and above the higher switching temperature a first of two switching states (closed; open) and the other between these two switching temperatures which assumes both switching states.

The switch should be as simple as possible, have only a small volume, and be producible at low cost be.

According to the invention this is achieved in that two permanent magnets, whose Curie points are above the operating range of the switch are provided and at least two of them temperature-absorbing ferromagnetic bodies with different Curie points in the operating range of the switch

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are assigned in such a way that the Viege of the magnetic flux of the two permanent magnets limited by different course in relation to the 'reed contacts in "two-" of-the-Curie points Temperature ranges the reed contacts- in their first Move the switch position and in a further temperature range between the two Curie points to its second switch position.

Various arrangements are to each other and configurations of both the permanent magnets and possible der'ferromagnetischen body, the different ways of _"; the magnetic flux of the permanent magnets shown die.für various purposes are particularly advantageous, as such, or are particularly simple in construction ·.

Embodiments of the invention and its advantageous developments are explained below with reference to the accompanying drawings. They represent ^:

Fig. 1 shows the characteristic curve for the dependence of the density of the magnetic flux at "magnetic saturation of the Temperature for two different ferromagnetic substances;

Fig * 2a is a partially sectioned side view of the dnes Embodiment;

FIG. 2b shows a section along the line Ub-IIb in FIG. 2a; FIG.

3a shows a schematic representation of the mode of operation of the switch according to FIGS. 2a and 2b; '

4a to Uc show a further exemplary embodiment in schematic form Representation at different temperatures;

Fig. 5,6,7a, 7b, 8a and 8b various modifications of the

Exemplary embodiment according to FIGS. 4a-4c; .- ■■ ■

9 is a perspective view of a further exemplary embodiment; ■■ ".- ',

Fig. 10 is a perspective view of a modification of the embodiment of Fig. 9; . .

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11a to 11c are schematic representations for explanation

the function of the switches according to FIGS. 9 and 10; FIGS. 12a to 12b show various schematic representations of a further exemplary embodiment in different cases

Temperatures;
13 to 15 show various modifications of the switch

Fig. 10. ■ ·

There are two ferromagnetic substances, as shown in FIG. 1 apparent different Curie point used; will also be several permanent magnets, as long as a reed switch is used. The resulting arrangement ensures that the reed switch is on two points along the temperature axis, i.e. at two different points Temperatures switches.

Fig. 1 shows the characteristic curves for the dependence of the density of the magnetic 'flux at magnetic saturation on the temperature (saturation flux density) for two ferromagnetic substances that are used in the invention to determine or record the temperature (hereinafter: temperature-absorbing substances or bodies ). You have the. Function of temperature sensors. Curve "A" is the characteristic for one of the two substances, curve "B" is the characteristic for the other of the two substances. The magnetic properties of both depend on the temperature. Substance A has the lower Curie point T ^, substance B the higher Curie point T _c2 , ie the temperature point of the appearance or disappearance of magnetism is different for the two substances. This is also expressed in the following in such a way that they change their state of magnetic conduction at these temperatures.

2a and 2b show an embodiment. It shows the reed switch 1, two elongated permanent magnets 2 and 3, and two ferromagnetic bodies U and 5 with after .Fig. 1 different Curie points.

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The reed switch 1 consists of ₅ like. known from an elongated envelope or housing 11, preferably made of glass, a pair of leaf spring-like contacts (reed contacts) 12, 13, which are arranged in the housing 11, and their leads 14 and 15 in the hermetically sealed housing 11 melted and thus sealed at their point of passage. The two reed contacts 12 and 13 are made of ferromagnetic and electrically riding material. Their two ends overlap in such a way that they can perform a closing or opening movement against one another. ■

The Curie point of the two permanent magnets 2 and 3 lies above the operating range of the entire switch, i.e. outside the range in which the temperatures T ₁ . and T _ lie. They are attached to the outside of the housing II with adhesive 60 and arranged so that the magnetic poles of one permanent magnet are opposite the opposite pole of the other permanent magnet with respect to the longitudinal axis of the reed switch; they are also arranged parallel to one another. They cover (in the axial direction) the two overlapping ends of the reed contacts 12 and 13. The ferromagnetic bodies 4 and 5 are each »seen from the inside of the reed switch 1 or its axis, over the permanent magnets 2 and 3 and are attached to these ^ ■ '

To break off the glass housing 11 at its ends by handling the supply lines 14 and 15 melted into it in practical use by bending them over,

electrical ■ -.- ■ ·. "Yokes

are at the ends' non-conductive and non-magnetic / 6 resp. 7 arranged so that they the ends of the housing 11 and still each short length of the supply lines 14 and 15 behind the place of their exit from dem.Gehäuse 11 surrounded. These small pieces of length cannot be bent over and their breaking off and breakage of the glass case can be prevented.

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The thermally conductive cylindrical part 8 is arranged so that it the permanent magnets 2, 3, the ferromagnetic body 4,5 and the reed switch 1 surrounds.

The mode of operation of the thermomagnetically controlled switch according to FIGS. 2a and 2b can be seen from FIGS. 3a-3c; of simplicity for the sake of only the permanent magnets 2 and 3, the temperature-absorbing ferromagnetic bodies 4 and 5, and the reed contacts 12 and 13 are shown.

If the temperature (T) of the environment or of an object whose temperature is to be measured is lower than the Curie point of both ferromagnetic bodies 4 and 5 (KT ₁ , T _c2 > then the magnetic flux of both permanent magnets 2 resp. 3 via the adjacently arranged and assigned ferromagnetic bodies 4 and 5, as shown by dashed lines in Fig. 3a, The two reed contacts 12 and 13 are open.

If the temperature rises' (T), - then the flux density is lower at magnetic saturation tables (see. Fig. 1). If it reaches a value between the Curie points of the two ferromagnetic bodies 4 and 5 (T _cl <T <T _c2 ), then the magnetic flux of the permanent magnet 2 flows via the reed contacts 12 and 13 (see FIG. 3b ) because the ferromagnetic body 4 becomes non-magnetic. The magnetic field strength between the overlapping ends of the reed contacts 12 and 13 overcomes the elastic spring force of the reed contacts, so that their overlapping ends close. The reed switch 1 is closed.

If the temperature rises further and reaches a value which is also greater than that of the other ferromagnetic body -5 (T> * T * , T 2), the magnetic flux flows over from each of the permanent magnets 2 or 3 the other of the permanent magnets. It does not flow through the reed contacts 12, 13,. because it cancels itself over this distance (see Fig. 3c). Therefore the reed contacts 12 and 13 open.

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This process goes, with regard to a change in temperature, vice versa in exactly the same way, is therefore reversible. .

The switch ^ after Fig. 2a and 2b can easily be used to control the to observe the internal temperature of an enclosed volume in such a way that that based on the observation the temperature in the area be held between two different values (T., T “) can. ■

FIGS. 4a, 4b and 4c show a further embodiment. It has, the reed switch 1, two permanent magnets 2 and 3 and two temperature-absorbing ferromagnetic bodies 4 and 5 on ..

The permanent magnets 2 and 3 are arranged and fastened on the housing in such a way that they are in the axial direction of the reed switch 1 is the same with regard to its polarity and to this are arranged in parallel. Their arrangement, in axial Direction takes place at different points in such a way that it is just before the overlapping ends of the reed contacts 12, 13 ends. The ferromagnetic body 4 lies over in the axial direction of the reed switch 1 and seen from the axis the two permanent magnets 2 and 3 and extends over their total axial length.

The ferromagnetic body 5 with the higher Curie point is arranged between the two permanent magnets 2 and 3 and below the ferromagnetic body 4. Its in the axial direction of the Reed-Sehalter & opposite 'opposite one another Ends are .an the pole faces of the permanent magnets adjoining it 2 or 3.

If the temperature of a monitored object (or its surroundings) is lower than the "Curie point of both ferromagnetic bodies 4 and 5 (T <T- ^, T _c2 ), then the magnetic fluxes of both permanent magnets 2 and 3 flow through both ferromagnetic ones Body 4th and 5th (cf. Fig. 4a) The reed contacts 12 and 13 are open. ■ '

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If the temperature rises to a value which is higher than the Curie point of the ferromagnetic body 4 and lower than that of the ferromagnetic body 5 (T ₁ <T <T-_), then the magnetic fluxes flow over the ferromagnetic body 5 and the Reed contacts 12 and 13, since the ferromagnetic body 4 is non-magnetic. As a result, the magnetic force of attraction between the overlapping ends of the reed contacts 12 and 13 overcomes the elastic spring force of the two reed contacts 12, 13. The reed contacts 12 and 13 close. If the temperature rises further to a value which is also above the Curie point of the ferromagnetic body (T> T ₂ , T ^) 5, then the magnetic flux of the permanent magnet 2 flows only via the adjacent reed contact 12 and the flux of the permanent magnet 3 only via the reed contact .13, since the body 5 has also become non-magnetic. Between the overlapping ends of the reed contacts 12 and 13 there is no longer any magnetic force that can overcome their elastic force. The reed contacts 12, 13 open.

An additional combination of two permanent magnets and two temperature-sensitive bodies in basically the same structure can be arranged along the circumference of the reed switch in different angular positions; such a switch is shown schematically in FIG. The components of the additional combination are designated with the same reference numerals but with a prime (2 ¹ , 3 ¹ , 4 ', 5 ¹ ).

In the exemplary embodiments according to FIGS. 4a-4e and 5, the temperature-absorbing ferromagnetic body 5 (or 5 ') had the same thickness at its thickest point as the permanent magnets 2 and 3 (or 2 ¹ and 3'). However, that is not critical.

For example, the body 4 (or 4 ^f ) can be formed by two sub-bodies UA and 4B (or U ¹ A and 4 ¹ B) made of ferromagnetic material with the same Curie point. Such an arrangement is shown in FIG. As can be seen, the bodies 5 and 5 'are thicker than the permanent magnets 2, 3. The ferromagne

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table part bodies · 4A, 4B, H ¹ A and 4 ¹ B each rest with their ends on the body 5 or 5 '.. -

The switch according to FIG. 6 functions in the same way as the switch according to FIG. ¹ Ia-Ic. The dashed lines shown in Fig. 6 show the magnetic flux at an ambient temperature below the Curie point of both bodies 4A, HB or 4 ¹ A, 4'B, and 5 or

From Fig. 5 it can also be seen that a functionally the same Switch can be constructed in such a way that it is next to a reed switch 1. Two cylindrical permanent magnets 2 and 3 and two cylindrical bodies 4 and 5 are used. Such an arrangement is shown in Figures 7a and 7b.

FIGS. 8a and 8b show a modification of the switch according to FIG Fig. 6. There are two cylindrical permanent magnets 2 and 3, one temperature-absorbing ferromagnetic cylindrical body 5 and two also temperature-absorbing ferromagnetic cylindrical. Partial bodies 4A and 4B are provided. The switches according to FIGS. 7a-8b. , work like the switches of Fig. 4a-4c and therefore need not to be repeated in detail.

In the case of the switches according to FIGS. 7a-8b, one can on the outer surface of the cylindrical body "4_ (Fig. 7a and 7b) or the part of the body 4A and 4B and the cylindrical body 5 (Fig. 8a and 8b) a Provide groove 9 extending in the axial direction - in the one of the feed lines, e.g. feed line 15, to the the same side on which the other supply line 14 is attached, is returned. The supply line 15 is in the vicinity of the bent into the area melted into the housing 11 and guided from there along the cylindrical body 5 (FIG. 8a) in the groove 9. A switch constructed in this way can be used very easily in applications in which the electrical lines should or can be fed in from only one side.

Similar to the switches according to FIGS. 2a and 2b, one can also in the switches according to Fig. 4a-8b yokes 6,7 and a cylindrical one

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Provide part 8. This is in FIGS. 4a-8b for the sake of simplicity not shown. ·

FIGS. 9 and 10 show further exemplary embodiments. Every v / eist each with a reed switch 1, two permanent magnets 2 and 3 a Curie point above the operating range of the switch temperature-absorbing ferromagnetic body 4 and one further temperature-absorbing ferromagnetic body 5, the Curie point of which is higher than that of the body 4, on.

The exemplary embodiments according to FIGS. 9 and 10 are basically the same as one another. That is true with the exception of the shape of the two Permanent magnets 2 and 3 and the two temperature-absorbing bodies 4 and 5, which are rectangular in the embodiment of FIG Cross-section and in the embodiment of FIG. 10 have a cylindrical shape. The relative arrangement of the permanent magnets 2 and 3 to the temperature-absorbing bodies 4 and 5 and the reed contacts 12, 13 of the reed switch 1 are in the Fig. 11a-11c shown; they show the function schematically.

This results in: The two permanent magnets 2 and 3 are arranged ¹ with respect to the reed switch in the axial direction at different points and parallel to the reed contacts 12, 13; in the axial direction they are not at the same level as the overlapping ends of the reed contacts 12, 13, but rather end shortly before them. The permanent magnets 2 and 3 are in terms of their

vice versa
Polarity ", ie the position of the poles of the permanent magnet 2 with respect to the axis of the reed switch 1 is opposite to that of the poles of the permanent magnet 3. The same poles indicate each other. The temperature-absorbing bodies 4 and 5 are axially between the permanent magnets 2 and 3 and arranged in series with one another One end of the body 4 rests on one pole of the permanent magnet 2. Its other end ends in the axial direction just before the overlapping end of the reed contacts 12, 13. One end of the body 5, which has the higher Curie point, abuts the adjacent pole of the permanent magnet 3; its other end

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^r extends in the axial direction beyond the overlapping ends of the reed contacts 12 and 13 'and rests on the changed end of the body 4.

Is the temperature lower than the Curie point of the body 4 (T-CT-,.), Then both bodies 4 and 5 behave ferromagnetically. The magnetic fluxes from the poles of the permanent magnets 2 and do not flow through bodies 4 and 5, since they have the same poles the permanent magnets 2 and 3, namely here the S-PoIe, each other opposite. The magnetic flux of the permanent magnet 2 flows solely through the reed contact 12; the magnetic flux of the Permanent magnet 3 flows only via reed contact 13 (cf. Fig. Lla). The overlapping ends of the reed contacts 12 and 13 remain open.

If the temperature rises to a value that is higher than that Curie point of the body 4 and lower than the Curie point of the Body 5 (T. <T <T V), then body 4 becomes non-magnetic. The magnetic flux from the permanent magnet 3 flows over both Reed contacts 12 and 13 and the body 5; the magnetic flux of the permanent magnet 2 flows through the reed contact 12 alone (see Fig. lic); The magnetic force between the overlapping ends of the reed contacts 12 and 13 overcomes the elastic spring force of the reed contacts. The reed switch 1 closes

If the temperature continues to rise to a value that is also higher is -5 as the Curie point of the body, then both bodies are 4 unc 5 non-magnetic. ' The magnetic flux of each of the permanent magnets 2 and 3 only flow through one of the * ReedHKontacts 12, 13 (see Fig. lic). The overlapping ends of the reed contacts 12 and'-13 open. From this it follows that the in FIGS and 10 switch shown two switching points along the Have temperature axis. "'·

FIGS. 12a-12c show a further embodiment, consisting from a reed switch, two permanent magnets 2 and 3 and two temperature-absorbing ferromagnetic bodies 4 and 5.

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As in the other exemplary embodiments, the Curie points of the two permanent magnets 2 and 3 are above the temperature of the operating range of the switch. They are along it like this arranged in the axial direction at different points that their orientation is the same with regard to their polarity. It

Pole,
so each has a different polarity opposite one another. They end shortly before the point at which the ends of the reed contacts 12, 13 overlap.

The two temperature-absorbing bodies 4 and 5 have different ones Curie points within the operating range of the switch. They are with each other and with the permanent magnets 2 and 3 in axial direction in series and arranged between the permanent magnets 2 and 3. Both bodies 4 and 5 lie in the axial direction at the same height as the overlapping ends of the reed contacts 12, 13 to one another. Their ends facing away from this point are in contact with one pole of one of the two permanent magnets.

If the temperature of the environment is lower than the Curie point of both ferromagnetic bodies 4 and 5 (T < T .., T "), then the magnetic flux flows from the permanent magnets 2 and 3 via the bodies 4 and 5 and the reed contacts 12 and 13 (see. Fig. 12a). The reed contacts 12 and 13 close.

The temperature rises to a value higher than the Curie point of one body 4 but lower than the Curie point of the other body is 5 (T. <T <T "), then the body becomes 4 non-magnetic. The magnetic flux of the permanent magnets 2 and 3 flows as indicated by the dashed line in Fig. 12b is shown. The magnetic force between the overlapping Ends of the reed contacts 12 and 13 is so small that they do not affect the elastic force of the reed contacts 12, 13 overcomes, so that the reed contacts 12, 13 open.

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If the temperature rises to a value which is higher than the Curie point of both bodies H and 5 (T ^ T., T _? ), Then both bodies become non-magnetic, so that the magnetic flux of permanent magnets 2 and 3 across the gap flows between the overlapping ends of the reed contacts 12 and 13; this is shown in Figure 12c by dashed lines. The reed contacts 12, 13 close.

With regard to its switching behavior (opening, closing) works the switch shown in Figs. 12a to 12b in relation to a Change in temperature in reverse as the switches according to the other exemplary embodiments. It can be used accordingly for temperature control systems can be used with correspondingly different requirements.

Also in the switch according to Fig. 12a-12c, the two permanent magnets, 12 and 13 and the two temperature-absorbing bodies 4 and 5 are cylindrical. The reed switch 1 is then arranged in a bore of the cylindrical components. Structure and function are basically the same as with switching: according to Fig. 10 "..."., .- '"

Fig. 13 shows an arrangement * in which a switch 10 in a Housing 20 is arranged. The switch 10 is constructed according to Fig. 10 » It works SOj as explained with reference to Fig. Lla ^ llc vmrde »Basically, however Fig. 13 also a / other than dei? switch shown in Fig. 10 can be used, which works in principle according to Fig * 12a-l2c.

The opposite ends 21 and 22 of the housing 20 .are made of non-magnetic and electrically non-conductive material, constructed similarly to the yokes 6 and 7 according to FIG. 2a. The case 20 also has a cylindrical part 23 made of non-magnetic note and thermally conductive material on the part B of the switch corresponds to Fig. 2a. The ends ″ 21 and 22 also serve to prevent the fused parts of the glass from breaking off Housing 'Ii *

The switch of Fig. 10 can also be modified as which is shown in FIG. In FIG. 14, two temperature-absorbing parts 4 and 5 are designed as incomplete rings. the Gaps are filled by non-magnetic material 41. This increases the heat capacity of the temperature-absorbing body 4 and 5 so reduced that the switch is more temperature sensitive.

A switch according to FIGS. 12a-12c can also be modified in the same way will.

Fig. 15 shows a switch according to FIG. 10, in which the outer Surface of the cylindrical components 2,3,4,5 with a groove 9 verr. see is. The supply line 15 is after the exit from the glass The housing is bent over, inserted into the groove 9 and guided along this to the other side, on which the supply line 14 from 'the reed' Switch 1 exits. Such a switch can be used in conditions of use that make it practical to feed both lines from one side. Similarly, a switch according to Fig.l2a-12c can also be designed.

Temperature-absorbing ferromagnetic bodies which are temperature-dependent in their magnetic properties according to FIG. 1 can e.g. made of ferrite. However, other ferromagnetic materials are also available which are so selected must be that they have the desired Curie points. The materials used to manufacture permanent magnets are known.

Patent claims :

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Claims (1)

-1S- Claims Thermomagnetically controlled switch using a reed switch, in which two leaf spring contacts (reed contacts) made of ferromagnetic material, the free ends of which overlap, are provided in a closed housing. Another "magnetic substance in the vicinity of the reed switch, depending on the temperature, can be drawn against each other and thus closed, characterized in that two permanent magnets (2,3), whose Curie points are above the operating range of the switch, are provided and these ( 2,3) at least two temperature-absorbing ferromagnetic bodies (4,5) with different Curie points (T., T _{2> in the contact area of the switch) are} spatially assigned in such a way that the paths of the magnetic flux of the two permanent magnets (2,3) by different course in relation to the reed contacts (12,13) in two of the Curie Pun kten (TT ₂ ) limited temperature ranges (T <T ^, T> T _c2 , where T _cl <T _c2 ) the reed contacts (12, 13) in their first switching 409829/0650 3Ό \ r, position and in another between the two Curies Points. Lying temperature range (T. < Bring T <T ") into its second switch position. Thermomagnetic switch according to Claim 1, characterized that the two permanent magnets (2,3) along the circumference of the reed switch (1) at different points with in the axial direction opposite arrangement. their poles like that are provided that they cover the overlapping ends of the reed contacts (12, 13) and that the two ferromagnetic Body (4, 5) are arranged outside the permanent magnets / and lying above them. Thermomagnetic switch according to claim 1, characterized in that that the two permanent magnets / er different points in the axial direction along the reed switch (1) with the same arrangement their poles are provided, each ending shortly before the overlapping ends of the reed contacts (12, 13), and the first ferromagnetic body (5,5 ') in the axial direction the overlapping ends of the reed contacts (12,13) covered and between the two permanent magnets (2,3) its end faces on each one of their poles is arranged adjacent, and the second ferromagnetic body (4,4 ') the two permanent magnets (2,3) overlaps in such a way that a Path of the magnetic flux between the other poles of the not adjacent to the first ferromagnetic body (5) Permanent magnets (2,3) can run. Thermomagnetically controlled switch according to claim 1, characterized characterized in that the two permanent magnets (2,3) at different points in the axial direction along the reed switch (1) are provided with the reverse arrangement of their poles and ■ just before the overlapping ends of the reed contacts (12,13) end, and that the first ferromagnetic body (4) in the axial Direction between the permanent magnets (2,3) arranged in this way 4098 29/065 0 is that its one end rests against a pole of a permanent magnet (2) and its other end just before άΦ. overlapping ends of the reed contacts (12,13} ends, and that the second ferromagnetic body (5) is arranged in the axial direction between the first ferromagnetic body (4) and the other permanent magnet (3) so that its one end one pole of which and its other end rests against the other end of the first ferromagnetic body (4) and that it (5) covers the overlapping ends of the reed contacts (12, 13). ⁵ · Thermomagnetically controlled switch according to claim 1, characterized in that the two permanent magnets (2, 3) are provided in the axial direction at different points with the same arrangement of their poles and just before the overlapping area of the reed contacts (12, 13) end, and that the first ferromagnetic body (4) is arranged in the axial direction between the permanent magnets (2,3) such that its one end rests against a pole of a permanent magnet and its other end just before the overlapping ends of the reed contacts (12,13) ends and the second ferromagnetic body (5) is arranged in the axial direction between the first ferromagnetic body (4) and the other permanent magnet in such a way that its one end at one pole and its other end at the other end of the first ferromagnetic body and that it covers the overlapping ends of the reed contacts (12,13). ⁶ · Thermomagnetxscher switch according to claim "f / ⁿ i §adurch ^following in that the reed switch (1), the permanent magnets (2,3) and the ferromagnetic body are received (4.5) in a housing (11,20) , in whose opposite end regions (6,7,21,22) made of non-conductive and non-magnetic material, the leads (14,15) are received, and that the part lying between these end regions (6,7,21,22) (8,20) of the housing is thermally conductive. 409829 / 0650- - 4 - 7. Thermomagnetically controlled switch according to claim 3, characterized in that the outer surface of the first ferromagnetic body (5) is flush with the outer surfaces of the two permanent magnets (2, 3) in the radial direction of the reed switch Cl), and the second is ferromagnetic body (4), the outer surfaces of both of said two permanent magnets (2,3) and enclosing the first f erromagnetischen body (5) and covers. 8 · Thermomagnetically controlled switch according to claim 3, characterized characterized in that the outer surface of the first ferromagnetic body (5) in the radial direction of the reed switch (1) over the The outer surface of the two permanent magnets (2, 3) protrudes and the second ferromagnetic body (4) through two partial bodies (4A, 4B) is formed, 'the outside of the outer surfaces of the two permanent magnets (2,3) are arranged with their ends resting against the first ferromagnetic body (5). ⁹ · Thermomagnetically controlled switch according to claim 7, characterized in that the two permanent magnets (2, 3) and the first ferromagnetic body ('5) are cylindrical and arranged coaxially to each other around the reed switch (1), and that the reed switch (1) is also cylindrical second ferromagnetic body (4) is arranged concentrically with and outside the permanent magnets (2,3) and the first ferromagnetic body (5). 10 · Thermomagnetically controlled switch according to claim 8, characterized in that the permanent magnets (2, 3) and the first ferromagnetic body (5) are of cylindrical design and are arranged coaxially around the reed switch (1), and that the two sub-bodies (4A and 4B) are also cylindrical and are arranged concentrically with and outside the permanent magnets (2, 3) (FIG. 6). 11 · Thermomagnetically controlled switch according to claim 9 or 10, characterized in that the outer surface of the cylindrical ferromagnetic body has an axially extending groove (9) 409829/06 5 0 are provided and one of the two supply lines ClU, 153 to the reed switch (1) when it emerges from the housing (11) bent over and in this groove (9) to the other side of the reed switch. Cl) is performed. '. ■ --.-. , '-. ■ ■ 12.'Thermomagnetisch controlled switch according to claim 4 ^ or 5, characterized .gekisiert _Si that the two. ■ Permanentmagne.te (2,3) and the two'Eerroiiiagnetisehen. Body (4, 5) designed to be z-ylindrisch and coaxial.; Are arranged to one another. . 13. Thermomagnetically controlled switch according to claim 12, characterized. - marked that on. the outer surfaces of the two permanent magnets (2,3) and the two ferromagnetic bodies (4,5) one groove extending in the axial direction. (9) provided ".is and one of the supply lines (14,15) to the reed switch Cl) after their Exit from the housing (11) bent and in this groove (9) for the other side of the reed switch (1). 14..Thermomagnetically controlled switch according to claim 4 or 5, characterized in that -the two permanent magnets (2,3) ■ Are cylindrical, and that between them one or more non-magnetic parts (41 -) - is arranged such that he or she - together with the two ferromagnetic bodies (4.5). also forms a cylindrical component. 40982 9/0650