EP0017129B1 - Polarised relay having contact blades - Google Patents

Description

The invention relates to a polarized tongue contact relay according to the preamble of patent claim 1.

Known relays of this type (DE-C-1 243 271, DE-C-1 909 940, DE-C-2 459 039 and DE-C-2 462 777) can be equipped with only one changeover contact. There are also reed contacts or reed relays with two or more changeover contacts, but because of their fundamentally different design, they are much less efficient. From FR-A-2296932 relays with changeover contacts are also known, in which the movable contact element is formed by a rigid armature. The overall structure of these relays is more complex since they already require a total of four fixed contacts and two movable contacts to achieve a switching effect.

The invention has for its object to design a relay of the type mentioned in such a way that at least two changeover contacts can be actuated synchronously with the proven permanent magnet system.

The inventive solution to this problem is specified in the characterizing part of claim 1.

The arrangement of the two contact tongues and the fixed contacts cooperating therewith enables the respective contacts to be opened and closed simultaneously due to the same magnetic influence and predetermined spatial relationships.

In order to maintain the advantage of this concept compared to conventional reed relays, namely the adjustability in the same magnetic field in which it is located during operation, the two contact tongues are arranged parallel to one another and welded at one end with electrically separate, also parallel center contact connections , so that they are recorded together by an adjusting device and are adjustable in terms of their response or drop values.

It is often necessary that both the contacting and the contact interruption of several contacts take place synchronously, even with slowly increasing or decreasing excitation voltage. An aid for this is a mechanical positive guidance of the contacts to be actuated, which can be achieved in that the contact springs are positioned parallel to one another by one or two insulating plates connected by riveting or ultrasound welding or, as shown in the exemplary embodiment, by extrusion coating. Correspondingly, the fixed contacts, which are electrically separated from one another, must then be positioned in one plane and, if possible, brought together to form a unit.

In addition, since a good insulation resistance between all pole shoes carrying contact currents is required, these are provided with a plastic sheathing which has a film thickness between them and the magnet and on the other sides has a thickness or profile corresponding to the mechanical requirements.

These pole shoe pairs and tongue contacts connected to form a unit can be connected to the coil body in various ways. In the case of two contact tongues or fixed contacts which are arranged parallel to one another and connected to form a unit, it is expedient to position them in corresponding shaped incisions in the coil former, the distance between the opposing fixed contacts being determined by intermediate layers which are formed in the coil former or, in the case of a two-part Coil body, can be formed by intermediate plates with a defined thickness. Such so-called spacers eliminate tolerances and simplify adjustment.

Another possibility of assigning two changeover contacts to the system described at the outset is to position the permanent magnet system with its pole pieces and fixed contacts in the center of the relay and on each side of the contact tongues in a mirror image so that the attachment of these tongues with their connections at each end of the Coil body - adjustable in a known manner - takes place.

This arrangement results in two coils, the windings of which, depending on the requirements, are either electrically connected to one another, ie to form a coil, or are designed separately from one another. In the case of separate, that is to say two mutually independent, coils, each changeover contact can also be actuated independently of the other. One switch can be impressed with monostable behavior and the other with bistable behavior by adjusting the spring preload accordingly. Furthermore, separate connections of two independent coils can be made externally to a common coil, e.g. by appropriate design of a circuit board in which the relay is used.

As a further embodiment of the invention, a capacitor which is connected in series with the coil and an IC with a trigger and flip-flop according to DE-A1-2747607 is provided for synchronous contact actuation, even when the excitation voltage rises or falls and mechanically uncoupled contact tongues. In this case, the contact tongue is set to bistable behavior. The trigger stage only switches at a predetermined voltage that is sufficient for both changeover contacts to respond suddenly. The capacitor charges and blocks the flow of current through the coil. A relay set to monostable would drop off again immediately, while the bistable relay would remain in this position until the supply voltage was interrupted and the capacitor over the coil winding tion and the flip-flop of the IC discharges, thus relocating the relay contacts to their initial position, also suddenly. Thus, the bistable relay is impressed with a monostable switching behavior, a synchronous actuation of both changeover contacts is guaranteed and, moreover, control energy is only required during the very short switch-on process of approx. 1 ms.

• Fig. 1 einen Längsschnitt entlang der Mittelachse eines fertigmontierten Relais mit parallel zueinander verlaufenden Kontaktzungen;
• Fig. 2a bis 2e eine Explosionsdarstellung, welche die in Fig. 1 geschnittenen Teile (mit Ausnahme der Relaiskappe) perspektivisch zeigt;
• Fig. 3, 4 und 5 ein Relais mit zwei Spulen, die spiegelbildlich zur Achse Y-Y' angeordnet und somit nur jeweils in einer Ansicht gezeichnet sind, wobei
• Fig. 3 ein Schnitt A-A' von Fig. 4,
• Fig. 4 ein Schnitt B-B' von Fig. 5 und
• Fig. 5 ein Schnitt C-C' von Fig. 4 ist;
• Fig. 6 ein Schaltschema zur synchronen Ansteuerung der Relais;
• Fig. 7 einen Längsschnitt entlang der Mittelachse eines Relais mit zwei Magneten, die spiegelbildlich zur Achse Y-Y' an den Stirnseiten des Spulenkörpers einander gegenüberliegen und entgegengesetzt gepolt sind, während die beiden Kontaktzungen im Schutzrohrgehäuse des Spulenkörpers mit ihren Breitseiten gegenüber stehen und deren freie Enden entgegengesetzt ausgeführt sind; und
• Fig. 8 einen Längsschnitt entlang der Mittelachse eines Relais mit einem Magneten, dessen zwei als Festkontakte ausgebildete Polschuhe je einer Kontaktzunge zugeordnet sind.

Further details of the invention can be seen in FIGS. 1 to 8. In detail shows:

• 1 shows a longitudinal section along the central axis of a fully assembled relay with parallel contact tongues.
• 2a to 2e show an exploded view which shows the parts cut in FIG. 1 (with the exception of the relay cap) in perspective;
• 3, 4 and 5 a relay with two coils, which are arranged in mirror image to the axis YY 'and are therefore only drawn in one view, wherein
• 3 shows a section AA 'of FIG. 4,
• Fig. 4 is a section BB 'of Fig. 5 and
• Figure 5 is a section CC 'of Figure 4;
• 6 shows a circuit diagram for the synchronous control of the relays;
• Fig. 7 is a longitudinal section along the central axis of a relay with two magnets, which are mirror images of the axis YY 'on the end faces of the coil body opposite and opposite to each other, while the two contact tongues in the protective tube housing of the coil body are opposite with their broad sides and their free ends opposite are executed; and
• 8 shows a longitudinal section along the central axis of a relay with a magnet, the two pole shoes of which are designed as fixed contacts and are each associated with a contact tongue.

1 and 2, a permanent magnet 1, preferably made of BaOFe, is located between four pole shoes 2a, 2b, 2c and 2d which are electrically insulated from one another. According to FIGS. 2c, 2d, a pair of pole shoes is encased with an injection-molded insulating part 7a, 7b, which has a relatively thin layer thickness d ₁ on its side facing the magnet and a much thicker layer thickness d ₂ on the outside. The layer thickness d should be thin so that there is the best possible coupling between the magnet and the pole piece, but on the other hand it should not be zero because it serves not only for insulation purposes but also as a magnetic air gap. If there is a magnet directly on the pole pieces without a magnetic air gap, there is theoretically an optimal coupling, but in practice this is different due to the unevenness of the magnet, so that the adjustment of the relay becomes difficult and then usually no longer automatic can be done. An air gap and a correspondingly stronger permanent magnet are therefore preferable to a system without an air gap. In addition, the extrusion coating has the advantage that a semi-cylindrical profile (FIG. 2c) can be formed, with the aid of which tolerances of the pole shoes with the fixed contacts 4a, 4b, 4c and 4d relative to the guide grooves 9a, 9b, 9c, 9d in the bobbin 10 and its contact surfaces 20a, 20b compensate. Thus, as tolerances influencing the contact spacing, only those of the thickness of the contact springs 3a, 3b and that of the spacer 11 formed in the coil body 10, on which the ends of the fixed contacts are supported, remain. Both tolerances can be kept below 0.01 mm.

The fixed contacts could also be replaced by appropriately cranked pole shoes; However, it is expedient to produce them separately, because they can then be subjected to a different surface treatment than is required for the pole shoes and their connections 8a, 8b, 8c, 8d because of the required contact conditions.

If these fixed contacts made of ferromagnetic material are provided with shoulders 4A, 4B (as shown in FIG. 3) for the purpose of spot welding with the pole shoes, this ensures that the contact material pad 4C remains intact. The two contact tongues arranged parallel to one another are preferably encased with a plastic part 6 for the purpose of parallel guidance. It does not matter whether this sheathing is carried out by ultrasonically welding two plastic films or by extrusion coating. In the case of overmolding, the center contact connections 5a, 5b could also be encapsulated with plastic after the spot welding with the contact tongues 3a, 3b in order to increase the security against loosening of the connection point, which is particularly stressed during the adjustment. This part connected to a unit (FIG. 2a) is also positioned in the cutouts 9 of the coil body.

The relay assembly assembled in this way is inserted with its connections into the openings 15g of the base body 15 (FIG. 2e) and, after the permanent magnet 1 has been inserted, can be inserted between the two pairs of pole shoes (FIGS. 2c and 2d) positioned in the coil body 10 and after the electrical connection Connection of the coil wire ends with the coil connections 15c, 15d or 15e, 15f located in the base body 15 are adjusted at the connection point of the contact tongues 3a, 3b with the center contact connections 5a, 5b. For this purpose, it is expedient to use a ferromagnetic cap which differs from the final cap 16 only by an opening which allows access to the adjustment point. The base body 15 has a shoulder 15b, on which the cap 16 rests, and one or two openings 15a, which serve both for filling with protective gas and for introducing potting compound 17.

The exemplary embodiment according to FIGS. 3 to 5 is constructed symmetrically with respect to its axis Y-Y and has two identical coil body halves 10a, 10b, in which both the pole shoes 2a, 2b and the coil connections 14a, 14b, 14c, 14d and the center contact connections 5a, 5b and an earth connection 5c are embedded. All of these connections are preferably punched from a ferromagnetic tape and are separated from one another in a known manner after the embedding by a further punching process.

Ferromagnetic flux guide pieces (fixed contacts 4a, 4b) are preferably spot welded to the pole pieces 2a, 2b, preferably over shoulders 4A, 4B. The end faces of the flux guide pieces are covered with contact material supports 4C and serve as fixed contacts with respect to the free end of the contact tongue 3, which is also covered with contact material supports. The other end of the contact tongue 3 is point-welded to the center contact connection 5a in a known manner via a connecting bridge 5. A window 5f is provided in the connecting bridge 5 to allow access for the adjustment of the contact tongue 3. The identical bobbin halves 10a, 10b are provided with guide pins 10f and, in mirror image thereto, with guide holes 10g which form a fit when assembled (FIG. 3). Between these two coil body halves there is an insulating plate which, as a spacer 11, holds the two fixed contacts 4a, 4b at a precise distance from one another, namely because the outer ends of the fixed contacts abut this spacer 11 and also position the permanent magnet 1. The spacer 11 is positioned by means of bores 11b through which the guide pins 10f protrude.

• (1) Durch den relativ grossen Abstand der beiden stirnseitig einander gegenüberliegenden Kontaktzungen 3 und der gegenseitigen Abschirmung durch den Dauermagneten 1 ist die Kapazität zwischen den Kontaktzungen sehr gering, so dass sich diese Anordnung zum Schalten von HF-Lasten eignet.
• (2) Die beiden Umschaltkontakte können über die Spulenanschlüsse 14a, 14b bzw. 14c, 14d unabhängig voneinander betätigt werden.
• (3) Da die beiden Kontaktzungen 3 unabhängig voneinander justiert werden, kann der einen Kontaktzunge mono- und der anderen bistabiles Verhalten eingeprägt werden.
• (4) Die Spulenanschlüsse können extern oder auch intern mit einer Leiterplatte 18 gekoppelt werden und
• (5) Die Leiterplatte 18 kann mit einem Kondensator und einer elektronischen Schaltung 13 nach Fig. 6 bestückt und verbunden werden, wodurch, wie bereits beschrieben, eine synchrone Betätigung beider Kontaktzungen erfolgt und gleichzeitig Erregerenergie eingespart wird.

The exemplary embodiment according to FIGS. 3 to 5 has the following special features:

• (1) Due to the relatively large distance between the two opposite contact tongues 3 on the face side and the mutual shielding by the permanent magnet 1, the capacitance between the contact tongues is very small, so that this arrangement is suitable for switching HF loads.
• (2) The two changeover contacts can be actuated independently of one another via the coil connections 14a, 14b or 14c, 14d.
• (3) Since the two contact tongues 3 are adjusted independently of one another, one contact tongue can be impressed with mono- and the other bistable behavior.
• (4) The coil connections can be coupled externally or internally to a printed circuit board 18 and
• (5) The circuit board 18 can be equipped and connected with a capacitor and an electronic circuit 13 according to FIG. 6, whereby, as already described, both contact tongues are actuated synchronously and excitation energy is saved at the same time.

In this exemplary embodiment, the hermetic closure takes place analogously to that described above by means of a ferromagnetic cap 16, base body 15 and casting compound 17.

Another embodiment of the invention is shown in FIG. 7 in half a longitudinal section along the central axis and in half a top view. This relay has a permanent magnet 1a, 1b on each of the two end faces of the coil body 10, these permanent magnets being coupled in opposite polarities to a pole shoe 4a, 4c designed as a fixed contact. These fixed contacts form in the de-energized state of the relay with one contact tongue 3a, 3b normally closed contacts. It is thereby achieved that, when excited, a synchronous actuation of the two contact tongues 3a, 3b can be realized much better than, for example, the magnetic conditions according to the exemplary embodiment according to FIGS. 1 and 2 allow. In the exemplary embodiment shown in FIG. 7, if a contact tongue opens its magnetic circuit by changing the electromagnetic field, this has an accelerating effect on the opening of the other magnetic circuit - that is to say the other contact tongue - because the total permanent magnetic circuit is practically in series. The exemplary embodiment is also space-saving, because the two contact tongues 3a, 3b with the broad sides, not shown here, face each other and thus run parallel to one another in the interior of the coil former 10. Expediently, two identical bobbin halves will also be used here, which are brought together in a known manner to form a bobbin after the connection of the contact tongue and center contact connection 5a, 5b and before application of the coil winding 12. For the purpose of adjustability of the contact tongues 3a, 3b at their connection point with the center contact connections 5a, 5b, recesses 10h are provided in the flanges of the coil body 10 in order to obtain a possibility of engagement of the adjustment device.

In the further embodiment of the invention according to FIG. 8, there is a permanent magnet 1 between two ferromagnetic pole shoes 4a, 4c designed as fixed contacts, each of which forms normally closed contacts with the free ends of the contact tongues 3a, 3b. This version is mainly suitable for monostable relays, especially since the permanent magnetic circuit, which runs over the pole shoes 4b, 4d designed as fixed contacts, is considerably weaker than the one running over the pole shoes 4a, 4c. In this exemplary embodiment too, an opening of one contact accelerates the opening of the other when the switching state is changed by the electromagnetic circuit.

Claims (15)

1. A polarized reed contact relay comprising a ferromagnetic contact reed (3a, 3b) supported at one end and extending through the bobbin (10) approximately in the direction of the coil axis, and a pair of fixed contacts (4a...4d) positioned in the bobbin, forming a change-over contact with the free end of the contact reed (3a, 3b) and having pole pieces (2a...2d) disposed in proximity of a permanent magnet (1; 1a, 1b), characterized in that two contact reeds (3a, 3b) electrically insulated against each other are disposed within the same bobbin (10), the free ends of the contact reeds forming two change-over contacts with a respective pair of fixed contacts (4a...4d), and that the fixed contacts (4a...4d) are positioned within the bobbin (10) in pairs and aligned with each other.

2. The relay of claim 1, characterized in that the two contact reeds (3a, 3b) are positioned with respect to each other and interconnected to form a unit by means of a piece (6) of insulating material.

3. The relay of claim 1 or 2, characterized in that each two of the pole pieces (2a, 2b and 2c, 2d) are positioned with respect to each other and interconnected to form a unit by means of a piece (7a, 7b) of insulating material.

4. The relay of any of claims 1 to 3, characterized in that the pole pieces (2a...2d) and/or the contact reeds (3a, 3b) have their terminals (5a, 5b and 8a, 8b, 8c, 8d) positioned in cut-outs (9, 9a, 9b, 9c, 9d) of the bobbin (10).

5. The relay of any of claims 1 to 4, characterized in that the fixed contacts (4a...4d) abut at a spacer (11) outside their contacting area, the spacer defining the contact air gap and, in case of a two-part bobbin, consisting of a punched or injection-molded plate of insulating plastics material disposed between the two bobbin halves (10a, 10b).

6. The relay of claim 1 or 5, characterized in that one coil (12a, 12b) is provided for each of the two change-over contacts, whereby the two change-over contacts are capable of being actuated independently or in common.

7. The relay of claim 1, 5 or 6, characterized in that the permanent magnet (1), the pole pieces (2a...2d) and the fixed contacts (4a...4d) are disposed in the center of the relay, and that the two contact reeds (3a, 3b) are positioned symmetrically thereto and are individually and adjustably connected to center contact terminals (5a, 5b) fixed in the two outer ends of the bobbin.

8. The relay of claim 6 or 7, characterized in that the two coils (12a, 12b) are interconnected, thereby acting as one coil.

9. The relay of any of claims 1 to 8, characterized in that a capacitor and an integrated element (13) are electrically connected to the coil terminals for the synchroneous contact closure of both change-over contacts.

10. The relay of any of claims 1 to 9, characterized in that the change-over contacts are independently adjustable for monostable or bistable operation and are capable of being actuated via coil terminals (14a, 14b and 14c, 14d) which are electrically separated from each other.

11. The relay of any of claims 1 to 10, characterized in that a base (15) of plastics material having at least one filling opening (15a) for a sealing compound (17) and a shoulder (15b) for positioning a ferromagnetic cap (16) is provided, and that the base (15) of plastics material and the cap (16) are sealingly interconnected by the sealing compound (17).

12. The relay of any of claims 1 to 11, characterized in that pole pieces (4a, 4b, 4c, 4d) formed as fixed contacts and one permanent magnet (1a, 1b) are disposed at each of the two ends of the bobbin (10).

13. The relay of claim 12, characterized in that one of the permanent magnets (1a, 1b) has its south pole and the other its north pole coupled with the respective pole piece (4a, 4c) which forms the normally-closed contact.

14. The relay of claim 13, characterized in that the bobbin is provided with recesses (10h) in the area where the ferromagnetic contact reeds (3a, 3b) are supported, through which recesses an adjustment of the contact reeds (3a, 3b) at their connection to the center contact terminals (5a, 5b) can be performed.

15. The relay of claim 1, characterized in that one permanent magnet (1) is disposed between two pole pieces (4a, 4c) forming the respective normally-closed contact.

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