EP1233433B1 - Electromechanical switching device - Google Patents

Description

The invention relates to an electromechanical switching device according to the preamble of claim 1, as it also eg in the document US 4,345,224 A. is disclosed. Such electromechanical switching devices or clocking line plate with rotary switches are used for example in hobs. By turning them switching functions can be triggered at certain rotational positions. This is done by either establishing or dissolving an electrical contact between a contact and a mating contact. Contact and mating contact can be compressed by spring forces. Against this spring force then takes place a release of the electrical contact or contact and mating contact from each other.

This shows in practice that the assembly is complex. Either the spring element must be inserted in front of the contact holder in the socket and pressed together to subsequently mount the contact holder itself. Or aids are needed for the attachment of the spring element, for example screws or caps or plug connections. In part, it has also been proposed to secure the spring by bending a component. However, these options are generally complex and require additional mounting parts and / or steps.

TASK AND SOLUTION

The invention is based on the object to provide a switching device mentioned above, in which the assembly of the spring element can be simple, safe and production-friendly.

This object is achieved by an inventive switching device having the features of claim 1. Advantageous embodiments of the invention are the subject of the dependent claims and are explained in more detail below. The content of the claims is made explicit reference to the content of the description.

The fastening according to the invention of the spring element on or against the base by means of retaining elements formed on the base or contact holder has the great advantage that these retaining elements are present even before the spring element is inserted. An elaborate hold down during a further assembly step can be saved. The insertion of a spring element can be performed easily, quickly and in a single assembly step or with a single assembly movement. Although it is in principle advantageous to provide the retaining elements on the base. In certain embodiments of the switching device, for example, depending on the arrangement of the contact and the mating contact, a holding element can also be provided on the contact holder. In the context of the invention, a combination of cooperating retaining elements on the base and the contact holder is possible.

A contact holder may be formed such that an elongated arm carries the contact, preferably a metal arm. The arm is stored or molded in a plastic body.

On the one hand, the holding elements may be part of another device on the base or contact holder and already placed or mounted by its assembly process. For strength reasons, a one-piece connection of the holding elements with base or contact holder is preferred. Particularly preferably, the holding elements are formed or manufactured in the manufacturing process of the base or contact holder equal. This has the great advantage that no further assembly step or additional effort is needed. When manufacturing the base or contact holder made of plastic, this can be easily provided in the injection mold.

The holding elements may preferably elastically overlap the spring element in such a way that they give way when inserting or mounting the spring element or move out of its way. When fully inserted spring element, they can automatically go to their original position or snap and lock the spring element against loosening. In this way, only the usual insertion of the spring element needs to be made, the holding elements do not need to be extra pressed or pushed away.

Preferably, an elongated spring element is used with spring action in its longitudinal direction. Advantageous is a coil spring made of metal. As another option come cylinder or similar forms made of elastic plastic, in particular temperature-resistant foam, in question.

The holding elements advantageously extend at least partially along the longitudinal direction or mounting direction of the spring element. Thereby For example, a guide can be effected. To hold them they can overlap its end in the inserted state with claw or hook-like projections or engage behind. So a kind of snap closure can be formed. The projections on the holding elements should be withdrawn or bevelled on their side pointing to a spring element to be inserted, so that they yield on their own for insertion of the spring element. In this way, a centering of the spring element during insertion can be done.

Preferably, a movement of the contact holder or the spring travel of a spring element is substantially rectilinear. For this purpose, the contact holder in a guide device or the like. Run on the base. The guide device can be designed, for example, as a guide rail or the like, which are matched to the outer dimensions of the contact holder or corresponding rails thereto.

For secure holding of the spring element can preferably be provided at least two or even better four retaining elements. These can either be distributed substantially uniformly, for example, around the circumference of the spring element around. For example, four retaining elements may be arranged in a cross shape around a helical spring as a spring element. In a further embodiment of the invention, a plurality of spring elements can be arranged side by side on a base for multiple contacts. To simplify the construction, at least one retaining element can be designed for at least two spring elements. For holding elements with a hook or projection for holding a spring, either such a projection should be provided per spring to be held. Or a projection is designed so that it acts as two individual.

On a base, the spring elements can be evenly distributed in a grid, both in a single row and in fields.

Retaining elements are preferably arranged at the cross points of the grid position boundaries, that is essentially in each case such that a holding element holds as many spring elements as possible.

Furthermore, it is possible to secure by a detent on the contact holder itself a spring element, such as a coil spring, in principle against loss. In this case, the contact holder and spring element need not be mounted as separate components to the base, but can be pre-assembled as a captive unit. The securing of the spring element on the contact holder should not adversely affect the function or holder on the base.

The holding elements or their projections or the like. May be designed so that they hold the spring element in a precisely defined desired position. For this purpose, on the one hand, the space within holding elements exactly predetermine this position. Alternatively, it is possible to position by barb-like projections on the holding elements for holding the spring element, this due to its restoring force and the resulting pressure against the holding elements.

These and other features will become apparent from the claims but also from the description and drawings, wherein the individual features each alone or more in the form of sub-combinations in an embodiment of the invention and in other fields be realized and advantageous and protectable Represent embodiments for which protection is claimed here. The subdivision of the application into individual sections as well as intermediate headings does not restrict the general validity of the statements made thereunder.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1

eine perspektivische Darstellung eines Ausschnitts eines Schaltgerätsockels mit einzusetzendem Kontakthalter sowie Schraubenfeder,

Fig. 2 und 3

in Seitenansicht einen zweistufigen Montagevorgang der Bauteile gemäß Fig. 1 und

Fig. 4

eine klauenartige Ausführung der Haken.

Embodiments of the invention are illustrated in the drawings and will be explained in more detail below. In the drawings show:

Fig. 1

a perspective view of a section of a switching device base with einzusetzendem contact holder and coil spring,

FIGS. 2 and 3

in side view a two-stage assembly process of the components of FIG. 1 and

Fig. 4

a claw-like execution of the hook.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Fig. 1 shows an oblique view of a part of a switching device base 11. The base 11 has downwardly projecting metal plug-in lugs 12, which serve as electrical connection option. With these plug-in lugs 12 mating contacts, not shown, are connected, s. For this purpose, also Fig. 3, which are interconnected for a switching operation. This connection takes over a contact holder 14 which is electrically conductive, for example, of a resilient metal. The contact holder 14 carries at its two continuous arms 15 and 16 each have a contact 17 which is intended to bear against the mating contact of the switching device socket 11. The arms 15 and 16 form with the contacts 17 an electrical connection between two mating contacts. The contacting takes place in contact chambers 19, which on the one hand serves to better guide the arms 15 and 16 and to improve the electrical insulation properties.

The contact holder 14 has a central body 21, which has integrally formed guide rails 22. These guide rails 22 extend in guide slots 23 of the switching device base 11. They serve to guide the contact holder 14 accurately in triggering movements in a predetermined path.

On its underside, the central body 21 has a projection 25. This protrusion protrudes through the switching device base 11 into the free intermediate region between the plug connection lugs 12. In this free region, the control axis runs with differently designed switching cams on which the projection 25 abuts. By appropriate rotation of the projection 25 can be pushed up and the contacts are separated.

Between the guide rails 22 and in the middle of the central body 21, a centering projection 27 is formed. About this centering projection 27 engages a coil spring 28 which is positioned by the centering projection with its lower end.

Both contact holder 14 and coil spring 28 are inserted in the insertion direction E in the switching device base 11. This will be apparent from the other figures as well as the following description.

On the inside of the guide slots 23 or as their boundary to the inside elongated retaining arms 30 are formed, at the end of inwardly facing hooks 31 are attached. The coil spring 28 comes between four such retaining arms 30 and is thereby held by the cross-hook 31. In this case, the distance of the inner edge of the hooks 31 to each other in the position shown in FIG. 1 is smaller than the cross section of the coil spring 28 or these hooks protrude into the cross section. At their top, the hooks 31, as shown, beveled to facilitate the insertion of the coil spring 28.

Such a contact holder is already used between the rear holding arms 30, the helical spring is shown schematically by a hollow cylinder 32. It can be seen how the hooks 31 engage over the cylinder 32. Instead of a helical spring, such a spring element may also be a cylindrical elastic body, for example of a foam or plastic.

In Fig. 2 it can be seen how a turned-up on the centering 27 coil spring 28 is held exactly in the center of the central body 21. The guide rails 22 point towards the guide slots 23. The mating contacts 18 are shown in dashed lines.

When inserted in the switching device base 11 contact holder 14 in the sectional view in Fig. 3 it can be seen how the hooks 31 of the support arms 30 of the switching device base 11, the coil spring 28 support. This takes place in a position of the contact holder 14, in which the contacts 19 abut against mating contacts 18 of the switching device base or the plug connection lugs 12. This system is elastic due to the spring force of the coil spring 28. Is pressed over the projection 25 of the contact holder 14 up to separate the contacts 18 and 19, this is done against the elastic resistance of the coil spring 28. A deflection of the same upward is prevented by the support arms 30 and their hooks 31.

Fig. 4 shows greatly enlarged another embodiment of the support arms 30. These have claw-like hooks 33, the claws facing down. The claws overlap the coil spring represented by the hollow cylinder 32 at its inner edge just as they would overlap a coil spring. This will be compared to normal in the manner of projections dastehenden hook even better grip not only achieved against rebound, but also an exact centering of the spring. In foam spring elements such claw-like hooks 33 can insert into the spring body and secure it so.

In Fig. 1 it can be seen how the middle slightly wider running support arms 30 can serve with wide hooks 31 for holding two adjacent coil springs 28. In this way, the production cost can be greatly reduced. It should be noted that the deflection of the retaining arms 30 resulting from the insertion of the helical spring 28 does not loosen an already supported helical spring again via the chamfering of the hooks 31. This alternative direction is at least partially in the direction of the already salaried coil spring, so that it does not dissolve again. Once held coil spring is not released by the subsequent assembly of other coil springs again. Particular attention is drawn to the additional function of the retaining arms 30 in addition to the holder as a guide of the contact holder 14 via the guide rails 22 running along it.

The free space formed between the retaining arms can be exactly as large as the outer diameter of a spring element. In this case, the limitation can be formed both by the retaining arms of the base and by corresponding elements on the contact holder itself, for example in the form of elongated arms or the like. In this way, a particularly secure recording of the spring element in the manner of an elongated channel is possible, which prevents lateral deflection especially in coil springs.

Claims (10)

1. Electromechanical switching device, in particular clocked power regulator with rotary switch, for an electrical appliance:

   - the switching device comprising a base (11),

   - the base carrying at least one countercontact (18),

   - a contact holder (14) being movably received on the base,

   - the contact holder carrying at least one contact (17) which is intended for optional abutment on the at least one countercontact,

   - a spring element (28) being provided for applying contact forces, the spring element comprising an active connection between the base and the contact holder,

   characterised in that

   - the spring element (28) is held on the base (11) by means of holding elements (30) and

   - the holding elements (30) are formed on the base (11) or contact holder (14).
2. Electromechanical switching device according to claim 1, characterised in that the holding elements (30) are connected in one piece to the base (11) or contact holder (14), and in particular are moulded on.
3. Electromechanical switching device according to either claim 1 or claim 2, characterised in that the holding elements (30) are formed on the base (11).
4. Electromechanical switching device according to any one of the preceding claims, characterised in that the holding elements (30) resiliently overlap the spring element (28) in such a way that when the spring element is inserted the holding elements give or yield and when the spring element is fully inserted automatically return to their original position and lock the spring element against detachment.
5. Electromechanical switching device according to any one of the preceding claims, characterised in that the spring element (28) is elongate with a spring effect in its longitudinal direction, wherein it is preferably a helical spring.
6. Electromechanical switching device according to any one of the preceding claims, characterised in that the holding elements (30) run at least partially in the longitudinal direction of the spring element (28) and overlap the end thereof with hook-like projections (31) to secure it.
7. Electromechanical switching device according to any one of the preceding claims, characterised in that the spring excursion for a spring element (28) extends substantially linearly, the contact holder (14) preferably running in a guide device (29) on the base (11) and the guide device being constructed in particular as a guide slot for guide rails (22) on the contact holder.
8. Electromechanical switching device according to any one of the preceding claims, characterised in that at least two, preferably four, holding elements (30) are provided for securing a spring element (28).
9. Electromechanical switching device according to any one of the preceding claims, characterised in that a plurality of spring elements (28) are arranged side by side, at least one holding element (30) being constructed for at least two spring elements, the holding element preferably comprising one projection (31) per spring element to be secured.
10. Electromechanical switching device according to any one of the preceding claims, characterised in that the spring elements (28) are uniformly distributed in a grid dimension, holding elements (30) preferably being arranged at the crossing points of the grid location limits.

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