DD148123A1 - MULTIPLE SPRING ELEMENT FOR AN ELECTRIC SWITCHEL - Google Patents

Abstract

The multiple spring element relates to the field of contact devices. The object of the invention is a technically-economically favorable solution for electrical switch springs for switching weak input signals. The invention has for its object to provide a plastic molding, which assumes the provision and limitation of the Betetigungskraefte, the inclusion of the switching elements and the attachment to the circuit board for several switches. This object is achieved in that the multiple spring element is formed from a box-shaped plastic molding whose bottom is divided into individual tongue or schneckenfoermige resilient elements. The possible applications of the multiple spring element are keyboards in controls of household electrical appliances such as microwave ovens, washing and drying machines and dishwashers.

Description

Inventor: Günter Schieferdecker Berlin, 14. 12.

Zustellungsbevollm .: Institute of control engineering

in the combine VEB Elektro-Apparate-Werke Berlin 1055 Berlin, Storkower Str. 101 Pat.-Ing. Harald Zühlsdorf ·

Multiple spring element for an electric switch panel

'H 01 H 1/14

Field of application of the invention

The invention relates to a multiple spring element for the simple construction of a suitable for 'weak input signals electrical switch panel on printed circuit boards.

Printed circuit boards for switching small voltages and currents are increasingly used in the form of program selection keyboards in electronic control units. The field of application includes electronically controlled household appliances such as microwave ovens, washing and drying machines and dishwashers.

Characteristic of the known technical solutions

In the known electrical switches, the actuating restoring force and the limitation of the actuating force is achieved by additional individual metallic leaf or coil springs. In this solution, however, a relatively high cost of assembly is necessary.

It is also the principle of an electric switch panel according to DE-OS 2 217 445 "electrical switching contact, in particular for devices of electrical communications technology" known in which a common for the individual switch contact pole simultaneously resets the actuating forces. This switch principle is only applicable if one contact pole of all individual switches has the same potential

leads. Another disadvantage is that .Daß for the mechanical and electrical connection of the common Kontaktpoles a contact on the circuit boards is required »

Object of the invention

With the invention, a multiple spring element for an electrical switch panel, in which by means of buttons or derglei ¬ chen formed on a printed circuit board electrodes are bridged via jumpers conductive films or mats, ensures that a reliable recovery ensures a long life and cost of a thermoplastic material can be produced.

Explanation of the essence of the invention

The invention I¬ the object of a spring element. which, as a molded plastic part, simultaneously takes over the setting and limitation of the actuation forces, the mounting of the switching elements and the fastening on the circuit board for several shifters «

According to the invention, this object is achieved in that the multiple spring element is formed from a box-shaped platform part whose bottom is divided into individual tongue or schnekkenförmige resilient elements.

Furthermore, it is provided that in order to achieve a parallel key arrangement, the tongue-like springs are meander-shaped and the Hubbegrenzung of the spring at the end of a stopper is formed «

As a further feature of the invention, latchable claws are arranged on the multiple spring element for attachment to the printed circuit board.

According to a further embodiment, a pin is formed on the tongue-like springs, with the indirectly via a membrane mat or directly actuation occurs.

embodiment

The invention will be explained with reference to exemplary embodiments of a spring element, which is shown in the drawing. Show it: '

1 is a sectional view through an arrangement of a spring element for a 8-fold switch in two rows of switches on a circuit board and

Fig. 2: a plan view of FIG. 1 with omitted cover plate

Fig. 3: another embodiment in section.

In Fig. 1, a multiple spring element 1 is shown using the example of a splash-proof keyboard. The multiple spring element 1 fixes the position of the conductive switching mat 2 and the insulating film 3 on the circuit board 4, in which the spring element 1 is engaged via the resilient claws 5. As a result of the labyrinth shape of the key 6, the spray water which has entered the keyboard does not reach into the area of the switch, but instead flows off again via openings 7. In order to produce an electrical contact on the printed circuit board 4, it is necessary to deflect the spring 8 of the multiple spring element 1 with the key 6, which brings the conductive retaining mat 2 into contact with the comb electrode pair 9 formed by conductor tracks. After pressing the button 6 is pressed by the spring 8 against the cover plate 10 and thus returned to the starting position. The limitation of the Tastenhubes or the actuating force via the arranged on the spring 8 stop 11. In order to avoid that upon actuation of the spring 8 adjacent springs are deflected with the multiple spring element 1 is on both sides by a molded U-shaped legs 12 against torsion stiffened. In the illustrated multiple spring element 1 for eight switches, the springs 8 are meander-shaped for the purpose of parallel arrangement. At the detail of the multiple spring element 1, one recognizes the contact poles of a pair of Kanim electrodes 9, which are applied to the printed circuit board 4 according to the technique of the printed circuit, with the insulating insulating layer lying above them.

foil 3, which is cut free in the region of the comb electrode pairs 9. In free cut 13 of the circuit board 4, the attachment of Mehrfactifederelementes 1 by means of the claws. 5

In the embodiment shown in FIG. 3, in contrast to the example of FIG. 1, the splash water protection is achieved by a membrane mat 14 inserted in the cover plate 10. By means of the pressure plate 15, the inserted membrane mat 14 is printed on the cover plate 10. The compound of the existing plastic moldings cover plate and pressure plate 15 is carried out by ultrasonic welding. The mechanical connection of the cover plate 10 with the circuit board 4 via resilient jaws 17, which are integrally formed on the pressure plate 1 5.

Upon actuation of a key (membrane) of the membrane mat 14, the spring 8 is deflected via a spigot 16 molded onto it and thus the conductive switching mat 2 is brought into contact with a comb electrode pair 9.

Claims (5)

217759 invention claim 1. Multiple spring element for an electric switching ele- ment, characterized in that the multiple spring element (1) is formed from a box-shaped plastic molding, the bottom of which in individual tongue or helical Fe ~ •. ·:.:. cLaa? nde elements is divided « 2. multiple spring element according to item 1, characterized in that the tongue-like springs (8) are meander-shaped to achieve a parallel Tastenanord-. 3. multiple spring element according to item 1 and 2, characterized in that the stroke limitation of the spring (8) at the end of a stop (11) is integrally formed. 4. multiple spring element according to item 1 to 3, characterized in that on the tongue-like springs (8), a pin (16) is integrally formed with the indirectly via a membrane mat (14) or directly the actuation takes place. 5. multiple spring element according to item 1 to 4, characterized in that on the multiple spring element (1) for attachment to the circuit board (4) latchable claws (5) are arranged. Here are drawings