EP0250433A1

EP0250433A1 - Slide switch

Info

Publication number: EP0250433A1
Application number: EP86902311A
Authority: EP
Inventors: Manfred Koslar
Original assignee: Siemens AG; Createc Gesellschaft fuer Elektrotechnik mbH
Current assignee: Siemens AG
Priority date: 1985-03-27
Filing date: 1986-03-27
Publication date: 1988-01-07
Also published as: US4746771A; JPS62502367A; WO1986005920A1; AU5664386A; DE3511600A1

Abstract

Un interrupteur multibroche à coulisse pour un appareil électrique de traitement de signaux comprend des zones de contact fixes agencées des deux côtés d'une couche porteuse isolante ayant la forme d'un circuit imprimé et une coulisse d'interrupteur avec des éléments de contact qui ont essentiellement la forme d'un omega et qui accrochent par élasticité les bords de la couche porteuse pour connecter alternativement des zones opposées de contact. La coulisse d'interrupteur comprend des évidements similaires à des cavités dans lesquels s'emboîtent lâchement les éléments de contact. Les éléments de contact sont montés de façon à pouvoir coulisser d'une certaine longueur dans un sens parallèle au sens de la pression de contact et/ou à pouvoir tourner dans les évidements autour d'un axe étendu dans le sens d'interruption.A multi-pin slide switch for an electrical signal processing apparatus comprises fixed contact areas arranged on both sides of an insulating carrier layer in the form of a printed circuit and a switch slide with contact elements which have essentially the shape of an omega and which elastically hook the edges of the carrier layer to alternately connect opposite contact zones. The switch slide has cavity-like recesses into which the contact elements fit loosely. The contact elements are mounted so as to be slidable by a certain length in a direction parallel to the direction of contact pressure and/or to be rotatable in the recesses about an extended axis in the direction of interruption.

Description

-. -

Slide switch

Description

The invention relates to a slide switch of the type specified in the preamble of claim 1.

Such a slide switch is known from German Utility Model No. 1 998 149. However, this switch has the disadvantage that the contact elements are firmly riveted to the back of the slide. As a result, the resilient ends of the contact elements can only follow height tolerances by giving in within their spring travel. This reduces the pressure force on one side, while it increases on the opposite side. The result is deterioration of contact on the one hand and increased wear on the other.

In contrast, the invention specified in claim 1 is based on the object of improving such a switch in such a way that the contact properties are retained even in the event of assembly tolerances and frequent operation. The switch should also be inexpensive to manufacture from a few parts.

The invention is based on the knowledge that the use of contact elements encompassing the carrier of the contact areas with tolerance-free manufacture means that the contact forces on both sides are of the same size and thus the operating properties of the two contact zones match - in practice, however, undesirable deviations occur that lead to deterioration.

The omega-shaped spring elements adjust themselves automatically during assembly and exert an identical compressive force on both contact surfaces. The individual elements are completely independent of one another with regard to their guidance transverse to the switching direction. Due to the shape of the chambers, the contact elements are secured against falling out even when the slide switch is not assembled. To assemble, the contact elements only need to be inserted into the chambers with slight pressure and engage there because of the arc-shaped extension of their omega shape. The beak-shaped area, which "rides" on the carrier element for making contact, is preferably convex on all sides in the direction of the contact surfaces. Due to the correspondingly widening opening of the "beak-shaped" end of the contact elements, the preassembled switching slide unit containing the contact elements can be assembled in a single operation.

As a result of the mechanical decoupling of the omega-shaped contact elements in the directions other than the sliding direction for actuation in the function as a switch, the mechanical drive processes with the necessary tolerances can be carried out by an externally guided push handle element Transfer slide switch, wherein the push handle element can remain connected to the housing and has tightly tolerated power transmission surfaces preferably only in the sliding direction. Since the grip element is guided through a corresponding recess in the housing, labyrinthine creepage distances can also be provided in a favorable manner here in order to achieve functional safety, which is particularly important in compact measuring devices for high-voltage applications.

The ability for self-adjustment caused by the floating assembly of the individual contact elements is so great. that it can also be used to operate several adjacent circuit boards with contact areas by rigidly connected slide switches.

With the stacked arrangement of the circuit boards, a single handle element can thus actuate a plurality of slide switches, which act on different circuit boards, so that in an advantageous further development in accordance with the respective requirements for complex switching operations influencing several switching stages in connection with an operating mode switchover, etc. Access to several boards with a compact design is possible. The boards can nevertheless be provided relatively closely adjacent to one another in accordance with the components of microelectronics available on the market, since the slide switches likewise have only a small design. By providing a mechanical switch arrangement with which the most extensive switching operations can be carried out, the construction volume of the finished device is hardly contributed to being enlarged.

Since the tolerance in the sliding direction for the transmission of force is chosen to be relatively small, in a preferred development of the invention the shifting catches are also connected to the housing in the form of pins or toothings, so that no additional measures are required for this Circuit boards must be taken. Such catches can be produced on circuit boards only with relatively complex measures, while they can easily be molded onto a plastic housing. In a measuring device in the manner of a universal signal processing device with a flat rectangular housing, the slide switch according to the invention is attached to one of the narrow sides and can be operated there ergonomically, for example with the thumb, when the device is held in the hand. The entire front surface is clear to the operator's view and with the other hand, further switching operations can be carried out inside the device via the operating elements on the front surface, which, however, preferably effect software switching in the measuring program, while the switch cone according to the invention presented here ¬ preferably affects the signal path in such a way that complete galvanic separations are generated, which cannot be easily achieved by program-controlled switching elements.

The setting elements of the slide switch and, in particular, striking markings can be recognized by a transparent front surface, so that - preferably with appropriate thermometer scales - the setting of the switch can be checked at any time without first having to look at the side surface of the device where the setting of the switch would be difficult to detect anyway, since the mechanical actuation handle in its various positions would conceal part of the symbols and designations applied to the surfaces available there.

Shields for the switch contacts, which are necessary to ensure the undisturbed operation of the device are in a U-shaped configuration and the U-shaped contacts within the slide switch can also be applied overlapping areas - above and below the corresponding area of the printed circuit board influenced by the slide switch, the movable part being in accordance with a preferred embodiment of the invention above and produces Uf ^'OER-shaped shield which is connected with the switching slide by means of grinders the necessary contact to the on-board below fixedly mounted or as conductor tracks on the map formed shields.

The grip element for the slide switch is guided by a slide preferably in such a way that the rails are formed at a separation point of the housing, so that the grip part is inserted before the housing is assembled and when the housing parts are connected (with the exception) the sliding direction) is fixed. These rails also contribute to an increase in the creepage distances required for electrical safety due to their surfaces which are at different angles to one another.

The slide switch can also be used for test purposes when the housing is removed, so that the complete function of the device is ensured for assembly and service even when the housing is removed.

With the type of device described here, there are particular difficulties in the construction. Since there is extremely little space available and the complexity of the switch functions is comparatively very high and If the operating comfort, the design and the safety were affected by this construction element, the switch had to be developed according to partly completely new construction principles.

As is known, in conventional measuring devices, even in small "hand-held" versions, switches are usually procured externally as purchase or add-on parts. This has the disadvantage of oversized volumes and the necessity to form openings and switch shapes according to the circumstances of the selected standard elements.

The slots of the carrier layer, which are oriented transversely to the sliding direction, between the contact areas provide self-cleaning of the contacts even in the event of abrasion or other migration of the contact material resulting from frequent actuation.

On the other hand, switch elements are often the cause of poor reliability of devices. Developing a switch that simultaneously meets the special requirements for density and complexity of modern circuits as well as for cost-effective production and precise reproducibility in production is an important task with regard to an overall device concept to be created, especially since the switch according to the invention is one A number of physical and technological requirements can be met simultaneously, which are listed below:

The switch should have a small volume. There should be rest opportunities.

As few components as possible are to be used.

The lowest possible tolerance requirements should be placed on the individual parts.

The materials used should be common in the field of electronics and precision engineering.

The production should be reproducible in all its steps.

The switch should contain connecting elements for the production of backs between fixed contacts provided at intervals.

The switch is to the electronic printed conductor plates firmly ^"can be connected, wherein the fixed contacts before ligand bridges between traces should also form in relatively larger intervals.

A certain contact pressure should be able to be exerted via spring elements.

Contact should be as extensive as possible.

Surfaces that are as free from oxidation as possible should be available.

The materials should be corrosion-free. The switch is said to have a self-cleaning effect.

The switch should be wear-resistant, i.e. no metal waste may arise from abrasion and the friction should be as low as possible but sufficient for self-cleaning.

The switch 'should be constructed to be as tolerant as possible to production variations, i.e. the electrical contact surfaces must not be influenced by the tolerances of the mechanical production.

The forces exerted on the actuating element of the switch must be decoupled from the contact elements.

The switch according to the invention fulfills all of these requirements in a surprisingly simple manner. There are also the main advantages:

A slide switch in a rectangular hand-held measuring device is easier to use than a rotary knob, which always requires a second hand to hold the device. The contact elements can be accommodated on the edge of the card in such a way that they do not disturb the rest of the structure of the device, and the switch can also be arranged such that the switch buttons essentially take up the space of the housing wall. This means that the entire interior volume of the housing is hardly affected and is retained for other mechanical installations. In this way, the switching elements shown here make a significant contribution to a universal measuring device concept, which makes it possible to implement a device program in the same housing using largely overriding electronic circuit boards to fulfill a wide variety of measuring and testing and signal processing functions .

Advantageous developments of the invention are characterized in the subclaims or are shown in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. Show it:

FIG. 1 a shows the exemplary embodiment of an electrical device having the switch according to the invention in the assembled state and

Figures lb to d the embodiment of Figure la in an exploded view,

FIG. 2 shows a top view of the device,

Figure 3 is a perspective cross section (B-B) indicated in Figure 2 through the assembled device and

Figure 4 is an enlarged detail view of the switch according to the invention.

The description of the design is carried out with simultaneous reference to the various

Figures that show the components in different view - as an exploded view or assembled - show. The description is given in the order of the subsequent assembly, which - as will be explained in the following - takes place in the inverted position of the device with the keyboard pointing downwards.

In the preferred exemplary embodiment shown, a membrane keyboard 1 is provided which consists of a plurality of insulating and conductor layers, individual areas of the internal matrix-shaped conductor arrangements coming into contact with one another by pressure on the corresponding surface areas and thus forming pushbuttons of a keypad. The membrane keyboard also has labels on the front that indicate functions to be triggered via the respective contact areas of the keypad. On the front panel there are also additional markings 2, which denote functional positions of further switching elements which are attached to the side walls of the housing. The positions of the relevant elements can be read from above through further recesses if these parts have movable display elements in the form of scale pointers or the like. The markings frame a recess for a display. All information to be recorded optically for operation and reading is thus presented on the top of the device - facing the operator. A tab 3 carries all connections for the membrane keyboard in the form of parallel conductor tracks.

In the illustrated embodiment, a front panel 4 carrying the membrane keyboard is made entirely of Shaped from highly transparent plastic and thus comprises the following elements in one piece: a window 14 for viewing the display, another window as a scale window 18 for viewing the movable display elements of the switching elements, and so far a surface 16 for receiving the membrane keyboard 1 In addition to these functions, the main task of the front plate 3 is to close off the housing at the top.

This ensures that elaborate assembly processes and the separate insertion of transparent windows and individual key parts are eliminated - as will be described in detail below. There are also no harmful creepage distances.

The front panel 4 was designed for the advantageous use of adhesive membrane keyboards so that the rectangular display window 14 for the display protrudes from the otherwise flat front panel by a few millimeters and that the remaining area of the plastic part forming the front panel 4 is reduced by one millimeter ¬ is reduced.

The recesses, which are otherwise opaque, are glued into this planar depression, so that only the display window 7 and scales 4, which are located next to this display window, remain transparent. The electrical connection of the keyboard 1 preferably in such a way that to be maintained for the safety of the operator creepage distance TERMS AND CONDITIONS ^'n by a correspondingly formed Contacting the internal circuits of the device can be observed.

There are narrow, rectangular recesses 19 on the two end faces, which can accommodate the rectangular plates 35 and 40 for holding connecting elements 38, 39 and 43.

Furthermore, on the inside of the front panel 4, four holding domes identified by holes 15 are provided for screwing on a display card 30. Furthermore, there is - approximately adjacent to the center of the keyboard - a mounting pin 10 as a centering and receptacle for the individual printed circuit boards 20, 60 and 70 present in the device.

At the four corners of the inside of the front plate, four pins 8, each with an inner bore, are attached, which will later serve to accommodate the screwing of the entire housing. Furthermore, a slot 5 is provided in the front part 4 in the lower part, through which the ribbon cable-shaped contacts 3 of the keyboard 1 can be guided and can be accommodated on the inside via small pins 6, which serve as an assembly aid. The pins 8 have threaded blind bores which contain screw openings which are open towards the inside of the device.

Due to the closed design of the front panel, the

The top of the device is hermetically protected. The front plate 4 forms a self-contained insulating plastic part, with any creepage distances Include the outer edge area and thus there is sufficient contact security according to the relevant regulations, which would not be possible with a design with separate button and window inserts.

The membrane keyboard 1 is glued from the front to the front panel 4 and the ribbon cable 3 is guided through the slot 5 just mentioned such that it points into the interior of the device, so that the front panel 4 with the front side facing down in a simple manner a mounting receptacle formed in this way is inserted. The ribbon cable 3 is inserted into two small receiving pins 6, a zebra rubber 11 being received by two small frame-shaped adjusting elements is connected to an adjacent controller card 20. The slot . In the massive front plate 4 it is arranged so that when the piercing on the adjacent controller card is essentially straight, no areas can be hit which lead to dangerous voltages or currents. The connections leading to contact elements 22 on the printed circuit board 20 are provided with protective resistors R, which form high-ohmic active resistances and ensure that all conductors in the corresponding outer zone of the plate 20 including the foil conductor 3 and the membrane keyboard 1 are protected. The area of high-voltage-resistant resistors R is free of creepage distances and conductor tracks.

The first of the circuit cards carrying the electronic structural elements, here called the controller card, is inserted over a pin 10, screwed onto the two screw pins and fixed by elastic tube pieces 9. On the controller card 20 there are two further zebra rubber arrangements 22 and 23. One is used to hold the membrane keyboard contacts 22, the other 23 is used to make contact with the display card 30, which is fastened by means of two screws 12.

Another middle card 60 is together with switch elements 50, 47, 40, 52, 49, 41, 50, 47, 40, 52, 49, 41, 53 and 54 on the by means of the front panel mounting device 4 in attached such that the creepage distance strips 19 serve on the respective longitudinal edges of the front panel simultaneously as a sliding device for the switch.

At the top is a printed circuit board 70 carrying the microprocessor - likewise placed over the central pin 10 and fastened by means of elastic spacer tubes. The end plates 75 and 80 are inserted and soldered to the plugs.

The actual housing is formed by the lower housing part 85. It is shaped as a plastic part in such a way that, as a counterpart to the front panel 4, it has recesses 89 on the side for receiving the slide switches. There are also cutouts 90 for receiving end plates 75 and 80 and housing screws 86.

The lower housing part 85 is made of an opaque

Made of plastic and contains crevices in the shape of deep on all outer edges

U-shaped grooves 91 or in the form of additional Areas that - embedded in the housing part - are not accessible from the outside.

The four receiving pins 92 for the housing screws 86 are designed in such a way that they in turn enclose the pins 8 of the front plate 4 in a tubular manner in order to give them additional hold when screwing plastic parts.

The contact surfaces for the housing screws 86 are set lower, on the one hand to take account of the safety aspect by means of an additional creepage distance and in addition to be able to press cylindrical cover parts 88 into the hollow cylinders of the screw feed holes, which act as measures against unauthorized opening, guarantee purpose and security.

The housing 85 has on its base plate on the edge of the side surfaces a number of cylindrical pins 93 which are sprayed out with the base. These pins serve to latch the slide switches, which slide along these solid cylinders and thus report the latching effect acoustically and mechanically when the slide switches are actuated.

In an alternative embodiment, these locking elements can also be provided in the front plate 4. In the exemplary embodiment shown here, they were moved into the lower housing part for reasons of the spatial arrangement of the other components. Geometrically opposite the pin 10 of the front plate 4, a plate-shaped receptacle 94 is provided for adjustment purposes.

In more - d.n. A 12-sided lateral catches of the lower housing part 85 can be attached to a stand 95 made of transparent material in different angular positions, so that a favorable viewing angle can be freely selected according to the lighting conditions. The stand 95 can also be used in a position rotated by 180 ° as a cover for the keyboard and protects against undesired operating errors. Feet 96 protect the stand from scratching. A rating plate 97 is embedded in the stand and is visible in the cover position.

The switch assembly can be seen in the partial representations _y according to FIG. 3 and the exploded representation according to FIG. 1c. It represents an essential construction element of the electronic device described above. The special way in which the slide switch interacts with the housing gives rise to the advantages of the switch concept according to the invention, in particular with a device design of the type described above. The housing division and circuit board design are the same in substantial interaction with the construction of the switch, it being apparent that several of the switching slides shown, which are rigidly connected, can also act simultaneously on different circuit boards from the edge, so that they are used in a wide variety can. In the "hand-held" type of device described here, there are particular difficulties in the construction. The chosen constructive solution takes into account a large number of constructive difficulties in the smallest of spaces, whereby the measures found support each other in an astonishing way.

On the basis of the consideration that printed circuit boards today represent the essential connecting element for electronic components, the contact surfaces 62 were brought directly onto the circuit board 60 in a geometrically favorable form. A concept known per se was modified here in such a way that on the long sides 69 of the cards, on the one hand on the top and on the other on the opposite underside, arranged as contact surfaces such that a spring 53 bent in the direction of the card edges in each case the can connect opposite contact surfaces on the top with corresponding counter-contact surfaces on the underside.

Since the omega-shaped spring (contact element) 53 is bent by itself by being pushed onto the edge of the card 69 - after initial "beaking" by a correspondingly divergent design of the ends pointing towards the board - it produces Restoring force the necessary contact pressure. The spring 53, which is made of a guiding spring material and is omega-shaped, can thus connect the corresponding contact surfaces 62 on the upper side to those on the underside of the card in a particular position. The individual contact surfaces 62 on the upper and lower side of the card 60 are connected in an electrically conductive manner to the other circuit parts in such a way that they achieve the required connection configurations in each case with a translational movement of the contact spring 53 in the direction of the card longitudinal edge 69.

Several such springs 53 in a switch bracket (switch slide) 50, 52 are accommodated at predetermined intervals so that, when guided in parallel, they connect the contact elements 62 on the top and bottom sides in the same constellation, so that the switch connects several contact elements 62 simultaneously opening or closing during its movement and can thus perform complex switching functions.

A number of cuboidal cavities (for example 51) are provided in the switch brackets 50, 52, 50, 52, into which contact springs 53 can be inserted. These cavities are designed in such a way that the individual spring 53 has a sufficient mechanical degree of freedom in the direction of movement perpendicular to the card 60, so that dimensional tolerances which relate to the position of the cards 60 themselves and that of the moved switch bracket 50 have no influence on the contact security, i.e. can take on the position of the contact springs 53. In this way it is ensured that the position of the springs 53 is determined exclusively by the geometry of the card 60 and not by the position of the switch bracket 50.

The switch bracket 50 is shaped such that when the switch bracket is pushed in the direction of the longitudinal edge 69 the card 60, the springs 53 are taken so as to achieve the other switching positions in parallel.

In practice, therefore, the switch bracket 50 can be moved a few millimeters perpendicular to the card 60 without the contact springs 53 mounted in it lifting off from the contact surfaces 62. The side edges of the springs can be guided step by step through the contact bracket with the least amount of friction, to which in particular burr-free cut surfaces on the side edges of the springs and highly polished side surfaces of the switch bracket made of an insulating plastic contribute.

In the present version, this switch bracket is equipped with an additional metal molding, e.g. surrounded a punched part 47, which serves for shielding in the present application.

If the switch bracket 50 and the shield part 47 placed over it are inserted into the switch button 40 with a screw 54 and then tightened with the self-tapping screw 54, then the switch button 40 forms together with the shield part 47, the switch bracket 50 and the one installed in the switch bracket Switch springs 53 the actual switch element.

If the shielding of the switch contact springs 53 can be dispensed with, the switch buttons and the switch brackets can also be made from a single, interrelated plastic part. The switch button 40, 41 fulfills several functions at the same time. On the one hand, it is designed in such a way that its switch button - corresponding to the function of a slide switch - simultaneously represents the slide path slot 89 to be provided as a screen for the Deim slide switch due to the large-area design.

Since the switch button must be accessible from the outer side of the device, in the present preferred embodiment the fulfillment of the creepage distance conditions was linked to the visual glare effect.

On the outer side of the switch button there is - a usual corrugation in order to create the necessary force connection with the palms of the hands or fingers.

The mechanical inner parts of the switch button consisting of a plastic piece are designed so that they can be guided in the form of rails in the slots in the housing.

On the underside of the switch button - pointing into the interior of the device - two elements 43 which can be described by spring arms and which act as detent spring elements 44 can be seen. The ends of the leaf spring-shaped detent 43 are cylindrical 44 so that they form a detent with the cylinder pins 93, which are located in the housing 85.

Furthermore, on the upper side - also pointing into the interior of the housing - there is a web 42 on the button that serves to hold position indicator elements 45 and 46 inside the device. These position display elements later serve together with the transparent front part 4 for display within the device scale.

In the application case described here for the switch according to the invention, four complex switch assemblies are provided, which nevertheless take up little space overall. These are the two operating mode switches with the switch buttons 41 and the two measuring range switches with the switch button 40.

It was also possible to ensure that the actual contact springs 53 - regardless of any tolerances in their position - are determined exclusively by the position of the card 60 on which the contact surfaces 62 are located.

The slide switch and the contact springs 53 moved with it ensure a certain self-cleaning of the contact elements 62. Their contact pressure can be determined by the design of the spring. The abrasion on the contact surfaces is thus to be kept within limits.

Since the contact button simultaneously represents the functions of aperture, sliding guide, detent, connecting element to the switch and support element for the position indicators 45 and 46 and forms the detent with the plastic housing 85, relatively complex functions can be performed with little design effort . The slide switch of the exemplary embodiment described here initially has an additional special design feature. A linearly movable switching element can generally only be shielded with a certain additional outlay. Since the switching movement of a rotary switch is carried out exclusively via an axis and this can be easily passed through a hole provided in a shield housing, a rotary switch is normally used for a measuring device - especially if this is the case in the present case is intended for a very broadband application - superior in terms of shielding effort and shielding safety. By inserting a shield plate 47, each provided with additional sliding contacts 48, over the switching bracket 50, this difficulty could be countered in a surprisingly simple manner.

4 shows the principle of erfindungsgeiuäßen switch is shown separately ergrößert ^'again.

Separate contact surfaces 402 and 403, which are formed by gold-plated conductor tracks, are attached to an upper and lower side on an insulating material carrier 401. Recesses 404 are provided between the contact areas, which ensure that abrasion does not settle between the contact surfaces and can therefore form bridges.

The omega-shaped contact element 405 clasps the edge of the printed circuit board 401 and connects the contact areas lying opposite one another. The contact element is passed through the circuit board and exerts on both contact surfaces equally large forces. The contact element has the simplest design, corresponding to its purpose. Due to the play in a direction parallel to the pressing forces within the recess 410, the contact spring "rides" on the edge of the printed circuit board 401 and its spatial position is largely determined by it. The bearing within the recess 410 (chamber) is floating. The pressure surfaces 406 and 407, which contact the contact areas, have an all-round convexity with "belly" in the direction of the printed circuit boards, which has two reasons:

On the one hand, when changing from one contact area to the next, the areas 406 and 407 should not "get caught" on the edges of the slots present between the contact areas, but rather glide smoothly over them.

On the other hand, due to the curvature of its pressure surfaces in the direction of the circuit board, the contact element 405 has the property that it can be easily pushed onto the circuit board as a result of the beak-shaped configuration which widens towards the end. If the height tolerances of the bearing within the chamber of the slide switch are not sufficient to accommodate the spatial path differences between the printed circuit board 401 and the holder 408, the rear part of the omega inside the chamber can additionally rotate slightly without the pressure conditions changing significantly . The directions of possible height deviations are symbolized in FIG. 4 by a double arrow 400. Does the circuit board move up or in these arrow directions below, the contact element initially yields within the scope of the existing play and then rolls on its back surface 409, the areas 406 and 407 likewise being able to "roll" slightly on the contact surfaces 402 and 403, but without the contact pressure conditions change significantly with regard to the electrical contact effect. The compensating movement in the direction of arrows 409 makes it unnecessary to adjust the contacts of this switch.

The contact elements are embedded in corresponding recesses 410 of the essentially omega-shaped carrier element 408 made of plastic, the carrier element being surrounded on the one hand by a metal shield 411 which is U-shaped in section. The recess 410 limits the movements of the contact element without substantial play in the direction of the relative movements occurring when the contact connections are switched over. The lower height of the passage area towards the board compared to the height of the recess in the interior secures the contact element from falling out when the slide switch has not yet been installed. The height difference between the chamber and the passage is dimensioned such that the omega-shaped element can easily be snapped into this recess during assembly due to its elasticity.

The embodiment of the invention is not limited to the preferred embodiment described above. Rather, a number of variants are conceivable which make use of the solution shown, even in the case of fundamentally different types.

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Claims

Expectations

1. Multi-pole slide switch for a signal-processing electrical device, which has:

fixed contact areas, which are provided on both sides of an insulating carrier layer designed as a printed circuit, and

a slide switch with resiliently engaging and essentially omega-shaped contact elements encompassing the edge of the carrier layer for alternately connecting mutually opposite contact areas,

characterized ,

that the slide switch has chamber-like recesses into which the contact elements are loosely inserted, the individual contact elements being displaceable by a length in a direction parallel to the direction of the contact pressure and / or being rotatably mounted within the recess about an axis pointing in the switching direction.

2. Slide switch according to claim 1, characterized in that the chambers are essentially cuboid, wherein they have a height in the direction parallel to the contact pressure direction which is greater than the corresponding dimension of the Spring element and a rectangular recess as a passage in the direction of the contact areas, with a height which is greater than the never corresponding dimension of the spring elements in this area but smaller than the maximum dimensions of the spring elements in the direction parallel to the direct pressure direction.

3. Slide switch according to a preceding claim, that the widening beak-shaped ends in the opening area have a distance which is greater than the thickness of the carrier layer with the contact areas.

4. Slide switch according to one of the preceding claims, characterized in that the edge carrying the contact areas extends along the outer wall of the outer housing of the electrical device, and in that the guide for an outer actuating element for the slide switch is provided by a housing provided in Forming direction extending slot ge is formed.

5. Slide switch according to claim 4, characterized in that adjacent to the slot extending in the sliding direction guide surfaces which limit the sliding element adjacent to the guide surfaces in its movement in the spatial directions transverse to the sliding direction.

6. Slide switch according to claim 5, d a d u r c h g e k e n n z e i c h n e t that the slot in each

Position of the slide switch is covered by an aperture.

7. Slide switch according to one of the preceding claims, d a d u r c h g e k e n e z e i c h n e t that the _ adjacent to the slot form meandering creepage distances.

8. Slide switch according to one of the preceding claims, d a d u r c h g e k e n e z e i c h n e t that the circuit board on which the slide switch is placed laterally carries electrical components which are connected to the contact elements.

9. Slide switch according to claim 8, d a d u r c h g e k e n n z e i c h n e t that several slide switches, which are placed on adjacent circuit boards, connected by a sliding element and guided together.

10. Slide switch according to one of the preceding claims, characterized in that the gold-plated contact area bearing edge has incision-like interruptions between the contact areas.

11. Slide switch according to claim 10, so that cut-like interruptions between the contact areas in the actuating direction of the switch have smaller dimensions than the contact elements, the contact elements with respect to their contact surface also being convexly rounded in the sliding direction.

12.. Slide switch according to one of the preceding claims, ie that the contact areas and / or contact elements are surrounded by shielding plates which extend in the sliding direction and are insulated from the contact elements.

13. Slide switch according to claim 12, so that a shielding plate is provided with the bottom and the top in the area of the edge guiding the sliding element and having the contact areas.

14. Slide switch according to one of claims 12 or 13, that a further shielding plate is connected to the sliding element carrying the contact elements and also surrounds the contact elements in a U-shape.

15. Slide switch according to claim 14, characterized in that with the sliding element-connected shielding plate has resilient wipers which contact at least one of the other shielding plates in a resilient manner.

16. Slide switch according to one of the preceding claims, d a d u r c h g e k e n e z e i c h n e t that the elastic elements connected to the sliding element in the individual switching positions engage in locking elements connected to the housing and form overcome obstacles.

17. Slide switch according to one of the preceding claims, that the sliding element is made of an insulating material and has a surface design for producing the necessary adhesion with the hand of the operator to the outer surface of the housing.

18. Slide switch according to claim 17, so that the surface design is formed by grooves which run transversely to the sliding direction and point outwards.

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