EP1355332A2 - Electric contact device and corresponding keyboard - Google Patents

Abstract

The device has electrical contact points (11) on a movable, essentially plate-shaped bearer (10) and opposing fixed contacts that contact the contact points after a switching movement of the bearer. The contact points are mutually insulated so that they can have different potentials relative to each other and/or relative to the bearer. The bearer has conducting tracks in addition to the bearer. AN Independent claim is also included for the following: a keyboard with an inventive device.

Description

The invention relates to an electrical contacting device with electrical contact points on one movable, essentially plate-shaped carrier and with these opposite fixed contacts, which after a Switching movement of the carrier contact the contact points. The invention further relates to a keyboard such a contacting device.

Such a contacting device is usually used for electronic devices, for switching devices and in particular Command devices used. For operating electronic Devices such as programmable logic controllers in the Automation industry are next to well-known voluminous mechanical control devices with large actuation paths Variety of compact flat short-stroke keys and keypads has been developed. The latter belong to the family of Short-stroke keys and membrane keyboards are very compact.

The known contacting devices usually have a jump switching behavior and electronic contact. The jump switching behavior is often determined by a e.g. Metallic, snap element realized that under pressure abruptly changes its shape, and thereby the switch contact closes. When the pressure drops, it jumps Snap element back to its rest position, causing the switch contact is opened again. This mechanical effect is known from a "crack frog". The strict requirements for safe operation in harsh industrial applications cannot fulfill these keys. Such may safe switches do not wear out during operation fail, or a failure must by the secure electronic Control can be recognized. Also the electrical path be sure to control. Depending on the security category this can be achieved through sufficient wear and failure-free Push button in connection with at least two-pole simultaneous galvanically isolated switching. A push button with high The US patent offers robustness and freedom from wear 5,990,772 described contact element. The published here 1 includes a substrate 2 with a Pair of spaced fixed switch contacts 3, the can be bridged by an electrically conductive armature 4 should. The armature 4 has a central axis with the first and second raised contact areas on both sides the axis. The anchor 4 is in the non-actuated state held by the attraction of a magnetic layer 5 and spaced from the switching contacts 3. Between the magnetic layer 5 and the substrate 2 is an insulating spacer layer 6 with an opening 7, in the area of which the armature 4 is included. The one as an electrically conductive metal disc trained armature 4 is by an actuating force for contacting movable with the switch contacts 3. As a result of Actuation of the armature 4 first breaks its one side away from the magnetic layer 5 and contacts one of the two Switch contacts 3. The armature 4 then rotates around the the side that is still connected to the magnetic layer 5 stands, opposite side until this side by the actuating force also breaks away from the magnetic layer 5, to contact the second switching contact 3. To this The two switch contacts 3 become electrically conductive bridged. The anchor 4 described here as a contact element as well as all other elements known so far not suitable, multiple galvanically isolated circuits cannot be manipulated to operate simultaneously.

Furthermore, electronic devices are becoming more and more common electronic preprocessing of the signals expected. For this are preferably corresponding components in or on the command device including their electrical wiring required. The short-stroke keys have so far been inside only limited possibilities for this, e.g. the integration a light emitting diode. Also for suitable lighting the actuating surface of the switching element electronic Components preferably needed inside the element.

In order to create several galvanically isolated contacts, Previously, large mechanical command devices were used or press several separate short-stroke keys in parallel. The simultaneous switching required for the safety functions within a very short time window can only with great additional effort with a simultaneous jump switching function achieved according to the technical concept of EMERGENCY STOP buttons become. However, this solution contradicts the required Robustness and reliability and is very voluminous. For setup operation, e.g. also combinations so-called release buttons with one or more others Commanders for setting up machines.

The positioning of the necessary electronic components usually takes place in addition to the short-stroke key on the existing one PCB, but this takes up extra space and in the case of Internal lighting of such an element awkward Light guides required. Here is the illumination can only be reached selectively or very unevenly.

A membrane keyboard is known from DE 100 40 151 C1, at the frequently used button in a "click frog technology" are executed, i.e. a mediated by a snap element Show snap switching behavior. In contrast, are less common used buttons in an inexpensive "switching bubble technology" executed. For the latter, the front film is the Keyboard in the area of the keypad to form a "Switching bubble" bulged outwards. The inner surface of the Front foil is in the area of the switching bladder, mostly printed, provided contact surface, which in the rest position with Distance faces one or more fixed contacts. to The front film is actuated in the area of the switching bladder pressed. The switching bubble is "dented", so to speak, the contact surface against the one or more fixed contacts pressed, and the switch contact is thus closed. When the actuation pressure is reduced, the front film returns their bubble-like starting position back, the switch contact is opened again. The well-known keyboard is through the use of the simple but wear-resistant manufacture bubble-like buttons inexpensively, wherein premature wear of the frequently used buttons the use there of the more complex but more durable Snap element button is avoided. For safety-related Switching is not the known keyboard suitable.

Therefore, the invention has for its object an electrical Contacting device of the type mentioned above create that with simple structure and cost-effective execution avoids the disadvantages mentioned above. Furthermore should a particularly suitable keyboard with such a contacting device can be specified.

With regard to the contacting device, the object is achieved according to the invention solved by the features of claim 1. Thereafter the contact points are so isolated from each other are different from each other and / or from the wearer Enable potential. Regarding the keyboard, the Object achieved by the features of the claim 12. After that there is at least within a keyboard a first keypad an inventive contacting device assigned. Furthermore, at least one second keypad a button in the form of a short-stroke switching element assigned, which is designed like a switching bubble or a snap switching behavior mediated by a snap element having. Here are the first keypad or the first keypads for safety-related Switching operations provided while the second keypad or the second keypad for non-safety-related ones Switching operations are determined.

The term keypad is a on the user interface understood the tactile area marked on the keyboard, each of which has an underlying button or a contacting device assigned. A pressurization the user interface in the area of a keypad to actuate the corresponding button or corresponding contacting device.

FIG 2,3,4

mehrere.Ansichten eines Trägers mit Öffnerkontakten einer erfindungsgemäßen elektrischen Kontaktierungseinrichtung,

FIG 5,6,7

die Schaltpositionen des Trägers gemäß FIG 2, 3, 4,

FIG 8,9,10

mehrere Ansichten eines Trägers mit Schließerkontakten einer erfindungsgemäßen elektrischen Kontaktierungseinrichtung,

FIG 11,12,13

die Schaltpositionen des Trägers gemäß FIG 8, 9, 10,

FIG 14,15

mehrere Ansichten eines Trägers mit einem Öffner- und einem Schließerkontakt einer erfindungsgemäßen elektrischen Kontaktierungseinrichtung,

FIG 16,17,18

die Schaltpositionen des Trägers gemäß FIG 14, 15,

FIG 19,20,21,22

mehrere Ansichten eines Trägers mit einer Schaltung einer erfindungsgemäßen elektrischen Kontaktierungseinrichtung,

FIG 23

in Draufsicht eine Kontaktierungseinrichtung gemäß FIG 5 umfassende Folientastatur und

FIG 24

in einem schematischen Querschnitt XXIV-XXIV die Tastatur gemäß FIG 23.

Advantageous developments of the invention can be found in the subclaims. Further embodiments of the invention are explained in more detail below with reference to the following drawings. Show it:

FIG 2,3,4

several views of a carrier with break contacts of an electrical contact device according to the invention,

5,6,7

the switching positions of the carrier according to FIG 2, 3, 4,

FIG 8,9,10

several views of a carrier with make contacts of an electrical contacting device according to the invention,

FIG 11, 12, 13

the switching positions of the carrier according to FIG 8, 9, 10,

FIG 14.15

several views of a carrier with a break contact and a make contact of an electrical contacting device according to the invention,

FIG 16, 17, 18

the switching positions of the carrier according to FIG 14, 15,

FIG 19, 20, 21, 22

several views of a carrier with a circuit of an electrical contacting device according to the invention,

FIG 23

in plan view a contacting device according to FIG 5 comprehensive membrane keyboard and

FIG 24

in a schematic cross section XXIV-XXIV the keyboard according to FIG. 23.

The present electrical contacting device according to the invention e.g. from a basic structure, as in 1 is shown. This basic structure is extremely compact and guarantees a high level of wear and reliability. For the movable plate-shaped designated as an anchor in FIG According to the invention, there are carriers according to FIGS 22 very different configurations. The carrier 10 is provided with mutually insulated contact points 11, 21, that these differ from one another and / or from the carrier 10 Enable potential.

The carrier 10 is e.g. as soft magnetic and electrical conductive metal plate on which a partial or full-surface electrical insulation layer 12 applied is. The insulating layer 12 can be applied by varnish, Foil application, insulating surface treatment or The corresponding can be realized. The insulating layer 12 is as required on the top, bottom or both sides applied. The conductive layers are on this insulating layer 12 Contact points 11, 21 and / or conductor tracks 20 applied, the different from each other and / or to the carrier 10 enable electrical potential.

The carrier 10 shown in Figures 2, 3, 4 has soft magnetic Properties, is electrically conductive and on its top with two contact points 11 executed serve as contact bridges for break contacts. The two contact points 11 are shown in FIG 2 by an intermediate Decoupling slot 13 for tolerance compensation against each other mechanically decoupled so that despite inevitable Manufacturing tolerances when operating a good contact pad is guaranteed on the opposite fixed contacts. The one contact point 11 on one side of the Decoupling slot 13 is through the electrically conductive Carrier 10 itself formed. The contact point 11 on the other side of the decoupling slot 13 is on the Insulating layer 12 applied to the carrier 10. this will by the corresponding sectional diagrams in FIGS. 3 and 4 clarified.

For actuation, the carrier 10 has a raised pressure area 14 on. In addition, the carrier 10 is on its one Magnetic layer 16 (see FIG. 5) is the first area to break away provided with a counter bearing 15 around which the carrier 10 is pivoted on further actuation. For an even Distribution of the contact forces will be the two contact points 11 placed so that it with the counter bearing 15 form an equilateral triangle. The print area 14 for mechanical actuation is in the vicinity of the counter bearing 15 inside the triangle. By arranging the two contact points 11 at the outer end of the carrier 10 and thereby, that all four contact points of the contact points 11 in one Lying in flight is almost simultaneous jumping behavior the contact points 11 realized. Preferably the two are Contact points of each contact point 11 as close together as possible.

5, 6, 7 show the different switching phases of the Carrier 10 with the contact points designed as break contacts 11 in the basic structure of the invention described above electrical contacting device with a magnetic layer 16, a base support 17 and an intermediate one Spacer layer 18. In FIG. 5, the carrier 10 shown in its rest position, in which it is through the magnetic layer 16 is attracted and its contact points 11 here Contact fixed contacts, not shown. In the first Phase of the switching process is the side of the carrier 10 with the counter bearing 15 pressed onto a floor support 17. In the subsequent second phase, the contact points 11 on the other side lifted off the fixed contacts and jump towards the opposite floor support 17.

8, 9, 10, an embodiment of the carrier 10 is with two contact points designed as make contacts 11 shown, which in contrast to the embodiment according to FIG 2, 3, 4 arranged on the same side as the counter bearing are. Otherwise, the structure corresponds in detail to that of the previous one described carrier 10 with the opener contacts 11th 2, 3, 4. The switching phases in one with the carrier 10 with normally open contacts 11 switches are in the FIG 11, 12, 13 shown. The carrier is at rest here 10 held on a magnetic layer 16 via its upper side. This is spaced apart by the spacer layer 18 opposite the floor support 17, which with a substrate Fixed contacts is provided. After the carrier 10 after actuation on the side of the counter bearing 15 in the first switching phase 12 has broken away from the magnetic layer 16, pivots the carrier 10 in the second switching phase according to FIG 13 abruptly around the counter bearing 15 until the contact points 11 contact the fixed contacts on the underside of the carrier 10. The arrangement of the contact points 11 is fundamental here as with the normally closed contacts. However, the normally open contact points 11 preferably not at the extreme end of the Carrier 10, but arranged a little further inside. this causes cheaper contact forces and better contact opening behavior.

14, 15 show an embodiment of the carrier 10 with a Normally closed contact on the top and one normally open contact 11 on the underside, here again the break contact 11 by an insulation layer 12 relative to the carrier 10 and isolates the make contact 11 formed by this is. Basically, this function can also be reversed Can be achieved in this way, i.e. by opening contact 11 the carrier 10 itself is realized and the normally open contact 11 is applied to the insulating layer 12. Will only be one NC contact 11 plus a NO contact 11 implemented, the two contact points of the opener form the top described triangle, as well as the contact points of the Closer with the counter bearing 15 a slightly smaller isosceles Form a triangle. In this case they are the key points of a contact of the isosceles triangle described above.

With two NO contacts or two NC contacts, a height tolerance compensation is required the closely adjacent contact points each Contact point of the contact bridge carrier by suitable Slitting divided into independently resilient elements.

16, 17, 18 are the switching phases for a switch shown with such a carrier 10, the principle correspond to those of the previously described embodiments and therefore need no further explanation at this point.

With the processing of the support 10 described above in addition to the contact functions, a circuit carrier, of the electronic components in SMD design, chip design or Can hold a keystroke. The power supply or electrical coupling of the electronic circuit is over raised contact points realized. A sensible expression such a circuit is shown in FIG 19, 20, where the operating surface of the contact module with a light-emitting diode circuit is illuminated. Integration can also make sense of an electronic touch sensor, which the Touching the button regardless of the electrical contacts detected.

19, 20 show an embodiment of a carrier 10, which is a circuit, e.g. in multi-layer design (multi-layer technology) wearing. The carrier 10 has on its top and Underside of an insulating layer 12. On the top 19 is an electrical circuit applied. In the present example, this comprises a as Contact bridge 11 made contact point, electrical components 19, e.g. a bonded chip and resistance pressure, Contact points 21 for the electrical supply of the components 19 and interconnects 20 connecting them.

There are also contact points on the underside insulating layer 12 21 applied to the electrical supply with the corresponding top contact points 21 a via as shown in FIG 22 electrically connected are. The electrical connection line to Vias on an insulating layer in the opening 22 applied.

21 shows a cross-sectional illustration of the carrier 10 according to FIG 19, 20 with its top and bottom insulation layers and components 19 and / or applied thereon Contact points 11, 21.

The button described in connection with FIGS 2 to 22 is alternatively as a single commander or as part of an in 23 uses a membrane keyboard 30 shown in plan view. The membrane keyboard 30 comprises several key fields 31, provided for non-safety-related switching processes are. These keypads 31 are, for example around number or letter keypads 31a and an associated confirmation keypad 31b. Also includes the membrane keyboard 30 two for safety-related Switching processes provided keypads 32. These keypads 32 are used, for example, to control an electronic one Equipment, e.g. as a start or stop button.

The one shown in FIG. 24 in a diagram, and in particular membrane keyboard not shown to scale 30 is common to all key fields 31, 32 Floor support 17 built. To the assembled state the outside visible to a user Membrane keyboard 30 from a user interface Front film 33 covered. The shelf support 17 and the Front foil 33 are essentially flat and to one another arranged approximately in parallel. The with openings 7 in the area of the keypads 31, 32 provided spacer layer 18 fills in the area of the keypads 31 between the floor support 17 and the front film 33 distance formed completely out. In the area of the keypads 32 is the spacer layer 18 and the front film 33, the magnetic layer 16 temporarily stored. The floor support 17 is preferably by a conventional one PCB realizes and carries in the area of the keypads 31 arranged fixed contacts 34. No further details Fixed contacts shown are in the area of the keypads 32 provided on the shelf support 17.

To implement the safety-related assigned to the keypads 32 Switching processes is related with the electrical contacting device described in detail in FIGS. 2 to 22 used. One carrier is 10 each for this purpose arranged in the respective in the area of each keypad 32 Opening 7 of the spacer layer 18 in the previously described Wisely placed and lying with its print area 14 against the inner surface 35 of the front film 33. The front film 33 is convexly curved in the area of the keypad 32. By pressing the flexible front film 33 in the area of the keypad 32, the carrier 10 in the manner described and Moved to actuate the contact device.

For the switching processes to be triggered with the keypads 31 are not intended to be any special safety precautions required. The associated buttons 36 are therefore preferred in a simple and therefore inexpensive technology designed. The button assigned to the keypad 31a 36a is designed as a switching bubble. This is the front film 33 in the area of the keypad 31a with an embossed with respect to the base support 17 convexly domed and carries on its inner surface 35 the corresponding one Fixed contacts 34 at a distance from each other electrically conductive contact surface 37. By pressure on the front film 33 in the area of the keypad 31a it becomes convex Rest position in a plane or in relation to the floor support 17 Concave actuation position deformed. This will make the Contact surface 37 pressed against the fixed contacts 34, and releases by bridging the switching process. When canceled the actuation pressure, the front film 33 goes into its convex Rest position, whereby the switch contact opens again becomes.

For frequently used keypads without security-relevant Function, e.g. confirmation keypad 31b is preferred one provided with a disc-like snap element 38 Push button 36b used. The snap element 38 is there at a distance from the base support 17 approximately parallel to this arranged and preferably lies directly on the inner surface 35 the front film 33. The snap element 38 is in its Rest position with respect to the floor support 17 convex, see above that the keypad 31b is raised similarly to the keypad 31a is arched out of the level of the user interface. The Snap element 38 carries one of the floor supports 17 and thus the corresponding fixed contacts 34 facing contact surface 37. Pressing the button surface 31b changes the snap element 38 leaps its shape from the convex rest position in a plane or concave actuation position with respect to the base support 17. The contact surface 37 is again against the Fixed contacts 34 pressed and the associated with the keypad 31b Switch contact closed. With decreasing actuation pressure the snap element 38 jumps to the starting position back, whereupon the electrical contact is interrupted.

The with the membrane keyboard described in Figures 23 and 24 30 linked advantages are in particular that the Membrane keyboard 30 by using the comparatively simple built buttons 36 is inexpensive to manufacture. There for all safety-relevant switching processes which are shown in FIG 2 to 22 described contacting device used is used, the membrane keyboard 30 can also be used for such purposes for which the use of conventional membrane keyboards due to high security requirements so far was not possible or only possible to a limited extent. This is particularly from Advantage because the membrane keyboard 30 compared to conventional safety-related commanders extremely flat and is compact. There is also a big advantage in that all keypads 31, 32 over the as a circuit board executed floor support 17 are contacted and thus wiring of the buttons, which is difficult to automate, is eliminated. It is also a great advantage that all keypads 31, 32 from a common, essentially flat front film 33 are covered. In addition to being easy to assemble and the possibility of a uniform design a high dirt resistance of the membrane keyboard 30 reached, which in turn has a positive impact on their operational safety effect.

Claims (14)

Electrical contacting device with electrical contact points (11, 21) on a movable, essentially plate-shaped carrier (10) and with fixed contacts opposite these, which contact the contact points (11) after a switching movement of the carrier (10), characterized in that the contact points (11, 21) are mutually insulated in such a way that they enable different potentials to one another and / or to the carrier (10). Electrical contacting device according to claim 1, characterized in that the carrier (10) in addition to contact points (11, 21) also has conductor tracks (20). Electrical contacting device according to claim 1 or 2, characterized in that at least one of the contact points (11) is designed as a contact bridge. Electrical contacting device according to one of the preceding claims, characterized in that the carrier (10) is designed with at least one partial insulating layer (12). Electrical contacting device according to one of the preceding claims, characterized in that the carrier is designed as an integrated circuit (10). Electrical contacting device according to one of the preceding claims, characterized in that the carrier (10) has soft magnetic properties and is held in the idle state by a magnetic force. Electrical contacting device according to one of the preceding claims, characterized in that the contact points (11, 21) and / or conductor tracks (20) which are insulated from one another by at least one of the insulating layers (12) are selectively electrically connected to one another. Electrical contacting device according to one of the preceding claims, characterized in that the carrier (10) has at least one opening (21) which is used for through-contacting between contact points (11, 21) and / or conductor tracks (20) in different planes. Electrical contacting device according to one of the preceding claims, characterized in that the carrier (10) is electrically conductive and takes over the function of a contact bridge. Electrical contacting device according to one of the preceding claims, characterized in that the carrier (10) has at least two mutually insulated contact bridges (11). Electrical contacting device according to one of the preceding claims, characterized in that a decoupling slot (13) is provided between the contact points (11). Keyboard (30) with at least a first keypad (32), which is followed by an electrical contacting device is assigned to one of the preceding claims, and at least a second keypad (31), the associated Button (36) is designed as a switching bubble or a through a snap element (38) conveys jump switching behavior having. Keyboard (30) according to claim 12, characterized by an essentially flat front film (33) covering all key fields (31, 32) together. Keyboard according to one of Claims 12 or 13, characterized by a common printed circuit board (17) on which both the electrical contacting device assigned to the or each first keypad (32) and the push button (36) assigned to the or each second keypad (31) are contacted.

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