Electrical switching element

Abstract

An electrical switching element comprising a carrier (6) having a first and a second side (7, 7'), a fixed contact (8, 8') located on the carrier (6), and a switching contact arranged on the carrier (6) for switching interaction with the fixed contact (8, 8'), wherein the switching contact is designed as a snap element (9, 9') with an approximately dome-shaped curved area (10), and wherein the curved area (10) folds inwards by the action of an actuating force to electrically contact the fixed contact (8, 8'), characterized in that two snap elements (9, 9') are arranged on the carrier (6), and that one snap element (9) is arranged on the first side (7) of the carrier (6) and the other snap element (9') is arranged on the second side (7') of the carrier (6).

Description

[0001] The invention is based on an electrical switching element according to the preamble of claim 1.

[0002] These electrical switching elements are used as contact elements for electrical switches. In particular, they can be used in control units or control panels in motor vehicles, such as those located on the steering wheel, dashboard, center console, door area, or similar locations. Furthermore, these switching elements can also be used as window switches, steering wheel switches, start-stop switches, cruise control switches, interior lighting switches, or similar functions in motor vehicles, as well as garage door openers.

[0003] Such an electrical switching element comprises a carrier having a first and a second side, with a fixed contact located on the carrier. A switching contact is arranged on the carrier for switching interaction with the fixed contact. The switching contact is designed as a snap-action element with an approximately dome-shaped curved area, wherein the curved area folds or snaps shut to electrically contact the fixed contact upon application of an actuating force. A disadvantage of the known switching element is that it can only trigger a single switching operation.

[0004] The invention is based on the objective of further developing the switching element in such a way that it is suitable for triggering at least two switching operations.

[0005] This problem is solved in a switching element of the generic type by the characterizing features of claim 1.

[0006] In the switching element according to the invention, two snap elements are arranged on the carrier, one snap element being located on the first side of the carrier and the other snap element on the second side of the carrier. Advantageously, this arrangement provides a switching element with a double switching point. Thus, the switching element is designed to trigger two independent switching operations. Further embodiments of the invention are the subject of the dependent claims.

[0007] In a further, space-saving embodiment, the two snap elements can be arranged opposite each other on both sides of the carrier. If required, the two snap elements can also be offset from each other on the carrier. Furthermore, the actuation force at which the snap element buckles or snaps shut can be different for the two snap elements. This provides the switching element with two successive switching points, the distance between which is advantageously adjustable. Likewise, for easy adjustment of the actuation force, several snap elements can be arranged one above the other on at least one side of the carrier.

[0008] In a simple and cost-effective further development, the carrier can be a printed circuit board (PCB). The fixed contact can consist of an electrically conductive, and in particular a metallized, area in the form of a conductor track on the PCB, making it producible using a standard PCB manufacturing process. Conductive tracks on the PCB can be provided for applying electrical voltage to the fixed contact and / or the snap-action element. Furthermore, the snap-action element can be designed as a snap disc, similar to a "click switch," made of electrically conductive metal. Alternatively, the snap-action element can be designed as a snap disc, similar to a "switch cap," made of plastic. In this case, an electrically conductive layer, particularly carbon, can be present on the side of the snap disc facing the fixed contact.Advantageously, the electrically conductive layer can be designed to bridge two adjacent electrically conductive areas on the circuit board when the snap disc is bent.

[0009] A housing can be provided for the switching element, thus forming an electrical switch in the form of a component. A movable actuating element for switching the switch can be arranged on the housing. For example, a lever pivotably mounted on the housing can serve as the actuating element for the user. To trigger the switching operation of the switching element, the actuating element can be designed to act on at least one snap-action element and / or on the support.

[0010] In a simple and compact design, the carrier can be movably mounted, and in particular floatingly, within the housing. A retainer can be provided in the housing to facilitate this floating mounting of the carrier. Actuation by the actuator then causes one snap element and subsequently the other to fold or snap into place, thus providing a kind of "double stroke" for the switching element. In a further embodiment of the mounting for the printed circuit board, one of the snap elements can rest against a projection in the housing.

[0011] In a functionally reliable design, a plunger can be arranged on the actuating element. Furthermore, an opening with an elastic sealing element can be located in the housing, thus protecting the interior of the housing against the ingress of contaminants from the outside. The plunger can act on the snap element and / or on the carrier via the sealing element at the opening. Thus, while the plunger on the actuating element acts on one snap element to switch the switch, the projection on the housing acts on the other snap element in the manner of an actuating dome.

[0012] The following can be stated regarding a particularly preferred embodiment of the invention.

[0013] An electrical switching system with the following requirements has been created: - Strong actuating force, - Double switching point, - Pronounced haptic feedback, - Compact installation space, - Few individual parts and - The actuation force of both switching points is adjustable, both absolutely and / or relative to each other.

[0014] Based on the concept of using snap discs as electromechanical switching elements on printed circuit boards, the switching system according to the invention includes a special arrangement of these snap discs so that the aforementioned requirements can be met. For this purpose, the snap discs are arranged on both sides of the printed circuit board, specifically on the top and bottom surfaces. The printed circuit board is thus able to detect actuation of both the top and bottom surfaces of the snap discs and to transmit a corresponding electrical and / or electronic signal. The spring assembly, consisting of the printed circuit board and the snap discs, is the core of the electrical switching system and has a dual switching point. When actuated, for example by a lever, the weaker snap disc, located, for example, on the top surface, triggers first once a certain force is reached.The second switching point requires an actuating dome located in the housing base, which activates the snap disc situated between the underside of the circuit board and the housing. The circuit board functions not only as a signal receiver but also as an actuator and should be able to move horizontally. For this purpose, the circuit board is mounted in the housing in a way that allows movement, for example, by floating, or it is connected via a clamp that provides a pivot point for the circuit board. The latter can be used to reduce stress on the cable connections if the cables are attached near the pivot point. To prevent the snap discs on both sides from triggering consecutively under force, a different number of stackable snap discs or different types of snap discs with varying release forces can be used on each side.

[0015] The distance between the switching points can be adjusted by changing the ratio of the actuation forces of the snap discs located on the top side of the circuit board to those on the underside. This can also be achieved by selecting the position of the snap discs on the circuit board. For example, they can be positioned directly opposite each other on the circuit board, which can further reduce bending stresses on the board.

[0016] The invention thus provides an electrical switching system with double-sided snap discs mounted on a circuit board.

[0017] The advantages achieved with the invention lie particularly in the creation of an electrical switching system in the form of a double-stroke push button. The switching system offers an extremely compact design. It requires only a few components and has a simple and cost-effective construction. High actuation forces are possible with the switching system if required.

[0018] Exemplary embodiments of the invention with various further developments and configurations are shown in the drawings and are described in more detail below. They show Fig. 1 an electrical switch in perspective view, Fig. 2. Position the switch in a top view according to direction arrow II. Fig. 1 and Fig. 3 a cut along line 3-3 in Fig. 2.

[0019] In Fig. Figure 1 shows an electrical switch 1, which has a housing 2. A movable actuating element 3 is arranged on the housing 2; the actuating element 3 is designed as a lever pivotally mounted on a bearing 4 on the housing 2. Thus, the switch 1 can be switched by a pivoting movement of the actuating element 3, for example manually by a user.

[0020] To switch the electrical switch 1, the actuating element 3 acts on an electrical switching element 5 located in the housing 2, which is described in more detail in Fig. Figure 3 shows the switching element 5 comprising a carrier 6, which has a first side 7 and a second side 7'. A fixed contact 8 is located on the first side 7 of the carrier 6, and another fixed contact 8' is located on the second side 7' of the carrier 6. Two snap elements 9, 9' are arranged on the carrier 6. One snap element 9 on the first side 7 of the carrier 6 faces the fixed contact 8, and the other snap element 9' on the second side 7' of the carrier 6 faces the fixed contact 8'. Each snap element 9, 9' serves as a switching contact for switching interaction with the respective fixed contact 8, 8'. For this purpose, the snap element 9, 9' is designed with an approximately dome-shaped curved area 10, whereby the curved area 10 folds inwards to make electrical contact with the fixed contact 8, 8' when an actuating force is applied.In other words, when a predetermined force acting on the curved area 10 is reached, the curved area 10 snaps from the curved shape into a bent shape and comes into contact with the fixed contact 8, 8'.

[0021] In a compact design, the two snap elements 9, 9' are as shown in Fig. As shown in Figure 3, the snap elements 9, 9' are arranged opposite each other on the two sides 7, 7' of the carrier 6. The actuation force required for each snap element 9, 9' to engage or snap shut can be differentiated for the two snap elements 9, 9' by appropriate design. This results in two successive switching points corresponding to the snapping action, similar to a "double stroke". The switching points can be set as desired by selecting the appropriate actuation forces required for the snapping of the snap elements 9, 9'. If desired, the arrangement of the snap elements 9, 9' on the two sides 7, 7' of the carrier 6 can also be offset from each other, although this is not shown further, in order to create different switching points for the two snap elements 9, 9'.Furthermore, several snap elements 9, 9' can be arranged one above the other on the respective side 7, 7' of the carrier 6 in order to create further switching points for the switching element 5.

[0022] The carrier 6 can be a printed circuit board. The fixed contact 8, 8' consists of an electrically conductive and / or metallized area in the form of a conductor track on the printed circuit board 6. Of course, the carrier 6 can also consist of a plastic part with appropriately applied fixed contacts. Furthermore, it is advantageous for conductor tracks on the printed circuit board 6 to be provided for applying electrical voltage to the fixed contact 8, 8' and / or to the snap element 9, 9'. The snap element 9, 9' is designed as a snap disc made of electrically conductive metal. Thus, the curved area 10 of the snap disc 9, 9' simultaneously forms the contact surface for the switching contact. The snap element 9, 9' can also be designed as a snap disc made of plastic.In this case, an electrically conductive layer, consisting in particular of carbon, is located on the side of the curved area 10 of the snap disc 9, 9' facing the fixed contact 8, 8', serving as a contact surface for the switching contact. Advantageously, when the snap disc 9, 9' is folded, the electrically conductive layer can be designed as fixed contacts on the circuit board 6 to bridge two adjacent electrically conductive areas.

[0023] As already mentioned, the actuating element 3 is designed to actuate the switching element 5. For this purpose, a plunger 11 is arranged on the actuating element 3, by means of which the actuating element 3 acts on at least one of the snap elements 9, 9' and / or on the carrier 6. Furthermore, an opening 12 is again provided in the housing 2, which is equipped with an elastic sealing element 13, as shown in Fig. 2 can be seen. The plunger 11 acts according to Fig. 3 at the opening 12 via the sealing element 13 onto the snap element 9, 9' and / or onto the carrier 6.

[0024] The carrier 6 is movably mounted in the housing 2. For this purpose, the carrier 6 is fixed at one end in the housing 2 by means of a hold-down device 14. Furthermore, the carrier 6 is guided at both ends by guide elements 15. One of the snap elements 9, 9', specifically snap element 9', rests against a projection 16 in the housing 2, while the plunger 11 acts on the other snap element 9. This creates a kind of floating mounting for the carrier 6, so that when the switch 1 is activated by the actuating element 3, first one snap element 9 and then the other snap element 9', resting against the projection 16, snaps into place.

[0025] The invention is not limited to the described and illustrated embodiment. Rather, it also encompasses all technically advanced developments within the scope of the invention defined by the claims. Thus, the switching element can be suitable not only for performing a double stroke. Furthermore, additional switching operations can be triggered by the arrangement of further snap elements. Moreover, the switching element 5 can be used not only in control units in motor vehicles but also in keyboards for computers, audio equipment, video equipment, machines, and the like. In particular, the switching element 5 can be used in the field of white goods and / or the home sector, such as in washing machines, vacuum cleaners, coffee machines, power tools, smart home control units, and the like, as well as in the field of electromobility, such as in a gear selector switch, an HMI (Human-Machine Interface) switch, and the like. Reference symbol list 1 (electrical) switch 2 housings (of switches) 3 Actuating element 4 bearings 5 (electrical) switching element 6 Carrier / Circuit board 7 (first) page (of carrier) 7' (second) side (of carrier) 8.8' Fixed contact 9.9' Snap element / Snap disc 10 curved area (of snap element) 11 plungers (on the actuating mechanism) 12 Opening (in the housing) 13 Sealing element 14 hold-down devices 15 guide element 16 Approach (in the housing)

Claims

[1] Electrical switching element with a carrier (6) having a first and a second side (7, 7'), with a fixed contact (8, 8') located on the carrier (6), and with a switching contact arranged on the carrier (6) for switching interaction with the fixed contact (8, 8'), wherein the switching contact is designed as a snap element (9, 9') with an approximately dome-shaped curved area (10), and wherein the curved area (10) folds inwards by the action of an actuating force to make electrical contact with the fixed contact (8, 8'), characterized by , that two snap elements (9, 9') are arranged on the carrier (6), and that one snap element (9) is arranged on the first side (7) of the carrier (6) and the other snap element (9') is arranged on the second side (7') of the carrier (6). [2] Electrical switching element according to claim 1, characterized by, that the two snap elements (9, 9') are arranged opposite each other or offset from each other on the support (6), and / or that several snap elements (9, 9') are arranged one above the other on at least one side (7, 7') of the support (6). [3] Electrical switching element according to claim 1 or 2, characterized by , that the actuation force at which the snap element (9, 9') buckles is different for the two snap elements (9, 9'). [4] Electrical switching element according to claim 1, 2 or 3, characterized by , that the carrier (6) is a printed circuit board, that preferably the fixed contact (8, 8') consists of an electrically conductive, in particular metallized, area in the form of a conductor track on the printed circuit board (6), and that furthermore preferably conductor tracks are provided on the printed circuit board (6) for applying electrical voltage to the fixed contact (8, 8') and / or to the snap element (9, 9'). [5] Electrical switching element according to one of claims 1 to 4, characterized by , that the snap element (9, 9') is designed as a snap disk made of electrically conductive metal. [6] Electrical switching element according to any one of claims 1 to 5, characterized by , that the snap element (9, 9') is designed as a snap disc made of plastic, that preferably an electrically conductive layer, in particular made of carbon, is located on the side of the snap disc (9, 9') facing the fixed contact (8, 8'), and that furthermore preferably the electrically conductive layer is designed to bridge two adjacent electrically conductive areas on the circuit board (6) when the snap disc (9, 9') is bent. [7] Electrical switching element according to any one of claims 1 to 6, characterized by, that a housing (2) is provided, that preferably a movable actuating element (3), in particular a lever pivotably mounted on the housing (2), is arranged on the housing (2), and that further preferably the actuating element (3) is designed to act on at least one snap element (9) and / or on the carrier (6). [8] Electrical switching element according to any one of claims 1 to 7, characterized by , that the carrier (6) is movably mounted, in particular floating by means of a retainer (14), in the housing (2) such that, by action of the actuating element (3), first one snap element (9) and then the other snap element (9') buckles, and that preferably one of the snap elements (9') bears against a projection (16) in the housing (2). [9] Electrical switching element according to any one of claims 1 to 8, characterized by, that a plunger (11) is arranged on the actuating element (3), that preferably an opening (12) provided with an elastic sealing element (13) is located in the housing (2), and that further preferably the plunger (11) acts on the snap element (9) and / or on the carrier (6) at the opening (12) via the sealing element (13).

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