Leaf spring and leaf spring arrangement

Abstract

The invention relates to a leaf spring (10) for electrically contacting a plurality of contacts (20), which lie in a first plane and are insulated from one another, in each case, said leaf spring (10) comprising: a support body (11) for supporting on a surface lying in the first plane; a deformable body (12) connected to the support body (11); and a plurality of contact bridges (13) arranged on the deformation body (12), spaced apart from the support body (11) and insulated from one another, the deformation body (12) being designed to hold the contact bridges (13) in a second plane spaced apart from the first plane in an undeformed stable state; and elastically deforming in the direction of the first plane by a force (K) acting from the second plane to the first plane into a deformed, unstable or metastable state in which the contact bridge (13) lies in or on the first plane, the contact bridge (13) being each designed to electrically connect at least two mutually insulated contacts (20) in the deformed state.

Description

[0001] The present invention relates to a spring sheet for electrically contacting multiple contacts respectively, and a spring sheet arrangement having such a spring sheet.

[0002] Essentially, spring sheets are known in the prior art, for example, as documented in US11,127,543B2. Spring sheets are generally understood as components used in push-button switches that should have a perceptible pressure point. For this purpose, these components are typically made of spring steel or similar materials, where the key to conventional spring sheets lies in their material and shape being stamped to give them both a stable and metastable state. By applying force, the component can be bent and abruptly transition from a stable to a metastable state; this abrupt state change produces the perceptible pressure point and the feedback that is typically audibly perceived, known as a "click."

[0003] According to existing technology, spring sheets are arranged on push-button switches or on two mutually insulated contacts. In a stable state, these contacts are electrically separated, i.e., insulated, while in a metastable state, they are contacted by conductive spring sheets and thus connected to each other.

[0004] Its disadvantage is that a single spring contact can only represent one switch, meaning a connection can only be established between exactly two contacts. Therefore, if multiple individually switchable connections are required, a separate push-button switch or spring contact must be installed, which takes up space and is costly.

[0005] Furthermore, existing technologies are generally unable to detect the presence of accidental short circuits, and therefore cannot distinguish whether the connection is established through a spring or a faulty short circuit.

[0006] Therefore, the objective of this invention is to overcome the above-mentioned disadvantages and to provide a spring sheet and related arrangement by means of which multiple separate switching signals can be reliably generated.

[0007] This task is solved by the combination of features described in claim 1 of the patent.

[0008] Therefore, according to the present invention, a spring sheet is provided for electrically contacting a plurality of mutually insulated contacts located in a first plane. In this application, "insulation" is understood as electrical insulation. Regarding the contacts, it should be clarified that these contacts are designed to be electrically insulated from each other, but can be electrically interconnected via contact bridges mentioned below. Regarding the contacts, the plurality of contacts preferably includes at least three contacts, wherein preferably exactly one contact is a collection contact as described below, and wherein at least two contacts are switch contacts as described below. According to the present invention, the spring sheet has: a support body for support on a surface in the first plane; a deformable body connected thereto; and a plurality of contact bridges arranged at the deformable body, spaced apart from the support body, and insulated from each other. The deformable body is designed to: hold the contact bridges in a stable, undeformed state in a second plane spaced from the first plane, and correspondingly preferably maintain electrical separation from the contacts; and to elastically deform towards the first plane by a force acting from the second plane towards the first plane into a deformed, unstable, or metastable state, in which the contact bridges are located in or adjacent to the first plane. Furthermore, the contact bridges are designed to electrically connect at least two mutually insulated contacts in the deformed state of the deformable body, i.e., in an unstable or metastable state, thereby establishing an electrical connection between each of the at least two contacts via each contact bridge. Thus, each of the at least two contacts, together with the associated contact bridge, forms a switch, and a spring sheet can form a switch or serve as a switching element for each contact bridge. Regarding the aforementioned collecting contacts and switching contacts, the collecting contacts preferably form a switch with each of the aforementioned switching contacts; therefore, the number of switches or switching elements corresponds to the number of switching contacts.

[0009] The same applies to the spring sheet proposed in this paper, which, or its variants, is preferably designed such that the transition from a stable state to an unstable or metastable state is abrupt; that is, once the applied force reaches a threshold, the spring sheet "suddenly changes" from a stable state to a metastable or unstable state. Depending on the selected material and the molding and imprinting of the variant, this abrupt transition can produce tactile feedback as a pressure point and audible acoustic feedback as a "click."

[0010] Since multiple contacts need to be electrically connected in a targeted manner via spring sheets, it is undesirable for electrical connections to be accidentally established through supports or deformable bodies. Therefore, various variations have been proposed to prevent such undesirable electrical connections achieved through supports and deformable bodies.

[0011] In the first variant, it is specified that the support and deformable body are made of non-conductive material. Accordingly, electrical connections can only be established via contact bridges.

[0012] According to the second variant, the support is made of a conductive material, while the deformable body is made of a non-conductive material. Accordingly, the deformable body insulates the contact bridge from the support. To prevent accidental electrical connection of the support to the contacts already mentioned and further described below, insulating spacers or insulating layers may be provided between the support and the contacts. Furthermore, the support does not necessarily have to be supported on the contacts. The support and / or contacts may be designed such that the support has support points outside the contacts. Alternatively, the support may be designed to support the contacts, but each support point has a segment insulated from each other, so that the contacts are not electrically connected through the support.

[0013] The third variant specifies that the support is made of a non-conductive material, while the deformable body is made of a conductive material, wherein the deformable body is insulated from the contact bridge, for example, by a spacer or insulating layer between them, or the deformable body has a segment for each contact bridge, and these segments are insulated from each other. In this variant, it may be specified that the deformable body and the contact bridge are integrally formed, and each segment of the deformable body forms a contact bridge, wherein these segments are insulated from each other, for example, by their respective spacers or their respective insulating layers.

[0014] Furthermore, the fourth variant specifies that the support and deformable body are made of conductive material, wherein the deformable body is insulated from the contact bridge, for example, by a spacer or insulating layer, or the deformable body has a segment for each contact bridge, and these segments are insulated from each other. As described with respect to the second and third variants, the support and / or deformable body may be segmented, and the contact bridge may be integrally formed with the deformable body, for example. Additionally, a spacer or insulating layer may be provided between the support or its support point and the contact.

[0015] Preferably, the deformable element is designed as a dome-shaped or frustoconical element, with its base connected to the support. Accordingly, the support may be arranged radially outward while the contact bridge is arranged radially inward on the deformable element, wherein the support may surround the deformable element.

[0016] Furthermore, the deformable element may have a centrally located opening, allowing a light-emitting element, such as an LED, to be centrally positioned within the spring sheet. The light-emitting element may be electrically connected to one or more contacts. In particular, the light-emitting element may contact a collection contact, which is preferably used for connection to GND.

[0017] The spring sheet has a connecting section on the support, particularly formed as a weld point, for fastening to a surface in the first plane. The connecting section is preferably a fulcrum or support point, as mentioned above, by which the spring sheet can be supported relative to the first plane or a surface located in the first plane.

[0018] Another aspect of the invention relates to a spring arrangement having springs according to the invention and a circuit carrier, which may be, for example, a printed circuit board. The circuit carrier has a surface defining a first plane, and a plurality of mutually insulated contacts are arranged within or on the surface.

[0019] Multiple contacts preferably consist of at least one collecting contact and at least two switching contacts, thus multiple contacts include at least three contacts. The contact bridges are designed to connect the collecting contact to each of the switching contacts. The number of switching contacts corresponds to the feasible number of individually switchable connections.

[0020] The contacts, which may include both collecting contacts and switching contacts, are designed as slats or have at least one, preferably multiple, slat segments, and are arranged such that a slat portion of a second contact, preferably one of the switching contacts, is arranged adjacent to the slat portion of a first contact, preferably a collecting contact. The contact bridges are designed to connect the slat portions of the two contacts to each other, or to connect at least one slat portion of the collecting contact to at least one slat portion of the switching contact.

[0021] If collecting contacts and switching contacts are correspondingly provided and designed as slat portions or having slat-shaped sections, it is further preferred that the collecting contacts are centrally arranged relative to an imaginary central axis, while the switching contacts are distributed circumferentially around the collecting contacts. Each switching contact has at least one slat portion, wherein the slat portions of the collecting contacts extend radially outward. It is further specified that the slat portions of the switching contacts extend radially inward, thereby forming an annular overlapping area in the circumferential direction, wherein at least one slat portion of each switching contact is arranged adjacent to the slat portion of the collecting contacts.

[0022] Furthermore, the spring arrangement may also include circuitry for identifying an electrical connection between two contacts that can be connected via a contact bridge. Such circuitry includes a voltage divider, consisting of a bypass resistor and a measuring resistor, connected in series with one of the two contacts, and a voltage measuring device designed to measure the voltage across the measuring resistor. Thus, when the contacts are contacted by the contact bridge, the voltage measuring device can measure a known voltage, depending on the measuring resistor, that indicates, i.e., demonstrates, an electrical connection established between the contacts via the contact bridge.

[0023] For a variant having one collecting contact and multiple switching contacts, it is preferably specified that the spring arrangement has circuitry for identifying the respective electrical connections established between the collecting contact and the switching contacts via a contact bridge. A measuring branch is provided for each switching contact. Alternatively, a measuring branch is provided for each group of switching contacts, wherein the group contains at least one switching contact, and the switching contacts within the group are connected in parallel or electrically conductively to each other. The circuit has a voltage divider consisting of a bypass resistor and a measuring resistor connected in series with the respective switching contact for each measuring branch. To detect the electrical connection between the collecting contact and the respective switching contact, and preferably a short circuit intentionally established therefrom, the circuit has at least one voltage measuring device with at least one measuring input terminal, designed to measure the voltage across the measuring resistor at each measuring input terminal, so that when the switching contact is electrically connected to the collecting contact via the contact bridge, the voltage measuring device can measure a known voltage at each measuring input terminal, depending on the respective measuring resistor, indicating that an electrical connection has been established between the collecting contact and the corresponding switching contact via the contact bridge.

[0024] Preferably, a voltage measuring device with a measuring input terminal is provided for each measuring branch, but alternatively, a voltage measuring device may be provided for each measuring branch.

[0025] A voltage divider can have the same measuring resistor and the same bypass resistor, so that the same voltage is established when each switch contact is connected to the collection contact.

[0026] Advantageously, the measuring resistor and bypass resistor of the voltage divider have different values, so that when the contacts are connected, an individual voltage is established across each measuring resistor, which is assigned to a specific switch contact or a specific group of switch contacts. Since this voltage is known, the measured voltage can be compared as the actual voltage with a stored, known voltage as the rated voltage, thereby determining whether a faulty short circuit or desired connection exists.

[0027] To evaluate the measured voltage, it can be further specified that the voltage measuring device is designed as a control unit or connected to a control unit. If multiple voltage measuring devices are provided, they can each be connected to a control unit. The control unit is designed to compare the voltage measured across the measuring resistor as the actual voltage with the voltage allocated to each measuring branch as the rated voltage.

[0028] Furthermore, one aspect of the invention relates to a push-button switch having a spring sheet according to the invention and / or a spring sheet arrangement according to the invention, wherein the push-button switch further includes a key body for transmitting force to the spring sheet. The key body is here designed to transmit force to the spring sheet such that the contact bridge can move from a second plane to a first plane, and the deformable body can thus deform accordingly. Furthermore, the key body is preferably also designed to change the point of application of the transmitted force, i.e., the point where the force is applied to the spring sheet, so that, for example, the contact bridge can be placed on the contact point individually and independently.

[0029] Provided it is technically feasible and not contradictory, the features disclosed above can be combined as needed.

[0030] Other advantageous embodiments of the invention are described in the dependent claims, or are described in more detail below together with the description of preferred embodiments of the invention, with reference to the accompanying drawings.

[0031] Figure 1 A spring sheet is shown arranged on the contacts of a circuit carrier;

[0032] Figure 2 The contacts of the circuit carrier are shown;

[0033] Figure 3 This illustrates a first variation of the spring sheet arrangement;

[0034] Figure 4 A second variation of the spring sheet arrangement is shown.

[0035] The accompanying drawings are schematic examples. The same reference numerals in the drawings denote the same functional and / or structural features. Herein, according to... Figure 2 The contacts, especially Figure 1 The contacts shown. Furthermore, according to... Figure 1 and Figure 2 The contacts can correspond to according to Figure 3 and Figure 4 The contacts, where according to Figure 3 and Figure 4 The arrangement of the spring sheets can be configured according to... Figure 1 Spring sheet.

[0036] The main idea of ​​this invention is to generate multiple separate switching signals using only one spring sheet, thereby enabling multiple connections between contacts to be established, preferably independently of each other, using only one spring sheet.

[0037] Therefore, a spring sheet 10 is proposed, which is exemplarily shown in Figure 1The spring sheet 10 is segmented for this purpose, so that a conductive connection is not simultaneously established between all connectable contact points 20, 21, 22, 23, 24, 25. However, segmentation can be achieved through different variations. Basically, the spring sheet 10 has a support 11, a deformable body 12, and a plurality of contact bridges 13, wherein the plurality of contact bridges are designed to establish a conductive connection between each contact point 20, 21, 22, 23, 24, 25 to be connected.

[0038] from Figure 1 Starting from the stable state of the spring sheet 10 shown, when the applied force K exceeds the threshold force, it can become metastable or unstable. In this state, the contact bridge 13 deflects toward contacts 20, 21, 22, 23, 24, and 25. However, depending on which area or segment of the spring sheet 10 the force K is applied to, only one or only specific contact bridge 13 contacts its respective associated contact 20, 21, 22, 23, 24, and 25. In this example, there are five contacts 20, which are designed as one collecting contact 25 and four switching contacts 21, 22, 23, and 24. The collecting contact 25 can be connected to the switching contacts 21, 22, 23, and 24 via one switching bridge 13 each, thereby achieving four independent switches or connections.

[0039] Depending on the location and / or area of ​​the applied force K, one or more connections may be established.

[0040] To support the spring sheet 10 on the surface defined by contacts 20, 21, 22, 23, 24, and 25, the spring sheet 10 also has multiple connecting segments 14 evenly distributed in the circumferential direction formed on the support body 11. If the spring sheet is directly supported on contacts 20, 21, 22, 23, 24, and 25 and as... Figure 1 As shown, and since at least the support 11 is made of a conductive material, it is important that the connecting sections 14 are insulated from each other or that the spring sheet 10 as a whole is insulated from the contacts 20, 21, 22, 23, 24, 25. For this purpose, for example, an insulating layer may be coated on the side of the support 11 facing the contacts 20, 21, 22, 23, 24, 25, or the support 11 may be divided into insulating sections.

[0041] like Figure 2As shown in detail, a collecting contact 25 is centrally arranged, around which switching contacts 21, 22, 23, and 24 are distributed. The collecting contact 25 and the switching contacts 21, 22, 23, and 24 each form a slat-shaped section 26 or slat portion 26. The slat portion 26 of the collecting contact 25 extends radially outward, while the slat portions 26 of the switching contacts 21, 22, 23, and 24 extend radially inward. A slat portion 26 of each switching contact 21, 22, 23, and 24 is respectively located between two slat portions 26 of the collecting contact 25, thus overlapping circumferentially in an annular contact area. If one or more contact bridges 13 press against the surface, electrical contact between the collecting contact 25 and the respective switching contacts 21, 22, 23, and 24 is established accordingly in the annular contact area through the slat portions 26.

[0042] Now, to identify whether and which connection is closed, according to Figure 3 and Figure 4 Each spring arrangement is provided with a circuit 30.

[0043] Except according to Figure 1 and Figure 2 The circuit 30 is connected to contacts 21, 22, 23, 24, and 25, and equivalent circuit diagrams (40) are also shown in parts.

[0044] according to Figure 3 Circuit 30 specifies that a measurement branch is provided for each switch contact 21, 22, 23, 24, each having a voltage divider composed of bypass resistors R1-R4 and measuring resistors R5-R6. The voltage across measuring resistors R5-R6 is determined by a voltage measuring device, wherein the voltage measuring device 35, currently designed as a control unit, has an input terminal 31-34 for each measurement branch, thereby detecting the voltage across measuring resistors R5-R6.

[0045] Different sizes or resistance values ​​are set for the bypass resistors R1-R4 and the measuring resistors R5-R6, so that when the connection between each switch contact 21-24 and the collecting contact 25 is closed accordingly, an individualized voltage that can be assigned to that connection is established. This voltage is measured by the voltage measuring device 35 as the actual voltage and compared with the associated voltage stored for this purpose, thus determining whether the connection is closed through the contact bridge. If a voltage that cannot be assigned or associated with any connection is measured, a fault short circuit exists.

[0046] Figure 4 The variants basically correspond to Figure 3 The implementation form. However, if fewer possible or establishable connections are required, switch contacts 21-24 can be combined into a switch contact group, where it is then sufficient to evaluate the switch contact group. Accordingly, in Figure 4The device includes two switch contact groups, each with two interconnected switch contacts 21-24. The first switch contact group thus includes interconnected switch contacts 21 and 23, and the second switch contact group includes interconnected switch contacts 22 and 24. Each of the two switch contact groups is assigned a measurement branch, thus a voltage measuring device 35 with two input terminals 31 and 32 is sufficient. Therefore, if a connection is established between the collecting contact 25 and one of the switch contacts 21 and 23 via their respective associated contact bridges 13, it can be detected via the first input terminal 31. If a connection is established between the collecting contact 25 and one of the switch contacts 22 and 24, it can be detected via the second input terminal 32.

[0047] The present invention is not limited to the preferred embodiments described above. Rather, many variations are conceivable, and the solutions shown can be used even in substantially different types of embodiments.

Claims

1. A spring leaf (10) for electrically contacting a plurality of mutually insulated contacts (20) each located in a first plane, wherein the spring leaf (10) having a support body (11) for being supported on a surface located in the first plane, a deformation body (12) connected to the support body (11), and a plurality of contact bridges (13) arranged on the deformation body (12) spaced apart from the support body (11) and insulated from one another, wherein the deformation body (12) is designed to hold the contact bridges (13) in a second plane spaced apart from the first plane in an undeformed stable state, and to be elastically deformed by a force (K) acting from the second plane towards the first plane into a deformed, unstable or metastable state in which the contact bridges (13) are located in or on the first plane. wherein the contact bridges (13) are each designed to electrically connect at least two mutually insulated contacts (20) in the deformed state.

2. The spring leaf according to claim 1, wherein the support body (11) and the deformation body (12) being made of an electrically non-conductive material, or wherein the support body (11) is made of an electrically conductive material and the deformation body (12) is made of an electrically non-conductive material, or wherein the support body (11) is made of an electrically non-conductive material and the deformation body (12) is made of an electrically conductive material, wherein the deformation body (12) is insulated from the contact bridges (13) or is divided into sections each for one contact bridge (13), the sections being insulated from one another, or wherein the support body (11) and the deformation body (12) are made of an electrically conductive material, wherein the deformation body (12) is insulated from the contact bridges (13) or is divided into sections each for one contact bridge (13), the sections being insulated from one another.

3. The spring leaf according to claim 1 or 2, wherein, the deformation body (12) being designed as a dome or truncated cone element, the base of which is connected to the support body (11).

4. The spring leaf according to any of the preceding claims, wherein a connection section (14) being provided on the support body (11) for fastening on a surface located in the first plane.

5. A spring leaf arrangement having a spring leaf (10) according to any of the preceding claims and a circuit carrier, wherein the circuit carrier having a surface defining the first plane, a plurality of mutually insulated contacts (20) being arranged in or on the surface.

6. The spring leaf arrangement according to the preceding claim, wherein the plurality of contacts consisting of at least one collection contact (25) and at least two switch contacts (21, 22, 23, 24), and wherein the contact bridges (13) are each designed to connect the collection contact (25) with one switch contact (21, 22, 23, 24) each.

7. The spring leaf arrangement according to any of the two preceding claims, wherein The contacts (20) are designed as strips or have strip sections (26) and are arranged in such a way that the strip sections (26) of the second contact are arranged next to the strip sections (26) of the first contact, wherein the contact bridges (13) are designed to connect the strip sections (26) of two contacts (20) to one another.

8. Spring leaf arrangement according to the two preceding claims, wherein the collecting contact (25) is arranged centrally with respect to an imaginary central axis, and the switching contacts (21, 22, 23, 24) are arranged in a circumferential manner around the collecting contact (25), wherein the strip sections (26) of the collecting contact (25) extend radially outward in a star shape, with at least one strip section (26) per switching contact (21, 22, 23, 24), wherein the strip sections (26) of the switching contacts (21, 22, 23, 24) extend radially inward, thereby forming a circumferential overlap region, in which a strip section (26) of one switching contact (21, 22, 23, 24) is arranged next to a strip section (26) of the collecting contact (25).

9. Spring leaf arrangement according to any one of claims 5 to 8, further comprising a circuit (30) for identifying an electrical connection between two contacts (20, 21, 22, 23, 24, 25) connected by a contact bridge (13), wherein, the circuit having a voltage divider consisting of a bypass resistor (R1, R2, R3, R4) and a measurement resistor (R5, R6, R7, R8) in series with one of the two contacts (20, 21, 22, 23, 24, 25), and a voltage measurement device (35) designed to measure the voltage across the measurement resistor (R5, R6, R7, R8), so that the voltage measurement device (35) can measure a known voltage depending on the measurement resistor (R5, R6, R7, R8) when the contacts (20, 21, 22, 23, 24, 25) are contacted by the contact bridge (13), the known voltage indicating that an electrical connection has been established between the contacts (20, 21, 22, 23, 24, 25) by the contact bridge (13).

10. Spring leaf arrangement according to any one of claims 6 to 8, further comprising a circuit (30) for identifying an electrical connection between the collecting contact (25) and a switching contact (21, 22, 23, 24) by a contact bridge (13), wherein one measurement branch is provided for each switching contact (21, 22, 23, 24) or for each switching contact group having at least one switching contact (21, 22, 23, 24), wherein the switching contacts (21, 22, 23, 24) of one switching contact group are electrically connected to one another, wherein the circuit (30) has, per measuring branch, a voltage divider consisting of a bypass resistor (R1, R2, R3, R4) and a measuring resistor (R5, R6, R7, R8) in series with the respective switch contact (21, 22, 23, 24), and wherein the circuit (30) has at least one voltage measuring device (35) with at least one measuring input (31, 32, 33, 34) and is designed to measure the voltage over the measuring resistor (R5, R6, R7, R8) at the respective measuring input (31, 32, 33, 34), so that the voltage measuring device (35) can measure, at the respective measuring input (31, 32, 33, 34), a known voltage dependent on the respective measuring resistor (R5, R6, R7, R8) when the switch contact (21, 22, 23, 24) is electrically connected to the collection contact (25) by means of the contact bridge (13), the known voltage indicating that an electrical connection has been established between the collection contact (25) and the respective switch contact (21, 22, 23, 24) by means of the contact bridge (13).

11. Spring blade arrangement according to the preceding claim, wherein, the voltage measuring device (35) being designed as a control unit or being connected to the control unit, and wherein the control unit is designed to compare the voltage measured over the measuring resistor (R5, R6, R7, R8) with the voltage assigned to the respective measuring branch.

12. Control unit according to the preceding claim, the control unit being designed to compare the voltage measured over the measuring resistor (R5, R6, R7, R8) with the voltage assigned to the respective measuring branch.

13. Control unit according to one of the preceding claims, the control unit being designed to compare the voltage measured over the measuring resistor (R5, R6, R7, R8) with the voltage assigned to the respective measuring branch.

14. Control unit according to one of the preceding claims, the control unit being designed to compare the voltage measured over the measuring resistor (R5, R6, R7, R8) with the voltage assigned to the respective measuring branch.

15. Control unit according to one of the preceding claims, the control unit being designed to compare the voltage measured over the measuring resistor (R5, R6, R7, R8) with the voltage assigned to the respective measuring branch.

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