WO2015036911A1

WO2015036911A1 - Microswitches control device

Info

Publication number: WO2015036911A1
Application number: PCT/IB2014/064328
Authority: WO
Inventors: Fabio Tallone; Massimo Giolitti; Michelangelo Bono
Original assignee: Bitron S.P.A.
Priority date: 2013-09-10
Filing date: 2014-09-09
Publication date: 2015-03-19
Also published as: MX2016003102A; EP3044802B1; CN105659347B; ITTO20130733A1; CN105659347A; MX348416B; EP3044802A1

Abstract

Switch control device comprising: a key (2), secured to a housing structure (3); at least one actuating element (4), operationally connected on a first end to the key (2), thus moving integrally therewith; a base (32), adapted to fit into a lower portion of the housing (3), to which an electric circuit (5) comprising at least one microswitch (5) is mechanically fastened. The device comprises at least one actuating device (6), appropriately constrained in order to switch from a first idle configuration to a second actuation configuration to actuate the microswitch (51). The actuating device comprises: at least one striker portion (61), upon which a second end of said at least one actuating element (4) acts for the purpose of moving said actuating device (6) depending on the movements of the key (2); a contact portion (63) adapted to act upon said at least one microswitch (51) as a function of the action of said at least one actuating element (4) upon the device (6). The control device comprises a silicone mat (7) comprising at least one silicone dome (71) against which an abutment portion (65) of the actuating device (6) abuts, adapted to counter the movement of the actuating device (6) itself.

Description

TITLE: MICROSWITCHES CONTROL DEVICE.

The present invention relates to a microswitches control device adapted to provide a switching perception or feeling substantially similar to that of actuating devices only utilizing silicone domes or bubbles, while also generating an audible metallic noise similar to a metallic click, as is typical of a microswitch. In particular, the present invention provides a microswitch control device wherein the force/displacement graph, in its initial part, i.e. before the dome switches or collapses, is substantially similar to that which could be obtained by using only a silicone dome, while also providing, however, fast switching characteristics of the electric contacts, which could not otherwise be obtained by using only silicone domes associated with electric contacts. Moreover, when the microswitch switches, the characteristic metallic noise of microswitches can be perceived.

The parallel action of a silicone dome and of the actuation of a microswitch allows obtaining the desired force/displacement graph, which may be, for example, substantially similar to that of a silicone dome, but with fast switching characteristics as regards the closing of the electric contacts.

Microswitch actuation or control devices are known wherein a silicone dome is superimposed on microswitches via silicone mat portions, which dome collapses under the thrust exerted thereon by an actuator. The same bubble, after it has collapsed, will press the key of the microswitch, thus causing the electric switching thereof. In such a solution, the user only perceives the action of the silicone dome, without perceiving the contribution given by the microswitch, in particular the fast clicking thereof. The force/displacement graph will be non-linear and substantially bell-shaped, as is typical of the behaviour of silicone domes.

Aiming at preventing the pressure exerted on the bubble upon switching from causing damage to the silicone dome due to it pressing against the microswitch, the solutions known in the art comprise suitably shaped support structures that prevent the forces applied to the dome after switching has occurred from directly discharging from the dome onto the microswitch. In particular, such solutions will cause any excess force applied to the silicone dome to be discharged onto said support structure.

Moreover, such solutions have a very slow switching speed, which is dictated by the behaviour of the silicone dome .

Fast-switching actuating devices are also known which act directly upon the microswitches , wherein the microswitch is actuated by means of systems of levers. Such solutions require a complex housing structure, including inclined planes for ensuring that switching will only occur after a predetermined travel, i.e. at predetermined angles of rotation of the key.

The user' s perception of the switching action will essentially be dictated by the microswitch, leading to force-displacement graphs with broad linear sections.

The market now requires that control devices be as waterproof as possible, so as to avoid that water or condensate seeping in might cause short circuits in the electronic devices attached to the electric circuit. The use of microswitches connected to the electric circuit considerably complicates the making of a waterproof control device.

In particular, due to the very complexity of the housing structure of the control device, the above- described solutions do not allow using simple and economical solutions for waterproofing the electric circuit .

The present invention aims at solving the above- mentioned technical problems by providing an actuation device wherein the actions of the silicone dome and of the microswitch occur in parallel, so that a desired feeling will be attained. In particular, it is desired that the user perceives, prior to the switching of the microswitch, a soft action that is typical of a silicone dome, followed by a metallic noise as switching occurs. In addition, the present invention allows obtaining a fast switching, which is typical of microswitches, and the waterproofing of the electronic circuit.

One aspect of the present invention relates to a microswitches control device having the features set out in the appended independent claim 1.

Auxiliary features are set out in the appended dependent claims.

The features and advantages of the present invention will become apparent from the following description of two equivalent embodiments of the control device and from the annexed drawings, wherein:

• Figures 1A and IB show different views of the control device in the assembly enclosed in a casing, in particular: Figure 1A is a perspective view and Figure IB is a top view of the device;

• Figure 2 is an exploded view of a first embodiment of the control device, comprising a mobile actuating element countered by an elastic element;

• Figures 3A, 3B and 3C are sectional views of the control device along line A-A, at different instants while switching from an idle operating configuration to a push operating configuration of the control device shown in Figure 2, in particular: Figure 3A shows an idle operating configuration, Figure 3B shows it at the instant immediately following the collapse of a silicone dome, but prior to the switching of the microswitch, Figure 3C shows the push operating configuration immediately following the switching of the microswitch;

• Figure 4 is an exploded view of a second embodiment of the control device comprising an actuating element rigidly secured to or integrated with the key;

• Figures 5A, 5B and 5C are sectional views of the control device along line A-A, at different instants while switching from an idle operating configuration to a push operating configuration of the control device shown in Figure 4, in particular: Figure 5A shows an idle operating configuration, Figure 5B shows it at the instant immediately following the collapse of a silicone dome, but prior to the switching of the microswitch, Figure 5C shows the push operating configuration immediately following the switching of the microswitch;

• Figure 6 is an enlarged view of an exemplary and non-limiting embodiment of the actuating device included in the control device according to the present invention; • Figure 7 shows a comparison between a force/displacement curve of the control device according to the present invention and the characteristic curve of a control device only using silicone bubbles and a control device only using microswitches , without using any silicone bubbles; in particular, the figure shows, from top to bottom, the typical trend of a control device using silicone domes only, the typical trend of a control device using a microswitch with no silicone domes, and the trend of the force/displacement graph of the control device according to the present invention.

With reference to the above-listed drawings, the switch control device comprising a key 2, which is secured to a housing structure 3 in a manner such that it can switch from at least one first operating configuration to at least one second operating configuration. Said housing structure is, for example, a box-like structure preferably open at the top and at the bottom with respect to a vertical axis "Z".

The control device comprises an actuating element 4, operationally connected on a first end to key 2, thus moving integrally therewith.

The device according to the present invention comprises a base 32, into which a connector seat 33 can be integrated. Said base 32 is adapted to be secured to a lower portion of housing 3 in order to form a closed casing .

To said base 32 an electric circuit 5 is mechanically fastened, which in turn comprises at least one microswitch 51. Said electric circuit 5 is, for example, a printed circuit board whereon said at least one microswitch 51 is electrically attached.

Preferably, said microswitch 51 comprises at its top, opposite to the portion thereof which is fixed to electric circuit 5, a button 52 that can be pressed in order to switch the electric contacts comprised in the microswitch. The electric contacts of said microswitch may be such as to create a push-button or a switch.

The control device according to the present invention comprises at least one actuating device 6, appropriately constrained in order to switch from a first idle configuration to a second actuation configuration to actuate microswitch 51.

Actuating device 6 comprises at least one striker portion 61, upon which a second end of actuating element 4 acts for the purpose of moving said actuating device 6 depending on the movements of key 2. The same actuating device 6 comprises a contact portion 63 adapted to act upon said at least one microswitch 51 as a function of the action of actuating element 4 upon said actuating device 6.

The control device comprises a silicone mat 7, in turn comprising at least one silicone dome 71 against which an abutment portion 65 abuts, which is distinct from said contact portion 63 of actuating device 6. Said silicone dome 71 is preferably adapted to counter the movement of actuating device 6 itself.

The control device according to the present invention acts upon said at least one silicone dome 71 through said abutment portion 65 in parallel to the action of contact portion 63 upon microswitch 51, so as to obtain a fast switching action. The parallel action exerted on both silicone dome 71 and microswitch 51 causes the user to perceive a soft action or feeling that is characteristic of silicone domes and to hear the metallic noise characteristic of microswitches .

For the purposes of the present invention, the term

"soft feeling" refers to the sensation perceived by the user in the case corresponding to a non-linear force/displacement graph, typically a curved graph, in particular having a bell-like shape or a horizontal asymptote, as is typical of silicone domes or bubbles like those shown, for example, in Figure 7.

The exemplary embodiment of the control device according to the present invention illustrated in Figures 1-6 has the following features:

- key 2 is secured to housing structure 3 in a manner such that it can rotate about a first fulcrum "0" and switch from at least one first operating configuration to at least one second operating configuration;

- actuating element 4 is a tip mostly extending longitudinally and operationally connected on a first end to key 2, thus moving integrally therewith;

- the device comprises at least one actuating device 6 appropriately constrained, in particular hinged, in order to rotate about a second fulcrum "T", so that it can switch from a first idle configuration to a second actuation configuration to actuate microswitch 51;

- said at least one striker portion 61, which is acted upon by a second end of actuating element 4, is an inclined plane on which the second end of actuating element 4 slides in order to rotate said actuating device 6 about the second fulcrum "T", as a function of the movements of key 2; - said at least one silicone dome 71, whereon an abutment portion 65 abuts, which is distinct from said contact portion 63 of actuating device 6, is adapted to counter the rotation of the actuating device itself. Any other features not specified or mentioned herein can be deduced by a man skilled in the art from the annexed drawings; for this reason, they will have to be considered as belonging to the present invention, even though they will not be specifically described.

Said second fulcrum "T" can be formed, with substantially equivalent results, either on housing structure 3 or on base 32. As shown by way of example in Figure 6, actuating device 6 is removably secured to the second fulcrum "T" through a fastening portion 67. Said fastening portion 67 is, for example, a housing, preferably plastic hooks, adapted to be hinged, e.g. via a joint, to at least one protuberance that defines said second fulcrum

In general, when key 2 is turned, actuating element 4 will act upon actuating device 6, which will behave as a third-type lever hinged to the second fulcrum "T".

With reference to Figures 3A-3C and 5A-5C, when the control device according to the present invention actuates a microswitch 51, the following steps are carried out, preferably in succession:

- a first step wherein, starting from an idle configuration shown in Figures 3A and 5A, said actuating device 6, as it moves, mainly acts upon silicone dome or bubble 71 until it reaches a point of maximum force, thereby causing the same silicone dome or bubble to collapse, - a second step wherein actuating device 6, as it moves, continues to exert its action mainly on microswitch 51, in particular on button 52, as shown in Figures 3B and 5B, until the electric contacts included in the microswitch close or switch, e.g. as shown in Figures 3C and 5C;

- a third step wherein the continuation of the movement of key 2 until it reaches a mechanical stop provided on housing structure 3 holds the switching that occurred in the previous step.

Preferably, in a first step actuating device 6 actuates only silicone dome or bubble 71 until it reaches a point of maximum force of the force/displacement function, thereby causing it to click. In the second step, actuating device 6 starts actuating microswitch 51 as well by pressing onto button 52, until the electric contacts included in the microswitch close or switch. Key 2 will then continue its travel until it reaches a mechanical stop provided on housing structure 3.

Said steps summarize the trend of the force/displacement graph of the control device according to the present invention shown in Figure 7.

In Figure 7, by way of example, the three above- mentioned steps are indicated in the graph relating to the control device according to the present invention.

In the embodiment shown in Figures 2, 3A-3C, said actuating element 4 is movable along a longitudinal axis "k" of its own, countered by an elastic means 41, such as a coil spring. When key 2 is in the idle operating configuration, said longitudinal axis "k" is substantially parallel to vertical axis "Z". As actuating element 4 moves, in particular as it slides on striker portion 61, said elastic means 41 is adapted to be compressed, thereby accumulating elastic energy. Said elastic energy accumulated by elastic means 41 increases even further the speed at which actuating device 6 acts upon microswitch 51, thus improving the clicking or switching speed at which, for example, it operates button 52. This phenomenon is reflected in the force/displacement graph, wherein the section that connects the point of maximum force to the relative minimum point after switching is substantially vertical.

In the equivalent embodiment shown in Figures 4, 5A- 5C, actuating element 4 is rigidly secured to key 2 or is integrated with key 2. In particular, said actuating element 4 is prevented from moving along its longitudinal axis "k".

Also this embodiment allows obtaining a fast contact switching speed, as shown in Figure 7, in the graph concerning the control device according to the present invention there is a substantially vertical section corresponding to the switching of the electric contacts of microswitch 51.

As shown in Figure 6, said actuating device 6 has, for example, a substantially longitudinal shape, e.g. with a longitudinal extension "1", wherein said fastening portion 67 is arranged at one end, which is adapted to be fastened in such a way as to be able to rotate about the second fulcrum "T". At the opposite end of actuating device 6 there is contact portion 63, which is adapted to act upon microswitch 51. In an intermediate position between said fastening portion 67 and said contact portion 63, striker portion 61 is arranged, which is acted upon by actuating element 4 for the purpose of creating a third-type or third-class lever operating microswitch 51.

Said contact portion 63 preferably has a substantially beak-like shape that hangs over said microswitch 51 in order to exert constant pressure onto button 52 of microswitch 51 during its action.

Said abutment portion 65 is arranged, with respect to vertical axis "Z", at a lower height than striker portion 61.

Preferably, abutment portion 65 is arranged underneath striker portion 61, substantially aligned therewith, with respect to said vertical axis "Z".

Said striker portion 61 is preferably a non-linear inclined plane, with a preferably concave curvilinear profile. Said striker portion 61 is preferably so shaped as to describe an arc of circumference comprised between 90° and 180° .

Longitudinal extension "1" of said actuating device 6 is substantially aligned with the direction of a first axis "X", perpendicular to said vertical axis "Z".

In the exemplary embodiment described in the annexed Figures, the control device according to the present invention is so shaped that, at least in the idle operating configuration of actuating device 6, said actuating element 4 is substantially aligned with silicone dome 71, as shown by way of example in Figures 3A, 5A and 6.

The dimensional characteristics of actuating device 6 and the position of abutment portion 65 with respect to striker portion 61, in particular the position of silicone dome 71 with respect to the point where actuating element 4 applies force onto striker portion 61, provide an advantageous lever.

In general, said silicone mat 7 covers the whole electric circuit 5 and the electronic devices and elements, such as microswitches 51 themselves, attached thereto. Silicone mat 7 is adapted to provide the required feeling via said at least one silicone dome 71. Said electric circuit 5, preferably a printed circuit board, also comprises, for example, components for lighting key 2.

As can be seen in Figures 2 and 4, said silicone mat 7 has a surface extension at least equal to the area of electric circuit 5, in particular of the printed circuit board. Said silicone mat 7 comprises an edge 72, which is perimetric relative to said mat 7, and which is preferably thicker than mat 7 itself.

In general, said mat 7, preferably said edge 72 of mat 7, is set between housing structure 3 and base 32, as shown by way of example in Figures 3A, 5A and 6, thus making electric circuit 5 waterproof. More preferably, said edge 72 is nipped between housing structure 3 and base 32.

As can be seen in Figures 3A-3C and 5A-5C, said silicone mat 7 covers every electronic device comprised in electric circuit 5, including said at least one microswitch 51.

In general, said first fulcrum "0" and said second fulcrum "T" respectively cause key 2 and actuating device 6 to rotate about two parallel axes normal to the plane described by the two perpendicular axes, in particular vertical axis "Z" and said first axis "X". In the present description, a control device has been described wherein key 2 is adapted to take a push-type operating configuration.

The scope of the present invention includes, however, a control device that can actuate microswitches in both a push configuration and a pull configuration.

An explanatory embodiment of a control device capable of operating with key movements in both a push configuration and a pull configuration is shown by way of example in Figures 2 and 4. In such an embodiment, key 2 is horizontally pivoted, starting from an idle operating configuration, between a push operating configuration and a pull operating configuration. Said control device preferably comprises at least one actuating element 4, preferably two parallel actuating elements 4, adapted to act upon at least one actuating device 6 as a function of the operating configuration taken by key 2. Preferably, each actuating element 4 is adapted to act upon a respective actuating device 6, which in turn is adapted to act upon a corresponding microswitch 51, preferably in only one operating configuration of key 2. More preferably, one of said two actuating devices 6 is adapted to actuate a corresponding microswitch 51 only for movements of key 2 towards the push operating configuration, while the other one is adapted to actuate a corresponding microswitch 51 only for movements of key 2 towards the pull operating configuration .

In general, each actuating device 6 is adapted to act upon a corresponding microswitch 51, preferably only one, and to be countered, as it moves, by a respective silicone dome or bubble 71. Preferably, a single silicone dome 71 is associated with each actuating device 6 for countering the movement thereof.

This control device ensures the characteristic soft feeling of silicone domes as well as the metallic clicking sound of microswitches , with fast switching times that are typical of snap-type switches.

Said microswitch 51 may be either a simple switch, e.g. a normally-closed or normally-open one, or a two-way switch, depending on electric circuit 5 to be created.

The sizing of fulcrum points "T" of key 2 and of actuating device 6, as well as the shape of silicone dome 71, will allow obtaining the desired forces and travels.

The control device according to the present invention provides a simple mechanisms that allows implementing a silicone mat ensuring the waterproofing of electric circuit 5.

This solution prevents the silicone mat or the microswitch from deteriorating because of the action of an actuating device upon a silicone dome.

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REFERENCE NUMERALS :

Key 2

Housing structure 3

Base 32

Connector seat 33

Actuating element 4

Elastic means 41

Electric circuit 5

Microswitch 51

Button 52

Actuating device 6

Striker portion 61

Contact portion 63

Abutment portion 65

Fastening portion 67

Silicone mat 7

Silicone dome 71

Edge 72

First fulcrum 0

Second fulcrum T

Longitudinal axis k

Longitudinal extension 1

Vertical axis z

First axis X

Claims

CLAIMS :

1. Switch control device comprising:

a key (2), secured to a housing structure (3) in a manner such that it can switch from at least one first operating configuration to at least one second operating configuration;

- at least one actuating element (4), operationally connected on a first end to the key (2) , thus moving integrally therewith;

- a base (32), capable of fitting into a lower portion of the housing (3), to which an electric circuit (5) comprising at least one microswitch (51) is mechanically fastened;

the device comprises at least one actuating device (6), appropriately constrained in order to switch from a first idle configuration to a second actuation configuration to actuate the microswitch (51), comprising:

- at least one striker portion (61), upon which a second end of said at least one actuating element (4) acts for the purpose of moving said actuating device (6) depending on the movements of the key (2) ;

- a contact portion (63) capable of acting upon said at least one microswitch (51) as a function of the action of said at least one actuating element (4) upon said actuating device ( 6 ) ;

the control device comprises a silicone mat (7) comprising at least one silicone dome (71) against which an abutment portion (65) abuts which is distinct from said contact portion (63) of the actuating device (6), capable of countering the movement of the actuating device (6) itself.

2. Device according to claim 1, acting upon said at least one silicone dome (71) through said abutment portion (65) in parallel to the action of the contact portion (63) upon the microswitch (51), so as to obtain a fast switching and to allow the user to perceive the soft action or feeling which is characteristic of silicone bubbles and the metallic noise which is characteristic of microswitches .

3. Switch control device according to claim 1, wherein:

- said key (2) is secured to the housing structure (3) in a manner such that it can rotate about a first fulcrum (0) ;

- said at least one actuating device (6) is hinged in a manner such that it can rotate about a second fulcrum (T) ;

- said at least one striker portion (61) is an inclined plane on which the opposite second end of the actuating element (4) slides in order to rotate said actuating device (6) about the second fulcrum (T) , as a function of the movements of the key (2) ;

- said at least one silicone dome (71), on which said abutment portion (65) of the actuating device (6) abuts, counters the rotation of the actuating device itself.

4. Device according to claim 3, wherein said second fulcrum (T) is formed on the housing structure (3) or on the base ( 32 ) .

5. Device according to claim 3 or 4, wherein the actuating device (6) is removably secured to the second fulcrum (T) through a fastening portion (67) .

6. Device according to one of the preceding claims, wherein said silicone mat (7) covers the whole electric circuit (5) as well as the electronic devices and elements (51) attached thereto.

7. Device according to claim 6, wherein said silicone mat (7) is set between the housing structure (3) and the base (32), thus making the electric circuit (5) waterproof.

8. Device according to claim 3, wherein, when the key (2) is turned, the actuating element (4) acts upon the actuating device (6), which behaves as a third-type lever hinged to the second fulcrum (T) .

9. Method of actuating a device according to claim 1, wherein the following steps are carried out in succession: - a first step wherein said actuating device (6), as it moves, mainly acts upon the silicone dome or bubble (71) until it reaches a point of maximum force, thereby causing the same silicone dome or bubble (71) to collapse,

- a second step wherein the actuating device (6), as it moves, continues to exert its action mainly on the microswitch (51) until the electric contact closes;

- a third step wherein the continuation of the movement of the key (2) until it reaches a mechanical stop provided on the housing structure (3) holds the switching that occurred in the previous step.

10. Device according to claim 1, wherein said actuating element (4) is movable along a longitudinal axis (k) of its own, countered by an elastic means (41), such as a coil spring .

11. Device according to claim 3, wherein the key (2) is horizontally pivoted, starting from an idle operating configuration, between a push operating configuration and a pull operating configuration, and at least one actuating element (4) is capable of acting upon one of at least two distinct actuating devices (6) as a function of the operating configuration taken by the key (2), and each actuating device (6) is capable of acting upon a corresponding microswitch (51) and to be countered during its motion by a respective silicone dome or bubble (71) .