Electric switch

Abstract

 An electric switch comprising at least one knob 10, integrally secured to a control lever 1 and adapted to be handled by the user, and at least one electronic circuit 6 comprising a plurality of electric tracks 7.
Said switch also comprises: at least one pad 3, comprising a plurality of domes or bubbles 4 and an elastic element 5; an actuation lever 2, which are adapted to permit the closing of at least one electric circuit, comprised in the electronic circuit 6, for the activation of at least one corresponding command as a function of the handling of the knob 10 by the user.

Description

[0001] The present invention relates to a joystick-type switch with a silicone keypad, comprising an elastic element adapted to take up the clearance in the mechanism and a dual-lever actuation mechanism.

[0002] Joystick-type switches are known in the automotive field which comprise mechanisms including, for example, a lever which, when actuated by means of a control knob, drags a slide carrying the electric contacts that provide the switching function.

[0003] Normally said lever is pushed into the idle position by a push rod and a spring.

[0004] Said push rod and said spring also perform the function of taking up any clearance of the mechanism.

[0005] Furthermore, said clearance take-up function carried out by the spring and by the push rod determines the sensitivity perceived by the user when operating said switch, depending on the mechanical/physical characteristics thereof.

[0006] This known solution has inherent mechanical characteristics that in many cases no longer meet the latest requirements of the automotive industry.

[0007] Such unsatisfactory mechanical characteristics include the following: relatively great forces must be applied to said switch; excessive strokes of the various mechanisms, in view of the reductions in size that must be obtained; the noise generated by such devices when switching takes place. The use of sliding contacts involves both an increase in the generated noise and the necessity of employing long components' travels to allow for proper switching. Normally joystick-type switches are used, for example, for adjusting rearview side mirrors of vehicles such as cars, campers, trucks, etc.

[0008] In addition, this typology of switches can be used for controlling many other devices included in a vehicle.

[0009] The present invention aims at providing a joystick-type switch comprising a dual-lever actuation mechanism acting upon a silicone keypad, which optimizes the required forces and the stroke of the mechanisms while reducing noise and making said switch suitable for the new requirements of the automotive market.

[0010] The present invention also reduces the number of components necessary for manufacturing the switch, thus making it easier to assemble.

[0011] The object of the present invention is to provide a joystick-type switch having the features set out in the appended claim 1.

[0012] Accessory features will be set out in the dependent claims. The features and advantages of said switch will become more apparent from the following description of an embodiment thereof with reference to the annexed drawings, wherein:

● Fig. 1 is an exploded view of one embodiment of the joystick-type switch according to the present invention;

● Fig. 2 is a sectional side view of the switch of Fig. 1 in the idle operating condition;

● Fig. 3 is a sectional side view of the switch of Fig. 1 in the active operating condition;

● Fig. 4 shows a detail of the switch according to the present invention, which includes a contact portion ensuring the closing of an electric circuit.

[0013] With reference to the above-listed drawings, the joystick-type switch comprises at least one control knob 10 integrally secured to a control lever 1 and adapted to be handled by the user; at least one electronic circuit 6, preferably a printed circuit, which comprises a plurality of electric tracks 7.

[0014] Said joystick further comprises at least one pad 3, comprising a plurality of domes or bubbles 4 and an elastic element 5; an actuation lever 2, which are adapted to permit the closing of at least one electric circuit, comprised in the electronic circuit 6, for the activation of at least one command as a function of the handling of knob 10 by the user.

[0015] The closing of an electric circuit occurs through the movement of corresponding dome 4 by said actuation lever 2, fulcrum 8 of which being at the base of the lever itself, which in turn is moved by an actuation portion 9, preferably spherical, comprised at the lower end of control lever 1.

[0016] Said switch can take the following operating conditions when operated by a user:

● an idle condition, wherein knob 10 and associated control lever 1 are arranged parallel to a vertical longitudinal axis "Z" of the switch itself;

● an actuated condition, wherein a force is applied to knob 10 to tilt it by an angle such that both control lever 1 and actuation lever 2 are moved, thereby activating the associated command.

[0017] In the embodiment shown in Fig. 1, said actuation lever 2, preferably made of plastic material, has a substantially discoidal shape at the centre of which, on the upper face, there is a protuberance 21 adapted to house actuation portion 9.

[0018] Control lever 1, preferably made of plastic material, has a substantially cylindrical shape and comprises actuation portion 9 at the lower end of lever 1 itself; and a spherical joint, comprising two protuberances 91 arranged at the centre of the spherical joint, perpendicular to axis "Z", and adapted to rotatably drag a second constraining means.

[0019] Said spherical joint is adapted to act as a fulcrum for said control lever 1, without preventing the possibility of rotating about axis "Z".

[0020] The number of domes 4 included in pad 3 depends on the characteristics of the switch and on the functions that must be carried out.

[0021] Preferably, said domes 4 are arranged radially and are evenly spaced.

[0022] As shown in Fig. 1, there are four domes 4, e.g. two arranged along an axis "X" and two arranged along an axis "Y", wherein said axes "X" and "Y" are perpendicular to each other.

[0023] At each dome 4, electronic circuit 6 comprises tracks 7 adapted to generate at least one electric circuit, which must be closed to activate a corresponding command.

[0024] In the embodiment shown in Fig. 2, each bubble or dome 4 comprises a junction portion 31 adapted both to join single domes 4 with pad 3 and to deform as a function of the forces applied onto pad 3 by the levers included in the switch, thus allowing dome 4 to move along an axis parallel to axis "Z".

[0025] Said junction portion 31 contributes to taking up the clearance in the plurality of mechanisms comprised in the switch.

[0026] Said dome 4 has a radial bevel 12, connected to junction portion 31 and adapted to limit the influence upon said bubbles or domes 4 by forces other than the one exerted for actuation.

[0027] Radial bevel 12 is specifically sized to limit the compression of the neighbouring domes when a dome 4 is compressed, thus limiting the influence upon the switch. The silicone-based material ensures better control of the movements of domes 4, improving the sensitivity of the switch.

[0028] Elastic means 5, positioned at the centre of pad 3, comprises a plurality of junction elements 13 adapted to join elastic means 5 itself to pad 3 and to minimize the influence of forces other than the actuation ones.

[0029] Each junction element 13 and elastic means 5 cooperate to take up the clearance in the plurality of mechanisms included in the switch.

[0030] In the explanatory and non-limiting embodiment shown in the drawings, said junction element 13 essentially is an arm made of silicone-based material which is adapted to deform as a function of the forces applied onto pad 3 by the levers included in the switch.

[0031] The number of said junction portions 13 is preferably equal to the number of domes 4 in the switch; for example, there is a junction portion 13 for each dome 4.

[0032] In the embodiment shown in Figs. 1, 2 and 3, electronic circuit 6 is a printed circuit which also performs a support function for the devices comprised in the switch according to the present invention.

[0033] Each bubble or dome 4 comprises, preferably in its upper portion, a conductive layer 11 made of conductive materials suited to transporting electric current.

[0034] Said conductive layer 11 is adapted to close an electric circuit on electronic circuit 6 when said dome 4 is moved by actuation lever 2.

[0035] In the actuated operating condition, said conductive layer 11 abuts on a portion of electronic circuit 6, thus closing an electric circuit that comprises tracks 7, which activates a command associated therewith.

[0036] In an alternative embodiment, the electric connection between a dome 4 and electronic circuit 6 is established by a contact portion 62, which is interposed between dome 4 and at least one track 7 of circuit 6. Said contact portion 62, which is made of a conductive material such as, for example, copper or equivalent materials, is supported by circuit 6 or is secured to pad 3 and/or to rear housing 82 and/or to printed circuit 6 itself.

[0037] The shape and thickness of said contact portion 62 are adapted to allow portion 62 to subside when subjected to a force.

[0038] When switching to the actuated operating condition, dome 4 presses against said contact portion 62.

[0039] Due to the compression exerted by dome 4, said contact portion 62, shown in Fig. 4, subsides and presses against electronic circuit 6, thus closing an electric circuit comprising at least one track 7.

[0040] As shown in Fig. 3, when control knob 10 is tilted in one direction, control lever 1 is tilted as well and acts upon actuation lever 2 through actuation portion 9.

[0041] Said actuation lever 2 will then be tilted relative to fulcrum 8 in the direction opposite to the inclination of knob 10 relative to axis "Z".

[0042] Thanks to the dual-lever system, said actuation lever 2 will thus rise, at an angle with respect to axis "Z", in the direction of inclination of control knob 10.

[0043] In the portion opposite to that at which dome 4 is raised, said actuation lever 2 abuts on a lower housing 82, thus defining the end-of-travel position of said lever and preventing a greater force from being exerted on electronic circuit 6.

[0044] The raised portion of lever 2 acts upon corresponding dome 4 in a manner such that conductive layer 11 abuts on tracks 7 of electronic circuit 6, thereby closing the corresponding electric circuit.

[0045] As actuation lever 2 is pressing against corresponding dome 4, junction portion 31 associated with same dome 4 deforms, thereby storing elastic energy.

[0046] Said elastic energy contributes to taking said switch back to the idle condition when the user stops applying force onto knob 10.

[0047] As each dome 4 is being activated, elastic element 5 undergoes a deformation and releases elastic energy, whereas link element 13 contributes to taking said switch back to the idle condition when the user stops applying force onto knob 10.

[0048] When the switch is put into the actuated operating condition, junction elements 13 will deform; in particular, junction element 13 corresponding to the dome being moved will tend to grow longer, opposite element 13 will be compressed, and junction elements 13 in the remaining places will only undergo slight deformations, depending on their position.

[0049] The exploded view of Fig. 1 shows a switch that comprises an upper covering 81 with a hole 811, on which control knob 10 is arranged and secured integrally with control lever 1; a display portion 812 referring, by means of writings and/or icons, to a plurality of commands available on said switch and the direction of the force to be applied onto knob 10 in order to activate each command.

[0050] Said upper covering 81 accommodates a first constraining means 83 and a second constraining means 84 adapted to constrain control lever 1 to predetermined movements by means of a plurality of elastic means 85, appropriately arranged.

[0051] The switch also comprises a lower housing 82, which comprises electric contacts 821 for interfacing to the plurality of devices included in the vehicle.

[0052] Said lower housing 82 accommodates actuation lever 2 and pad 3, as shown in Figs. 2 and 3.

[0053] Elastic element 5 is inserted into protuberance 21 of actuation lever 2, and junction elements 13 are inserted into suitable grooves comprised in protuberance 21, so that pad 3 made of silicone-based material can be properly positioned on actuation lever 2.

[0054] Electronic circuit 6 is secured to said housing 82, above the pad 3, by means of joining or welding means.

[0055] Electronic circuit 6 is positioned in a manner such that, above each dome 4, there is at least one electric circuit comprising a plurality of tracks 7 on the underside of said circuit.

[0056] Electronic circuit 6 comprises a through hole 61 into which protuberance 21 comprised in actuation lever 2 is inserted during assembly.

[0057] The same protuberance 21 also houses actuation portion 9, as clearly shown in Figs. 2 and 3.

[0058] Said protuberance is preferably so designed as to hold inside actuation portion 9 when the switch is operated.

[0059] The insertion of actuation portion 9 inside protuberance 21 allows transmitting the movement of knob 10, controlled by the user, to corresponding dome 4.

[0060] Upper covering 81 is finally assembled together with lower housing 82, and the switch can be installed in the vehicle. The switch according to the present invention allows control knob 10 to rotate, so that other functions can be assigned to such a switch, e.g. by turning control knob 10 to control other devices installed in the vehicle.

[0061] In an alternative embodiment (not shown), electronic circuit 6 comprises an electronic device adapted to detect the rotation of knob 10 about axis "Z" and, depending on said rotation, to associate different functions with domes 4 acting upon tracks 7.

REFERENCE NUMERALS:

[0062] 

1

Control lever

2

Actuation lever

21

Protuberance

4

Domes or bubbles

6

Electronic circuit

62

Contact portion

8

Fulcrum

811

Hole

82

Lower housing

10

Control knob

3

Pad

5

Elastic element

61

Through hole

7

Electric tracks

81

Upper covering

812

Display portion

821

Electric contacts

83

First constraining means

84

Second constraining means

9

Actuation portion

12

Radial bevel

31

Junction portion

85

Elastic means

11

Conductive layer

13

Junction elements

Claims

1. Electric switch comprising at least one knob (10), integrally secured to a control lever (1) and adapted to be handled by the user, at least one electronic circuit (6) comprising a plurality of electric tracks (7), characterized in that it comprises:

● at least one pad (3), comprising a plurality of domes or bubbles (4) and an elastic element (5);

● an actuation lever (2);

which are adapted to permit the closing of at least one electric circuit, comprised in the electronic circuit (6), for the activation of at least one corresponding command as a function of the handling of the knob (10) by the user.

2. Switch according to claim 1, wherein the closing of an electric circuit occurs through the movement of a corresponding dome (4) by said actuation lever (2), the fulcrum (8) of which being at the base of the actuation lever (2) itself, which in turn is moved by an actuation portion (9) comprised at the lower end of the control lever (1).

3. Switch according to claim 2, wherein the pad (3) is made of silicone-based material.

4. Switch according to claim 3, wherein each bubble or dome (4) comprises a junction portion (31) adapted to join each dome (4) with the pad (3), allowing movement along an axis parallel to a vertical longitudinal axis (Z) of the switch as a function of the thrust applied by the actuation lever (2).

5. Switch according to claim 3, wherein the elastic means (5) comprises a plurality of junction elements (13) adapted both to join the elastic means (5) itself with the pad (3) and to deform as a function of the forces applied onto the pad (3) by the actuation lever (2), thus contributing to taking the switch back to an idle operating condition.

6. Switch according to claim 4, wherein as the actuation lever (2) is exerting a thrust against the corresponding dome (4), the junction portion (31) associated with said dome (4) deforms, thus storing elastic energy which contributes to taking the switch back to an idle operating condition when the user stops applying a force onto the knob (10).

7. Switch according to claim 3, wherein each dome (4) comprises a conductive layer (11) adapted to ensure the closing of at least one electric circuit positioned on the electronic circuit (6) when said dome (4) is moved.

8. Switch according to claim 3, wherein at each dome (4) there is a contact portion (62), interposed between the dome (4) and at least one track (7), secured to the circuit (6), adapted to close at least one electric circuit when said dome (4) is moved.

9. Switch according to claim 2, wherein the spherical actuation portion (9) is inserted into a protuberance (21) comprised at the centre of the actuation lever (2), thus allowing for the transmission of the movement of the knob (10), controlled by the user, to the corresponding dome (4).

10. Switch according to claim 3, wherein the control knob (10) rotates about the axis (Z) and allows other functions to be assigned to said switch to control another set of devices.

11. Switch according to claim 4, wherein each dome (4) has a radial bevel (12) adapted to limit the influence upon said bubbles or domes (4) by forces other than the one exerted for actuation.

Drawing