WO2002063647A1

WO2002063647A1 - Multiple electrical switch with three main switching ways and one-piece actuator

Info

Publication number: WO2002063647A1
Application number: PCT/EP2002/000673
Authority: WO
Inventors: Sylvain Rochon; Eric Sermet
Original assignee: Itt Manufacturing Enterprises Inc.
Priority date: 2001-02-02
Filing date: 2002-01-24
Publication date: 2002-08-15
Also published as: FR2820543A1; FR2820543B1

Abstract

The invention proposes a triple electrical switch (10) comprising a contact-carrier casing (12) which delimits at least two switch housing (20A, 20B, 20C) each one of which receives a tripping device (22A, 22B, 22C) which is elastically deformable in order to establish an electrical connection between two fixed contacts, and comprising a common actuating plate (46) which is mounted in an articulated manner in order to rock, about a horizontal axis (70AB, 70BC, 70CA), towards an actuating position in which it acts individually on a tripping device by the intermediary of an associated actuating stud (40A, 40B, 40C), characterized in that it comprises three switch housings (20A, 20B, 20C) arranged in a triangle formation, and in that the axis of articulation of the plate (46) passes through the other two studs.

Description

MULTIPLE ELECTRICAL SWITCH WITH THREE MAIN SWITCHING WAYS AND ONE-PIECE ACTUATOR

The present invention relates to an electrical switch. The invention relates more particularly to a multiple electrical switch, particularly one with a tactile effect, of small size.

The invention relates to an electrical switch making it possible, by means of a single actuating member, to carry out separate electrical switching operations in view, in particular, of controlling a function of an electronic apparatus for example subsequent to choices made by selection from a menu or list on a display screen.

Such a function must for example be provided in a portable telephone set, for example of the GSM type, which comprises in particular means making it possible for example for the user to store in a register a series of telephone numbers that he can then call directly without having to key in the number of his correspondent on the keyboard. For this purpose, the telephone comprises a display screen on which the user can cause to scroll, for example in two opposite scrolling directions, the list of correspondents each one of which being with its previously stored number.

According to a known design , this scrolling display operation necessitates two electrical switches on one or other of which the user presses, in separate pulses or continuously, in order to cause the list to scroll in one or other of the two directions of scrolling .

Once the user has selected the correspondent he wishes to call, he must then confirm this selection and initiate the automatic dialling calling operation by pressing on a third electrical switch. This design therefore in principle necessitates the provision of three electrical switches which, according to a first known design, are produced in the form of separate components which must be mounted on a printed circuit board of the telephone.

Such a solution is therefore particularly costly in that it makes use of a large number of components, in that it necessitates mounting the components, for example by the surface mounting technique, on the printed circuit board and in that it necessitates, for each switch, making use of a separate actuating button.

Furthermore, the function of selection and then of confirmation for calling a stored number must be as ergonomic as possible for the user. In fact, it is particularly desirable that the user can operate his telephone set with just one hand , that is to say the hand with which he is holding his telephone.

The recent developments and rapid evolution of telecommunications means, such as portable radiotelephones, portable computers and other devices making it possible, in particular, to store data electronically, necessitate the availability of increasingly smaller electromechanical components and , in particular in the previously mentioned field, the scanning of menus, allowing the movement of a symbol on a screen and , more generally, the combination of several electrical switching functions in a single component.

In the case of scanning menus and of selection switching , in particular for applications to portable telephones, the basic combination mentioned above making use of three electrical switching ways has proved essential.

Many efforts have been made in order, in a general way, to produce so-called "multiple" electrical switches configured in the form of a single electromechanical component making it possible to provide, by means of a single actuating device, up to eig ht scanning switchings and one selection switching .

Among the various solutions proposed for integrating the switching elements in a single switch, it is observed that the designs are of the type comprising a lower insulating contact-carrier casing which delimits at least two switch housings each one of which comprises a bottom in which are disposed at least two fixed contacts and which receives a tripping device, of generally bulged shape, which is elastically deformable starting from a position of rest, substantially in a direction perpendicular to the horizontal plan.e of the bottom of the housing , in order to establish an electrical connection between the two fixed contacts, and of the type comprising a common upper actuating device having the general form of a common actuating plate which is mounted in an articulated manner with respect to the casing , starting from a position of rest, towards which it is elastically returned and in which it extends in a horizontal plane substantially parallel with the bottoms of the housings, in order to rock, about a horizontal axis, towards an angular actuating position in which it acts individ ually on a tripping device by the intermediary of an associated actuating stud which is provided u nder the lower face of the common actuating plate, facing this tripping device, and which comprises a lower end portion which, in the position of rest of the plate, bears vertically on a facing central convex zone of the said tripping device.

This is particularly the case of the complex design described in the document FR-A-2.770.022 which makes use of an actuating device that is common to the different "individual" switches in which the actuating plate common to some of the switches is bound to a vertical control rod to constitute a control lever. This design is not adapted to the basic combination of a multiple switch with three main switching ways for which it is desirable to have a component of small total height, of generally flat shape, and in which the control of the tripping of each of the three switching ways can be provided simply and reliably, even when the tripping force, of generally vertical orientation , is totally offset with respect to the tripping device to be controlled , whilst retaining a stable tactile effect and a substantially constant tripping force. With this objective, the invention proposes a multiple switch of the type mentioned above, characterized in that it comprises three switch housings arranged in a triangle formation , and in that the horizontal axis of articulation of the common actuating plate, for the individual actuation of each of the three tripping devices, passes through the two lower end portions of the two actuating studs associated respectively with the other two of the three tripping devices.

According to other characteristics of the invention:

- the lower end portion of each actuating stud is of truncated cone or hemispherical shape and determines a lower actuating point bearing on the facing central convex zone of the associated tripping device;

- the lower end portions of the three actuating studs are substantially coplanar; - in the position of rest of the common actuating plate, each lower portion of an actuating stud is elastically bearing on the facing central zone of the associated tripping device which is elastically prestressed in the vertical direction;

- the bottoms of the three switch housings are substantially coplanar;

- the upper face of the common actuating plate comprises three control blocks each of which is arranged substantially in alig nment with an associated actuating stud in order to constitute an individual control key of the tripping device associated with this said actuating stud;

- each tripping device is of the type that is elastically deformable starting from a stable position of rest in order to procure for the user a tactile effect of its tripping ;

- the actuating force in order to obtain the tripping of one of the three tripping devices is greater than the actuating force of the other two tripping devices; - the lower insulating casing comprises a flat horizontal bearing and articulation surface for a convex spherical part of a control button of the switch;

- the common actuating plate comprises a window, formed between two of the three control blocks, through which protrudes, vertically upwards, a pad of the lower insulating casing whose upper face delimits the said flat horizontal bearing and articulation su rface for the control button of the switch;

- each control block is delimited vertically upwards by an upper face parallel with the general plane of the common actuating plate, and, in the position of rest of the common actuating plate, the upper faces of the three control blocks and the upper face of the said pad are substantially coplanar;

- the three switch housings are arranged in an isosceles triangle formation; - the switch has an overall symmetry of desig n with respect to a median vertical plane passing through the mid-perpendicular of the third side of the isosceles triangle;

- the common actuating plate is a part moulded from plastic. Other characteristics and advantages of the invention will appear on reading the following detailed description in which , in order that it may be understood , reference will be made to the appended drawings in which:

- Fig ure 1 is an exploded perspective top view of the main components of a preferred example of embodiment of a multiple electrical switch according to the teachings of the invention;

- Figure 2 is a perspective view similar to that of Fig ure 1 in which the switch is shown in the state in which its various components are assembled;

- Figure 3 is a perspective bottom view of the common actuating plate shown in Figure 1 ;

- Fig ure 4. is a cross-sectional view through the median vertical plane of symmetry passing throug h the line 4-4 of Figure 2; and

- Fig ure 5 is a cross-sectional view through a vertical plane passing through the line 5-5 of Figure 2.

In order to facilitate comprehension of the description and of the claims, a vertical orientation from bottom to top in consideration of Figure 1 will be adopted hereafter in a non- limitating way. The switch 10 principally comprises a lower casing 12 which is delimited by a horizontal flat lower face 14 which is provided to bear against the upper face of a printed circuit board (not shown) and by a horizontal flat upper face 16.

Seen from above, the switch 10 has an overall symmetry of design with respect to a vertical plane of symmetry PS passing throug h the line 4-4 of Figure 2.

The switch 1 0 is a multiple switch having at least three individ ual and independent switching ways, that is to say that it comprises three individual switches 1 8i. The three individual switches 18i are of overall similar desig n and they will not all be described in detail, each respective component of one of the switches 1 8i being denoted by the same reference numbers followed by the corresponding index "i", that is to say "A, B or C".

The multiple switch 10 thus comprises three individ ual switches 18A, 18B and 18C each of which comprises a switch housing 20A, 20B, 20C in which there is arranged a tripping device 22A, 22B, 22C on which an actuating stud is capable of acting in order to cause a change of state of the tripping device, that is to say of the corresponding switching way.

As can be seen in the figures, the three switches 1 8i are arranged in a triang le formation, in this case according to an isosceles triang le at "A"; that is to say that the three overall vertical axes 24A, 24B, 24C substantially pass through the centres of the three tripping devices 22A, 22B, 22C constituting the three corners of a triangle. The three housings 20i are formed in the bottom 26 of the lower housing 12 whose upper face is open and each housing is thus itself also open vertically upwards.

Each housing 20i is delimited by a peripheral wall of overall rectangular profile and by a lower flat horizontal bottom 30i. The three bottoms 30i are substantially coplanar and parallel with the horizontal upper face 16 which is itself parallel with the lower face 14.

According to a known design, the lower housing 12 is produced by overmoulding an insulating plastic around various conductive elements among which are various fixed contact elements.

Thus, the bottom 30i of each housing 20i comprises a central fixed contact 32i which is part of a conductive element which comprises a connection end 34i which extends to the outside of the casing 12, from a vertical side face, in order to allow the fitting of the switch on a printed circuit board , for example using the surface mounting techniq ue. The bottom 30i also comprises another fixed contact 36i which is connected to a connection terminal 38i.

The housing 20i is dimensioned in order to receive a tripping device 22i, of known general design , which is a component made of conductive material of generally bulging shape, in this case by way of example having a rectangular contour, which bears against the bottom by its lower lateral edge of rectangular contour and , in particular, with the fixed contact 36i, and whose central apex, of axis 24i, can extend , in the rest state, above the central fixed contact 32i in such a way as to optimize the tactile effect resulting from the use of the rectangular lateral tripping devices of known general design .

It will be noted here that the tripping device 22A received in the housing 20A of the switch 18A is "double", that is to say it is constituted by the superimposition of two identical and superimposed domes.

The concavity of the tripping device 22i faces the bottom 30i and the device 22i is capable of being deformed , against its own elasticity, in a substantially vertical direction of tripping parallel with the axis 24i, in order to establish an electrical connection between the fixed contacts 32i and 36i. The tripping device 22i changes state suddenly, after a predetermined tripping travel, in such a way as to transmit to the user a tactile sensation of its tripping . According to the teachings of the invention, each actuating stud 40i of a tripping device is of truncated cone shape, or hemispherical shape by way of a variant that is not shown , whose lower end is a pad 42i of very small diameter which constitutes an actuating point which is globally centred with respect to the upper zone 44i, in this case rectangular and globally flat, of the associated tripping device 22i, that is to say that the actuating point is globally centred on the tripping axis 24i.

According to the teachings of the invention, the three actuating studs 40i are part of a common actuating device constituted by a common actuating plate 46.

The actuating plate 46 is in this case a part made by moulding from plastic delimited by two parallel faces, an upper one 48 and a lower one 50, and it comprises several cut-outs or openings which give it a generally triang u lar appearance comprising , in particular, a transverse top branch or tab 52A and two lateral base branches or tabs 52B and 52C.

Each branch 52i comprises an actuating stud 40i which extends vertically under the lower face 50 of the common actuating plate 46. Each upper control block 54i is in this case in the form of a rectangular parallelepipedic block delimited vertically upwards by a flat upper horizontal face 56i.

The three control blocks are therefore in the form of three control keys 54i each comprising an upper control face 56i on which a user can apply, directly or indirectly, an actuating force Fi in order to actuate the associated individual switch 18i.

The three actuating points 42i are coplanar in a horizontal plane parallel with the body of the plate 46 which , in the assembled and rest position of the plate 46, is horizontal. In this assembled position, each actuating point 42i bears vertically on the associated corresponding zone 44i by applying on the tripping device a very light prestress or preload against the elasticity of the tripping device itself 22i.

In order to define this position of rest of the plate and to assemble all of the components of the switch 10, the latter comprises an upper closing plate 58 or closing case, of generally rectangular shape and which in this case comprises folded and/or crimped lateral vertical tabs 60 for closing the lower casing like a crimped case.

The upward vertical position of the actuating plate 46 is thus defined by the butting of its upper face 48 against facing portions of the lower face 62 of the closing plate 58.

The closing plate 58 of course comprises three windows

64i each of which allows the passage of the corresponding operating key 54i carried by the common actuating plate 46 and each of these keys thus protrudes upwards beyond the upper face 66 of the closing plate 58.

The closing plate, when it is made of metal, can comprise an additional tab 67 for connecting it to the electrical earth of the printed circuit board which carries the switch 10.

The functioning of the multiple switch 1 0 is as follows. When the user wishes to change the state of an individual switching way, that is to say by operating one of the individual switches 18i, he presses on the upper face 56i of the associated control key 54i. This actuating force, when is it g reater than the tripping force of the associated tripping device 22i, causes the latter to change state.

During the actuation, the common actuating plate 46 rocks globally about a substantially horizontal axis of rocking or articulation passing through the actuating points of the other two actuating studs. Thus, by way of example, the control of the individual switch 20A is obtained by acting on the key 54A-56A, which causes a rocking of the plate 46 about the axis 70BC passing through the points 42B and 42C, that is to say about an axis generally corresponding with the side of the triangle opposite the apex referenced "A".

When the user releases his pressure on the key 54i in q uestion , the tripping device returns to its stable rest state, each tripping device 22i thus constituting a means for the elastic return of the actuating plate 46 to its position of rest.

The one-piece actuator constituted by the common actuating plate 46 thus makes it possible to actuate each individual switch, even if the actuating force is offset or off-axis with respect to the corresponding axis 24i, and this occurs with a stable tactile sensation or effect and with a constant force.

The tactile effect is thus independent of the point of application of the force, that is to say that no matter at what position the studs 56A, 56B or 56C are pressed , the tactile effect or sensation is identical because of the one-piece desig n of the actuator 46.

The switch 1 8A, due to its two superimposed domes, has a higher tripping force and it can for example constitute the selection or confirmation switch , whilst the other two switches 1 8B and 18C are menu scrolling switches.

The triple switch 1 0 also makes it possible, without departing from the scope of the invention, to combine the simultaneous actuation of two individual switches , or even of all three switches 18i.

The closing plate 58 also comprises a window 72 which is located centrally between the two windows 54B and 54C and which allows the passage of a fixed pad 74, in this case produced as part of the moulding with the body of the lower casing 12, which is delimited vertically upwards by a flat and horizontal upper face 76 which is preferably coplanar with the upper faces 56i of the control keys 54i, when the common actuating plate 46 is in its position of rest.

The upper face 76 therefore constitutes a flat support surface for a common button (not shown) for controlling the triple switch 1 0. The lower part of the control button is then a convex hemispherical part which makes it possible, in the assembled position of the electronic apparatus (for example of the telephone), for the button to be connected to the switch by a ball- joint type link.

It can also be seen in the figures that the lower insulating casing 12 comprises a open central well 78 which frees up an area on the printed circuit board for other components which , if their height so requires, can also extend through a window 80 in the upper closing plate.

Claims

CLAIMS 1 . Multiple electrical switch (10) of the type comprising a lower insulating contact-carrier casing (12) which delimits at least two switch housings (20A, 20B, 20C) each one of which comprises a bottom in which are disposed at least two fixed contacts (32A-36A, 32B-36B 32C-36C) and which receives a tripping device (22A, 22B, 22C) , of generally bulged shape, which is elastically deformable starting from a position of rest, substantially in a direction (24A, 24B, 24C) perpendicular to the horizontal plane of the bottom of the housing , in order to establish an electrical connection between the two fixed contacts, and of the type comprising a common upper actuating device (46) having the general form of a common actuating plate which is mounted in an articulated manner with respect to the casing (12) , starting from a position of rest, towards which it is elastically returned and in which it extends in a horizontal plane substantially parallel with the bottoms of the housings, in order to rock, about a horizontal axis (70AB, 70BC, 70CA), towards an angular actuating position in which it acts individually on a tripping device by the intermediary of an associated actuating stud (40A, 40B, 40C) which is provided under the lower face (48) of the common actuating plate, facing this tripping device, and which comprises a lower end portion which, in the position of rest of the plate, bears vertically on a facing central convex zone (44A, 44B, 44C) of the said tripping device, characterized in that it comprises three switch housings (20A, 20B, 20C) arranged in a triangle formation , and in that the horizontal axis of articulation (70BC, 70CA, 70AB) of the common actuating plate (46), for the individual actuation of each of the three tripping devices, passes through the two lower end portions of the two actuating studs (40B-40C, 40C-40A, 40A-40B) associated respectively with the other two of the three tripping devices.

2. Electrical switch according to the preceding claim, characterized in that the lower end portion of each actuating stud is of truncated cone or hemispherical shape and determines a lower actuating point (42A, 42B, 42C) bearing on the facing central convex zone (44A, 44B, 44C) of the associated tripping device (22A, 22B, 22C).

3. Switch according to either of the preceding claims, characterized in that the lower end portions (42A, 42B, 42C) of the three actuating studs (40A, 40B, 40C) are substantially coplanar.

4. Switch according to any one of the preceding claims, characterized in that, in the position of rest of the common actuating plate (46) , each lower portion of an actuating stud (40A, 40B, 40C) is elastically bearing on the facing central zone (44A, 44B, 44C) of the associated tripping device which is elastically prestressed in the vertical direction.

5. Switch according to any one of the preceding claims, characterized in that the bottoms (30A, 30B, 30C) of the three switch housings (20A, 20B, 20C) are substantially coplanar.

6. Switch according to any one of the preceding claims, characterized in that the upper face (50) of the common actuating plate (46) comprises three control blocks (54A, 54B, 54C) each of which is arranged substantially in alignment with an associated actuating stud (40A, 40B, 40C) in order to constitute an individ ual control key of the tripping device associated with this said actuating stud.

7. Switch according to any one of the preceding claims, characterized in that each tripping device (22A, 22B, 22C) is of the type that is elastically deformable starting from a stable position of rest in order to procure for the user a tactile effect of its tripping .

8. Switch according to any one of the preceding claims, characterized in that the actuating force in order to obtain the tripping of one (22A) of the three tripping devices (22A, 22B, 22C) is greater than the actuating force of the other two tripping devices (22B, 22C).

9. Switch according to any one of the preceding claims, characterized in that the lower insulating casing (12) comprises a flat horizontal bearing and articulation surface (76) for a convex spherical part of a control button of the switch.

10. Switch according to Claim 9, considered in combination with Claim 6, characterized in that the common actuating plate (46) comprises a window (72), formed between two (54B, 54C) of the three control blocks, through which protrudes, vertically upwards, a pad (74) of the lower insulating casing (12) whose upper face (76) delimits the said flat horizontal bearing and articulation surface for the control button of the switch.

1 1 . Switch according to the preceding claim , characterized in that each control block (54A, 54B, 54C) is delimited vertically upwards by an upper face (56A, 56B, 56C) parallel with the general plane of the common actuating plate (46), and in that, in the position of rest of the common actuating plate, the upper faces (56A, 56B, 56C) of the three control blocks and the upper face (76) of the said pad (74) are substantially coplanar.

12. Switch according to any one of the preceding claims, characterized in that the three switch housings (20A, 20B, 20C) are arranged in an isosceles triangle formation .

1 3. Switch according to the preced ing claim , characterized in that it has an overall symmetry of design with respect to a median vertical plane (PS) passing through the mid- perpend icular of the third side of the isosceles triangle.

14. Switch according to any one of the preceding claims, characterized in that the common actuating plate (46) is a part moulded from plastic.