FR2698719A1 - Switch with auxiliary element associated with conductor blade - minimises noise to environment on switching using auxiliary element of synthetic material to contact two lateral contacts - Google Patents

Abstract

The switch has a casing (10), a movable switch (11) mounted on a pivot, at least two contact points (12A,12B), and a conducting blade (14) that is under control of the moving switch and it is mounted on a pivot to contact the central contact. The blade conductor has an auxiliary organ (40) in contact with the central contact (12A) and extends laterally and moves with elastic means and has elastically deformable ends. The conductor moves in coordination with the manoeuvrable switch so that the ends of the conductor come into contact with the contacts and the blade pivots about the central pivot. USE - Manoeuvrable switch with conducting blade having on-off positions.

Description

"Switch mechanism with auxiliary member associated with
conductive broom "
The present invention relates in general to switch mechanisms of the kind comprising, in a housing, an operating button pivotally mounted available to the user, at least two contact pads established remotely one of the 'other, and, for the establishment of an electrical connection between these contact pads, a conductive brush which, under the control of the operating button, is pivotally mounted in contact with one of the contact pads, between a first position, opening, for which it is jointly remote from the other contact pad, and a second position, closing, for which it is on the contrary jointly in contact with this other contact pad.

 Such a switch mechanism is for example described in the French patent which, filed on May 11, 1984 under No. 84 07371, was published under No. 2,564,234.

 In practice, three contact pads are provided, namely a central contact pad, in contact with which the conductive brush is pivotally mounted, and two lateral contact pads each disposed respectively on either side of this central contact pad.

 In operation, these switch mechanisms are almost inevitably noise generators, to the detriment of the surrounding comfort.

 For the most part, noise arises when the conductive broom comes into contact with a lateral contact pad, this coming into contact being done suddenly in practice, and, amplified by the inevitable rebounds of the conductive broom on this pad of lateral contact, this noise then propagates from this conductive brush to the rest of the mechanism.

 The present invention generally relates to a provision capable of minimizing this noise.

 More specifically, it relates to a switch mechanism of the kind previously stated and characterized in that it is associated with the conductive brush an auxiliary member, which, in engagement with it at the level of the central contact pad, of the 'other side of it relative to this central contact pad, extends generally parallel to it.

 In practice, the auxiliary member thus implemented according to the invention is made of synthetic material, and when, for cooperation, alternately, with one or the other of two lateral contact pads, the conductive brush has two arms, it also comprises, like this conductive brush, two arms, which, each respectively, extend generally parallel to those of the conductive brush.

 Anyway, the auxiliary member used according to the invention intervenes first of all by mass effect, both because of its own mass and because of its configuration.

 Indeed, it increases by itself the general inertia of the crew that it forms with the conductive brush, and this results in better operating flexibility for the whole, for the benefit of noise reduction.

 Jointly, according to various possible embodiments, an additional advantage is taken of this auxiliary member to oppose the propagation of noise from the conductive brush to the rest of the mechanism.

 For example, the auxiliary member extends at a distance from the conductive brush over at least part of its length between the central contact pad and the lateral contact pad, and between it and the conductive brush there are elastic means which, not only oppose any rebounds of the conductive broom, but also advantageously dampen the noise which it can be the source.

 As a variant, the auxiliary member, on the contrary, extends in contact with the conductive brush over at least part of its length between the central contact pad and the lateral contact pad, in order to directly muffle the noise.

 Alternatively, again, or in addition to the above arrangements, the auxiliary member comprises, between the central contact pad and the lateral contact pad, a zone of reduced thickness forming a hinge which, forming a constriction, prevents propagation noise.

 In any case, a better quality of acoustic comfort for the environment is advantageously obtained.

 Certainly, in certain embodiments of the French patent No 84 07371 mentioned above, there is provided between the operating button and the conductive brush, an auxiliary organ made of synthetic material.

 But this auxiliary member, which is in no way engaged with the conductive brush, since it does not even bear directly on it, in this French patent constitutes only a driving finger intervening in the mode of action of the operating button on the driver's broom.

 It is in no case a member capable of ensuring noise attenuation, and, moreover, in addition to the auxiliary member used on the contrary implemented for this purpose according to the invention, the mechanism of 'switch according to the invention can also include if desired, and actually includes in the embodiments shown, such a drive finger between the operating button and the conductive brush.

The characteristics and advantages of the invention will become more apparent from the description which follows, by way of example, with reference to the appended schematic drawings in which
Figure 1 is, with local cutaway, a partial view in longitudinal elevation-section of a switch mechanism according to the invention, for a first position of its operating button and its conductive brush
Figure 2 is a partial view in cross section along the line Il-Il of Figure 1
Figure 3 shows, on a larger scale, a detail of Figure 1
Figure 4 is a longitudinal sectional elevation view similar to that of Figure 1, for the other of the positions of the operating button and the conductive brush
Figure 5 shows another detail of Figure 1
Figures 6, 7, 8, 9, 10 and 11 are partial views in longitudinal section which, similar to that of Figure 5, each relate respectively to various alternative embodiments
Figures 12A, 12B are views which, taking that of Figure 11, illustrate the mode of operation of the alternative embodiment shown in this Figure 11
Figure 13 is a partial view in longitudinal section which, similar to that of Figure 5, relates to another alternative embodiment
FIG. 14 is a view which, taking again that of FIG. 13, illustrates the operation of the variant embodiment shown in this FIG. 13.

 As illustrated in these figures, the switch mechanism according to the invention comprises, overall, in a manner known per se, in a housing 10, an operating button 11, which is available to the user, on the front of the housing 10, and which is pivotally mounted on this housing 10, at least two contact pads 12A, 12B, which are established at a distance from each other, in practice under the operating button 11, and, for the establishing an electrical connection between these contact pads 12A, 12B, a conductive brush 14, which, under the control of the operating button 11, is pivotally mounted in contact with one of the contact pads 12A, 12B, in this case, a central contact pad 12A, between a first, open position, FIG. 1, for which it is jointly at a distance from the other contact pad, in this case a lateral contact pad 12B, and a closed position, Figure 4, for which it is on the contrary jointly in contact with this contact pad act 12B lateral.

 Since the housing 10 is not in itself concerned by the present invention, and moreover pertaining to those skilled in the art in its production, it has not been shown in all its details in the figures.

 Only the parts of this box necessary for understanding the invention have been shown thereon.

 It will therefore suffice to indicate that, in a unitary form, or in two shells, this box 10 essentially comprises two side walls 15, on which the operating button 11 is articulated, and a bottom wall 16, which carries the contact pads 12A, 12B.

 In the embodiment shown, the operating button 11 is articulated to the housing 10 by an articulation of the knife type.

 To this end, it comprises two pins 18, in the form of a dihedral, by which it engages with two recesses 19 each provided respectively in the two side walls 15 of the housing 10.

 For the intervention of the user, the operating button 11 comprises, on the front, a plate 20, which extends substantially parallel to the bottom wall 16 of the housing 10, and, for its intervention on the conductive brush 14, it comprises a drive member 22, which extends generally projecting from the lower surface of the plate 20, substantially perpendicular thereto, in the middle zone of this plate 20.

 In the embodiment shown, the drive member 22 comprises a leg 23, which is in one piece with the plate 20, and a drive finger 24, which, forming a separate part, is movably mounted in a housing 25 provided for this purpose in the leg 23, and which is permanently urged by elastic means in the direction of the conductive brush 14.

 In practice, these elastic means are constituted by a spring 26, which, bearing on the bottom of the housing 25, bears on the drive finger 24, being engaged, for its guidance, in a bore 27 thereof.

 The operating button 11 and its drive finger 24 can advantageously be made of synthetic material.

 In the embodiment shown, a lateral clearance is provided between the drive finger 24 and its housing 25 in the direction of tilting.

 In other words, and as shown, this drive finger 24 can be more or less biased in its housing 25.

 In the embodiment shown, there are two lateral contact pads 12B, 12C, and these are each arranged respectively on either side of the central contact pad 12A.

 For the constitution of an inverter, both of the side contact pads 12B, 12C are active contact pads.

 In other words, these two lateral contact pads 12B, 12C are then each respectively connected to two connection terminals, not shown, intended to be connected alternately with a connection terminal connected to the central contact pad 12A.

 For the constitution of a simple switch, only one of the lateral contact pads 12B, 12C is active, the other then being a simple rest contact pad, which, possibly, can even be omitted.

 In the embodiment shown, the central contact pad 12A is reduced to a simple plate 28A, duly connected to the corresponding connection terminal.

 The side contact pads 12B, 12C themselves have, in addition to such a plate 28B, 28C, a contact grain 29B, 29C projecting therefrom.

 In the embodiment shown, the conductive brush 14, which is metallic, being for example made from a strip duly cut and shaped, comprises, overall, in V, on the one hand, a middle part 30A, and , on the other hand, two lateral arms 32B, 32C.

 Through its central part 30A, the conductive brush 14 is in pivoting and sliding contact with the central contact pad 12A, this central part 30A locally exhibiting for this purpose, in its central zone, a half-wave deformation 33, which extends transversely over its entire width, and whose profile is in practice semi-circular.

 By its lateral arms 32B, 32C, the conductive brush 14 is able to carry alternately on the lateral contact pads 12B, 12C, these lateral arms 32B, 32C each having respectively for this purpose projecting on their lower surface contact grains 34B , 34C.

 In the embodiment shown, the middle part 30A forms the bottom of a depression 36, of trapezoidal profile, and the V formed between them by the lateral arms 32B, 32C is much more open than that formed between them by the sides of this depression 36.

 In practice, the lateral arms 32B, 32C extend almost in alignment with one another.

 According to the invention, it is associated, with the conductive brush 14, an auxiliary member 40, which, engaged with it at the level of the central contact pad 12A, on the other side of it relative to this central contact pad 12A , generally extends parallel to it from the latter.

 Preferably, and as shown, the auxiliary member 40 extends to the level, at least, of one or the other of the lateral contact pads 12B, 12C.

 In practice, in the embodiments shown, this auxiliary member 40 comprises, like the conductive brush 14, two arms 41B, 41C, at the rate of one by contact pad 12B, 12C lateral, and, in a generally symmetrical manner, the one relative to the other, these arms 41B, 41C each extend respectively respectively generally parallel to those 32B, 32C of the conductive brush 14, up to the level of the lateral contact pads 12B, 12C.

 In practice, also, this auxiliary member 40 is made of synthetic material, and, at least locally, it has a multiple thickness, and, preferably, at least double, that of the conductive brush 14.

 In practice, finally, it is through this auxiliary member 40 that the operating button 11, and, more precisely, the drive member 22 thereof, acts on the conductive brush 14.

 In the embodiment shown, the conductive brush 14 is engaged by shape configuration with the auxiliary member 40.

 To this end, the auxiliary member 40 forms in its middle part a boss 42 by which it is engaged in the depression 36 of the conductive brush 14.

 Preferably, this engagement is done without play.

 In other words, the conductive brush 14 is wedged on the auxiliary member 40.

 Preferably, also, the conductive brush 14 is jointly secured to the auxiliary member 40.

 For example, this joining can be simply ensured by gluing or welding.

 However, in the embodiment shown, it is ensured by crimping.

 To this end, the auxiliary member 40 comes in one piece at least one lug 43, which protrudes from the lower surface of its boss 42, and which, engaged in a bore 44 of the middle part 30A of the conductive brush 14, is duly subdued, for example by ultrasound, in this one, FIG. 3.

 In practice, two pins 43 are provided, each being respectively disposed on either side of the half-wave deformation 33 of the conductive brush 14, and, for their anchoring therein, the corresponding holes 44 go to s flaring from the inside, on the side of the auxiliary member 40, towards the outside, on the side of the central contact pad 12A.

 The arms 41B, 41C of the auxiliary member 40 each extend respectively on either side of its boss 42.

 On the side of the drive member 22 of the operating button 11, this boss 42 forms, in the embodiment shown, a depression 36 ′, in the manner of the depression 36 of the conductive brush 14.

 Thus, the auxiliary member 40 generally has the same V shape as the conductive brush 14, and, like the lateral arms 32B, 32C of the latter, its arms 41B, 41C are almost in alignment with one of the other.

 A positioning boss 45 being associated with the conductive brush 14 for passing from neutral to tilting, this positioning boss 45 is in practice carried by the auxiliary member 40.

 More specifically, it protrudes from the bottom of the depression 36 'thereof.

 It is against this positioning boss 45 that the drive finger 24 carries.

 In the embodiment shown, this positioning boss 45 is flanked, longitudinally, of two flanges 46, for better rigidity of the auxiliary member 40.

 Finally, in the embodiment shown, the auxiliary member 40 laterally carries two pins 48 by which it engages with slides 49 provided for this purpose on the side walls 15 of the housing 10, perpendicular to the bottom wall 16.

 It is therefore through it that, in this embodiment, the conductive brush 14 is articulated to slide on the housing 10.

 For example, and as shown, the slides 49 are each simply formed between two ribs 50 provided for this purpose projecting from the side walls 15 of the housing 10.

 In the various embodiments shown, the arms 41B, 41C of the auxiliary member 40 generally have a massive shape and their ends extend substantially flush with those of the lateral arms 32B, 32C of the conductive brush 14.

 Their cross section is for example generally quadrangular, and, for example, rectangular.

 In the embodiment more particularly shown in Figures 1 to 5, the auxiliary member 40 extends at a distance from the conductive brush 14 over at least part of its length, that is to say over at least part the length of its arms 41B, 41C, between the central contact pad 12A and one and the other of the side contact pads 12B, 12C, thus being at a distance from the conductive brush 14 at, at least, these lateral contact pads 12B, 12C.

 In practice, in this embodiment, the auxiliary member 40 extends at a distance from the conductive brush 14 over the entire length of its arms 41B, 41C, progressively moving away from the conductive brush 14 from the part median 30A of it.

 In other words, the arms 41B, 41C of the auxiliary member 40 extend in this case overhanging over their entire length.

 In operation, the conductive brush 14 switches from a contact pad 12B, 12C lateral to the other, when the operating button 11 is itself tilted from one of its positions to the other.

 The auxiliary member 40 then intervenes by mass effect, both because of its own mass and because of its configuration.

 In the variant embodiment shown in FIG. 6, the auxiliary member 40 extends in contact with the conductive brush 14 over at least part of its length, that is to say over at least part of the length of its arms 41B, 41C, between the central contact pad 12A and one and the other of the side contact pads 12B, 12C, thus being in contact with the conductive brush 14 at the level, at least, of these contact pads 12B, 12C lateral.

 In practice, in this embodiment, the auxiliary member 40 is in contact with the conductive brush 14 over the entire length of its arms 41B, 41C, and therefore, jointly, over the entire length of the lateral arms 32B , 32C of the conductive brush 14 from the middle part 30A of this conductive brush 14.

 As a corollary, it is thickened to accentuate the mass effect.

 In the alternative embodiments shown in Figures 7 to 9, the auxiliary member 40 extends at a distance from the conductive brush 14, as in the embodiment of Figures 1 to 5, but, between it and the conductive brush 14 intervene elastic means.

 For example, in FIG. 7, it is, for each of the arms 41B, 41C of this auxiliary member 40, a blade 52, made of elastically deformable material, which, on one side, is in contact with this auxiliary member 40 , and which, on the other side, is in contact with the conductive brush 14, and, more precisely, the corresponding lateral arm 32B, 32C of this conductive brush 14.

 Alternatively, Figures 8 and 9, the elastic means used comprise at least one spring.

 For example, in FIG. 8, it is a spring 52 ′ of the coil spring type which, inserted between the auxiliary member 40 and the conductive brush 14, is for example, and as shown, at least partially engaged in a housing 53 provided for this purpose recessed in the auxiliary member 40.

 As a variant, in FIG. 9, it is a leaf spring 52 "folded in a U.

 In the variant embodiment shown in FIG. 10, the auxiliary member 40 extends in contact with the conductive brush 14 over at least part of its length, as in the embodiment of FIG. 6.

 But, jointly, between the central contact pad 12A and each of the lateral contact pads 12B, 12C, the auxiliary member 40 comprises a zone of reduced thickness 54, forming a hinge, at the right of which it extends locally away from the conductive broom 14.

 In the embodiment shown, this thinner zone 54 extends at the root of the arms 41B, 41C of the auxiliary member 40, at the connection of these arms 41B, 41C to the middle part of the auxiliary member 40 comprising ledges 46.

 In practice, it generally results from a notch 55 recessing transversely in V the lower surface of the corresponding part of the auxiliary member 40.

 Be that as it may, such a thinner zone 54 may as well be provided in any one of the preceding embodiments, in combination with the provisions specific to these.

 In the variant embodiment shown in FIG. 11, the auxiliary member 40 extends away from the conductive brush 14, as in the embodiment of FIGS. 1 to 5.

 But, jointly, it is extended by an elastically deformable tab 56 beyond each of the lateral contact pads 12B, 12C, for cooperation with a fixed projection 57 which, linked to the housing 10, is interposed on the path of this elastically tab deformable 56.

 In other words, each of the arms 41B, 41C of the auxiliary member 40 is extended, in practice in one piece, by such an elastically deformable tab 56.

 In operation, this elastically deformable tab 56 comes to bear on the corresponding fixed projection 57, FIG. 12A, before crossing it by elastic deformation, FIG. 12B.

 This results in momentary braking of the auxiliary member 40.

 In the variant embodiment illustrated in FIGS. 13 and 14, braking of the same type is obtained by the "dash-pot" effect.

 To this end, the auxiliary member 40 struggles in an enclosure 58 which it closes at least partially and which can, for example, be mobile, by being linked to the operating button 11.

 Of course, the present invention is not limited to the embodiments described and shown, but encompasses any variant and / or combination of their various elements.

Claims (16)

 1. A switch mechanism of the kind comprising, in a housing (10), an operating button (11) pivotally mounted available to the user, at least two contact pads (12A, 12B) established remotely. one from the other, and, for the establishment of an electrical connection between these contact pads (12A, 12B), a conductive brush (14) which, under the control of the operating button (11), is mounted pivoting in contact with one (12A) of the contact pads (12A, 12B), said central contact pad, between a first position, of opening, for which it is jointly spaced from the other (12B) pad contact, said lateral contact pad, and a second, closed position, for which it is on the contrary jointly in contact with this lateral contact pad (12B), characterized in that it is associated with the conductive brush (14) an auxiliary member (40), which, engaged with it at the level of the central contact pad (12A), on the other side of it relative to this central contact pad (12A), extends generally parallel to it.  2. Switch mechanism according to claim 1, characterized in that the auxiliary member (40) extends to the level, at least, of the lateral contact pad (12B).  3. Switch mechanism according to any one of claims 1, 2, characterized in that, over at least part of its length, between the central contact pad (12A) and the lateral contact pad (12B), the auxiliary member (40) extends in contact with the conductive brush (14).  4. Switch mechanism according to claim 3, characterized in that, at least at the contact pad (12B) side, the auxiliary member (40) is in contact with the conductive brush (14).  5. Switch mechanism according to any one of claims 1, 2, characterized in that, over at least part of its length, between the central contact pad (12A) and the lateral contact pad (12B), the auxiliary member (40) extends away from the conductive brush (14).  6. Switch mechanism according to claim 5, characterized in that, at least at the level of the lateral contact pad (12B), the auxiliary member (40) extends at a distance from the conductive brush (14).  7. Switch mechanism according to claim 6, characterized in that, between the auxiliary member (40) and the conductive brush (14), intervene elastic means.  8. Switch mechanism according to claim 7, characterized in that said elastic means comprise a blade (52) of elastically deformable material which, on one side, is in contact with the auxiliary member (40), and which, on the other side, is in contact with the conductive brush (14).  9. Switch mechanism according to claim 7, characterized in that said elastic means comprise at least one spring (52 ', 52 ").  10. Switch mechanism according to claim 6, characterized in that, beyond the lateral contact pad (12B), the auxiliary member (40) is extended by an elastically deformable tab (56), for cooperation with a fixed projection (57) interposed on the path thereof.  11. Switch mechanism according to claim 6, characterized in that the auxiliary member (40) struggles in an enclosure (58) which it closes at least partially.  12. Switch mechanism according to any one of claims 1 to 9, characterized in that, between the central contact pad (12A) and the lateral contact pad (12B), the auxiliary member (40) comprises a thinner zone (54) forming a hinge.  13. Switch mechanism according to any one of claims 1 to 12, characterized in that, the conductive brush (14) comprising two lateral arms (32B, 32C), for cooperation, alternatively, with one or the other than two lateral contact pads (12B, 12C), the auxiliary member (40) also comprises two arms (41B, 41C), which, each respectively, extend generally parallel to those (32B, 32C) of the brush conductor (14).  14. Switch mechanism according to any one of claims 1 to 13, characterized in that the auxiliary member (40) is made of synthetic material.  15. Switch mechanism according to any one of claims 1 to 14, characterized in that, at least locally, the auxiliary member (40) has a thickness multiple of that of the conductive brush (14).  16. Switch mechanism according to any one of claims 1 to 15, characterized in that the operating button (11) acts on the conductive brush (14) via the auxiliary member (40).