EP0054465B1 - Electrical switch with pivoted control member - Google Patents

Description

The present invention relates generally to electrical switches of the kind comprising a body, an operating finger pivotally mounted on said body in two extreme positions, at least two contact pads disposed in said body, a conductive brush carried by the finger. of mancevre and comprising at least one contact strip suitable for cooperating with one of the contact pads, and means for controlling the conductive position which, acting between the other of said contact pads and the conductive brush, comprise a yoke positioning carried by said other contact pad and a positioning tab integral with the conductive brush and able to cooperate with said positioning yoke.

Such an electrical switch is found in particular in document FR _' -A-1219900.

It has the advantage of satisfying a great simplification of construction, the conductive brush which it comprises constituting by itself the positioning tongue of the position control means, so that the same part, namely this conductive brush , suitably cut and shaped, assumes a multiplicity of functions, and in particular those of current flow, contact pressure on the contact pads, and control of the position of the maneuvering finger.

But, in practice, in the embodiment described in the document FR-A-1 219 900 mentioned above, the conductive brush is reduced to a metal strip which, by its central zone, shaped for this purpose in V or U open, constitutes the positioning tongue intended to cooperate with the positioning yoke, and, by its lateral wings, constitutes contact strips in continuity with its central zone, and which, at its ends, is engaged in recesses of the operating finger in which it is thus buttressed, and therefore restrained.

This clamping of the conductive broom, combined with a cylindrical shape of the positioning yoke with which it cooperates, does not in practice allow safe operation of the assembly, since it can lead to untimely rebounds of the conductive broom on its pads. contact, and therefore the production of arcs detrimental to the longevity of said assembly.

It also does not guarantee good contact pressure on the contact pads, which excludes the possibility of a relatively high service intensity, of the order of ten amps for example.

Finally, it leads to a limited stroke for the operating finger and to a noisy operation thereof.

The reason is that, due to the clamping of the conductive brush at its ends, any elastic play of the contact strips reacts on the positioning tab formed between them, and vice versa.

The present invention generally relates to a provision making it possible to avoid these drawbacks, while making it possible to retain the advantages of a single embodiment of the conductive brush and of any one of the positioning members, tongue or yoke, associated with the operating finger.

More specifically, the present invention relates to an electrical switch of the kind comprising a body, an operating finger pivotally mounted on said body between two extreme positions, at least two contact pads arranged in said body, a conductive brush carried by the operating finger and comprising at least one contact strip capable of cooperating with one of the contact pads, and conductive position control means which, acting between the other of said contact pads and the conductive brush, comprise a positioning yoke carried by said other contact pad and a positioning tab integral with the conductive brush and able to cooperate with said positioning yoke, this electrical switch being characterized in that the positioning tongue is dissociated from the contact strip and is thus able to play elastically independently of it, and in that the free end at least of the contact strip extends to the right of a recess of the operating finger, so that it can play elastically freely.

For example, the positioning tab is offset transversely relative to the contact strip.

Alternatively, arranged in the axis of this contact strip, it is formed by means of a puncture in the conductive brush.

In both cases, although belonging to the same part, the positioning tab and the contact strip, which assume different functions, can advantageously play elastically independently of one another, it that is to say without inter-reaction between them, which guarantees the independence of execution between these functions.

This is all the more so as, preferably, according to the invention, the fixing of the conductive brush of the operating finger is done in passages or tongues of said conductive brush, at least some of which are offset transversely with respect to the lamella of contact.

Thus, the physical dissociation made according to the invention between the positioning tab and the contact strip advantageously results in a dissociation between the functions performed by these two parts.

In addition it is accompanied by the presence of elastic parts between the functional parts, which ensures free play to them.

This results in safe operation for the assembly, and, in particular, good contact pressure on the contact pads, and good position control for the maneuvering finger.

Admittedly, in document DE A 2 801 336 there is described an electrical switch in which the contact strip and positioning tab are dissociated.

But there is an electrical switch of another family than that to which belongs, like that described in the document FR-A-1 219 900, the electrical switch object of the present invention, since, unlike of these, the electric switch body carries by itself both the conductive brush and the corresponding contact pads.

Assuming possible a combination of the characteristics of the electrical switches described in this document DE-A-2 801 336 and the document FR-A-1 219 900, this does not lead to an electrical switch having the characteristics of the object of the present invention.

• la figure 1 est une vue, partie en élévation, et partie en coupe, suivant la ligne I-I de la figure 2, des principaux constituants d'un commutateur électrique suivant l'invention;
• la figure 2 est une vue en plan, suivant la ligne II-II de la figure 1, du balai conducteur mis en oeuvre dans ce commutateur électrique, représenté isolément;
• la figure 3 est, à échelle supérieure, une vue en coupe de ce balai conducteur, suivant la ligne III-III de la figure 2;
• les figures 4A, 4B, 4C sont des vues reprenant pour partie celle de la figure 1 et illustrant le fonctionnement du commutateur électrique suivant l'invention;
• la figure 5 est une vue analogue à celle de la figure 1, pour une variante de réalisation;
• la figure 6 est une autre vue analogue à celle de la figure 1, pour une autre variante de réalisation;
• la figure 7 est une vue en élévation d'une variante de réalisation d'un des constituants du commutateur électrique suivant l'invention, représenté isolément;
• les figures 8 et 9 sont des vues analogues à celle de la figure 3 et concernent chacune respectivement une forme de réalisation du balai conducteur mis en oeuvre dans un tel commutateur électrique;
• la figure 10 est une vue analogue à celle de la figure 1, et concerne une autre variante de réalisation;
• la figure 11 est une vue analogue à celle de la figure 2, pour le balai conducteur mis en oeuvre dans cette variante de réalisation;
• la figure 12 est une vue analogue à celle de la figure 2, pour une autre variante de réalisation de ce balai conducteur;
• la figure 13 est une vue en coupe longitudinale de cette variante de réalisation, suivant la ligne XIII-XIII de la figure 12;
• la figure 14 en est une vue en coupe transversale, suivant la ligne XIV-XIV de la figure 13;
• la figure 15 est une vue analogue à celle de la figure 1 et concerne une autre variante de réali sation.

The characteristics and advantages of the invention will become apparent from the description which follows, by way of example, with reference to the appended schematic drawings in which:

• Figure 1 is a view, partly in elevation, and partly in section, along line II of Figure 2, of the main components of an electric switch according to the invention;
• Figure 2 is a plan view, along line II-II of Figure 1, of the conductive brush used in this electrical switch, shown in isolation;
• Figure 3 is, on a larger scale, a sectional view of this conductive brush, along the line III-III of Figure 2;
• FIGS. 4A, 4B, 4C are views partly reproducing that of FIG. 1 and illustrating the operation of the electrical switch according to the invention;
• Figure 5 is a view similar to that of Figure 1, for an alternative embodiment;
• Figure 6 is another view similar to that of Figure 1, for another alternative embodiment;
• Figure 7 is an elevational view of an alternative embodiment of one of the components of the electrical switch according to the invention, shown in isolation;
• Figures 8 and 9 are views similar to that of Figure 3 and each relate respectively to an embodiment of the conductive brush used in such an electric switch;
• Figure 10 is a view similar to that of Figure 1, and relates to another alternative embodiment;
• Figure 11 is a view similar to that of Figure 2, for the conductive brush used in this embodiment;
• Figure 12 is a view similar to that of Figure 2, for another alternative embodiment of this conductive brush;
• Figure 13 is a longitudinal sectional view of this alternative embodiment, along the line XIII-XIII of Figure 12;
• Figure 14 is a cross-sectional view along the line XIV-XIV of Figure 13;
• Figure 15 is a view similar to that of Figure 1 and relates to another alternative embodiment.

In general, and as illustrated by these figures, the electrical switch according to the invention comprises a body 10, which, not forming part of the present invention, has only been shown diagrammatically by its outline, in lines interrupted, in FIG. 1, an operating finger 11, which is pivotally mounted on the body 10 between two extreme positions, and a conductive brush 12, which is carried by the operating finger 11.

The body 10 and the operating finger 11 are made of insulating material.

For its pivoting mounting, the operating finger 11, which is generally parallelepipedic, carries an axis 13 transversely.

It can be a separate part, but it can also be two pins projecting laterally projecting from the longitudinal sides of the operating finger 11.

In the body 10 are arranged at least two contact pads.

In the exemplary embodiments shown, these contact pads are three in number: there is a central pad 14, and two lateral pads 15, 15 '.

In the embodiment shown in FIGS. 1 to 4, the lateral contact pads 15, 15 ′ are each disposed respectively on either side of the central stud 14, in alignment with one another, but, for reasons which will appear below, the central contact pad 14 is offset transversely relative to the alignment formed by the lateral contact pads 15, 15 '(not visible in the figures).

Furthermore, in the embodiment shown in FIGS. 1 to 4, the contact pads 14 and 15, 15 ′ all form connection terminals by themselves, and these are connection terminals with hole 17 , for engagement of a driver, and screw 18, for tightening thereof, but this is not necessarily so.

On the contrary, the contact pads can constitute separate parts from the connection terminals with which they are associated, by being suitably electrically connected to them, and / or these connection terminals can be of a different type from those described above. above, and for example be tab connection terminals, or the like, allowing direct engagement of the conductors concerned or rapid connection thereof.

The conductive brush 12, which is shown in isolation in FIG. 2, is a part which comes in one piece from a metal strip, suitably cut and shaped.

It comprises at least one contact strip.

In the embodiment shown, two lateral contact pads 15, 15 'being provided, the conductive brush 12 comprises two contact strips 20, 20' each suitable for cooperating with the corresponding lateral contact pad 15.15 'respectively.

In the embodiment shown in Figures 1 to 4, the contact strips 20, 20 ' leave, at their end, for cooperation with the lateral contact feet 15, 15 ′, contact grains 21, 21 ′, in silver for example, or in silver metal, in a manner known per se; but it is not necessarily so.

For cooperation with these contact grains 21, 21 ', the contact pads 15, 15' have, in the embodiment shown in Figures 1 to 4, a rounded boss 22, 22 ', which can also be a boss reported, in silver or silver metal, if desired.

The operating finger 11 is associated with position control means, and these are conductive position control means which, acting between the central contact pad 14 and the conductive brush 12, comprise on the one hand a yoke positioning 25 carried by said central contact pad 14, and on the other hand a positioning tab 26 integral with the conductive brush 12 and able to cooperate with the positioning yoke 25.

According to the invention, the positioning tab 26 is dissociated from the contact strips 20, 20 ′ of the conductive brush 12 and is thus able to play elastically independently of these, and the free end at least, and in practice all , of each contact strip 20, 20 'of the conductive brush 12, extends in line with a recess 24, 24' of the operating finger 11, so that it can play elastically freely in contact with the contact pad 15 , 15 'corresponding, elastically deforming.

In practice, in the embodiment illustrated by FIGS. 1 to 4, the positioning tongue 26 extends in overhang from a rooting zone 27 belonging to the conductive brush 12, and it is transversely offset with respect to the contact strips 20, 20 ′, its rooting zone 27 being disposed at the end of a part 28 of the conductive brush 12 which, elongated in a strip parallel to the positioning tongue 26, is intermediate between it ci and the contact strips 20, 20 ′, connecting this positioning tab 26 and these contact strips 20,20 ′ in continuity.

In the embodiment shown in Figures 1 to 4, the positioning tab 26 is separated from the strip 28 by a slot 29 with disjointed lips, and similarly, this strip 28 is separated from the contact strips 20, 20 ' by slots 30, 30 'similar.

However, this is not necessarily so, the corresponding separations being able, on the contrary, to be made by joined lip slots, resulting from simple shearing and not from cutting.

The main thing is that the contact strips 20, 20 'on the one hand, and the positioning tab 26 on the other hand, can play elastically freely independently of each other.

At one of its ends, the strip 28 of the conductive brush 12, which forms a median part thereof, forms, by a development, the rooting zone 27 of the positioning tongue 26; at its other end, it has, in the embodiment illustrated in FIGS. 1 to 4, another similar opening 27 ′.

These openings 27, 27 ′, which are coplanar and correspond to the initial plane of the strip from which the conductive brush 12 is cut, are used to fix the latter to the operating finger 11.

In the embodiment illustrated by FIGS. 1 to 4, this fixing is done by crimping: crimping pins 32, 32 'coming from pillars 33, 33' of the operating finger 11 pass through passages 34, 34 'provided at this effect in the openings 27, 27 ′ of the conductive brush 12.

Likewise, a crimping pin 35 coming from a central pillar 36 of the operating finger 11 crosses a passage 31 of the conductive brush 12 provided for this purpose at the root of the contact strips 20, 20 ′ thereof, in position intermediate.

In the embodiment shown, the passages 34, 34 'and 31 are circular.

From its rooting zone 27, the positioning tongue 26 extends obliquely.

In the embodiment shown in Figures 1 to 4, its free end, or nose 37, forms a dihedral with a V-profile.

As shown in this exemplary embodiment, for the rest configuration of the positioning tongue 26, the bisector plane of the dihedron formed by its free end 37 is coincident with the plane containing the edge 48 of this dihedron 37 and the axis of rotation 13 of the operating finger 11.

Jointly, in this exemplary embodiment, the positioning yoke 25 with which the positioning tongue 26 cooperates has a convex profile, said here, for convenience, convex dihedral profile.

Preferably, as shown, the top zone of this screed is softened by a rounding.

In such a case, the electrical switch concerned constitutes a back-and-forth.

Indeed, the two extreme positions of its operating finger 11 are then stable.

For example, when the positioning tab 26 is supported on the side of the positioning yoke 25 opposite the lateral contact pad 15, FIG. 1, this support results in the application to the operating finger 11 of a tilting torque which, according to arrow F in FIG. 1, keeps the contact strip 20 of the conductive brush 12 in contact with this lateral contact pad 15.

As a result, electrical continuity is established between, on the one hand the central contact pad 14, which constitutes an arrival terminal, and, on the other hand, the lateral contact pad 15, which constitutes an output terminal .

The corresponding contact pressures are ensured by the fact that both the positioning tab 26 and the contact strip 20 are elastically deformed, independently of one another.

In FIGS. 1 and 4A, the elastic deformation that the contact strip 20, made possible by the corresponding recess 24 of the operating finger 11, is illustrated by the fact that this contact strip 20 deviates from the plane of the strip in which the conductive brush 12 is cut, materialized by the rooting zone 27 of the positioning tongue 26.

By acting on the operating finger 11 in the direction opposite to that of the arrow F in FIG. 1, a corresponding tilting of this operating finger 11 is caused, which leads, on the one hand, to the contact strip 20 to lose the contact with the lateral contact pad 15, and on the other hand, the positioning tab 26 to be crossed, by elastic deformation, the positioning yoke 25, FIG. 4B.

Beyond this neutral position corresponding to the crossing of the positioning yoke 25, the operating finger 11 continues to tilt by itself, until the contact strip 20 'comes to bear against the stud corresponding lateral contact 15 ′, according to methods analogous to those described above, the positioning tab 26 then bearing on the side of the positioning yoke 25 opposite this lateral contact pad 15 ′, FIG. 4C.

The central contact pad 14 is then, in a stable manner, in electrical continuity with the lateral contact pad 15 '.

In the variant embodiment illustrated in FIG. 5, the positioning yoke 25 has a concave dihedral profile.

The electric switch concerned then constitutes a mid-point reverser with momentary continuity, its operating finger 11 being permanently resiliently returned to the middle position for which, as shown, the contact strips 20, 20 ′ of the conductive brush 12 are the one and the other at a distance from the lateral contact pads 15,15 '.

In such a case, in fact, the extreme positions of the operating finger 11 are unstable, and the electrical continuity between the central contact pad 14 and the corresponding lateral contact pad 15, 15 ′ is only maintained as long as a corresponding action is exerted on this operating finger 11.

In the alternative embodiment illustrated in FIG. 6, which combines the two preceding ones, the positioning yoke 25 has a concave dihedral profile but it also comprises two oblique sides 38, 38 ′ on either side of the concave dihedral that it forms, in the opposite direction to that of the flanks of this dihedral, and it therefore has two edges 39, 39 '.

The electric switch concerned in this case constitutes a mid-point inverter with maintained continuity.

Indeed, its operating finger 11 can occupy one or the other of three stable positions, namely two extreme positions for which the central contact pad is in electrical continuity with the corresponding lateral contact pad 15, 15 ′, and a middle position for which this electrical continuity is interrupted.

In the foregoing, the positioning yoke 25 has a generally symmetrical profile.

This is not necessarily so.

On the contrary, in the embodiment schematically illustrated in FIG. 7, it can comprise an asymmetrical profile, by forming in continuity first a convex dihedral then a concave dihedral.

The electric switch concerned then constitutes a mid-point inverter with continuity maintained for one of the extreme positions of its operating finger, which is stable, and with momentary continuity for the other of the extreme positions thereof, which is unstable. .

In the embodiment illustrated in FIG. 8, the free end, or nose 37, of the lan = positioning spout 26, forms a gutter with a semicircular profile.

In the embodiment shown in FIG. 9, it forms a V-shaped dihedron, as before, but, for the rest configuration, the bisector plane of this dihedral is oblique with respect to the plane containing the edge 48 thereof and the axis of rotation 13 of the operating finger 11.

This arrangement is such as to facilitate the sliding of the positioning tongue 26 on the corresponding positioning yoke, at least for one of the sides thereof.

In the embodiment illustrated in FIGS. 10, 11, the free end, or nose 37, of the positioning tongue 26 is subjected to a spring 40 intended to reinforce the contact pressure of this positioning tongue 26 on the positioning yoke 25 with which it cooperates, in the case where, for at least certain applications, the position control of the operating finger 11 must be particularly firm.

To maintain this additional spring 40, which rests on the bottom of a well 41 formed for this purpose in the operating finger 11, the free end 37 of the positioning tongue 26 protrudes, in the embodiment shown , a spoiler 42 on which said additional spring 40 is engaged; alternatively, the groove of the V formed by this free end 37 serves as a support and support housing for the additional spring 40 (not shown).

In addition, in the embodiment shown, the positioning tab 26 is separated from the central strip 28 of the conductive brush 12 only by a slot with joined lips, and this strip 28 runs only over one half of the conductive brush 12 , between the positioning tab 26 and the contact strip 20.

Finally, in this embodiment, the passages 34 and 31 provided in the conductive brush 12 for the crimping pins suitable for fixing the latter to the operating finger 11 form buttonholes elongated in oval shape.

In the embodiment illustrated in FIGS. 12 to 14, the positioning tab 26 extends in the axis of the contact strips 20, 20 ′, and is formed by a punctured 43 of the conductive brush 12.

In addition, the contact strips 20, 20 'are offset relative to the plane of the frame 44 surrounding the puncture 43, this frame 44 extending in a bowl relative to these contact strips 20, 20'.

Finally, in this embodiment, the connection of the conductive brush 12 to the operating finger 11 is effected by snap-fastening, the frame 44 of this conductive brush 12 laterally projecting from the tongues 45 by which it is engaged in grooves 46 formed in a complementary manner in the operating finger 11, the corresponding engagement being effected by elastic deformation of this operating finger 11.

In the embodiment schematically illustrated in FIG. 15, the lateral contact pad 15 ′ is arranged opposite to the lateral contact pad 15, and a single contact strip 20 is provided on the conductive brush 12 for cooperation either with this contact pad 15, or with this contact pad 15 ', this contact strip 20 carrying for this purpose, on its opposite faces, two contact grains 21, 21'.

Furthermore, in this embodiment, the lateral contact pad 15 ′ does not by itself form a connection terminal, but a simple tab suitably connected to such a connection terminal.

In the foregoing, it has been admitted that the flanks of the dihedron of the positioning yoke used are generally planar. This is preferably so, except as regards the positioning yoke shown in FIGS. 1 to 4, for which, in order to avoid precise angular positioning of this positioning yoke, and therefore of the central contact pad 14 which the door, a conical shape is preferably given to this positioning yoke.

The qualifier dihedral given here to this clevis must therefore be understood broadly, to designate the corresponding profile, without necessarily resulting in the presence of an edge.

In addition, only two contact pads can be provided, a central contact pad and a side contact pad.

In all cases, and as will be understood, it is advantageously possible, by virtue of the dissociation occurring according to the invention between the positioning tab and the contact blade (s) of the conductive brush, to confer on this positioning tab, and to these contact strips, the required elasticity, independently of each other, by cutting to an appropriate width of the corresponding parts of the initial strip.

Claims (14)

1. An electrical change-over switch of the kind comprising a body (10), an operating finger (11) mounted pivotally on said body (10) between two limit positions, at least two contact studs (14, 15, 15') which are disposed in said body (10), a conducting arm member (12) which is carried by the operating finger (11) and which comprises at least one contact blade (20, 20') co-operable with one of the contact studs (15,15'), and conducting positional control means which, intervening between the other (14) of said contact studs and the conducting arm member (12), comprise a positioning cap (25) carried by said other contact stud, and a positioning tongue portion (26) which is integral with the conducting arm member (12) and which is co-operable with said positioning cap (25), characterised in that the positioning tongue portion (26) is dissociated from the contact blade (20, 20') and is thus capable of moving resiliently independently thereof, and that the free end at least of said contact blade (20, 20') extends in line with an opening (24, 24') of the operating finger (11) so that it can freely move resiliently.

2. An electrical change-over switch according to claim 1 characterised in that the conducting arm member (12) is fixed to the operating finger (11) at openings (31, 34, 34') or tongue portions (45) of said conducting arm member (12), at least some of which are offset transversely with respect to the contact blade (20, 20').

3. An electrical change-over switch according to claim 1 wherein the positioning tongue portion (26) extends in a cantilever configuration from a root region (27) and the free end (37) of said positioning tongue portion (26) forms a dihedron of V-shaped profile, characterised in that, for the rest configuration of the positioning tongue portion (26), the plane bisecting the dihedron formed by the free end (37) thereof is coincident with the plane containing the intersection edge (48) of said dihedron and the axis of rotation (13) of the operating finger (11).

4. An electrical change-over switch according to claim 1 wherein the positioning tongue portion (26) extends in a cantilever configuration from a root region (27) and the free end (37) of said positioning tongue portion (26) forms a dihedron of V-shaped profile, characterised in that, for the rest configuration of the positioning tongue portion (26), the plane bisecting the dihedron formed by the free end (37) thereof is inclined with respect to the plane containing the intersection edge (48) of said dihedron and the axis of rotation (13) of the operating finger (11).

5. An electrical change-over switch according to claim 1 wherein the positioning tongue portion (26) extends in a cantilever configuration from a root region (27), characterised in that the free end (37) of the positioning tongue portion (26) is subjected to a spring (40).

6. An electrical change-over switch according to claim 5 characterised in that the free end (37) of the positioning tongue portion (26) comprises a projecting lug portion (42) for holding the spring (40) acting thereon.

7. An electrical change-over switch according to claim 6 characterised in that the free end (37) of the positioning tongue portion (26) forms a groove acting as a housing for holding and supporting the spring (40) acting thereon.

8. An electrical change-over switch according to any one of claims 3 to 7 wherein the positioning tongue portion (26) is offset transversely with respect to the contact blade (20, 20'), characterised in that the root region (27) of the positioning tongue portion (26) is disposed at the end of a part (28) of said conducting arm member (12) which, elongated to form a strip parallel to said positioning tongue portion (26), is intermediate between same and the contact blade (20, 20'), connecting said positioning tongue portion (26) and said contact blade (20, 20') to provide continuity thereof.

9. An electrical change-over switch according to claim 8 characterised in that, at its end remote from the root region (27) of the positioning tongue portion (26), the strip connecting same to the contact blade itself comprises a root region (27') by way of which it is connected to the operating finger (11).

10. An electrical change-over switch according to any one of claims 3 to 9 and wherein the positioning tongue portion (26) extends on the axis of the contact blade characterised in that said positioning tongue portion (26) is formed by means of an opening (43) cut in the conducting arm member (12).

11. An electrical change-over switch according to any one of claims 1 to 10 characterised in that the positioning cap (25) is of a convex profile, for example a profile in the form of a convex dihedron.

12. An electrical change-over switch according to any one of claims 1 to 11 characterised in that the positioning cap (25) has a profile in the form of a concave dihedron.

13. An electrical change-over switch according to claim 12 characterised in that the positioning cap (25) comprises two inclined sides (38, 38') which are each disposed on respective sides of the concave dihedron formed thereby, in a direction opposite to that of the sides of said dihedron, and accordingly has two ridges.

14. An electrical change-over switch according to any one of claims 1 to 13 characterised in that the positioning cap (25) is of an asymmetric profile with a concave dihedron and a convex dihedron.

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