FIELD OF THE INVENTION

[0001] The present description relates to the technical field of electrical installations and, more particularly, it relates to a changeover switch with rocking control member .

BACKGROUND ART

[0002] As is known, the use of modular electric apparatuses such as modular switches or modular sockets - each designed to carry out a predetermined function - is widespread in modern electrical systems such as for example, household electric installation systems. Relatively more complex assemblies may be obtained by conveniently combining such modular apparatuses with one another, such assemblies making available the sum of the various functions.

[0003] So-called changeover switches are among the possible various types of modular switches.

[0004] A changeover switch 1 of the known art is depicted in figure 1, which shows a side view of the changeover switch 1, and in figure 2, which shows an exploded axonometric view of the changeover switch 1.

[0005] The changeover switch 1 comprises a support structure 2 made of insulating material, or case 2, having a box-like shape and defining an inner compartment for housing and supporting electromechanical components belonging to the changeover switch 1. The changeover switch 1 further comprises two sliding buttons 3a, 3b, each of which is under a respective covering member 4a, 4b, which is mechanically coupled, for example snap coupled, with the associated sliding button 3a, 3b so as to slide together therewith. The sliding buttons 3a, 3b are adapted and configured to slide with respect to case 2 along a respective sliding axis. The sliding button 3a in particular is adapted to slide along axis A-A while the sliding button 3b is adapted to slide along axis B-B .

[0006] The changeover switch 1 comprises two movable contacts 7a, 7b and two fixed contacts 8a, 8b. The movable contacts 7a, 7b are arranged on two opposite ends of an electrically conductive rocking switching member 6 comprised in the changeover switch 1 and having a central portion 6c resting on an electrically conductive support fulcrum 9. The support fulcrum 9 is made according to the teachings of European Patent EP2304749 B1.

[0007] A user may operate the changeover switch 1 by means of the actuation buttons 3a, 3b by sliding the aforesaid buttons 3a, 3b by applying a manual pressure force thereon in order to cause a rotation of the rocking switching member 6. The latter has three stable angular positions : - a first angular end of stroke position, in which the movable contact 7a is in contact with the fixed contact 8a and in which the movable contact 7b is separate from the fixed contact 8b;

- a second angular end of stroke position, in which the movable contact 7b is in contact with the fixed contact 8b and in which the movable contact 7a is separate from the fixed contact 8a;

- a central angular position in which both movable contacts 7a, 7b are separate from the respective fixed contacts 8a, 8b.

[0008] The changeover switch 1 further comprises a rocking control member 5 operatively coupled, and in particular hinged, to both buttons 3a, 3b and which may be moved, in particular rotated, by means of the aforesaid buttons 3a, 3b so as to cause the rocking switching member 6 to selectively take on one of the three stable angular positions. A support frame 10 made of electrically insulating material is also comprised in the changeover switch 1, the support frame being inserted in case 2 to support the buttons 3a, 3b and the rocking control member 5. From a functional perspective, the support frame 10 may be considered part of case 2, given that it also performs a housing and support function for certain components of the changeover switch 1. [0009] A changeover switch 1 of the above-described type has been widely used to date for example, for generating electric control signals in order to raise or lower rolling shutters or automated blinds associated with doors or windows in residential or commercial buildings.

[0010] Although it is widely used, a changeover switch of the above-described type, which in certain aspects is similar to the switch described in Patent US 4,166,935, nevertheless has certain drawbacks.

[0011] A first drawback is given by the fact that the changeover switch 1 has a relatively high axial volume.

[0012] A second drawback is given by the fact that the manual pressure exerted on one of the two buttons 3a, 3b to push it towards case 2 automatically causes a sliding of the other of the two buttons in the direction moving away from case 2, whereby when the rocking switching member 6 is in one of the angular end of stroke positions, one button is lowered while the other button is raised, thus causing an unpleasant appearance due to the misalignment between the buttons 3a, 3b. Apart from this drawback of an appearance-related nature, the fact that the movement of one of the two buttons also results in the movement of the other button moreover increases the overall inertia of the kinematic mechanism perceived by a user when the user manually operates the changeover switch 1.

[0013] A third drawback is given by the fact that starting from this circumstance in which the rocking switching member 6 is in one of the two angular end of stroke positions, if there is a desire to bring said rocking member 6 into the central angular position, there is a need to exert a manual pressure on the button which is higher with respect to the other one. If the manual pressure force applied to the button is not sufficiently accurately controlled, the central angular position may be overtaken and the rocking switching member 6 may be undesirably brought into the other of the two angular end of stroke positions.

[0014] Thus, the need is felt to make a changeover switch with a rocking control member which is capable of entirely or partly overcoming the drawbacks of the changeover switch of the above-described known art.

[0015] It is the object of the present description to make available a changeover switch which is such that it meets the above-described need.

[0016] Such an object is achieved by means of a changeover switch with rocking control member as defined in general in claim 1. Preferred and advantageous embodiments of the aforesaid changeover switch are defined in the appended dependent claims. [0017] The invention will be better understood from the following detailed description of particular embodiments thereof, given by way of example and therefore non limiting in relation to the accompanying drawings briefly described in the paragraph below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a side plan view of a changeover switch of the known art.

[0019] Figure 2 is an exploded three-dimensional view of the changeover switch in figure 1.

[0020] Figure 3 is a side plan view of an embodiment of a changeover switch comprising a covering and actuating member .

[0021] Figure 4 is a three-dimensional view of the changeover switch in figure 3, from which the covering and actuating member has been removed.

[0022] Figure 5 is an exploded three-dimensional view of the part of changeover switch shown in figure 4.

[0023] Figure 6 is a side view of a part of the changeover switch in figure 3, in which two side buttons, a rocking control member and a central button are shown.

[0024] Figure 7 is a side view of the part of changeover switch in figure 6, from which the central button has been removed.

[0025] Figure 8 is a three-dimensional view of one of the two side buttons of the changeover switch in figure 3.

[0026] Figure 9 is a three-dimensional view of a part of the changeover switch in figure 3, in which three connecting terminals and a rocking switching member are shown .

[0027] Figure 10 is a three-dimensional view of a mounting frame of the changeover switch in figure 3.

[0028] Figure 11 is a three-dimensional view of a rocking control member of the changeover switch in figure 3.

[0029] Figure 12 is a three-dimensional view of the central button of the switch in figure 3.

[0030] Figure 13 is a three-dimensional view of the covering and actuating member in figure 3.

DETAILED DESCRIPTION

[0031] With reference to accompanying figures 3 to 13, a particular non-limiting embodiment of a changeover switch 100 is now described. Such a changeover switch 100 for example is a modular electric apparatus. For the purposes of the present description, modular electric apparatus means an electric apparatus intended to be installed in a wall mounting frame placed side-by-side with other electric apparatuses of the same type or other modular electric apparatuses in general, such as for example, electric sockets or sockets of other electric control apparatuses for controlling and distributing electric power .

[0032] The changeover switch 100 can be operated manually by a user and can be used for example, however without any limitation, to control an electromechanical device electrically connected thereto, such as for example, a rolling shutter or automated blind or curtain, or to control an optical signaling device, for example an optical signaling device adapted to take on three different signaling statuses.

[0033] The changeover switch 100 comprises a case 20 made of electrically insulating material, e.g. plastic, a first side button 30a and a second side button 30b, both sliding with respect to case 20. The side buttons 30a, 30b preferably are both directly or indirectly restrained to case 20 so as to slide with respect to the latter, along a respective sliding axis A-A, B-B between an initial backward position and a final forward position. For the purposes of the present description, "final forward position" means an end of stroke position in the approaching movement of the side buttons 30a, 30b to case 20, while "backward position" means an end of stroke position in the distancing movement of the side buttons 30a, 30b from case 20. Therefore, it is apparent that the terms "forward" and "backward" refer to the position of the side buttons 30a, 30b with respect to case 20. According to an advantageous embodiment, the side buttons 30a, 30b are independent from each other in the translation along the respective sliding axes A-A, B-B, in particular they are mechanically directly or indirectly coupled to case 20 so as to be independent from each other in translation.

[0034] According to a particularly advantageous embodiment, the first side button 30a and the second side button 30b are adapted and configured to translate with respect to case 20 along the respective sliding axes A-A, B-B independently from each other.

[0035] According to an advantageous embodiment, the changeover switch 100 comprises, for each of the two side buttons 30a, 30b, at least one elastic return element 32a, 32b configured to push the respective side button 30a, 30b into the initial backward position. According to a preferred embodiment, such an initial backward position is the only stable position of the side buttons 30a, 30b. In the non-limiting example depicted in the drawings, the changeover switch 100 in particular comprises two helical springs 32a, 32b, each of which pushes the respective side button 30a, 30b into the final backward position.

[0036] The side buttons 30a, 30b preferably are made of electrically insulating material, e.g. plastic.

[0037] Case 20 of the changeover switch 100 comprises a tubular side wall 22 and a bottom wall 23 joined to the side wall 22. Case 20 comprises an open side 24 opposite the bottom wall 23. The tubular side wall 22 and the bottom wall 23 delimit an inner compartment adapted to accommodate the electromechanical components of the changeover switch 100 and at least three electric connecting terminals 73a, 73b, 73c, for example three screw operated clamps.

[0038] The changeover switch 1 further comprises a rocking control member 50 adapted to be rotated in two opposite directions by means of the first side button 30a and the second side button 30b, respectively. According to one embodiment, the side buttons 30a, 30b are independent from the rocking control member 50, for example the changeover switch 1 being devoid of any direct mechanical constraint between the side buttons 30a, 30b and the rocking control member.

[0039] According to a particularly advantageous embodiment, the side buttons 30a, 30b do not interfere in abutment with the rocking control member 50 in the initial backward position thereof, said side buttons 30a, 30b being adapted and configured to come into contact with the rocking control member 50 from a certain point onward, along the sliding thereof from the initial backward position to the final forward position thereof.

[0040] According to an advantageous embodiment, each of the side buttons 30a, 30b comprises at least one respective pressure transmission element 31a, 31b adapted to come into abutment with the rocking control member 50 from a certain point onward, along the sliding from the initial backward position to the final forward position. The pressure transmission elements 31a, 31b allow a manual pressure applied to the side buttons 30a, 30b to be transmitted to the rocking control member 50 in order to cause a rotation of the latter. The rocking control member 50 has three stable angular positions and in particular, one central angular position and two side angular end of stroke positions.

[0041] The pressure transmission elements 31a, 31b preferably each comprise at least one wing protruding from the side buttons 30a, 30b towards the rocking control member 50. According to an advantageous embodiment, each side button 30a, 30b comprises two pressure transmission elements spaced apart from each other, in particular two wings protruding from the side buttons 30a, 30b towards the rocking control member 50.

[0042] According to an advantageous embodiment, the rocking control member 50 comprises a central body 51c from which two side abutment portions 51a, 51b protrude, each protruding towards a respective side button 30a, 30b. Such side abutment portions 51a, 51b each come into contact with a respective side button 30a, 30b during the sliding of the side button from the backward position to the forward position. In the particular example depicted in the drawings, such side portions 51a, 51b are two brackets, preferably flat brackets, which protrude from the opposite sides with respect to the central body 51c and which are adapted to come into contact with the protruding wings 31a, 31b of the side buttons 30a, 30b during the sliding of the side buttons 30a, 30b from the initial backward position to the final forward position.

[0043] According to a preferred embodiment, the rocking control member 50 is arranged between the two side buttons 30a, 30b in a central position with respect to said side buttons 30a, 30b.

[0044] The changeover switch 100 further comprises a rocking switching member 60 having a first end portion 61 and a second end portion 62 opposite the first end portion 61. The rocking switching member 60 preferably comprises a main plate-like body made of electrically conductive material, e.g. copper. The rocking switching member 60 is made for example of cut metal sheet.

[0045] The changeover switch 100 further comprises a first movable contact 70a and a second movable contact 70b arranged on the rocking switching member 60. The rocking switching member 60 is therefore a movable contact-holder support, in particular a rotatable contact-holder. The first movable contact 70a and the second movable contact 70b preferably are arranged on the first end portion 61 of the rocking switching member 60, on opposite sides of the rocking switching member 60.

[0046] The changeover switch 100 further comprises a first fixed contact 80a and a second fixed contact 80b and an electrically conductive support fulcrum 90 on which the rocking switching member 60 rests. According to a particularly advantageous embodiment, the support fulcrum 90 is fastened to the bottom wall 23 of case 20 by means of a coupling system made according to the teachings of Patent Application No. W02017141093 A1 entitled "Modular circuit breaker with a coupling system of the supporting fulcrum".

[0047] The support fulcrum 90 is made of bent and cut metal sheet, for example.

[0048] The support fulcrum 90 preferably comprises a support and contact portion 91 shaped so as to define a groove, for example having a V-shaped cross section. The support fulcrum 90 more preferably further comprises a connection portion 93 which forms part of a connecting terminal 73c of the changeover switch 100.

[0049] The second end portion 62 of the rocking switching member 60 rests on the support fulcrum 90, in particular on the support and contact portion 91.

[0050] According to an advantageous embodiment, the rocking switching member 60 is an L-shaped plate having a larger base which rests on the support fulcrum 90 and an arm which is narrower than the base and to which the movable contacts 70a, 70b are fastened.

[0051] The movable contacts 70a, 70b are for example, two opposite pads made of electrically conductive material, for example made of silver alloy, fastened, e.g. welded, at opposite sides of the first end portion 61 of the rocking switching member 60.

[0052] The rocking control member 50 is adapted and configured to rotate the rocking switching member 60 between the following three stable angular positions:

- a first angular end of stroke position, in which the movable contact 70a is in contact with the fixed contact

80a and in which the movable contact 70b is separate from the fixed contact 80b;

- a second angular end of stroke position, in which the movable contact 70b is in contact with the fixed contact 80b and in which the movable contact 70a is separate from the fixed contact 80a;

- a central angular position in which both movable contacts 70a, 70b are separate from the respective fixed contacts 80a, 80b.

[0053] According to a preferred embodiment, the fixed contacts 80a, 80b are fastened, e.g. welded, to respective electrically conductive contact-holder supports 83a, 83b, for example made of copper, fastened to or integrated in the respective connecting terminals 73a, 73b. The fixed contacts 80a, 80b are for example, two opposite pads made of electrically conductive material, for example made of silver alloy.

[0054] According to an advantageous embodiment, the first movable contact 70a and the second movable contact 70b are adapted and configured to move in a space defined between the first fixed contact 80a and the second fixed contact 80b. The first fixed contact 80a and the second fixed contact 80b preferably are spaced apart and facing each other in such an embodiment .

[0055] According to an advantageous embodiment the changeover switch 100 comprises a support frame 21 inserted in case 20, to which a given number of components of the changeover switch 100 are fastened, such as for example, the side buttons 30a, 30b and the rocking actuator 50. The support frame 21 is for example, snappingly fitted in case 20. The support frame 21 preferably is made of electrically insulating material, e.g. plastic. From a functional perspective, the support frame 21 may be considered part of case 20 given that it also performs a housing and support function for certain components of the changeover switch 100. It is therefore correct to affirm that case 20 comprises the support frame 21.

[0056] The support frame 21 comprises one or more side walls 25, 26 and a bottom wall 27.

[0057] An opening 28 adapted to be crossed by the fixed contacts 80a, 80b and by the movable contacts 70a, 70b preferably is defined in the bottom wall 27. The aforesaid opening 27 preferably is crossed by the rocking switching member 60 and by the contact-holder supports 83a, 83b of the fixed contacts 80a, 80b so that the fixed contacts 80a, 80b and the movable contacts 70a, 70b are arranged in the support frame 21.

[0058] According to an advantageous embodiment, the elastic return elements 32a, 32b have an end portion which reacts against the bottom wall 27 of the support frame 21 and which preferably rests on the latter. It is worth noting that the elastic return elements 32a, 32b in this embodiment are operatively interposed between the support frame 21 and the side buttons 30a, 30b.

[0059] The provision of the support frame 21 has the advantage of simplifying the assembly of the changeover switch 100 and of allowing the use of the space available in case 20 to be optimized. In the practice, such a support frame 21 causes a division of the space in case 20 and also for this reason is called partition frame or baffle. Although the provision of the support frame 21 in case 20 is advantageous, the support frame 21 may be omitted in an alternative embodiment. From now on, however without any limitation, reference will be made to the case in which the changeover switch 100, and case 20 in particular, comprises the support frame 21. Thus, when it is described that certain components of the changeover switch 100 are fastened to the support frame 21, this is to be understood in the sense that such components may be directly fastened to case 20, if the support frame 21 is not provided.

[0060] According to one embodiment, the rocking control member 50 comprises two opposite coupling elements, which allow the rocking control member 50 to be rotatably coupled to case 20, in particular to two opposite side walls 25 of the support frame 21. In the particular example depicted in the drawings, the aforesaid opposite coupling elements comprise two opposite pins 59 which protrude from the central body 51c in opposite directions. Such opposite pins 59 are for example engaged in respective through holes or recesses 29 defined in two opposite side walls 25 of the support frame 21.

[0061] According to an advantageous embodiment, the opposite pins 59 have a cross section shaped like a letter T. The through holes or recesses 29 in such an embodiment preferably have a trapezoidal shape, in particular the shape of an isosceles trapezoid.

[0062] According to one embodiment, the central body 51c of the rocking control member 50 comprises an internally hollow seat 52 adapted to receive an elastic element, e.g. a helical spring 32c, operatively interposed between the rocking control member 50 and the rocking switching member 60. The rocking switching member 60 comprises for this purpose for example a protruding appendix 72c arranged on the first end portion 61 and engaged in an end of the helical spring 32c. The aforesaid internally hollow seat 52 preferably is surrounded by a collar having a recess 56, or even better, a pair of diametrically opposite recesses 56, adapted to be engaged with the first end portion 61 of the rocking switching member 60.

[0063] According to a particularly advantageous embodiment, the changeover switch 100 comprises snap fitting elements 33, 233 such that they slidingly restrain the side buttons 30a, 30b to case 20 and in particular, to the support frame 21 (if provided) .

[0064] Such snap-fitting elements 33, 233 comprise for example complementary snap-fitting elements provided on the support frame 21 and on the side buttons 30a, 30b.

The aforesaid complementary snap-fitting elements 33, 233 are shaped so as to promote a forced insertion of the side buttons 30a, 30b into the support frame 21 in the step of assembling the side buttons-mounting frame assembly, and once a snapped position is crossed, they are shaped so as to achieve a snap coupling between the side buttons 30a, 30b and the support frame 21, according to which the side buttons 30a, 30b are slidingly restrained to the support frame 21.

[0065] According to an advantageous embodiment, the aforesaid complementary snap-fitting elements 33, 233 comprise a plurality of teeth 33 protruding from the side buttons 30a, 30b towards the support frame 21 and a plurality of recesses or elongated slits 233 defined in the support frame 21, each adapted to house a respective tooth 33, so that tooth 33 is engaged in the recess or elongated slit 233, thus being able to slide therein.

[0066] Should the support frame 21 not be provided, the above-described complementary snap-fitting elements 33, 233 could be provided on the side buttons 30a, 30b and on case 20.

[0067] The changeover switch 1 preferably comprises a spatially distributed guide system adapted to guide the sliding of the side buttons 30a, 30b with respect to the case 20 or the support frame 21 (if provided) along the respective sliding axes A-A, B-B . The spatially distributed guide system comprises the above-described complementary snap-fitting elements 33, 233 and further guides provided between the side buttons 30a, 30b and case 20, or the support frame 21 (if provided), comprising for example guide seats 240a, 240b and sliders 34a, 34b adapted to slide in said guide seats 240a, 240b. According to a particularly advantageous embodiment, the spatially distributed guide system is made according to the teachings of Patent Application W02017141089 A1.

[0068] According to an advantageous embodiment, the changeover switch 100 comprises a central button 30c, which is sliding with respect to case 20 and which is operable to bring the rocking switching member 60 into the central angular position from the first and from the second angular end of stroke positions. The central button 30c preferably is directly or indirectly constrained to case 20 so as to slide with respect to the latter, along a sliding axis C-C between an initial backward position and a final forward position.

[0069] The central button 30c preferably is slidingly constrained to case 20, and in particular to the support frame 21 (if provided) . For this purpose, the changeover switch 100 comprises snap-fitting elements 33c, 233c adapted to slidingly constrain the central button 30c to case 20 and in particular, to the support frame 21 (if provided) .

[0070] Said snap-fitting elements 33c, 233c comprise for example, complementary snap-fitting elements provided on the support frame 21 and on the central button 30c. The aforesaid complementary snap-fitting elements are shaped so as to promote a forced insertion of the central button 30c into the support frame 21 in the assembly step, and once a snapped position is crossed, they are shaped so as to achieve a snap coupling between the central button 30c and the support frame 21, according to which the central button 30c is slidingly contrained to the support frame 21.

[0071] According to an advantageous embodiment, the aforesaid complementary snap-fitting elements 33c, 233c comprise a plurality of teeth 33c protruding from the central button 30c towards the support frame 21 and a plurality of recesses or elongated slits 233c defined in the support frame 21, each adapted to house a respective tooth 33c, so that tooth 33c is engaged in the recess or elongated slit 233c, thus being able to slide therein.

[0072] Should the support frame 21 not be provided, the above-described complementary snap-fitting elements 33c, 233c could be provided on the central button 30c and on case 20.

[0073] The changeover switch 1 preferably comprises a spatially distributed guide system adapted to guide the sliding of the central button 30c with respect to case 20 or to the mounting frame 21 (if provided) along the sliding axis C-C . In addition to the above-described complementary snap-fitting elements 33c, 233c, the spatially distributed guide system comprises for example further guide elements 34c, 240c provided between the central button 30c and case 20, or the support frame 21 (if provided) . Said further guide elements for example, comprise projections 34c protruding from the central button 30c towards the mounting frame 21, and protruding wings 240c interposed between said projections 34c. According to a particularly advantageous embodiment, also this spatially distributed guide system is made according to the teachings of Patent Application W02017141089 A1.

[0074] According to an advantageous embodiment, the central button 30c is placed over the rocking control member 50 between the two side buttons 30a, 30b. [0075] According to a particularly advantageous embodiment, the central button 30c does not interfere in abutment with the rocking control member 50 in the initial backward position thereof, said central button 30c being adapted and configured to come into contact with the rocking control member 50 from a certain point onward, along the sliding thereof from the initial backward position to the final forward position thereof along the sliding axis C-C .

[0076] According to an advantageous embodiment, the initial backward position is the only stable position of the central button 30c. The side buttons 30a, 30b preferably are adapted and configured to push the central button 30c into the initial backward position. The side buttons 30a, 30b apply for example, a thrust force on the central button 30c by means of the protruding wings 31a, 31b. Such a thrust force preferably is a consequence of the thrust action exerted by the elastic return elements 32a, 32b on side buttons 30a, 30b.

[0077] According to an advantageous embodiment the changeover switch 100 comprises centering elements 37c, 57c, 38c provided on the central button 30c and on the rocking control member 50, which are such that they return the rocking control member 50, and therefore the rocking switching member 60, to the stable central position thereof during the sliding of the central button 30c towards the forward position. Such elements comprise for example, a centering appendix 57c provided on the rocking control member 50 adapted to be received in a joint centering seat 37c provided on the central button 30c. Such centering elements additionally or alternatively include a plurality of abutment elements 38c provided on the central button 30c, adapted to come into abutment with the rocking control member 50, for example with the side abutment portions 51a, 51b, during a sliding of the central button 30c from the initial backward position to the final forward position.

[ 0078 ] According to a particularly advantageous embodiment, the changeover switch 100 further comprises a covering and actuating member 40, which can be operated manually to cause both the first button 30a and the second button 30b to slide independently from each other. With reference to figure 3 in particular, by applying a manual pressure force on the covering and actuating member 40 towards one of the two end portions of said element 40, for example the left-hand end portion in figure 3, the sliding may be caused of one alone of the two side buttons 30a, 30b, for example the left-hand button 30a, while by applying a manual pressure force on the other of the two end portions, for example the right- hand end portion in figure 3, the sliding may be caused only of the other of the two side buttons 30a, 30b, for example the right-hand button 30b.

[0079] In a further advantageous embodiment, the covering and actuating member 40 comprises a through opening, which allows access to the central button 30c to actuate said central button 30c. In such an embodiment, the central button 30c preferably has a protruding portion 39c, which crosses said opening to protrude with respect to the covering and actuating member 40, from the opposite part with respect to case 20.

[0080] In a particularly advantageous and non-limiting embodiment, the changeover switch 100 comprises a first and a second rotatable pressure transmission member 41a, 41b operatively interposed between the covering and actuating member 40 and the first 30a and second 30b side button, respectively. Such rotatable pressure transmission members 41a, 41b allow a pressure force applied to the covering and actuating member 40 to be transmitted to the side buttons 30a, 30b, respectively. [0081] According to a particularly advantageous embodiment which allows reducing the stroke that is required for the covering and actuating member 40 to cause a sliding of the side buttons up to the final forward position, the aforesaid rotatable pressure transmission members 41a, 41b each comprise at least one respective stroke multiplier lever 42a, 42b. Such stroke multiplier levers 42a, 42b are for example pivoted to the covering and actuating member 20 and have a first end portion 43a, 43b adapted to come into abutment with a respective side button 30a, 30b and an opposite end portion 44a, 44b adapted to react against an outer support operatively interposed between the changeover switch 100 and the covering and actuating member 40, such as for example a cover or a frame for wall mounting the changeover switch 100.

[0082] The changeover switch 100 proposed allows the preset objects to be completely achieved in terms of overcoming the drawbacks of the switches of the known art. Indeed, a significant reduction of the axial volume was obtained due to fact that the rocking switching member 60 rests on the support fulcrum 90 with an end portion thereof because the rotation angle of such a member may be kept more limited with respect to the known art while successfully ensuring the provision of three stable angular positions of such a rocking member 60.

[0083] Moreover, due to the fact that the two side buttons 30a, 30b may be moved independently from each other, they may always be kept perfectly aligned, whatever the stable angular position taken on by the rocking switching member 60. Moreover, the inertias are reduced during the movement of the side buttons 30a, 30b.

[0084] Moreover, the presence of the central button 30c allows the rocking switching member 60 to accurately take on the stable central angular position.

[0085] A changeover switch 100 of the above-described type may be for example, however without any limitation, used in hotels for controlling a signaling device aiming to inform the hotel service personnel of a do not disturb request and a please make up my room request. Pressing the side button 30a may be carried out for example to signal a do not disturb request. Successively pressing the central button 30c brings the changeover switch 100 to a neutral position, which practically resets the aforesaid signaling. Pressing the side button 30b signals a please make up my room request and successively pressing the central button 30c brings the changeover switch 100 to a neutral position, which practically resets the aforesaid signaling. Moreover, the central button 30c may be made so that it may transmit an optical radiation therein, for example by making it of clear material. By associating the changeover switch 100 here with a multicolor LED (or several single-colored LEDs), a user may be informed of the status of the changeover switch 100 and therefore the signaling status associated with the changeover switch 100.

[0086] The principle of the invention being understood, the embodiments and manufacturing details may largely vary with respect to what described and illustrated by mere way of non-limiting example, without thereby departing from the scope of the invention as defined in the appended claims .