WO2019145890A1

WO2019145890A1 - Control mechanism for switches and the like

Info

Publication number: WO2019145890A1
Application number: PCT/IB2019/050596
Authority: WO
Inventors: Volpato Alberto; Cavalli Antonio
Original assignee: Vimar SpA
Current assignee: Vimar SpA
Priority date: 2018-01-24
Filing date: 2019-01-24
Publication date: 2019-08-01
Anticipated expiration: 2020-07-24
Also published as: IT201800001763A1

Abstract

A control mechanism for switches and the like, including a frame, a button for activating the control mechanism, a piston supported on the frame so that it can tilt with respect to a switching axis, and connected to the button in a spring- mounted manner, a support for a movable contact hinged to the piston and thrust by the piston against a contact surface connected to the frame, and a corresponding fixed contact attached to the frame; the piston and the support (3) can be oscillated around a mutual hinging axis so as to move the movable contact from and into a closed position on the fixed contact. The support comprises an oscillating portion that extends from the mutual hinging axis in the opposite direction to the contact surface, the movable contact being configured so as to contact the oscillating portion when placed in the closed position on the fixed contact.

Description

CONTROL MECHANISM FOR SWITCHES AND THE LIKE

DESCRIPTION

The present invention relates to a control mechanism for switches and the like, that is able to carry out the closing or switching of electrical contacts, of a type with the characteristics referred to within the preamble to claim 1.

Switches of an electro-mechanical type, by means of which electrical contacts are closed or switched, are commonly used within the civil engineering and industrial electrical installations technical sector, for example, for turning on or turning off lighting points.

In one of their most common configurations, switches contain a rocker mechanism operated by means of manual pressure, which moves a mobile anchor. Movement of the anchor enables a flexible conductive plate to be subjected to stress, taking it from an initial position where an electrical contact is open, to a second position where the contact is closed.

An example of such mechanisms is described within United States patent US 5,436,421, which relates to a switch within which a rocker actuator moves a mobile contact plate by means of the action of a pin.

The pin is connected to the rocker actuator in such a way as to protrude towards the mobile contact, and is pushed onto the contact by means of a spring supported on the contact itself. As a result of this configuration, when the rocker actuator is activated, the pin is drawn along the contact, and causes it to oscillate around its central area.

However, some known mechanisms based on this operating principle are subject to malfunction phenomena, as a result of the continuous switching.

Another example of the mechanism is represented by patent EP 1430496, within which a compression action mechanism is described, also operating by means of a rocker button, with provision for at least one fixed contact and one mobile contact, attached to an anchor.

The anchor operates in rotation to move the mobile contact closer to - or further away from - the fixed contact, by means of a pin controlled by the rocker button and pushed against the anchor by a compression spring, in a way substantially similar to the previous case.

In this case, however, the pin acts against the anchor by means of a coupling configured as a fork, connected so as to rotate in the opposite manner to the rocker button. In this way, the two branches of the fork are arranged within the corresponding areas of the anchor, substantially symmetrically with respect to its centre.

But it would be desirable to have mechanisms able to reduce for the dimensions of the electrical apparatus within which they are used, particularly in relation to their depth, i.e. in terms of their dimensions within the wall-mounted box typically used for their installation.

The technical problem that is the basis of this invention is therefore to provide for a control mechanism for switches and the like that is structurally and functionally designed to overcome one or more of the difficulties reported with regard to the prior art cited.

Within the framework of this problem, one aim of this invention is to provide a control mechanism that has particularly reduced dimensions, specifically in terms of depth.

Another aim of this invention is to provide a control mechanism that is particularly reliable. This problem is resolved, and one or more of these aims are achieved by the invention, using a control mechanism as stated within claim 1.

The control mechanism for switches and the like of the invention is particularly suitable for installation within a wall-mounted box. This solution allows for a particularly compact structure, specifically in terms of depth, as the position of the contact only requires minimal movement away from the hinging axis. In this way, dimensions may be obtained that are contained in terms of depth, since there is no need to make provision for the movable contact to be subject to any deformation during switching of the button.

In fact, the structure of the mechanism within this invention allows the point of contact between the movable contact and the fixed contact to be positioned above the mutual hinging axis of the support, thus permitting reduction of the dimensions in terms of the depth of the button.

In addition, in the contact's closed position, the oscillating portion of the support abuts the movable contact, thus preventing the movable contact from being deformed in this position, or in any case controlling its deformation in a precise manner.

On the basis of the above-mentioned configuration, the support preferably has an elongate shape, and the mutual hinging axis is positioned along a longitudinal axis of extension of the support, in an intermediate position between the point of contact with the contact surface, and the area where the oscillating portion touches the movable contact.

In other words, the point of contact with the contact surface is positioned approximately diametrically opposite the centre of rotation defined by the mutual hinging axis for the oscillating portion. Another aspect of the invention is that the oscillation of the support is preferably limited with respect to the piston, and a mechanical connection between the support and piston is provided so as to transfer the initial rocker movement of the button to the support, in the form of oscillation of the support with respect to the piston.

This aspect also makes it possible to avoid, or in any case limit, any locking phenomena that may occur during the transition phase between the closed position and the closing of the contact, or, more generally, during switching of the switch.

The mechanical connection enables action to be applied to the support, and therefore to the contact moved by it, to overcome the dead centre, i.e. an end or balance point, within the mobile assembly formed by the piston and support between the two limit positions of opening and closing of the contact. In one embodiment, the dead centre corresponds to the position in which the piston and support are aligned.

The combination of the presence of the mechanical connection within the configuration described above, with the use of a movable contact in the form of an anchor is also especially advantageous, as it enables a particularly compact and resistant structure to be obtained.

Also as a result of the unlocking capacity provided by the mechanism within this invention, switching of the contact may also be achieved by using a relatively short path of the support, a characteristic that is particularly favourable when combined with the specific position of the contact, which is effectively pushed directly by the oscillating portion of the support.

The movable contact is preferably held so that it can oscillate within a cradle attached to a primary contact, corresponding to a point of contact on the contact surface positioned opposite the mechanical connection with respect to the mutual hinging axis.

In a preferred embodiment, the piston and support form an oscillating assembly able to overcome the dead centre, with the mechanical connection being configured so that the oscillation of the support with respect to the piston precedes, and is independent from overcoming the dead centre of the piston and support assembly.

In addition, also on the basis of a further preferred aspect, and still with the aim of obtaining the effect of unlocking from the dead centre, thus actively avoiding locking phenomena, the mechanical connection is maintained between the piston and support as far as the vicinity of the dead centre.

In one embodiment, the mechanism comprises a retaining element that limits the capacity for movement of the assembly formed by the piston and support, so that when the piston and support assembly are caused to oscillate by means of the button, relative rotation occurs by means of the piston and support themselves. Also with regard to optimising the dimensions, the support will preferably be hinged to one end of the piston, on the side opposite the button.

In a preferred embodiment, the movable contact comprises an anchor with two sides co-extending from the same base in a substantially U-shaped structure, with this anchor being linked to the support by means of these sides. The movable contact preferably closes on the fixed contact corresponding to one of the said sides.

It may be seen that this solution enables a resistant structure and a simple assembly for the mechanism to be obtained within this invention. In a preferred embodiment, the anchor and cradle are electrical conductors in mutual electrical conduction contact, so as to link the contact to the terminal box to which the electrical wires for the installation within which the mechanism is applied are connected.

In order to obtain a sufficiently stable connection between the contact and the support, in one embodiment the anchor has a hole in each side, and the support has a corresponding protuberance on each surface, facing the corresponding hole, or vice-versa, to engage the corresponding hole so as to retain the anchor on the support.

The anchor is preferably held so that it can oscillate within a cradle which is integral with a primary contact, thus holding the support appropriately with the movable contact in order to obtain the oscillation between the piston and support about the mutual hinging axis in tilting mode so as to move the movable contact from and into a closed position on the fixed contact.

In one embodiment, the mechanical connection between the piston and support includes, on the respective surfaces of the piston and support, or vice-versa, a limb contained within a recess, and a collar at one end, at least, of the recess, acting as a stop for the limb. The surfaces that form the limb and the recess respectively on each of the said pistons and the support preferably face one another. In one embodiment, the recess has a curved shape, with the centre of the curvature on the mutual hinging axis of the support. Preferably, the limb is received in the curved recess in a sliding manner.

Precise sliding between the support and piston is thus obtained, making the switching movement of the mechanism within this invention fluid and exact.

Both circumferential ends of the recess will preferably provide stops for the limb, in order to create the mechanical connection, again benefiting the precision of movements. In addition, in one embodiment, the limb extends from a pad interacting with the respective surfaces around the recess.

In order to obtain a particularly compact structure that can be assembled simply, in one embodiment the piston comprises a fork with two prongs, with the aforementioned support hinged to their respective ends, and the recess positioned on a wall between these prongs.

The piston preferably comprises, on the side opposite the prongs, a coupling portion which is received in a sliding manner in a guide attached to the button, with the piston springing being positioned between the guide and the coupling portion on the piston.

Also, in a preferred embodiment, the free ends of the prongs are supported in a sliding manner on the corresponding juxtaposed collars of the support.

In one embodiment, the button is of a rocker type.

According to another aspect, the mechanism also comprises a motion conversion mechanism that can convert the axial movement of the button into oscillation of the piston.

The characteristics and additional advantages of the invention will become more apparent from the following detailed description of a preferred, but not exclusive, embodiment, illustrated by way of non-limiting indication, with reference to the appended drawings, in which:

- Fig. 1 is an exploded perspective view of a control mechanism for switches and the like within this invention;

- Figs. 2A and 2B are two schematic lateral views, in partial section, that illustrate the control mechanism within this invention in two respective operating positions; - Figs. 3, 4 and 5 are perspective views of a piston, a support and a movable contact respectively, which are details of the mechanism in fig. 1;

- Fig. 6 is a schematic view of electrical apparatus that comprises the control mechanism within this invention.

With reference initially to fig. 1, a control mechanism for switches and the like is indicated globally by reference number 100.

It may be seen that, in the present embodiment, the mechanism is intended to be used within electrical apparatus of the type commonly called a two-way switch, i.e. electrical apparatus that is used to control an electrical device, for example a lamp, in two different positions.

It should be observed in this regard that the mechanism within this invention may be contained within an independent module that can be wall-installed and wired by means of a suitable terminal box; the basic components of this are illustrated within the drawing, and indicated with reference number 102, as will be shown in greater detail below.

The basic components of electrical apparatus within which the control mechanism 100 is used are illustrated within fig. 6, indicated in their entirety by reference number 200.

In general, it should be observed that the mechanism within this invention may also have application within other apparatus for electrical installations, such as, for example, switches, three-way switches, push buttons and the like.

With reference to fig. 1 again, the control mechanism 100 comprises a frame 101, supporting a button 1 designed to activate the control mechanism 100.

The frame 101 is preferably connected to the casing 201, which may be seen in fig. 6, of the apparatus within which the device 100 is used. It should also be noted that the button 1 may comprise a button-cover 10, also illustrated in fig. 6. These components are however only illustrated schematically, since they have characteristics which in themselves are known.

In a preferred embodiment, the button 1 is a rocker, and, as such, is supported on the frame 101 by means of a pair of pins 11, housed within corresponding seats 110 formed on the frame. In one embodiment, the pins 11 are wedge-shaped, with the apex turned towards the outer face of the button, with the seats 110 having a complementary form.

More generally, the connection between the frame and the button will be implemented in such a way as to allow limited oscillations about a switching axis C, thus obtaining the rocker movement.

In an alternative embodiment, the button 1 may move axially. In other words, in this case switching takes place by pushing the button in an axial direction, specifically along an axis that is substantially perpendicular to the plane defined by the button itself, rather than by means of a rocker movement.

The mechanism 100 also comprises a piston 2, connected to the button 1 in a spring-locked manner. In one embodiment, the piston 2 is mounted on the button 1 in a spring-locked manner. In this way, in one embodiment of the invention, the piston 2 can carry out movements towards/away from the button 1, and is thrust away from the button by means of a spring or other resilient element 12.

It should be noted that, in the case of an axial movement button, the mechanism 100 comprises a motion conversion mechanism that can convert the axial movement, i.e. a linear movement, of the button, into oscillation of the piston. An example of a mechanism of this type is described in patent application EP2672498, in the name of the same applicant. A support 3 is hinged onto the piston 2, and a movable contact 4 is connected to the support.

The support 3 is preferably hinged to one end of the piston 2, the part opposite the button 1.

In a preferred embodiment, the movable contact 4 is suitable for closing an electrical contact on a fixed contact 5, also connected to the frame 101, thus electrically connecting the electric cables connected to the terminal boxes 102.

The movable contact 4 is preferably in contact with a contact surface 60 on a primary contact 6, to which one of the terminal boxes 102 is connected, in such a way as to connect the electrical power cable, generally the phase cable, for the device to be controlled, by means of the invention mechanism. More generally, it should be observed that the movable contact 4 is urged by means of the piston 2 against the contact surface 60, which is integral with the frame 101.

In some embodiments, the movable contact 4 may touch the contact surface 60 in such a way as to be supported so that it can oscillate within a cradle 61 integral with the primary contact 6, corresponding to a point of contact 60A.

As may be observed from the drawings, in one embodiment the contact surface 60 extends from the primary contact 6 so that the cable connected to the primary contact 6 is electrically connected to the movable contact 4.

It may therefore be seen that, by urging the movable contact 4 against the contact surface 60, the electrical connection can be maintained during oscillation of the movable contact 4 and the related movement.

As may be observed from the drawings, in particular figs. 1 and 2B, the piston 2 and the support 3 can oscillate about a mutual hinging axis X, preferably in tilting mode, so as to move the movable contact 4 from and into a closed position on the fixed contact 5.

On the basis of this configuration, as may be observed from figs. 2A and 2B, the oscillation movement of the button 1 produces a corresponding oscillation of the assembly formed by the piston 2 and the support 3. However, since the support 3, connected to the movable contact 4, is urged against the contact surface 60, it is retained against the contact surface 60. In this regard, provision may be made for the presence of an appropriate retaining element that limits the capacity for movement of the assembly formed by the piston and support. As will be better illustrated later, in one embodiment the retaining element comprises a cradle 61, within which the movable contact 4 is retained, although different solutions may also be provided for. For example, the retaining element could also be constituted by the friction generated by the force with which the resilient element 12 urges the piston 2.

Therefore, as the movable contact is partially linked, the oscillation of the button 1 will generate rotation of the support 3 with respect to the piston 2 about a mutual hinging axis X, thus enabling the support 3 to oscillate to a limited extent with respect to the piston 2.

Because of this movement, the movable contact 4 can be moved from an initial position where contact with the fixed contact 5 is open, represented in fig. 2A, to a second position where this contact is closed, illustrated in fig. 2B.

It may be seen, for example in the embodiment illustrated within the drawings, that the mechanism comprises an auxiliary contact 8, onto which the movable contact 4 closes in the initial position. The presence of the auxiliary contact 8 enables an electrical connection to be closed between the primary contact 6 and another deflector switch-type apparatus when contact between the movable contact 4 and fixed contact 5 is open, so as to create the circuit diagram required for the purposes of controlling a gap from two different positions.

It will be appreciated that the auxiliary contact 8 need not be present if it is not required by the apparatus within which the mechanism according to this invention is being used.

In one aspect of the invention, the control mechanism comprises a mechanical connection 7 positioned between the support 3 and the piston 2, so as to transfer an initial tilting movement of the button 1 to the support 3, in the form of oscillation of the support 3 with respect to the piston 2.

In some embodiments, the point of contact 60A, against which the movable contact 4 is supported in oscillating mode, is positioned opposite the mechanical connection 7 with respect to the mutual hinging axis X.

It should be noted that this layout enables the support 3 to be retained appropriately with the movable contact 4 against the primary contact 6, in order to obtain oscillation between the piston 2 and the support 3 about the mutual hinging axis X in tilting mode, so as to move the movable contact 4 from and into a closed position on the fixed contact 5.

In other words, the mutual hinging axis X is not in a fixed position, but oscillates between two limit positions.

In a preferred embodiment, the mechanical connection 7 between the piston 2 and the support 3 comprises a limb 31 contained within a recess 21, and a collar 22 at one end, at least, of the curved recess 21, acting as a stop for the limb 31. The limb 31 and the recess 21 are formed on the support 3 and the piston 2 respectively, or vice-versa, preferably at respective facing surfaces.

In one embodiment, the recess 21 has a curved shape, with the centre on the mutual hinging axis X of the support 3, so that the limb 31 can slide into it.

The mechanical connection 7 may therefore be advantageously obtained by using one or both of the ends of the recess 21 in a way that forms stops on the motion of the limb 31.

More generally, the mechanical connection 7 may be configured so that the oscillation of the support 3 with respect to the piston 2 is in advance of, and independent from, overcoming the dead centre of the assembly formed by the piston 2 and the support 3. This dead centre, like the motion of a piston within the respective cylinder, corresponds to a position where the piston 2 and the support 3 are aligned.

It should also be noted that, in this position, the axis of oscillation C of the button, the mutual hinging axis X, and the point of contact between the movable contact 4 and the contact surfaces are aligned.

In order to make the movement between the support 3 and the piston 2 more fluid and precise, in one embodiment, the limb 31 can extend from a pad 32, illustrated in fig. 4, interacting with the respective surface 26, represented in fig. 2B, bordering the curved recess 21.

Also, in one embodiment, the mechanical connection 7 is advantageously configured so that it is maintained between the piston 2 and the support 3, as far as in the vicinity of the dead centre.

On the basis of another aspect of the invention, the support 3 comprises an oscillating portion 30, which extends from the mutual hinging axis X in the opposite direction to the contact surface 60.

Preferably, the movable contact 4 comprises an anchor 40 with two sides 41 co extending from the base 42 in a substantially U-shaped structure. The sides 41, as will be better illustrated later, enable the anchor 40 to be linked to the support 3.

In a preferred embodiment, the mobile 4 contact closes on the fixed contact 5 at one of the sides 41 in such a way that, when it is in this position, the side 41 touches the surface of the oscillating portion facing it.

More generally, in the mechanism within this invention, the movable contact 4 can be configured so that it touches the oscillating portion 30 when placed in the closed position on the fixed contact 5, and/or in the closed position on the auxiliary contact 8, if present.

In this way, in contrast to what occurs with known mechanisms, use of contacts which require appreciable deformation in order to obtain closure of the contact can be avoided.

In some embodiments, the support 3 has an elongate shape.

The mutual hinging axis X is preferably positioned along a longitudinal axis Y of the support 3, in an intermediate position between a point of contact with the contact surface 60, and the area where the oscillating portion 30 touches the movable contact 4.

In some embodiments, the point of contact 60A is positioned diametrically opposite the oscillating portion with respect to a centre of rotation of the support 3, defined by the mutual hinging axis X.

With reference now to figs. 4 and 5, in a preferred embodiment, the anchor 40 has a hole 43 on each side 41, and the support 3 has a corresponding protuberance on each surface, facing the corresponding hole 43, or vice-versa, to engage the corresponding hole 43 in order to retain the anchor 40 on the support 3.

More generally, in some embodiments, the support 3 and the movable contact 4 are formed as separate interconnected components.

Also, in a preferred embodiment, the cradle 61 may be configured in such a way as to support the anchor 40 in oscillating mode. For example, the cradle 61 may have extensions 62, between which a shaped portion 44, moulded on the base 42 of the anchor 40, engages. More generally, the cradle 61 may be configured in such a way as to allow oscillation of the movable contact 4, and prevent or limit linear movements thereof.

The cradle 61 is preferably attached to the primary contact 6, and the anchor 40 and cradle 61 are electrical conductors in mutual electrical conduction contact.

With reference now to fig. 3, the piston 2 preferably comprises a fork 23 with two prongs 24, with the support 3 hinged to their respective ends.

It will therefore be seen, within the context of this invention, that the term piston indicates a mobile element, with predominantly axial extension, able to slide into a respective guide, which is not necessarily cylindrically shaped.

The recess 21 into which the limb 31 slides is preferably positioned between the prongs 24, thus optimising the dimensions the structure.

In one embodiment, the piston 2, on the side opposite the prongs 24, includes a coupling portion 25 that slides into a guide 15 attached to the button 1. The springing of the piston 2 is preferably positioned between the guide 15 and the coupling portion on the piston 2, with the resilient element 12 retained by a pin 28 that extends from the coupling portion.

In a preferred embodiment, the free ends 27 of the prongs 24 are supported in a sliding manner on the corresponding juxtaposed collars 36 of the support 3.

The invention therefore solves the problem raised, while providing a number of advantages at the same time. In particular, the control mechanism within this invention enables switches, deflector switches, inverters and similar apparatus to be obtained, within which the possibility of locking can be minimised, and which have dimensions within the box intended for their installation, i.e. in the direction of their depth, which are particularly reduced.

Claims

1. Control mechanism (100) for switches and the like, comprising:

- a frame (101 );

- a button (1 ) for actuating the control mechanism (100);

- a piston (2) which is supported on the frame (101 ) such that it can tilt with respect to a switching axis (C) and is connected to the button (1 ) in a spring- mounted manner;

- a support (3) for a movable contact (4), which is hinged to the piston (2) and is urged against a contact surface (60), which is integral with the frame (101 ), by means of the piston (2);

- a corresponding fixed contact (5) connected to the frame (101 );

- wherein the piston (2) and the support (3) can be oscillated about a mutual hinging axis (X) so as to move the movable contact (4) from and into a closed position on the fixed contact (5),

characterised in that said support (3) comprises an oscillating portion (30) which extends from the mutual hinging axis (X) in the opposite direction to the contact surface (60), the movable contact (4) being designed so as to contact said oscillating portion (30) when arranged in the closed position on the fixed contact (5).

2. Control mechanism (100) according to claim 1 , wherein said support (3) has an elongate shape, with the mutual hinging axis (X) being positioned along a longitudinal axis of extension (Y) of said support (3), in an intermediate position between a point of contact with said contact surface (60) and an area where said oscillating portion (30) touches said movable contact (4).

3. Control mechanism (100) according to either claim 1 or claim 2, wherein said support (3) and said movable contact (4) are formed as separate interconnected components.

4. Control mechanism (100) according to any one of the preceding claims, wherein a point of contact (60A) of the support (3) is defined on the contact surface (60), said point of contact (60A) being positioned diametrically opposite the oscillating portion with respect to a centre of rotation of the support (3) defined by the mutual hinging axis (X).

5. Control mechanism (100) according to any one of the preceding claims, wherein said support (3) can be oscillated to a limited extent with respect to the piston, and in that a mechanical connection (7) is arranged between the support (3) and the piston (2) so as to transfer an initial tilting movement of the button (1) to the support (3) in the form of an oscillation of the support (3) with respect to the piston (2).

6. Control mechanism (100) according to claim 5, wherein the piston (2) and the support (3) form one entity which can oscillate so as to pass over a dead centre, said mechanical connection (7) being designed such that the oscillation of the support (3) with respect to the piston (2) is anticipated and is independent of the entity, which is formed by the piston (2) and the support (3), passing over said dead centre.

7. Control mechanism (100) according to claim 6, wherein the mechanical connection (7) is designed so as to be held between the piston (2) and the support (3) until close to the dead centre.

8. Control mechanism (100) according to either claim 6 or claim 7, wherein said dead centre is reached in a position where the piston (2) and the support (3) are aligned.

9. Control mechanism (100) according to any one of the preceding claims, wherein the movable contact (4) comprises an anchor (40) having two sides (41), which both extend from a common base (42) in the shape of a U, said anchor (40) being connected to the support (3) by means of said sides (41).

10. Control mechanism (100) according to claim 9, wherein one of said sides (41) of the movable contact (4) closes onto the fixed contact (5).

1 1. Control mechanism (100) according to either claim 9 or claim 10, wherein the anchor (40) is supported so as to be able to oscillate in a cradle (61) which is integral with a primary contact (6).

12. Control mechanism (100) according to one or more of the preceding claims, wherein said mechanical connection (7) between the piston (2) and the support (3) comprises, on respective surfaces of the piston (2) and the support (3), or vice versa, a limb (31) that is received in a recess (21), and a shoulder (22), which acts as a stop for said limb (31), at at least one end of the recess (21).

13. Control mechanism (100) according to claim 12, wherein the surfaces that form the limb (31) and the recess (21) respectively on each of the pistons (2) and the support (3) are facing one another.

14. Control mechanism (100) according to either claim 12 or claim 13, wherein said recess (21) has a curved shape.

15. Control mechanism (100) according to claim 14, wherein the centre of the curvature of said recess (21) is on the mutual hinging axis (X) of the support (3).

16. Control mechanism (100) according to any one of claims 12 to 15, wherein the limb (31) is received in a sliding manner in the recess (21).

17. Control mechanism (100) according to any one of claims 12 to 16, wherein the circumferential ends of the recess (21) provide stops for the limb (31), in order to create said mechanical connection (7).

18. Control mechanism (100) according to any one of claims 12 to 17, wherein the limb (31) extends from a slide (32) which cooperates with a particular surface (26) that borders the recess (21).

19. Control mechanism (100) according to any one of claims 12 to 18, wherein said piston (2) comprises a fork (23) having two prongs (24), to the respective ends of which the support (3) is hinged, said recess (21) being formed between said prongs

(24).

20. Control mechanism (100) according to claim 19, wherein the piston (2) comprises, on the opposite side to the prongs (24), a coupling portion (25) that is slidably received in a guide (15) that is integral with the button (1), the spring of the piston (2) being provided between the guide (15) and said coupling portion

(25) of the piston (2).

21. Control mechanism (100) according to any one of the preceding claims, also comprising a motion conversion mechanism that can convert a linear movement, in an axial direction, of the button (1) into an oscillation of the piston (2).

22. Control mechanism (100) according to any one of the preceding claims, wherein said support (3) and said one movable contact (4) are thrust against said contact surface (60), so that the mutual hinging axis (X) oscillates between two limit positions during movement of the movable contact (4) from and into a closed position on the fixed contact (5).

23. Control mechanism (100) according to any one of the preceding claims, wherein the piston (2) is configured so as to carry out movements towards/away from the button (1), and is thrust away from the button (1) by means of a resilient element (12).

24. Control mechanism (100) according to claim 23, wherein said piston (2) comprises a coupling portion (25) that is received in a sliding manner in a guide (15) that is integral with the button (1), the spring of the piston (2) preferably being provided between the guide (15) and the coupling portion (25) of the piston (2).