MONOSTABIL OR BISTABILITY ELECTRIC PUSH BUTTON SWITCH

Description

TECHNICAL FIELD

[0001] The present invention relates to electric switches, in particular to push button switches, for example for electrical installations.BACKGROUND ART

[0002] Electrical switches are ubiquitous in today's world, and there is a wide variety of switch types, including rotary switches, toggle or rocker switches, slide switches, and push-button switches.

[0003] The most familiar form of switch is a manually operated electromechanical device with one or more sets of electrical contacts, which are connected to external circuits. Each set of contacts can be in one of two states, "open" or "closed". "Closed" means the contacts are touching and electricity can flow between them, and "open" means the contacts are separated and the switch is nonconducting. Depending on the mechanism actuating the transition between these two states, open or closed, a switch can be monostable or bistable. Monostable switches will assume a first state as long as the switch is not operated, and the other state only while the switch is operated. Bistable switches will remain in any of the states and will assume the respective other state only when operated accordingly.

[0004] The terms "pole" and "throw" may be used to describe switch contact variations. The number of "poles" is the number of electrically separate switches which are controlled by a single physical actuator. For example, a "2-pole" switch has two separate, parallel sets of contacts that open and close in unison via the same mechanism. The number of "throws" is the number of separate wiring path choices other than "open" that the switch can adopt for each pole. A single-throw switch has one pair of contacts that can either be closed or open. A double-throw switch has a contact that can be connected to either of two other contacts, a triple-throw has a contact which can be connected to one of three other contacts, etc.

[0005] A rotary switch operates with a twisting motion of the operating handle with at least two positions. One or more positions of the switch may be momentary, e.g., biased with a spring, requiring the operator to hold the switch in the position. Other positions may have a detent to hold the position when released. A rotary switch may have multiple levels or "decks" in order to allow it to control multiple circuits. One form of rotary switch consists of a spindle or "rotor" that has a contact arm or "spoke" which projects from its surface like a cam. It has an array of terminals, arranged in a circle around the rotor, each of which serves as a contact for the "spoke" through which any one of a number of different electrical circuits can be connected to the rotor. The switch may be layered to allow the use of multiple poles, each layer being equivalent to one pole. Usually such a switch has a detent mechanism, so it "clicks" from one active position to another rather than stalls in an intermediate position. Thus, a rotary switch provides greater pole and throw capabilities than simpler switches do. Other types use a cam mechanism to operate multiple independent sets of contacts.

[0006] A toggle switch, tumbler switch, or rocker switch is a class of electrical switches that are manually actuated by a mechanical lever, handle, or rocking mechanism. Toggle switches are available in many different styles and sizes and are used in numerous applications. Many are designed to provide the simultaneous actuation of multiple sets of electrical contacts, or the control of large amounts of electric current or mains voltages. The word "toggle" is a reference to a kind of mechanism or joint consisting of two arms, which are almost in line with each other, connected with an elbow-like pivot. However, the phrase "toggle switch" is applied to a switch with a short handle and a positive snap-action, whether it actually contains a toggle mechanism or not. Similarly, a switch where a definitive click is heard is often referred to as a "positive on-off switch". A very common use of this type of switch is to switch lights or other electrical equipment on or off. Multiple toggle switches may be mechanically interlocked to prevent forbidden combinations.

[0007] A slider switch is a switch that is operated in a linear motion parallel to a surface in which the switch is mounted. Slider switches may have one or more poles, and typically establish or break contact between two adjacent contacts, though establishing contact between multiple adjacent contacts is also possible.

[0008] A push-button switch has a mechanism that is likewise operated in a linear motion, but the motion is essentially perpendicular to the surface in which the switch is mounted. Push-button switches may use a mechanism to convert the linear motion into a toggle motion of a contact member. The mechanism may be designed such that the push button is monostable or bistable. Push-button switches may have multiple poles, and may be single throw, double throw or even triple throw, depending on the mechanism.

[0009] WO2004 / 066329 A1, US 2009 / 0000935 A1 and DE 2 140 161 U1 all disclose a respective push-button arrangement that has an inner rocker for moving a movable contact, the inner rocker being operated via an intermediate actuator pivotable coupled to a push-button operable by a user. The actuator, which is spring-loaded for returning to a central position when the push-button is not operated, has two prongs acting on one for two arms of the inner rocker depending on the respective prior position of the inner rocker.

[0010] DE 2 060 752 U1 discloses a switch having an pivotable operating element that acts on an inner rocker through an actuator in a way similar to the push-button arrangements discussed in the preceding paragraph.

[0011] Push-button switches are typically designed for specific purposes, e.g., either monostable or bistable, as the required mechanisms for each of the purposes may differ significantly.SUMMARY OF THE INVENTION

[0012] It is desirable, to provide a push-button switch having a compact design and a simple yet reliable mechanism while at the same time offering a comparatively long travel path of the button. It is also desirable to provide a push-button that can be easily converted from bistable to monostable operation.

[0013] In accordance with the present invention, a push-button switch as set forth in claim 1 is provided. Further embodiments are inter alia disclosed in the dependent claims.

[0014] When the button is depressed, an engagement surface of one of the prongs of the actuator engages with an associated engagement surface of the under rocker and will cause the under rocker to rotate. As the engagement surfaces of the under rocker are disposed at a distance from the axis of rotation, the actuator, while engaged with the under rocker, will be pivoted as the under rocker rotates. The engagement surface of the other prong that is not engaged, due to the pivoting of the actuator, will be moved away from the associated engagement surface of the under rocker and, thus, will not interfere with the rotation of the under rocker. The under rocker and the movable contact cooperate in such a way that the under rocker will remain in the first or the second position when no force is applied, keeping the movable contact in electrical contact with the respective electric terminal, if present. Due to the under rocker remaining rotated in the first or the second position when no force is applied, one of the engagement surfaces of the under rocker remains elevated over the other engagement surface when no force is applied. In addition, the projected distance between the elevated engagement surface and the first axis is smaller than the actual distance. This allows for the engagement surface of one of the prongs of the actuator, while still in a non-pivoted position, to engage with the associated engagement surfaces of the under rocker before the engagement surface of the respective other prong does. After each full operation of the push-button switch the under rocker is in a respective opposite position than before.

[0015] As the prongs of the actuator at least partially embrace the first axis of the under rocker, the comparatively long travel of the button is not blocked by the actuator coming into contact with the first axis, and yet the closest distance between the button and the first axis can be reduced, for obtaining a compact push-button switch. A long travel, together with the engagement surfaces of the under rocker being disposed at a distance from the first axis, provide a comparatively low operating force and a smooth feel when operating the button.

[0016] In one or more embodiments of the push-button switch the resilient member comprises two resilient arms, one extending to each side of the actuator, away from the second axis, each arm applying a force directed towards the second surface when the actuator is pivoted to the side of the respective arm, the force targeting to return the actuator into the central, non-pivoted position.

[0017] The arm may rest against the second surface, against an intermediate element disposed between the second surface and the actuator, or a respective structure arranged thereon.

[0018] In one or more embodiments of the push-button switch an intermediate element is arranged between the second surface and the actuator, the intermediate element being arranged to pivotably receive or support the actuator.

[0019] In one or more embodiments of the push-button switch the resilient member comprises one or more resilient arms extending from the second surface or from the intermediate element in a direction essentially perpendicular to and away from the second surface. At least one of the one or more resilient arms is resiliently deflected by the actuator when the actuator is pivoted. The at least one arm may engage with a corresponding structure, surface or coupling element of the actuator to be deflected and exert a force opposing the deflection when the actuator is pivoted. If an intermediate element is provided, the one or more resilient arms extending from the second surface may pass through corresponding openings in the intermediate element.

[0020] In one or more embodiments of the push-button switch the under rocker has a support for receiving a resilient element that forces the under rocker into one of the first or second position when no force is applied to the button. The resilient element may, for example, include a helical spring or a leaf spring supported against the base housing.

[0021] In one or more embodiments of the push-button switch the intermediate element is made from a translucent or opaque material of a first colour, and wherein the button has at least one opening through which a part of the gem is visible. The button may have a different colour. The intermediate element may have a protruding structure that at least partly fills the opening in the button.

[0022] In one or more embodiments of the push-button switch the base housing is arranged to receive a light source for illuminating the button and / or the intermediate element. The light source may be received in a corresponding mount of the base housing. The mount for the light source is preferably accessible from the outer side of the base housing. The button or the intermediate element may be translucent and may guide light coupled into the button or the intermediate element at one point to other parts of the button or the intermediate element.

[0023] In one or more embodiments of the push-button switch the protrusion of the under rocker that acts on the movable contact is spring-loaded and movable in a direction perpendicular to the first pivot axis. This embodiment may support maintaining the under rocker in the first or the second position when no force is applied, as any rotation of the under rocker needs to also overcome the spring-loading of the protrusion.

[0024] In one or more embodiments of the push-button switch a resilient means is provided that applies a force on the button or the intermediate element for returning the button to the first, idle position when no force is applied. The resilient means may comprise a spring, helical or otherwise, or a structure made from a flexible, compressible material that provides spring-loading.

[0025] In one or more embodiments of the push-button switch one of the opposite inner surfaces of the prongs of the actuator are shaped to come into contact with the first pivot axis when the button is depressed by a predetermined distance, wherein, when the button is depressed further, the shape of the inner surface of that prong that is not in contact with the corresponding engagement surface of the under rocker causes a rotation of the actuator that forces the engagement surface of the other prong of the actuator to slidingly separate from the corresponding engagement surface of the under rocker, with which it was in contact. This embodiment may prevent the prongs of the actuator from being deformed or otherwise damaged when the force exerted on the button is too high. The button may be provided with a stop that rests against a corresponding part of the base housing when the button is depressed beyond the point at which the engagement surface of the prong of the actuator has been disengaged from the engagement surface of the under rocker.BRIEF DESCRIPTION OF DRAWINGS

[0026] In the following section the invention will be described in greater detail with reference to the attached drawings, in which Fig. 1shows a perspective view of a push-button switch according to the invention, Fig. 2shows a partially exploded view of main elements of a first variant of a first version of the push button switch according to the invention, Fig. 3shows a partially exploded view of main elements of a second variant of a first version of the push button switch according to the invention, Fig. 4a) to c) shows various stages of the movement of the actuator of the first version of the push button in accordance with the invention relative to the button and an intermediate element, respectively, Fig. 5shows a partially exploded view of main elements of a first variant of a second version of the push button switch according to the invention, Fig. 6shows a partially exploded view of main elements of a second variant of a second version of the push button switch according to the invention, Fig. 7a) to c) shows various stages of the movement of the actuator of the second version of the push button in accordance with the invention relative to the button and an intermediate element, respectively, and Fig. 8a) through f) show the interaction of the actuator and the under rocker of the push button in accordance with the invention for moving the mobile contact when the button is depressed.

[0027] In the figures of the drawings like or similar elements are referenced using the same reference signs.DESCRIPTION OF EMBODIMENTS

[0028] Figure 1 shows a perspective view of a push-button switch 100 according to the invention, having a base housing 102, three electric terminals 104a-c, of which only the screws for fixing the electrical wires are visible, and a button 124. The button 124 has a first surface 130, for receiving a force that moves the button into the base housing 102. The first surface may have an opening 148, through which a part of an intermediate element 138 located underneath the button 124 is visible. The base housing may have mounting features 150 for mounting the push-button switch 100 in an electrical installation. In the figure, the mounting features 150 may engage with corresponding features of the electrical installation, permitting a bayonet-like mounting.

[0029] Figure 2 shows a partially exploded view of main elements of a first variant of a first version of the push button switch 100, the first variant being bi-stable, i.e., a respective switching position remaining valid until changed through a further operation of the push-button 100. Topmost, a button 124 and its guiding elements, for guiding the button 124 inside the base housing 102 is shown. Push button 124 has a first, outer surface 130 that may receive a force for operating the push button switch, and a second, inner surface 132, which is not visible in the figure, that is essentially opposite of the first surface 130. Below the button 124 an intermediate element 138 is shown. Intermediate element 138 has a protrusion that fits inside opening 148 of the button (not visible in this figure). Next, an actuator 116 is visible, from which resilient arms 136a, 136b is extend to either side, each of the resilient arms representing a resilient member. Underneath the actuator 116 an under rocker 108 is visible, that is pivotable between a first and a second position around a first axis 110. Under rocker 108 is shown in a central position, between the first and the second position. Under rocker 108 has a cone-shaped support 144 for receiving a resilient element, which is not used in this variant. Under rocker 108 further has a protrusion 112 that is in contact with and acts on movable contact 106, which is in permanent electrical contact with electric terminal 104b, for selectively bringing the movable contact 106 in electrical contact with one of the electric terminals 104a or 104c. Movable contact thus alternatively establishes an electrical connection between electric terminal 104b and 104a or 104b and 104c. Resilient means 154 are provided for returning the button 124 into an idle position when no external force is applied.

[0030] Figure 3 shows a partially exploded view of main elements of a second variant of a first version of the push button switch 100, the second variant being mono-stable, i.e., a respective switching position remaining valid only while the push-button 100 is operated. The elements of the second variant are mostly identical to those of the first variant and will not be described again. However, in the second variant a resilient member is received in support 144 of the under rocker 108. The resilient member, in this example a helical spring, will provide a force that acts to rotate the under rocker 108 into a position in which it acts on the movable contact 106 such that is connects electric terminals 104b and 104c.

[0031] Figure 4 a) to c) shows various stages of the movement of the actuator 116 of the push button in accordance with the invention relative to the button 124 and the intermediate element 138, respectively, as well as the actions of the resilient arms 136a, 136b in response to the respective movement. In figure 4 a) the actuator 116 is in a central, non-pivoted position. The resilient arms 136a, 136b, which are in contact with protruding features 156 of the intermediate element 138, are equally loaded or not loaded at all. The actuator 116 is pivotable around the second axis, which is defined by the point where a recess 158 of the actuator receives a protrusion 160 of the intermediate element 138. The actuator 116 may be secured against losing contact with the intermediate element 138, e.g., by engaging with a bearing 162 of the actuator 116.

[0032] In figure 4 b) the actuator 116 is pivoted to the left, and the left resilient arm 136a is pushed against the protruding feature 156 of intermediate element 138. While not clearly visible in the figure, resilient arm 136a will be deflected and produce a corresponding force that pushes against the deflection, targeting to return the actuator 116 back to the non-pivoted position. The right resilient arm 136b has come free from the corresponding protruding feature 156 and does not provide any force.

[0033] In figure 4 c) the actuator 116 is pivoted to the right, and the right resilient arm 136b will provide a force that pushes against the deflection, targeting to return the actuator 116 back to the non-pivoted position.

[0034] Figure 5 shows a partially exploded view of main elements of a first variant of a second version of the push button switch 100, the first variant being bi-stable, i.e., a respective switching position remaining valid until changed through a further operation of the push-button 100. Topmost, a button 124 and its guiding elements, for guiding the button 124 inside the base housing 102 is shown. Push button 124 has a first, outer surface 130 that may receive a force for operating the push button switch, and a second, inner surface 132 that is essentially opposite of the first surface 130. Below the button 124 an intermediate element 138 is shown, which has two resilient arms 140a, 140b that extend essentially perpendicular to and away from the second surface 132, each of the resilient arms representing a resilient member. Like in the first variant of the push button switch, in this variant, too, intermediate element 138 has a protrusion that fits inside opening 148 of the button (not visible in this figure). Next, an actuator 116 is visible, underneath of which an under rocker 108 is visible. Under rocker 108 is pivotable between a first and a second position around a first axis 110. In the figure under rocker 108 is shown in a central position, between the first and the second position. Under rocker 108 has a coupling element 142 on which resiliently deflects at least one of the resilient arms 140a, 140b act when the actuator 116 is pivoted. Under rocker 108 further has a cone-shaped support 144 for receiving a resilient element, which is not used in this variant. Under rocker 108 further has a protrusion 112 that is in contact with and acts on movable contact 106, which is in permanent electrical contact with electric terminal 104b, for selectively bringing the movable contact 106 in electrical contact with one of the electric terminals 104a or 104c. Movable contact thus alternatively establishes an electrical connection between electric terminal 104b and 104a or 104b and 104c. Resilient means 154 are provided for returning the button 124 into an idle position when no external force is applied.

[0035] Figure 6 shows a partially exploded view of main elements of a second variant of a second version of the push button switch 100, the second variant being mono-stable, i.e., a respective switching position remaining valid only while the push-button 100 is operated. The elements of the second variant are mostly identical to those of the first variant and will not be described again. However, in the second variant a resilient member is received in support 144 of the under rocker 108, support 144 being not visible in the figure. The resilient member, in this example a helical spring, will provide a force that acts to rotate the under rocker 108 into a position in which it acts on the movable contact 106 such that is connects electric terminals 104b and 104c.

[0036] Figure 7 a) to c) shows various stages of the movement of the actuator 116 relative to the button 124 and the intermediate element 138, respectively, as well as the actions of the resilient arms 140a, 140b in response to the respective movement. In figure 7 a) the actuator 116 is in a central, non-pivoted position. The resilient arms 140a, 140b, which are in contact with coupling element 142 of the actuator 116, are equally loaded or not loaded at all. The actuator 116 is pivotable around the second axis, which is defined by the point where a recess 158 of the actuator receives a protrusion 160 of the intermediate element 138. The actuator 116 may be secured against losing contact with the intermediate element 138, e.g., by engaging with a bearing 162 of the actuator 116.

[0037] In figure 7 b) the actuator 116 is pivoted to the right, and the coupling element 142 of the actuator 116 is pushed against right resilient arm 140b of intermediate element 138. While not clearly visible in the figure, resilient arm 140b will be deflected and produce a corresponding force that pushes against the deflection, targeting to return the actuator 116 back to the non-pivoted position. The left resilient arm 140a has come free from the coupling element 142 of the actuator 116 and does not provide any force.

[0038] In figure 7 c) the actuator 116 is pivoted to the left, and the left resilient arm 140a will provide a force that pushes against the deflection, targeting to return the actuator 116 back to the non-pivoted position.

[0039] In figure 8 a) through f) show the interaction of the actuator 116 and the under rocker 108 for moving the mobile contact 106 when the button 124 is depressed. In figure 8 a) the under rocker 108 is rotated to the left around the first axis 110, and the protrusion 112 of the under rocker 108 has acted on the mobile contact 106, moving to into position for connecting terminals 104a and 104b. The protrusion 112 of the under rocker 108 is spring loaded and maintains the mobile contact 106 and the under rocker 108 in this position. The resilient means 154 acts on the button 124 for bringing it into the idle position 126, indicated by the upper dashed line that is flush with the first surface 130 lying above the solid line that is flush with the upper rim of base housing 102, and maintaining it in this position as long as no force is applied to the button 124. The corresponding part of the button 124 interacting with the resilient means 154 is not shown in the figure. The actuator 116 is in a non-pivoted position, and its first prong 120a is positioned above the first engagement surface 114a of the under rocker 108. The first engagement surface 114a of the under rocker 108 is shaped so as to accommodate the first engagement surface 122 a of the first prong 120a of the actuator 116 when the button 124 is depressed.

[0040] Figure 8 b) shows the first engagement surfaces 114a and 122a of the under rocker 108 and of the first prong 120a of the actuator 116, respectively, of figure 8 a) in an enlarged view. In figure 8 b) it is readily apparent that the tip of the first prong 120a of the actuator 116 is located above the first engagement surface 114a of the under rocker 108 and will temporarily rest in the shape of first engagement surface 114a of the under rocker 108 when the button 124 is depressed.

[0041] In figure 8 c) the button 124 is depressed and is in the operated position 128, indicated by the dashed line that is flush with the first surface 130 lying below the solid line that is flush with the upper rim of base housing 102. The first engagement surface 122a of the first prong 120a of the actuator 116 has engaged with the first engagement surface 114a of the under rocker 108 and has transferred the force pushing down the button 124 thereon. In response to the force acting on it, under rocker 108 has rotated around the first axis 110, and the protrusion 112 has moved the mobile contact 106, which now connects terminals 104b and 104c. The actuator 116, through its engagement with the under rocker 108, has been pivoted to the left in response to the rotation of the under rocker 108, and has moved the second prong 120b of the actuator 116 out of the way of the second engagement surface 114b of the under rocker, which has swivelled to a higher position in response to the rotation of the under rocker 108. The two prongs 120a, 120b of the actuator 116 embrace the first axis 110 in the operated position. The resilient means 154 is compressed by the movement of the button 124 and will return the button 124 to the idle position 126 as soon as the force acting on the button 124 is removed.

[0042] Figure 8 d) shows the first engagement surfaces 114a and 122a of the under rocker 108 and of the first prong 120a of the actuator 116, respectively, of figure 8 c) in an enlarged view. The tip of the first prong 120a of the actuator 116 rests in the shallow depression formed in the first engagement surface 114a of the under rocker 108 and will only come free again when the force that depresses button 124 is removed. In a variant of the push button switch the tips of the prongs 120a, 120b of the actuator 116 and the first and second engagement surfaces 114a, 114b of the under rocker 108, and the inner flanks of the opposing prongs 120a, 102b may have a shape that disengages the respective tip that is engaged with the under rocker, when the button 124 is depressed further. This variant is only partly visible in the figure: inner flank 164 of the prong that is not engaged with the under rocker 108 may come into contact with the first axis 110, and may, through its shape, pivot the actuator towards the non-pivoted position, when the button 124 is depressed further. This may also involve a deflection of the actuator 116 and / or of the prongs 120a, 120b of the actuator 116 essentially in a direction of the first axis 110. The variant may reduce the force that acts on the prongs of the actuator, preventing irreversible deformation thereof.

[0043] In figure 8 e) the button 124 is released and has been returned to the idle position 126 through the force provided by resilient means 154. The actuator 116 is brought back and maintained in a non-pivoted position by the resilient arms 136a, 136b extending therefrom. The first engagement surface 122a of the first prong 120a of the actuator 116 is no longer engaged with the first engagement surface 114a of the under rocker 108. The second engagement surface 122b of the second prong 120b of the actuator 116 is not yet engaged with the second engagement surface 114b of the under rocker 108 but is positioned there above and will engage as soon as the button 124 is depressed. Until then, the under rocker 108 keeps the position attained in response to the previous operation of the button 124.

[0044] Figure 8 f) shows the second engagement surfaces 114b and 122b of the under rocker 108 and of the second prong 120b of the actuator 116, respectively, of figure 8 e) in an enlarged view. In figure 8 f) it is readily apparent that the tip of the second prong 120b of the actuator 116 is located above the second engagement surface 114b of the under rocker 108 and will temporarily rest in the shape of second engagement surface 114b of the under rocker 108 when the button 124 is depressed.

[0045] The rotation of the under rocker 108 alternatingly brings one of the first or second engagement surface 114a, 114b of the under rocker 108 into a raised position that also is closer to a plane that extends along the first axis 110 and is essentially perpendicular to the first surface 130 of the button. As the resilient means bring the actuator 116 back into a non-pivoted position when the button 124 is in the idle position, the prongs 120a, 120b alternatingly engage with the corresponding first or second engagement surface 114a, 114b of the under rocker 108 on every depression of the button.REFERENCE SIGNS LIST (part of the description)

[0046] 100push button switch154resilient means102base housing156protruding feature104a-celectric terminals158recess106movable contact160protrusion108under rocker162bearing110first axis164inner flank112protrusion114afirst engagement surface (under rocker)114bsecond engagement surface (under rocker)116actuator120afirst prong120bsecond prong122afirst engagement surface (prong)122bsecond engagement surface (prong)124button126idle position128operated position130first surface132second surface136a-bresilient arm138intermediate element140a-bresilient arm142structure / surface / coupling element144support146resilient element148opening150mounting feature152light source

Claims

1. A push-button switch (100) comprising: - a base housing (102), - at least two electric terminals (104) for connecting electric wiring, - a movable contact (106) that is in permanent electric contact with a first one (104b) of the at least two electric terminals (104a-c) and that can selectively be brought into electric contact with a respective second one (104a, 104c) of the at least two electric terminals (104a-c), - an under rocker (108) that is rotatable between a first and a second position around a first pivot axis (110), having a protrusion (112) that acts on the movable contact (106), for selectively bringing the movable contact (106) in electrical contact with a respective second one (104a, 104c) of the at least two electric terminals (104a-c), wherein the under rocker (108) has a first and a second engagement surface (114a, 114b), the first and second engagement surface (114a, 114b) being disposed at a distance at opposing sides of the first pivot axis (110), - an actuator (116), pivotable between opposite sides around a second pivot axis, the second pivot axis and the actuator (116) being translatable in a direction towards the first pivot axis (110), the actuator (116) having a first and a second prong (120a, 120b) extending at an end opposite of the second pivot axis, each prong (120a, 120b) having a respective engagement surface (122a, 122b), for selectively engaging with an associated one of the first and second engagement surfaces (114a, 114b) of the under rocker (108), - a button (124), arranged in the base housing (102) and movable between an idle position (126) and an operated position (128), the button (124) having a first surface (130) configured for receiving a force that moves the button (124) from the idle position (126) towards the first pivot axis (110) into the operated position (128), wherein a second surface (132), located generally opposite of the first surface (130), is arranged to transfer the force received at the first surface (130) and the corresponding movement of the button (124) to the actuator (116), translating the second pivot axis and the actuator (116) towards the first pivot axis (110), wherein, depending on whether the under rocker (108) is currently rotated into the first or the second position, only the respective engagement surface (122a, 122b) of the first (120a) or the second (120b) prong of the actuator (116) makes contact with the respective first (114a) or second (114b) engagement surface of the under rocker (108), imparting the translation of the button (124), the second pivot axis and the actuator (116) on the under rocker (108) and causing the under rocker (108) to pivot into the respective other position, and - a resilient member comprising one or more resilient arms (136a, 136b; 140a, 140b) that is configured to maintain the actuator (116) in a central, non-pivoted position when the button (124) is in the idle position (126) and the second pivot axis and the actuator (116) are not translated towards the first pivot axis (110), characterised in that the first pivot axis (110) is located between and at least partially embraced by the first and second prongs (120a, 120b) of the actuator (116) when the button (124) is in the operated position (128), in which operated position (128) the second pivot axis and the actuator (116) are translated towards the first pivot axis (110).

2. The push-button switch (100) of claim 1, wherein the resilient member comprises two resilient arms (136a, 136b) extending from either side of the actuator (116), away from the second axis, each arm (136a, 136b) applying a force directed towards the second surface (132) when the actuator (116) is pivoted to the side of the respective arm (136a, 136b), the force targeting to return the actuator (116) into the central, non-pivoted position.

3. The push-button switch (100) of claim 1 or 2, wherein an intermediate element (138) is arranged between the second surface (132) and the actuator (116), the intermediate element (138) being arranged to pivotably receive the actuator (116).

4. The push-button switch (100) of claim 3, when depending from claim 1, wherein the resilient member comprises one or more resilient arms (140a, 140b) extending from the second surface (132) or from the intermediate element (138) in a direction essentially perpendicular to and away from the second surface (132), wherein at least one of the at least one resilient arms (140a, 140b) is resiliently deflected by the actuator (116) when the actuator (116) is pivoted.

5. The push-button switch (100) of claim 4, wherein at least one of the one or more resilient arms (140a, 140b) acts on a structure, surface or coupling element (142) of the actuator (116) when the actuator (116) is pivoted.

6. The push-button switch (100) of any one of the preceding claims, wherein the under rocker (108) has a support (144) for receiving a resilient element (146) that forces the under rocker (108) into one of the first or second position when no force is applied to the button (124).

7. The push-button switch (100) of any one of claims 3 to 7, wherein the intermediate element (138) is made from a translucent or opaque material of a first colour, and wherein the button (124) has at least one opening (148) through which a part of the intermediate element (138) is visible.

8. The push-button switch (100) of any one of the preceding claims, wherein the base housing (102) is arranged to receive a light source (152) for illuminating the button (124) and / or the intermediate element (138).

9. The push-button switch (100) of any one of the preceding claims, wherein the protrusion (112) of the under rocker that acts on the movable contact (106) is spring-loaded and movable in a direction perpendicular to the first pivot axis (110).

10. The push-button switch (100) of any one of the preceding claims, wherein a resilient means (154) is provided that applies a force on the button (124) or the intermediate element (138) for returning the button (124) to the idle position (126) when no force is applied.

11. The push-button switch (100) of any one of the preceding claims, wherein one of the opposite inner surfaces of the prongs (120a, 120b) of the actuator (116) are shaped to come into contact with the first pivot axis (110) when the button (124) is depressed by a predetermined distance, wherein, when the button (124) is depressed further, the shape of the inner surface of that prong (120a, 120b) that is not in contact with the corresponding engagement surface (114a, 114b) of the under rocker (108) causes a rotation of the actuator (116) that forces the engagement surface (122a, 122b) of the other prong (120a, 120b) of the actuator (116) to disengage from the corresponding engagement surface (114a, 114b) of the under rocker (108), with which it was in contact.