MAGNETIC PUSH BUTTON

Description

[0001] The present invention relates to a magnetic push button, also called a magnetic push switch.

[0002] More particularly, the present invention relates to the field of single-function push-button switches, or switches with a redundant or secure function, intended for activating critical functions. Advantageously, such a button can be used in the aeronautical field, for example in an aircraft cockpit.

[0003] This type of electrical switch intended for the activation of critical functions, used for example on aircraft dashboards, must meet a certain number of constraints. In particular, certain functions require that their operation be carried out by pressing a redundant or electrically secure switch, i.e. simultaneously establishing electrical contact for at least two electrical circuits implementing, for example, a single function, the two electrical circuits not having a common electrical mode.

[0004] This is the case, for example, in aircraft, for switches for engaging an autopilot (AP) device. For such applications, it is also preferable for the switches arranged on the dashboard to be of compact structure. In addition, it is desirable that the tactile sensation provided to a user by the switch when acting on it is pleasant, and provides feedback allowing the user to confirm the successful completion of the initiated action. The thrust force for such a switch must be between 0.5 and 20 N (typically 5 N). In order to allow its certification, the push switch must also be able to meet DAL safety levels (from the English « Design Assurance Level "), particularly at DAL A level. In such a device, we seek to generate a pleasant operation (or tactile sensation) whose main function is to guarantee that electrical detection (for validation) is ensured after the passage of a peak force (notching force). For a good tactile sensation, it is necessary that the button travel can be significant, for example greater than or equal to 0.3 mm.

[0005] In particular, with regard to compactness, a magnetic push switch can have the following dimensions: height (dimension depending on the direction of movement): between 5 and 20 mm (typically: 12 mm); width: between 10 and 38 mm (up to 70 mm in some cases, typically: 14 mm); length: between 10 and 38 mm (up to 70 mm in some cases, typically: 14 mm).

[0006] These dimensions can, for example, be determined according to the MIL-STD-1472 type standard. STATE OF THE ART

[0007] To meet the above-mentioned needs, there are electromechanical solutions based on domes (or equivalent). However, these solutions remain complex assemblies made up of numerous high-precision parts. Domes are exposed to the risks of fatigue and fretting corrosion, which limits the device's lifespan. In addition, the travel of a dome switch is rarely greater than 0.3 mm. These switches therefore do not meet all the requirements of the need.

[0008] Magneto-mechanical solutions are also known which provide activation detection by magnetic effects and a pushing and / or returning force by an elastic element, such as a spring. However, such an elastic element presents risks of fatigue and blocking or shifting which also limits the lifetime of the device. CH669076 A5 and US3622922 A also each describe a push button. SUMMARY OF THE INVENTION

[0009] The aim of the present invention is to propose a magnetic push button meeting all of the aforementioned needs, while having a detection function, a pushing force and possibly a return force without friction and without wear, with a limited number of parts, simplified assembly and reduced risks of blocking and shifting.

[0010] To this end, the invention relates to a magnetic push button comprising a fixed body and a body movable relative to the fixed body along an axis of movement;

[0011] One of the bodies, called the first body, comprises a magnetic element extending along the axis of movement and defining a magnetic alternation along this axis of movement.

[0012] The other body, called the second body, comprises a notching tooth made of ferromagnetic or magnetic material arranged opposite the magnetic element relative to a plane parallel to the axis of movement to create a thrust force by magnetic cooperation with the magnetic element, during a movement of the mobile body along the axis of movement and a magnetic detector arranged opposite the magnetic element and configured to generate measurements quantifying each movement of the mobile body along the axis of movement.

[0013] Equipped with these characteristics, the push button according to the invention makes it possible to implement a detection function and a pushing force which are created by the same magnetic effect between the moving body and the fixed body. Thus, the arrangement of these two bodies can be chosen so as to minimize their mechanical contact and therefore wear. For example, the elements detailed above of the fixed body and the moving body have minimal contact necessary to ensure the movement of one of the bodies relative to the other. Thus, these elements operate substantially without friction and without premature mechanical wear. This therefore guarantees the reliability of the button in use and considerably extends its service life even when plastic parts are used. In addition, these elements are limited in number, which allows them to be easily arranged within the corresponding bodies.

[0014] This makes mounting the button particularly simple and reduces the risk of jamming and misalignment of different parts.

[0015] According to certain embodiments of the invention, the magnetic element defines at least one central notch and two peripheral notches and a stable position in translation being defined when the notching tooth is arranged opposite the central notch.

[0016] Thanks to these characteristics, the magnetic element has three magnetic alternations and the notching tooth preferentially has a magnetization which allows an attraction with the central notch of the magnetic element. This consequently creates a stable position centered in the middle of the travel of the push button which intrinsically has a return to this stable position by magnetic return without contact. The interest of this magnetic arrangement is to avoid wear and use, in both directions of translation, of any elastic element to ensure a return force.

[0017] According to certain embodiments of the invention, the magnetic alternation of the magnetic element defines a notching pitch.

[0018] Thanks to these features, the stable position is positioned on the central notch and the push force profile starts substantially at 0 N without preload (target for an improved tactile sensation force profile).

[0019] According to certain embodiments of the invention, the surface of the notching tooth has an extent less than or equal to the notching pitch of the magnetic element.

[0020] Thanks to these characteristics, the magnetic alternation of the magnetic element corresponds to the size of the notching tooth and defines the translational travel of the push button. This translational travel is for example greater than or equal to 0.3 mm. Equipped with these characteristics, the number of teeth can thus be increased up to the number of magnetic alternations of 41. This then makes it possible to optimize the notching or push force.

[0021] According to certain embodiments of the invention, presenting a button activation detection profile as a function of the measurements generated by the magnetic detector; said detection profile comprising a button activation detection with an offset relative to a peak of the pushing force created by magnetic cooperation of the magnetic element with the notching tooth.

[0022] These features ensure an improved tactile sensation. In particular, in such a case, the aim is to generate a tactile sensation whose main function is to ensure that activation detection is ensured after the passage of a peak force (push force). This corresponds to a tactile sensation usually felt by the user when activating a conventional push button.

[0023] According to certain embodiments of the invention said offset in the detection profile is achieved by an offset along the axis of movement of the magnetic detector and the notching tooth.

[0024] Thanks to these features, the offset between the peak of the thrust force and the detection of the button activation can be achieved particularly simply. In fact, the magnetic sensor can simply be slightly offset along the axis of movement relative to the toothing, which ensures detection slightly offset from the peak of the thrust force.

[0025] According to certain embodiments of the invention, the second body comprises a plurality of notching teeth and / or a plurality of detectors distributed equidistantly along the axis of movement and / or around the axis of movement.

[0026] Thanks to these characteristics, increasing the number of notching teeth allows for an increase in the desired thrust force. This increase can be made simultaneously with increasing the surface area facing the magnetic element or with increasing the number of different parts of the magnetic element.

[0027] According to certain embodiments of the invention, the or each notching tooth and / or the magnetic element is (are) mounted on a magnetic or ferromagnetic support.

[0028] These features help to avoid field leaks and external parasitic emissions, without increasing the size of the corresponding element. Therefore, these features allow to optimize the notching or push force.

[0029] In some embodiments, the first body is the movable body and the second body is the fixed body.

[0030] In this case, the magnetic sensor and the toothing remain fixed. This is advantageous because the electrical cable, especially from the magnetic sensor, remains fixed in relation to the body of the button. This avoids complicated wiring, which is generally expensive and presents risks of wear and signal interruption.

[0031] According to certain embodiments of the invention, a travel stop for each end of travel during movement along the axis of movement.

[0032] Each stop can be mechanical (i.e. mechanical contact) or magnetic. In the latter case, such a stop can include magnets in repulsion at the end of the stroke.

[0033] According to certain embodiments of the invention further comprising a surface intended to be oriented towards an operator; said surface comprising at least one functional element chosen from the list comprising: a visual feedback element; a presence sensor; a haptic actuator.

[0034] Thanks to these features, it is possible to provide a number of additional button functionalities. For example, it is possible to implement visual feedback indicating to the operator, for example, the current state of the function associated with the button (enabled or disabled) or any other useful information, such as the function assigned to the button.

[0035] Thanks to the presence sensor, it is possible, for example, to activate additional button functions by detecting the position of the fingers on the button. For example, the button's functionality may differ depending on the number of fingers placed on the button.

[0036] Thanks to a haptic actuator it is possible to improve the haptic feeling for the user.

[0037] According to certain embodiments of the invention further comprising a complementary force controller comprising an electromagnetic coil secured to one of the bodies and configured to act on the or each notching tooth and / or on the magnetic element and / or on a ferromagnetic or magnetic support.

[0038] Thanks to these characteristics, it is possible to increase the pushing force felt by the operator.

[0039] According to certain embodiments of the invention, the button further comprises an additional electromechanical or optomechanical switch placed in the center of the second body and configured to be activated by a rod secured to the first body.

[0040] Thanks to these characteristics, it is possible to increase the security level of the device thanks to the switch forming a detector of different technology compared to the magnetic detector. Such a detector can for example form a so-called "dry contact" detector (i.e. mechanical contact) or even an optical detector. DESCRIPTION OF FIGURES

[0041] These characteristics and advantages of the invention will appear on reading the description which follows, given solely by way of example and not as a limitation, and made with reference to the appended drawings, in which: [ Fig.1 ] there figure 1 is a schematic perspective view of a push button according to a first embodiment of the invention; [ Fig.2 ] there figure 2 is an exploded perspective view of the button of the figure 1 ; [ Fig.3 ] there figure 3 presents a sectional view along plan III of the figure 1 ; [ Fig.4 ] there figure 4 is a perspective view of the functional internal elements of the fixed body and the movable body of the figure 1 , said elements comprising in particular a magnetic element; [ Fig.5 ] there figure 5 is a magnetic radiation diagram according to different examples of internal arrangement of the magnetic element of the figure 4 ; [ Fig.6 ] there figure 6 is a view analogous to that of the figure 3 , the push button being according to another embodiment; [ Fig. 7 ] there figure 7 is a top view of the push button of the figure 6 . [ Fig. 8 ] there figure 8 is a view analogous to that of the figure 2 , the push button being according to a second embodiment of the invention; [ Fig. 9 ] there figure 9 is a longitudinal sectional view of the push button of the figure 8 and in cross-section according to the arrows EE in this same figure; and [ Fig. 10 ] there figure 10 is a sectional view of a push button according to the second embodiment of the invention according to an example different from that of the figure 8 . DETAILED DESCRIPTION OF THE INVENTION FIRST MODE OF IMPLEMENTATION

[0042] There figure 1 illustrates a magnetic push button 10 according to the first embodiment of the invention. Preferably, the button 10 is mounted in a cockpit for piloting an aircraft.

[0043] By "aircraft" is meant any flying machine, such as an airplane, a helicopter or a drone for example. Such an aircraft can be piloted directly from it. In such a case, the cockpit is advantageously arranged inside the aircraft. According to another exemplary embodiment, such an aircraft is controlled remotely. In such a case, the cockpit is arranged at a distance from the aircraft and has for example a ground station. In all cases, the aircraft is configured to be piloted by an operator, also called a user, for example by a pilot from the cockpit arranged inside the aircraft.

[0044] According to the invention, the button 10 allows the operator to control at least one avionics functionality. For example, such a button 10 can be used by the operator to control an avionics system and is part of a control system for such an avionics system. Alternatively, the button 10 is part of a control system for several avionics systems. For example, the button 10 according to the invention is part of a system called a “Flight Control Unit” (FCU) or “Integrated Standby Instrument System” (ISIS) or “Closer Control Device” (CCD) or “Keyboard Cursor Control Device” (KCCD), etc.

[0045] In reference to the figure 2 , the button 10 comprises a movable body 21, also called in the example of this figure first body, and a fixed body 22, also called in the example of this figure second body. The movable body 21 is movable in translation relative to the fixed body 22 along a movement axis X also visible on the figure 2 .

[0046] The movable body 21 comprises a cover 31 and an interconnection element 32. The cover 31 makes it possible to protect all of the internal elements of the button 10 and notably comprises a visible surface 35 intended to be oriented towards the operator. According to different embodiments, the cover 31 may comprise connecting means allowing it to cooperate with the fixed body 22 during its movement along the axis of movement X. According to other embodiments, these connecting means are part of the interconnection element 32. The connecting means provide, for example, a sliding or pivoting connection along the axis of movement X. This connection may be: plain bearings (e.g. polymer bearings or sintered bronze bearings) preferably with flanges to serve as a mechanical stop; rolling element bearings (e.g. ball bushings); flat surface connections (e.g. dovetail).

[0047] Alternatively or additionally, at least some of these connecting means are integrated into the fixed body 22.

[0048] Alternatively or additionally, the connecting means between the bodies 21 and 22 may be an elastic body with equivalent stiffness. The stiffness may be different depending on the directions, for example low along the X axis and high along the other directions in order to counteract parasitic torques when the button is attacked at an angle. This type of connection may thus be without contact or rolling between the bodies 21 and 22. This type of connection may be: one (or more) membrane(s) (example: CuBe2 plates or elastomer membrane). one (or more) deformable plated part(s) placed in the center (or around the bodies 21 and 22).

[0049] The interconnection element 32 is integrally connected to the cover 31. The interconnection element 32 comprises a movable support 36 for holding functional internal elements inside the movable body 21, as will be explained in detail later. The movable support 36 has, for example, a magnetic or ferromagnetic part and is, for example, in the form of an arc or a “U” overhanging the fixed body 22 or at least certain internal elements thereof, as illustrated in the figure 4 . In particular, as illustrated in the figures 3 And 4 , the mobile support 36 may have two fixing arms extending substantially along the axis of movement X and a connecting piece extending substantially perpendicular to the axis of movement X to connect the two fixing arms.

[0050] The fixed body 22 makes it possible to cooperate with the mobile body 21 via the connecting means to ensure the movement of the mobile body 21 along the movement axis X. The fixed body 22 comprises a fixed support 37 (visible on the figure 3 ) capable of supporting at least some of the functional internal elements cooperating with the functional internal elements of the mobile body 21 as will be explained in more detail later. In particular, and as will be apparent later, the functional internal elements of the fixed body 22 are held by this fixed support 37 at a distance from those of the mobile body 21. The fixed support 37 has, for example, one or more magnetic or ferromagnetic parts extending along the axis of movement X.

[0051] The fixed body 22 further comprises a fixing surface 38 for fixing the button 10, for example, to a dashboard of the aircraft. The fixing surface 38 further defines, for example, at least one pair of contacts for transmitting electrical signals between the button 10 and the corresponding avionics system.

[0052] According to different embodiments, the mobile body 21 and / or the fixed body 22 may further comprise a travel stop for each end of travel during movement along the movement axis X. Each stop may be mechanical in nature (i.e. mechanical contact) or magnetic (via the use of repulsive magnets at the end of travel, for example).

[0053] In reference to the figure 4 , the functional internal elements of the mobile body 21 comprise a magnetic element 41 and the functional internal elements of the fixed body 22 comprise at least one notching tooth 42 capable of cooperating with the magnetic element 41 of the mobile body 21 and at least one magnetic detector 43 capable of generating measurements quantifying each movement of the mobile body 21 along the movement axis X.

[0054] The magnetic element 41 has an axial magnetic alternation and is fixed on the movable support 36. The magnetic element 41 may have any suitable shape such as for example a ring, a parallelepiped or a cylinder or a portion of a ring with an axial or radial magnetization. Furthermore, the magnetic element 41 may have a single part or several separate parts.

[0055] In the example of the figure 4 , the magnetic element 41 is in the form of two substantially identical parts 41A, 41B arranged opposite each other in a symmetrical manner relative to the axis of movement X. Each of these parts 41A, 41B is held by the corresponding fixing arm of the mobile support 36. In the same figure, each part 41A, 41B is of parallelepiped shape extending along the axis of movement X.

[0056] To ensure magnetic alternation along the axis of movement X, the magnetic element 41 and possibly each separate part 41A, 41B thereof, has a plurality of elementary magnetic parts arranged next to each other, for example by gluing. Each elementary part has, for example, a parallelepiped shape or, in the case of an annular shape of the magnetic element 41, a ring or a ring arc. Each elementary part has, for example, a conventional permanent magnet or a magnet from a “polymagnet” or a “programmable magnet” called Polymagnets ®<. In the example of the figure 4 , each part 41A, 41B of the magnetic element 41 has three elementary pieces 41-1, 41-2, 41-3 parallelepiped glued to each other along the axis of movement X. Each of these elementary pieces 41-1, 41-2, 41-3 has a permanent magnet defining the pole N and the pole S. These pieces are arranged along the axis of movement X so as to form an alternation of pole N and pole S along this axis X. In other words, in such a case, each elementary piece has a radial magnetization.

[0057] In a generic case, radial magnetization is achieved by arranging each elementary piece next to each other along the axis of motion so that adjacent elementary pieces are magnetized in opposite directions along the radial direction. This arrangement of the elementary pieces forms a D1 diagram of magnetic fluxes shown in the figure 5 in the case of five elementary pieces.

[0058] According to another example of a possible arrangement, an axial magnetic alternation is achieved by using a Halbach-type arrangement, a D2 diagram of the magnetic fluxes of which is also illustrated in the figure 5 . In particular, according to such a type of arrangement, the elementary parts are magnetized alternately in the radial and axial direction. Furthermore, the direction of magnetization of each elementary part is chosen so as to concentrate the magnetic field on the surface of the magnetic element 41 opposite the functional internal elements of the fixed body 22.

[0059] The magnetic element 41 and possibly each of its parts 41A, 41B have a length L1 corresponding to its extent along the axis of movement X. This length L1 defines the extent of the travel of the mobile body 21. This extent is advantageously greater than 0.9 mm. The length L1 is formed from a sum of the widths of the elementary parts forming this magnetic element 41. The width of each elementary part forms a notching pitch. According to an exemplary embodiment, the elementary parts have the same width. In such a case, the magnetic element 41 has a homogeneous notching pitch.

[0060] In the example of the figure 5 , three elementary parts 41-1, 41-2, 41-3 are arranged successively along the axis of movement X. Among these elementary parts 41-1, 41-2, 41-3, the elementary part 41-2 is arranged between the elementary parts 41-1, 41-3. The elementary part 41-2 is then called the central part and the elementary parts 41-1, 41-3 are called peripheral parts. The central part 41-2 then has a central notch and the peripheral parts 41-1, 41-3 have peripheral notches.

[0061] As illustrated in the figure 4 , the magnetic detector 43 is mounted on one of the parts forming the fixed support 37 opposite at least one of the parts of the magnetic element 41. The magnetic detector 43 makes it possible to quantify the displacement of this magnetic element 41 along the axis of movement X. In other words, the detector 43 makes it possible to code each displacement of the magnetic element 41 along the axis of movement X by detecting changes in the magnetic flux thanks to the axial magnetic alternation of the elementary parts constituting the magnetic element 41.

[0062] The magnetic detector 43 has, for example, a Hall effect sensor or a magnetoresistive sensor or a solenoid. Furthermore, the magnetic detector 43 is connected to an external controller of the button 10 by cables 44 visible on the figure 3 and capable of delivering to this external controller electrical signals quantifying the change in the magnetic field in the vicinity of the detector 43. These signals form a button activation detection profile. This profile comprises at least one activation point corresponding to the activation detection of the button 10, i.e. a particular value of the change in the magnetic field for which the button 10 is considered to be activated.

[0063] The notching tooth 42 is mounted on the fixed support 37, for example on a part of this support 37 separate from that supporting the detector 43. The notching tooth 42 is mounted opposite at least one part of the magnetic element 41. In particular, the notching tooth 42 is mounted opposite at least one part of the magnetic element 41 relative to a plane parallel to the axis of movement X. In particular, in the example of the figure 4 , the notching tooth 42 and the magnetic detector 43 are arranged opposite the different parts 41A, 41B of the magnetic element 41. The notching tooth 42 has a surface which is oriented towards the magnetic element 41 and has a dimension along the axis of movement X less than or equal to the notching pitch defined by the magnetic element 41. The notching tooth 42 is made of a ferromagnetic or magnetic material such as 400 series stainless steel. The notching tooth 42 is preferably a magnet. The notching tooth 42 is for example a parallelepiped magnet or a circular arc magnet. Such a magnet is for example derived from a “polymagnet” or a “programmable magnet” called Polymagnets ®< .

[0064] The distance between the notching tooth 42 and the corresponding part of the magnetic element 41 is adapted to ensure a necessary thrust force. Such a force along the axis of movement X is for example between 0.5 and 20 N and advantageously equal to 5 N. The thrust force can also be adapted by adapting the number of notching teeth along the axis of movement X and / or around the axis of movement X. Furthermore, advantageously according to the invention, the notching tooth 42 is in the stable position when it is arranged opposite the central notch, that is to say opposite the elementary part 41-2 of the magnetic element 41 in the example of the figure 4 To ensure such a stable position, the surface opposite the notching tooth 42 has a magnetization opposite to that of the surface opposite the corresponding elementary part 41-2 of 41B.

[0065] It is clear that the push force is variable depending on the respective positions of the or each notching tooth 42 relative to the magnetic element 41. For at least one particular respective position of these elements, the pushing force has a peak. Advantageously, according to the invention, the activation point in the detection profile of the magnetic detector(s) 43 is chosen as a function of this peak of the pushing force. In particular, this activation point is advantageously offset relative to the peak of the pushing force so that the activation of the button is detected after this peak. To achieve such an offset, the magnetic detector 43 may be slightly offset along the movement axis X relative to the notching tooth 42.

[0066] There figure 6 illustrates another example embodiment of the button 10. According to this example, the button 10 further comprises a complementary force controller 60 making it possible to further control the thrust force along the movement axis X. This controller 60 notably comprises a magnetic coil 62 integrated in the fixed body 22 and capable of creating a magnetic field making it possible to interact with the ferromagnetic or magnetic part of the mobile body 21 such as the mobile support 36, and / or with the magnetic element 41 of the mobile body 21.

[0067] In the example of the same figure, the button 10 may further comprise at least one functional element chosen from the list comprising: a visual feedback element; a presence sensor; a haptic actuator.

[0068] Such a functional element is for example integrated into the visible surface 35 of the cover 31 and / or housed in the cavities of the interconnection element 32 illustrated in the figure 2 .

[0069] In the example of the figure 7 , a visual feedback element 90 is integrated on the visible surface 35. The visual feedback element 90 may for example comprise an indicator indicating for example the function of the button 10 or an annunciator 91 indicating the validation of the command or any other ambient light.

[0070] This ambient light can, for example, be connected to the rest of the cockpit to create harmony that improves the aesthetic appearance of button 10. Indeed, the light marking in case of emergency or turbulence can represent an asset from the point of view of aircraft safety. This lighting can be connected and synchronized with the rest of the cockpit. In this case, it could change color depending on the context during the flight, for example, flashing red in an emergency situation.

[0071] When the functional element comprises a presence sensor, the latter can be integrated into the button 10 to activate additional functions and / or to detect finger positions on the button. For example, the functionality of the button 10 can be modified depending on the number of fingers placed on the visible surface 35.

[0072] When the functional element comprises a haptic actuator, this is preferably placed at the end of the button 10 to improve the haptic feeling for the user. It may have a piezoelectric actuator or an unbalanced vibration motor preferably secured to the fixed body 22. The actuator may also be an electromagnetic actuator and act between the fixed body 22 and the mobile body 21. The electromagnetic actuator may use a winding or a coil secured to the fixed body 22 which generates a magnetic field which attracts or repels a ferromagnetic or magnetic part along the axis of movement X.

[0073] Of course, at least one of the aforementioned functional elements can also be arranged in the button 10 without necessarily the complementary force controller 60. Finally, it must be understood that the notion of a first body with all the associated elements can be applied to a fixed body and the notion of a second body with all the associated elements can be applied to a mobile body. SECOND EMBODIMENT

[0074] The second embodiment will now be explained with reference to the figures 8 à 10 . Elements similar to the first embodiment are indicated in these figures by the same references and will not be detailed below.

[0075] In particular, and as illustrated in the figure 8 , the interconnection element 32 comprises a movable support 136 which is different from the movable support 36 explained previously. More particularly, the movable support 136 is adapted to hold a magnetic element having a structure different from that explained previously. Thus, this movable support 136 has a first arcuate or “U” shaped portion 136-1 which is similar to the movable support 36 explained previously and a second portion 136-2 which extends around the fixing arms of the first portion 136-1. As in the previous case, each fixing arm receives a portion 41A, 41B of the magnetic element. These portions 41A, 41B are visible on the figure 9 and are for example identical to those described previously. However, unlike the previous case, each of these parts 41A, 41B is able to cooperate with a dedicated notching tooth. Also unlike the previous case, the magnetic element according to the second embodiment further comprises two other parts 41C, 41D arranged for example perpendicular to each of the parts 41A, 41B. Each of these other parts 41C, 41D of the magnetic element is fixed on the second part 136-2 of the mobile support 136 and is able to cooperate with a dedicated magnetic detector. Each part 41C, 41D can be similar to each part 41A, 41B. According to an exemplary embodiment, the parts 41A to 41D are connected to each other and form for example a cylindrical shape of the magnetic element. According to another exemplary embodiment, the parts 41A to 41D are fixed on the mobile support 136 around the X axis.

[0076] According to the second embodiment, the fixed body 22 comprises a fixed support 137 having a hollow cylindrical shape extending along the X axis. In each cross-section, the fixed support 137 may have a polygon whose number of faces corresponds to the number of functional internal elements of the fixed body 22. In the example of figures 8 à 10 , this number is equal to 4 and the fixed support 137 therefore has a rectangle (square for example) in each cross section.

[0077] According to the second embodiment, the functional internal elements of the fixed body 22 comprise a plurality of notching teeth and / or a plurality of magnetic detectors. In the examples of the figures, these functional internal elements comprise two notching teeth 142A, 142B arranged opposite the parts 41A, 41B of the magnetic element and two magnetic detectors 143C, 143D arranged opposite the parts 41C, 41D of this magnetic element. These elements 41C, 41D, 143C, 143D are arranged on the corresponding faces of the fixed support 137 and are for example similar to those described previously.

[0078] In general, the magnetic detectors 143C, 143D and / or the notching teeth 142A, 142B may be arranged around the movement axis X. Doubling or even tripling the number of magnetic detectors and / or notching teeth makes it possible to improve the reliability of the device, particularly in the case of asymmetrical pressing, i.e. pressing offset from the center of the button to an edge. In the case of a plurality of magnetic detectors, the activation detection profile of the button 10 is formed, for example, by all of the signals delivered by these detectors.

[0079] Furthermore, in the case of a plurality of magnetic detectors and / or toothed teeth, these elements may be implemented using different and dissimilar technologies, in order to meet a high DAL level (DAL A for example). For example, in the case of a plurality of magnetic detectors, these detectors may be dissimilar in order to make detection more reliable.

[0080] There figure 10 illustrates another example of the button 110 according to the second embodiment. According to this example, the button 110 further comprises a switch 194 integrated in the center of the fixed body 22 (advantageously in the hollow part of the fixed support 137) and a rod 195 secured to the mobile body 21 and configured to cooperate with the switch 194 during the movement of the mobile body 21 along the X axis. In particular, the rod 195 is configured to cooperate with the switch 194 when the button 110 is pressed. The switch 194 therefore has a means redundant to the magnetic detectors making it possible to detect a press on the button 110.

[0081] Advantageously, the switch 194 is implemented using a technology different from magnetic detectors. It is, for example, electromechanical or optomechanical in nature. Preferably, it detects a press during mechanical contact with the rod 195.

[0082] Of course, the switch 194 and the rod 195 can also be implemented in the first embodiment.

Claims

1. A magnetic push-button (10; 110) comprising a fixed body and a movable body, movable relative to the fixed body along an axis of movement (X); one of the bodies, called first body (21), comprising: - a magnetic element (41) extending along the axis of movement (X) and defining a magnetic alternation along the axis of movement; the other body, called second body (22), comprising: - a notching tooth (42; 142A, 142B) made of ferromagnetic or magnetic material arranged opposite the magnetic element (41) with respect to a plane parallel to the axis of movement (X) in order to generate a push force by magnetic cooperation with the magnetic element (41), during a movement of the movable body (21) along the axis of movement (X); - a magnetic detector (43; 143C, 143D) arranged opposite the magnetic element (41) and configured for generating measurements quantifying each movement of the movable body along the axis of movement (X).

2. The magnetic push-button (10; 110) according to claim 1, wherein: - the magnetic element (41) defines at least one central notch and two peripheral notches; and - a position which is stable in translation is defined when the notching tooth (42; 142A, 142B) is arranged opposite the central notch.

3. The magnetic push-button (10; 110) according to any of the preceding claims, wherein the magnetic alternation of the magnetic element (41) defines a notching pitch.

4. The magnetic push-button (10; 110) according to claim 3, wherein the surface of the notching tooth (42; 142A, 142B) has an extent less than or equal to the notching pitch of the magnetic element (41).

5. The magnetic push-button (10; 110) according to any of the preceding claims, having a detection profile for the button activation according to the measurements generated by the magnetic sensor (43; 143C, 143D); said detection profile comprising a detection of activation of the button with an offset with respect to a peak of the push force generated by magnetic cooperation of the magnetic element (41) with the notching tooth (42; 142A, 142B).

6. The magnetic push-button (10; 110) according to claim 5, wherein said offset in the detection profile is achieved by an offset along the axis of movement (X) of the magnetic sensor (43; 143C, 143D) and of the notching tooth (42).

7. The magnetic push-button (110) according to any of the preceding claims, wherein the second body (22) comprises a plurality of notching teeth (142A, 142B) and / or a plurality of magnetic sensors (143C, 143D) distributed equidistantly along the axis of movement (X) and / or about the axis of movement (X).

8. The magnetic push-button (10; 110) according to any of the preceding claims, wherein the or each notching tooth (42; 142A, 142B) and / or the magnetic element (41) is mounted on a magnetic or ferromagnetic support (36, 37; 136, 137).

9. The magnetic push-button (10; 110) according to any of the preceding claims, wherein the first body (21) is the movable body and the second body (22) is the fixed body.

10. The magnetic push-button (10; 110) according to any of the preceding claims, further comprising a travel stop for each end of travel during the movement along the axis of movement (X).

11. The magnetic push-button (10; 110) according to any of the preceding claims, further comprising a surface (35) intended for being oriented towards an operator; the surface (35) comprising at least one functional element (90) selected from the list comprising: - an element of visual feedback; - a presence sensor; - a haptic actuator.

12. The magnetic push-button (10; 110) according to any of the preceding claims, further comprising a supplementary force controller (60) comprising an electromagnetic coil (62) rigidly attached to one of the bodies (21, 22) and configured for acting on the or each notching tooth (42) and / or on the magnetic element (41) and / or on a ferromagnetic or magnetic support (36, 37).

13. The magnetic push-button (10; 110) according to any of the preceding claims, further comprising an additional electromechanical or opto-mechanical switch (194) placed in the center of the second body (22) and configured for being activated by a rod (195) rigidly attached to the first body (21).