NON-AUXIC ELECTROMAGNETIC ALARM

Description

Technical field of the invention

[0001] The invention relates to a non-audible alarm intended to be fitted to a portable object.

[0002] The invention relates more particularly to a non-audible vibrating and resonant alarm of small dimensions, suitable for integration into a thin portable object, such as a watch part.

[0003] The invention also relates to a portable object, such as a timepiece, in particular a watch, comprising such a non-audible alarm. Technological background

[0004] Conventional alarms fitted to portable objects, and in particular timepieces, provide audible information, for example related to an event and / or time information, by emitting a sound chosen from a range or according to a particular tone.

[0005] These alarms have the major drawback of being audible and being perceived by the user's environment.

[0006] Furthermore, such audible alarms do not allow the user's (the wearer's) portable object to be differentiated from other portable objects belonging to people in their environment.

[0007] Thus, we understand that these audible alarms have several disadvantages: they are not discreet and are perceptible to people other than the user, which can be problematic in certain environments; they do not allow the wearer to distinguish between their wearable object and other wearable objects in their environment, for example within groups of several people.

[0008] To address this, silent, or non-audible, vibrating alarms have been proposed. These alarms use motors to drive a mass, the entire assembly being configured to provide a vibration effect that can be transmitted to the user. Such a vibration has the advantage of being perceived only by the user, allowing for discretion and avoiding disturbing those around the user when the alarm is triggered, for example, for a wake-up time, an incoming call, a notification related to the time change, etc.

[0009] Such a non-audible alarm is described for example in document EP 0349230. This alarm includes a piezoelectric motor which drives in rotation an eccentric mass mounted movably on a shaft.

[0010] However, because of the coaxial configuration of this alarm, it has a relatively large footprint, so that for its installation in a clockwork component, it requires specific modifications, or even a complete reconstruction of that clockwork component, which is problematic.

[0011] Furthermore, this silent alarm requires the use of a piezoelectric motor, the manufacture of which involves relatively complex techniques.

[0012] To address this issue, a non-audible alarm has been developed, described in document EP 0625738 A1, with a simpler design, reduced size and lower manufacturing cost.

[0013] The non-audible alarm of document EP 0625738 A1 includes an electromagnetic motor fixedly mounted on a support, the electromagnetic motor setting in motion a heavy mass to provide a vibratory effect with an oscillatory movement of the mass almost linear.

[0014] Such a non-audible alarm has a power consumption of around 10 mW.

[0015] However, in the field of wearable devices, there is a constant need to improve the design, size, and / or power consumption of the various components of wearable devices, such as alarms, particularly to increase the lifespan of wearable devices by minimizing the power consumption of the various components of the wearable device. Summary of the invention

[0016] In this context, the invention aims to provide a solution to at least one of the problems described above.

[0017] In particular, the invention aims to provide a non-audible alarm of simplified design that can be easily integrated into portable objects, especially watch parts, without significant modification of its structure, that can be produced at low cost, by automated operations at high speed for example, and that has improved power consumption.

[0018] In this context, the invention relates to a non-audible alarm for a portable object comprising electromagnetic motor means which can be electrically controlled to generate a vibratory effect, according to the characteristics of claim 1.

[0019] In addition to the characteristics mentioned in the preceding paragraph, the non-audible electromagnetic alarm according to the invention may have one or more additional characteristics according to the dependent claims.

[0020] The invention also relates to a portable object comprising a non-audible alarm according to the invention.

[0021] Preferably, the portable object is a timepiece, for example a watch. Brief description of the figures

[0022] The aims, advantages and features of the present invention will become apparent from the detailed description below, which refers to the following figures: there figure 1 is a perspective overview schematically illustrating an example of the implementation of a non-audible alarm according to the invention; the figure 2 represents an exploded view of the silent alarm illustrated in the figure 1 allowing visualization of the various constituent elements of the non-audible alarm according to the invention; the figure 3 represents a cross-sectional view of the silent alarm 100 illustrated in the figure 1 , according to a median cutting plane M1; the figure 4 is a detailed view of the figure 3 illustrating in particular the different polarities of the magnetic circuit of electromagnetic motors when the coil receives a positive electrical supply; the figure 5 is a detailed view of the figure 3 illustrating in particular the different polarities of the magnetic circuit of electromagnetic motors when the coil receives a negative electrical supply; the figure 6 is a diagram illustrating an example of powering the electromagnetic drive means of the non-audible alarm according to the invention, in order to generate a vibratory effect perceptible to the user; the figure 7 is a schematic view of a timepiece incorporating a silent alarm according to the invention illustrated in the figure 1 .

[0023] In all figures, common elements bear the same reference numbers unless otherwise specified. Detailed description of the invention

[0024] There figure 1 is a perspective view schematically illustrating an example of the realization of a non-audible alarm 100 according to the invention.

[0025] There figure 2 represents an exploded view of the silent alarm 100 illustrated in the figure 1 allowing visualization of the different constituent elements of the non-audible alarm.

[0026] There figure 3 represents a cross-sectional view of the silent alarm 100 illustrated in the figure 1 , according to the median section plane M1 illustrated in the figure 1 .

[0027] The non-audible alarm 100 according to the invention is a non-audible alarm, of electromagnetic type, comprising electromagnetic motor means 200 which can be electrically controlled to move a moving part to generate a vibratory effect by oscillation of the moving part.

[0028] The non-audible alarm 100 according to the invention is particularly suitable for equipping small portable objects, such as for example a watch part 1.

[0029] Such a timepiece 1 is schematically represented in the figure 7 , as an example of implementation

[0030] The timepiece 1 comprises a case 2 consisting of a case 3 and a case back 4 fixed in a conventional manner to the case 3. The case 2 delimits an internal space 5 configured to receive a horometric movement (not shown) as well as a non-audible alarm 100 according to the invention.

[0031] The timepiece 1 further includes a power source, not shown, for example a battery, configured to electrically power at least the non-audible alarm 100 according to the invention.

[0032] Preferably, the power source is electrically connected to an electronic control box 50 configured to control the electromagnetic motor means 200 of the non-audible alarm 100 according to the invention.

[0033] By now referring to figures 1 to 3 , we will describe in more detail the non-audible alarm 100 according to the invention equipping the timepiece 1.

[0034] The silent alarm 100 includes: a support 10 which may include ad-hoc fixing elements 70 allowing the non-audible alarm 100 to be fixed to the timepiece 1; the electronic control box 50 which is able to be electrically connected to the power source equipping the portable object; electromagnetic motor means 200 which are electrically connected to the electronic control box 50, which are able to generate a vibratory effect.

[0035] The electromagnetic drive means 200 are electrically controlled by the electronic control unit 50 to move a moving part, so as to obtain a vibratory effect perceptible to the user wearing the timepiece 1, or the portable object, for example via the bottom 4 in contact with the user.

[0036] The electronic control unit 50 is configured to excite the electromagnetic motor means 200 at the resonant frequency, or at a frequency close to the resonant frequency, of the non-audible alarm 100.

[0037] Preferably, the electronic control unit 50 is configured to excite the electromagnetic motor means 200 and generate a vibration at a frequency between 120 Hz and 250 Hz.

[0038] The electromagnetic motor means 200 comprise a magnetic circuit consisting of a movable magnetic circuit 210 and a fixed magnetic circuit 220. The movable magnetic circuit 210 and the fixed magnetic circuit 220 are carried by a support 10.

[0039] The support 10 is a multifunctional element comprising a fixed part 11a, 11b carrying the fixed magnetic circuit 220. The fixed part 11a, 11b of the support 10 also carries the electronic control box 50.

[0040] The fixed magnetic circuit 220 is for example made attached to the fixed part 11a, 11b of the support 10 by means of fixing, for example by electric welding, known as spot welding.

[0041] The support 10 further includes a movable part 12a, 12b shaped to carry the movable magnetic circuit 210.

[0042] The mobile magnetic circuit 210 is made integral with the mobile part 12a, 12b of the support 10 by means of fixing, for example by electric welding, known as spot welding.

[0043] The fixed part 11a, 11b of the support 10 is intended to be attached to the timepiece, for example at the base 4 of the timepiece 1, for example by screwing or gluing.

[0044] As depicted in the figure 2 , the fixed part 11a, 11b of the support 10 cooperates with the fixing elements 70, of the screw type, to secure the fixed part 11a, 11b of the support 10 to the watch part 1.

[0045] The electronic control unit 50 is for example attached to the fixed part 11a, 11b of the support 10 by gluing, or by the fixing means 70 allowing the support 10 to be attached to the watch part 1.

[0046] The support 10 further includes elastic linking elements 60 mechanically connecting the movable part 12a, 12b and the fixed part 11a, 11b of the support 10. The elastic linking elements 60 are formed by thin elastic flexible blades 60a, 60b, extending in a plane perpendicular to the plane formed by the fixed part 11a, 11b and the movable part 12a, 12b of the support 10, and parallel to the median plane M1.

[0047] The elastic linking elements 60 are configured to provide a support function for the moving part 12a, 12b of the support 10, and therefore for the moving magnetic circuit 210, in particular along the z and y directions, while allowing a lateral movement of the moving magnetic circuit 210, according to a translational movement, along the x direction.

[0048] The elastic connecting elements 60 are shaped to be flexible in a specific direction, here the x direction, in order to allow linear, or even quasi-linear, oscillation of the moving magnetic circuit 210 relative to the fixed magnetic circuit 220, in a lateral direction indicated by the arrow D of the figure 1 .

[0049] In other words, the support 10 as well as the shape and arrangement of the elastic linking elements 60 in relation to the mobile magnetic circuits 210 and fixed magnetic circuits 220 allow a lateral displacement, substantially in translation along the x direction, of the mobile magnetic circuit 210 in relation to the fixed magnetic circuit 220, under control of the electronic control box 50.

[0050] The elastic connecting elements 60 are flexible blades fixedly connected to the support 10 or made of material with the support 10.

[0051] The elastic connecting elements 60 border the mobile magnetic circuit 210 on both sides.

[0052] The elastic linking elements 60 also have an elastic return function tending to bring the mobile magnetic circuit 210 back into a rest equilibrium position, without electrical stress on the electromagnetic driving means 200.

[0053] As an example, each elastic linking element 60 is composed of a lower tab 60a and an upper tab 60b arranged symmetrically at the level of each slice of the electromagnetic motor means 200, with respect to a median plane M1, dividing the non-audible alarm 100 in two according to the height.

[0054] The support 10 is advantageously made of two separate parts forming a lower half-shell 10a and an upper half-shell 10b. The two half-shells 10a and 10b are configured to encapsulate and retain the electromagnetic drive means 200, and more specifically the moving magnetic circuit 210 and the fixed magnetic circuit 220. Each half-shell 10a and 10b have two lateral elastic tabs 60a and 60b forming the elastic connecting elements 60 described previously. The symmetrically arranged elastic tabs 60a and 60b thus allow for the lateral attachment of an upper portion of the electromechanical drive means 200 and a lower portion of the electromechanical drive means 200. With this configuration, displacements along the z-axis due to elastic deformation of the elastic tabs 60a and 60b are eliminated.

[0055] The half-shells 10a, 10b of the support 10 are for example made from a flat plate, for example metallic, of thin thickness, and the elastic tabs 60a, 60b come from material with the fixed parts 11a, 11b and the moving parts 12a, 12b of the support 10.

[0056] The mobile magnetic circuit 210 comprises a ferromagnetic core 212 and a coil 211 wound conventionally around the ferromagnetic core 212.

[0057] The ferromagnetic core 212 is coupled to a magnetic cage 213 at one of the poles of the ferromagnetic core 212, so that the magnetic cage 213 forms an extension of the ferromagnetic core 212. The ferromagnetic core 212 is made fixed to the magnetic cage 213 by ad hoc fastening means, for example by a screw element 216.

[0058] The magnetic assembly of the mobile magnetic circuit 210 is heavy enough to constitute a moving mass capable of generating a vibratory effect that can be perceived by the user.

[0059] In the example of implementation illustrated in figures 1 to 3 , and as particularly visible in the figure 2 The ferromagnetic core 212 is separated from the magnetic cage 213; however, the ferromagnetic core 212 and the magnetic cage 213 may be a single unit. This separate arrangement facilitates the winding of the coil 211 around the ferromagnetic core 212.

[0060] According to the invention, the vibrating moving mass of the non-audible alarm 100 is formed from the moving part 210 of the magnetic circuit of the electromagnetic motor means 200. The vibrating mass therefore belongs to the magnetic circuit of the non-audible alarm 100.

[0061] In other words, the mobile magnetic circuit 210 also has the role of mobile mass of the vibrating system, so that in the non-audible alarm 100 according to the invention, it is not necessary to use a specific mass, added, for example in non-magnetic metal, mechanically coupled to a part of the magnetic circuit, having a unique role of vibrating mass and which does not participate in the magnetic circuit of the electromagnetic motor means.

[0062] Thus, unlike state-of-the-art solutions, the moving mass of the non-audible alarm 100 according to the invention is a magnetic, or ferromagnetic, mass, also constituting the moving magnetic circuit 210 of the electromagnetic driving means 200.

[0063] The fixed magnetic circuit 220 comprises two elements 221, 222 made of magnetic material.

[0064] Preferably, the two elements made of magnetic material are permanent magnets.

[0065] Each permanent magnet 221, 222 has a north-south permanent magnetization axis (denoted NS) which is oriented perpendicular to the translational movement of the moving magnetic circuit 210. The two permanent magnets 221, 222 have a magnetization axis that is reversed with respect to each other.

[0066] The fixed magnetic circuit 220 also includes a shunt 223 to close the magnetic flux at the fixed magnetic circuit 220 and minimize magnetic leakage. This optimizes the performance of the silent alarm.

[0067] The magnetic cage 213 has two parallel branches 214, 215 which laterally border the coil 211 and which are heard in the direction of the fixed magnetic circuit 220.

[0068] The two branches 214, 215 constitute polar expansions of the ferromagnetic core 212 of the coil 211 configured to guide the magnetic flux of the moving magnetic circuit 210 induced by the coil 211, in the vicinity of the fixed magnetic circuit 220, and more particularly in the vicinity of the permanent magnets 221, 222.

[0069] The two branches 214, 215 extend opposite the permanent magnets 221, 222.

[0070] The two branches 214, 215 and the ferromagnetic core 212 together with the permanent magnets 221, 222 define an air gap e extending perpendicularly to the lateral displacement of the moving magnetic circuit 210. Operation of the non-audible alarm according to the invention

[0071] Under the control of the electronic control unit 50, the coil 211 can be electrically powered and generate a magnetic flux which can circulate inside the ferromagnetic core 212 and propagate in the magnetic cage 213 at the polar flares 214, 215 and can close by passing through the permanent magnets 221, 222 and the shunt 223, via the air gap e.

[0072] When coil 211 receives a positive electrical supply, for example in a pulsed form, as illustrated in the figure 6 The ferromagnetic core 212 becomes polarized, as do the two branches of the magnetic cage 213, as shown on the diagram. figure 4The different polarities interact with the polarities of the permanent magnets 221, 222, so that the poles of the same sign repel each other and the poles of opposite sign attract each other, which creates a magnetic force moving laterally in translation, along the x direction, the mobile magnetic circuit 210 to the left under the effect of the polarities of the permanent magnets.

[0073] When coil 211 receives a negative electrical supply, for example in the pulsed form illustrated in the figure 6 , the polarities reverse and the mobile magnetic circuit 210 moves laterally in translation to the right, along the x direction, under the effect of the polarities of the permanent magnets, as illustrated in the figure 5 .

[0074] Thus, under an alternating electrical power supply, the moving magnetic circuit 210 will move laterally from left to right, in a translational motion along the x-direction, guided by the elastic connecting elements 60. These movements will constrain the elastic connecting elements 60, which will tend to return the moving magnetic circuit 210 to its initial position by elastic return, and so on, oscillating around this initial equilibrium, or rest, position in a back-and-forth lateral translational motion. Therefore, by choosing an electrical power supply with an appropriate frequency and amplitude, a vibratory effect is created in the case 2 of the timepiece 1, perceptible to the wearer.

[0075] Advantageously, the electronic control unit 50 is configured to generate a power supply for the coil 211, as shown as an example in the figure 6, in the form of alternating pulses to maintain the oscillatory motion of the mobile magnetic circuit 210, the pulses compensating for the damping of the oscillating motion of the mobile magnetic circuit 210.

[0076] The silent alarm 100 according to the invention, as described above, has a small footprint, making it ideally suited for watchmaking applications since its essentially flat and thin shape allows for easy integration into a watch case without major modifications to other components. For illustrative purposes only, such a silent alarm according to the invention has been achieved with a total height of approximately 3 mm.

[0077] The overall size and weight have been particularly reduced, notably by the elimination of a dedicated moving mass made of non-magnetic metal.

[0078] The silent alarm according to the invention features an optimized magnetic construction with polar expansions and a shunt, which prevents magnetic leakage and optimizes magnetic efficiency. This optimizes and reduces the power consumption of such an alarm. For illustrative purposes only, the power consumption of such a silent alarm has been measured at less than 10 mW.

[0079] The inverted architecture, of the moving coil type, of the non-audible alarm according to the invention with the movement of the part of the magnetic circuit containing the coil, also makes it possible to reduce the electrical consumption of such a non-audible alarm, by eliminating the need to move a dedicated non-magnetic heavy mass.

[0080] Finally, unlike state-of-the-art solutions, the proposed inverted architecture eliminates the need for a specific mass, such as tungsten. This also reduces the manufacturing costs of such a silent alarm.

Claims

1. Non-acoustic alarm (100) for a portable object (1) comprising a support (10) and electromagnetic motor means (200) which can be electrically controlled in order to generate a vibratory effect, said non-acoustic alarm (100) being defined in that: - the electromagnetic motor means (200) comprise a movable magnetic circuit (210) and a stationary magnetic circuit (220); said movable magnetic circuit (210) comprising a coil (211), a ferromagnetic core (212) coupled to a magnetic cage (213) forming an extension of the ferromagnetic core (212); the magnetic assembly of said movable magnetic circuit (210) constituting a movable magnetic mass of said non-acoustic alarm (100) capable of generating said vibratory effect; - the support (10) comprising a stationary part (11a, 11b) receiving the stationary magnetic circuit (220) and a movable part (12a, 12b) receiving the movable magnetic circuit (210), the stationary part (11a, 11b) of the support (10) comprising fastening means (70) capable of making the stationary part (11a, 11b) of the support (10) integral with the portable object (1); - and in that it comprises resilient connection elements (60) belong to a support (10) mechanically and resiliently connecting the movable part (12a, 12b) to the stationary part (11a, 11b, the resilient connection elements (60) being shaped to guide and ensure that the movable magnetic circuit (210) undergoes a linear, or quasi-linear, oscillatory motion during the electrical control of the electromagnetic motor means (200).

2. Non-acoustic alarm (100) for a portable object (1) according to the preceding claim, characterised in that the stationary magnetic circuit (220) comprises two elements made of magnetic material (221, 222).

3. Non-acoustic alarm (100) for a portable object (1) according to the preceding claim, characterised in that the two elements made of magnetic material (221, 222) are permanent magnets.

4. Non-acoustic alarm (100) for a portable object (1) according to the preceding claim, characterised in that the stationary magnetic circuit (220) comprises a shunt (223) to close the magnetic flux at the stationary magnetic circuit (220).

5. Non-acoustic alarm (100) for a portable object (1) according to one of the preceding claims, characterised in that the support (10) is formed by a lower half-shell (10a) and an upper half-shell (10b) shaped to encapsulate the movable magnetic circuit (210) and the stationary magnetic circuit (220) of the electromagnetic motor means (200).

6. Non-acoustic alarm (100) for a portable object (1) according to the preceding claim, characterised in that each half-shell (10a, 10b) of the support (10) comprises two lateral resilient tabs (60a, 60b) forming the resilient connection elements (60), configured to laterally flank the electromechanical motor means (200).

7. Non-acoustic alarm (100) for a portable object (1) according to one of the preceding claims, characterised in that the magnetic cage (213) comprises two branches (214, 215) forming pole shoes configured to guide a magnetic flux induced by the coil (211) in the vicinity of the stationary magnetic circuit (220).

8. Non-acoustic alarm (100) for a portable object (1) according to the preceding claim, characterised in that the two branches (214, 215) forming the pole shoes and the ferromagnetic core (212) delimit, together with the stationary magnetic circuit (220), an air gap (e) extending perpendicularly to the linear, or quasi-linear, oscillatory motion of the movable magnetic circuit (210).

9. Non-acoustic alarm (100) for a portable object (1) according to one of the preceding claims, characterised in that it comprises an electronic control unit (50) configured to supply electrical power to the coil (211) so as to cause the movable magnetic circuit (210) to oscillate at the resonant frequency thereof.

10. Non-acoustic alarm (100) for a portable object (1) according to one of the preceding claims, characterised in that it comprises an electronic control unit (50) configured to supply electrical power to the coil (211) so as to cause the movable magnetic circuit (210) to oscillate at a chosen frequency between 120 Hz et 250 Hz.

11. Portable object (1) comprising a non-acoustic alarm (100) according to one of the preceding claims.

12. Portable object (1) according to the preceding claim, characterised in that the portable object is a timepiece.