CH714264B1 - Case for electromechanical watch and set comprising it. - Google Patents

Abstract

The case (4) according to the invention is designed to receive an electromechanical watch (2) equipped with a stepper motor for driving the hands (6) of the watch. The case comprises a box (8) with a support (24) for receiving the watch, a system (10) for detecting the position of the hands (6), means for resetting the time of the watch, connected to the system (10) for detecting the position of the hands, and configured to reset the time of the watch (2) on the basis of information received from the system (10) for detecting the position of the hands and of a time reference, when the watch is placed on the receiving support (24). The time-setting means comprise a means for driving the stepping motor of the electromechanical watch, which is arranged in the case (4) opposite the stepping motor, when the watch ( 2) is placed on the receiving support (24), and is configured to control rotation of the stepper motor by magnetic coupling.

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to a case for an electromechanical watch equipped with a stepper motor for driving the hands of the watch.

The invention also relates to an assembly comprising the case and an electromechanical watch equipped with a stepper motor.

STATE OF THE ART

[0003] In the field of electromechanical watches fitted with hands, systems for correcting the time displayed by the watch are known. Such systems make it possible to reset the time of the watch, for example in the case of a change of time zone or even a change of summer/winter time.

[0004] Such a time correction system is for example described in patent application EP 1 553 469 A1. The system is provided with a time correction instruction device, comprising according to an exemplary embodiment a computer connected to a camera and to a circuit for generating a time correction signal. The watch includes communication means for receiving time correction data contained in this signal, and means for moving the hands to the exact time. The watch can be placed on a frame with the time indication by the hands visible on the top, and the camera can take a photograph of the position of the hands, which is sent to the computer to recognize the displayed time by the watch. The computer then generates correction data comprising a reference time, and transmits this data to the watch, via the signal generation circuit. However, a drawback of such a system is that it imposes a modification of the movement of the watch, in order to integrate therein communication means and means for moving the hands. In addition, such a system is cumbersome and restrictive, in particular requiring the use of a computer for time correction.

[0005] In order to overcome the aforementioned drawback, watch cases adapted to receive a watch on a support and comprising means for resetting the time of the watch are known. In this respect, mention may be made of patent application WO 2012/126978 A1, which describes such a case. According to a particular embodiment, the case described in this document comprises a removable support, which receives the watch and a device for winding the watch connected to a camera. The winding device comprises data analysis means. Once the watch has been placed on the removable support of the case, the camera records an image of the position of the hands, and sends it to the analysis means. The latter then determine the time displayed by the watch and, by comparison with a time reference, transmit a time correction instruction to the winding device. The winding device then makes it possible to wind the watch by direct mechanical action on its winding crown-stem. However, a drawback of the case proposed is that it is mechanically complex, and that it is limited to resetting watches with a winding stem-crown.

SUMMARY OF THE INVENTION

[0006] The object of the invention is therefore to provide a case for an electromechanical watch equipped with a stepping motor, making it possible to automatically reset the time of the watch, in an easy and non-binding manner, and overcoming the disadvantages aforementioned of the state of the art.

[0007] To this end, the invention relates to a case for an electromechanical watch equipped with a stepping motor for driving the hands of the watch, which comprises the characteristics mentioned in independent claim 1.

[0008] Particular forms of the case are defined in dependent claims 2 to 15.

[0009] An electromechanical watch, such as an electromechanical quartz watch, typically comprises a stepper motor, such as a Lavet motor, which drives the hands of the watch via a train of gears.

[0010] An advantage of the case according to the invention resides in the fact that the means for resetting the time of the watch comprise a means for driving the stepper motor, configured to control a rotation of the motor step by step by magnetic coupling. The drive means is arranged in the case so as to face the stepper motor when the watch is placed on the receiving support. Thus, the time of the electromechanical watch is reset easily and quickly in the case, by action of the drive means by inductive coupling on the stepper motor.

[0011] Another advantage of the case according to the invention is that the time-setting system that it offers does not require any modification of the watch movement of the watch. The case is thus functional for any electromechanical watch movement equipped with a stepping motor, without requiring modification of this movement.

According to a first embodiment of the invention, the drive means comprises at least one coil mounted on a ferromagnetic core and supplied via electrical supply means.

According to a second embodiment of the invention, the drive means comprises a rotatably mounted magnet. An advantage of this second embodiment is that it makes it possible to rotate the stepper motor, and therefore the hands, in both directions of rotation. This makes it possible to advantageously reduce the time for resetting the time of the watch.

[0014] Advantageously, the case further comprises a flap piece mounted on the box, an optical needle position detection system being fixed inside the flap piece so as to face the needles of the watch, when the flap piece is closed on the box and the watch is placed on the reception support. This makes it possible to optimize the space inside the case, by freeing up space within the box. The flap piece is for example a cover.

[0015] Advantageously, the case further comprises a cover, and a sensor for the presence of the watch and/or for closing the cover. Said sensor is connected to the time-resetting means of the watch, the time-resetting means being configured to trigger a process of resetting the time of the watch on the basis of a detection signal received from the sensor. This makes it possible to completely automate the process of resetting the time of the watch, from the moment when the watch is placed on the reception support and/or when the cover is closed.

[0016] To this end, the invention also relates to an assembly comprising the case described above, and which comprises the characteristics mentioned in independent claim 16.

BRIEF DESCRIPTION OF FIGURES

[0017] The aims, advantages and characteristics of the case for an electromechanical watch, as well as of the assembly comprising it, will appear better in the following description on the basis of at least one non-limiting embodiment illustrated by the drawings. in which: - Figure 1 is a perspective view of an assembly comprising an electromechanical watch and a case according to the invention; - Figure 2 shows a simplified block diagram of the electronic components of the case of Figure 1 according to an example embodiment; - Figure 3 is a perspective view of part of the case, according to a first embodiment of the invention; - Figure 4 is a top view of the case of Figure 3; - Figure 5 is a perspective view of part of the case, according to a second embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, reference is made to a case for an electromechanical watch, in particular a case for an electromechanical quartz watch. All the electronic components of the case, which are well known to a person skilled in the art in this technical field, are only described in a simplified manner. In particular, those skilled in the art will know how to adapt these various electronic components and make them cooperate for the operation of the case.

[0019] Figure 1 shows an assembly 1, which comprises an electromechanical watch 2 and a case 4 for receiving the watch 2. The electromechanical watch 2 is provided with a watch case 5, which can be made of any diamagnetic material conventionally used in watchmaking. Watch case 5 can also be made of paramagnetic, non-magnetic, sapphire, or even weakly ferromagnetic material. The watch case 5 contains a clock movement (not shown) of usual construction; as well as a dial above which move display means formed of hands 6. The dial is protected by a crystal 7, which closes the watch case 5. Conventionally, the watch case 5 contains also a stepper motor (not shown) to drive the hands 6 of the watch via a gear train of the clock movement. Such a stepping motor is typically a Lavet motor. The watch 2 is for example a quartz watch, without this being limiting in the context of the present invention.

In Figure 1, the case 4 further comprises a system 10 for detecting the position of the needles 6. The detection system comprises at least one camera 101 disposed in a cover 14 for closing the case above the hands 6 of watch 2 placed on a support 24 for receiving the watch. A set of light sources 102 can also be provided in an interior dome 103 of the cover 14 and forming, for example, a circle of light sources 102 parallel to the closure plane of the cover. The light sources, which may be light-emitting diodes, are preferably regularly spaced. The camera 101 is located on the upper part of the dome, being centered with respect to the circle of light sources 102. The inner dome 103 makes it possible to diffuse the light generated by the light sources in order to facilitate the detection of the position of the hands 6 by the camera 101. Of course, an optical sensor can also be provided instead of a camera to detect the position of the watch hands.

The case 4 comprises a box 8. As illustrated in Figure 2, the case 4 further comprises a system 10 for detecting the position of the hands 6 of the watch 2 and means 12 for resetting the time. of the watch 2. In the exemplary embodiment illustrated in FIG. 1, the case 4 further comprises a cover 14, mounted on the box 8. According to a preferred exemplary embodiment illustrated in FIG. 2, the case 4 also comprises a sensor 16 of the presence of the watch 2 and/or of the closure of the cover 14. Preferably, the case 4 can further comprise display and activation means 18, communication means 20, a receiver 21 of a mobile telephone signal, a receiver 22 of a radio or GPS (Global Positioning System) signal, a very precise and temperature-compensated time base, and power supply means 23.

[0022] Preferably, the case 4 is configured to contain a type and/or a shape of predefined electromechanical watch 2(es). To do this, the box 8 comprises a support 24 for receiving the watch 2, adapted to the type and/or the shape of the watch 2. Such a support 24 is particularly visible in FIGS. 3 to 5.

As illustrated in Figure 2, the system 10 for detecting the position of the hands 6 is connected to the means 12 for resetting the time of the watch 2. Preferably, the system 10 for detecting the position of the hands 6 is an optical system. According to a first exemplary embodiment, the system 10 for detecting the position of the hands 6 comprises a camera 101 shown in FIG. 1. The camera 101 is arranged so as to be substantially opposite the hands 6 of the watch 2, when the watch 2 is placed on the receiving support 24. To do this, the camera is for example fixed inside the lid 14 so as to be substantially opposite the needles 6, when the lid 14 is closed on the box 8. As shown in Figure 1, the camera 101, which can for example be equipped with an additional system consisting of light-emitting diodes 102 in a dome 103 and intended to illuminate the watch 2, is for example fixed to a position of the cover 14 such that it is located at a distance from the glass 7 of the watch case 5 substantially between 3 and 4 cm, when the cover 14 is closed on the box 8. The advantage of such a camera 101 is that it allows saving time for resetting the time of the watch 2, and that the detection of the position of the hands that it allows is very little dependent on the shape of the watch 2. Because the camera 101 does not require be positioned precisely opposite the hands 6 of the watch 2, it is possible to use a relatively standard case as the case 4. The use of a camera 101 as a needle position detection system s also proves to be particularly suitable in the case of a needle watch provided with a calendar.

According to a second embodiment, the system 10 for detecting the position of the needles 6 comprises an optical sensor (not shown). The optical sensor is arranged so as to be precisely opposite the hands 6 of the watch 2, when the watch 2 is placed on the receiving support 24. To do this, the optical sensor is for example fixed inside the cover 14 so as to be opposite the hands 6, when the cover 14 is closed on the box 8. The optical sensor is for example fixed to a position of the cover 14 such that it is flush with the crystal 7 of the watch case 5, for example at a distance of a few millimeters, when the lid 14 is closed on the box 8. The advantage of such an optical sensor is that it is a relatively simple and inexpensive component.

The time reset means 12 are configured to reset the watch 2 on time on the basis of information received from the system 10 for detecting the position of the hands 6, when the watch 2 is placed on the support. reception 24. To do this, the time reset means 12 comprise means 26 for analyzing data, a time reference, and a means 28 for driving the stepping motor of the watch 2 .

As shown in Figure 2, the data analysis means 26 are connected to the drive means 28 of the stepping motor of the watch 2, to the sensor 16 of the presence of the watch 2 and / or closing the lid 14, to the display and activation means 18, to an internal time reference, to the wired or wireless communication means 20, to the receiver 21 of a mobile telephone signal, to the receiver 22 of a radio or GPS signal, and to the power supply means 23. The data analysis means 26 are also connected to the system 10 for detecting the position of the hands 6, for example via a flexible electronic circuit 29. The means 26 d data analysis consist for example of a microprocessor. The microprocessor can also store a time reference.

The means 28 for driving the stepping motor of the watch 2 is arranged in the case 4 so as to face the stepping motor, when the watch 2 is placed on the support. 24. Preferably, the drive means 28 is arranged in the case 4 so as to be on the side of the bottom 30 of the watch case 5, when the watch 2 is placed on the reception support 24, in regard of this bottom 30. To do this, the drive means 28 is for example arranged inside the reception support 24, as illustrated in FIGS. 3 to 5. The drive means 28 is configured to control a rotation of the rotor of the stepping motor of the watch 2 by magnetic coupling. Different embodiments of the drive means 28 will be detailed below, with reference to Figures 3 to 5.

The sensor 16 of the presence of the watch 2 and/or of the closure of the lid 14 is for example fixed in the case 4, inside or outside the reception support 24. The sensor 16 of presence of the watch is for example a feeler arranged in the case 4 so as to face the side of the bottom 30 of the watch case 5, when the watch 2 is placed on the receiving support 24, facing this bottom 30. In a variant not shown, the sensor for the presence of the watch 2 and/or for the closing of the cover 14 consists of the optical system 10 for detecting the position of the hands 6 of the watch 2. The means 26 for analyzing data are for example configured to trigger a time reset process of the watch 2 on the basis of a detection signal received from the sensor 16, as will be detailed below.

The display and activation means 18 comprise for example several activation buttons and several light-emitting diodes. The light-emitting diodes are intended to provide visual indications relating to the operation of the case 4, and in particular to the time reset of the watch 2.

As illustrated in Figure 2, the communication means 20 include for example a micro-USB socket (English Universal Serial Bus) 32 and a module 34 for communication with a mobile communication device (not shown) accompanied of an antenna. The micro-USB socket 32 is connected to the electrical power supply means 23 and is intended to allow electrical recharging of the latter, via an external electrical power source compatible with the USB format. The communication module 34 is for example a two-way communication module conforming to the Bluetooth standard. As a variant, the communication module 34 can be a bidirectional communication module conforming to the NFC (Near Field Communication) standard, or even a unidirectional communication module of the "light programming" type.

The receiver 21 of a mobile telephone signal, for example a GSM (Global System for Mobile Communication) signal, is equipped with a communication module and a signal reception antenna.

The receiver 22 of a radio or GPS signal is equipped with a communication module and a signal reception antenna.

As illustrated in Figure 2, the power supply means 23 include for example a charger 36 and an accumulator 38. The charger 36 is connected to the data analysis means 26 and to the micro-USB socket 32. The accumulator 38 is connected to the charger 36, for example via two electric wires 40.

In the exemplary embodiment illustrated in Figure 2, the means 26 for analyzing data, the means 28 for driving the stepping motor of the watch 2, the means for displaying and activation 18, the means of communication 20, the receiver 21 of a mobile telephone signal, the receiver 22 of a radio or GPS signal, and the charger 36 are all connected to a common printed circuit 42.

[0035] Preferably, the time reset means 12, in particular the data analysis means 26, are adapted to set the time of the watch 2 according to the current time. The current time is synchronized using a reference system, for example an on-board or remote reference system. Such a remote reference system comprises for example the reception, by the receiver 22, of a radio or GPS signal, or the reception, by the communication means 20, of a signal from a computer network, or again the reception, by the receiver 21, of a mobile telephony signal. The reception of one or more of these signals makes it possible to update the time reference stored in the microprocessor 26 or in the printed circuit 42. For example, such a time reference can be provided by a precision quartz placed on the circuit board 42.

A first embodiment of the invention will now be described with reference to Figures 3 and 4. According to this first embodiment, the means 28 for driving the stepping motor of the watch 2 comprises at least one coil 44. In the exemplary embodiment illustrated in Figures 3 and 4, the drive means 28 comprises four coils 44. As illustrated in Figure 4, according to this example, the four coils 44 are connected in pairs in diagonal via two magnetic conductors 45, substantially forming a symmetrical cross shape, the coils 44 being arranged at the ends of the cross. The coils 44 are advantageously arranged so that the center 47 of the cross thus formed is substantially opposite the center of the watchcase 5 once the latter has been placed on the receiving support 24, when the watchcase 5 defines a rotational symmetry. This particular arrangement of the four coils 44 makes it possible to obtain, once they are electrically powered, a rotating magnetic field. This rotating magnetic field makes it possible to induce a magnetic coupling with the stepping motor of the watch 2. The coils 44 are for example chosen so that the value of such a magnetic field is typically of the order of 0.02 Tesla. An advantage of the use of four coils 44 thus arranged is that they make it possible to rotate the stepper motor of the watch 2, and therefore the hands 6, in both directions of rotation.

The coils 44 are each mounted on a ferromagnetic core 46 and are powered via an electrical power source. The ferromagnetic cores 46 are for example made of a soft ferromagnetic metal. Preferably, the electrical power source consists of the electrical power supply means 23. In the embodiment illustrated in FIGS. 3 and 4, the four coils 44 are inclined with respect to the plane of the printed circuit 42, towards the inside the center 47 of the cross arrangement they define. The coils 44 are inclined by defining an angle with the plane of the printed circuit 42, the value of this angle being identical for the four coils 44. This arrangement advantageously makes it possible to create a horizontal magnetic field inside the coils 44, so that the rotating magnetic field attacks the stepping motor of the watch 2 substantially horizontally. This makes it possible to improve the efficiency of the magnetic coupling.

In a variant not shown, the drive means 28 may for example comprise two coils 44. This variant embodiment makes it possible to obtain, once the coils 44 are electrically powered, a horizontal magnetic field. This only makes it possible to rotate the hands 6 of the watch 2 in only one direction of rotation. In this variant embodiment, the coils 44 are for example chosen so that the value of the magnetic field produced is typically of the order of 0.02 Teslas

Figure 5 illustrates a second embodiment of the invention for which the elements similar to the first embodiment, described above, are identified by identical references, and are therefore not described again.

According to this second embodiment, the drive means 28 of the stepper motor of the watch 2 no longer comprises coils, but comprises a magnet 48 rotatably mounted. In the exemplary embodiment illustrated in FIG. 5, the magnet 48 is rotatably mounted by means of an electric motor 50 supplied via the electric power supply means 23. The magnet 48 is mounted on the axis of the electric motor 50.

The rotary magnet 48 provides, once the electric motor 50 electrically powered, a rotating magnetic field. This rotating magnetic field makes it possible to induce a magnetic coupling with the stepping motor of the watch 2. The magnet 48 is for example chosen so that the value of such a magnetic field is typically order of 0.02 Teslas.

The speed of the electric motor 50 is controlled by the microprocessor 26. The electric motor 50 is for example a DC motor provided with an encoder. Alternatively, electric motor 50 may be a stepper motor.

An advantage of using a rotatably mounted magnet 48 is that it makes it possible to rotate the stepper motor of the watch 2, and therefore the hands 6, in both directions of rotation. This makes it possible to advantageously reduce the time for resetting the time of the watch 2.

The operation of the case 4 according to the invention will now be described. Watch 2 is initially placed in case 4, on reception support 24.

The method of resetting the time of the watch 2, implemented by the case 4, can be triggered either manually by a user, or automatically.

In the case of a manual triggering of the process by a user, the latter, after having closed the cover 14, presses for example a trigger button belonging to the display and activation means 18.

[0047] In the case where the case 4 comprises a sensor 16 for the presence of the watch 2 and/or for the closing of the cover 14, the triggering of the time-setting process is carried out automatically, following detection of the sensor 16. The sensor 16 then transmits a detection signal to the analysis means 26, which triggers the time reset process.

In both cases, the detection system 10, controlled by the analysis means 26, triggers a detection of the position of the hands 6 of the watch 2, and transmits position data of the hands to the means 12 of delivery at the time of the watch 2. More precisely, the analysis means 26 receive the position data of the hands and compare them with the available time reference. Optionally, an update of the time reference can be performed by the analysis means 26, via a remote reference system. The reception, by the analysis means 26, of a time reference signal allows for example this updating. The analysis means 26 then determine, as a function of the result of the comparison, a command to reset the watch 2 to the current time, and transmit this command to the drive means 28. The drive means 28 then commands , by inductive coupling, a rotation of the rotor of the stepping motor of the watch 2, which allows movement of the hands 6 driven by the motor. The stepping motor of the watch 2 is then driven in rotation, until the hands 6 reach a position corresponding to the current time, which puts an end to the process. An optical verification of the correct position of the hands can be added, if necessary.

An example of an automatic triggering of the method for resetting the time of a watch 2 with two hands 6, in the particular case where the case 4 comprises a sensor 16 of the presence of the watch 2 and where the detection system 10 comprises an optical sensor, is provided by the following sequence: • detection, by sensor 16, of the presence of watch 2 in case 4; • triggering, by the analysis means 26, of the process for resetting the time of the watch 2; • transmission to the drive means 28, by the analysis means 26, of a command to rotate the stepping motor of the watch 2; • rotation at high speed (typically at a frequency of 60 Hz), by the drive means 28, of the stepping motor of the watch 2. If the stepping motor is activated in normal mode every 20 seconds, ie 180 positions per revolution for the minute hand, it takes a maximum of 36 seconds to cause the two hands 6 to pass in front of the optical sensor; • detection, by the optical sensor, of the position of the needles 6, and transmission of the position data of the needles 6 to the analysis means 26; • calculation, by the analysis means 26, of the new position of the hands 6 according to the internal time reference; • transmission to the drive means 28, by the analysis means 26, of a command to reset the current time of the watch 2; • positioning, by the drive means 28, of the hands 6 of the watch 2, at high speed (typically at a frequency of 60 Hz).

[0050] In the variant in which the detection system 10 comprises a camera and not an optical sensor, the first step of rotating the stepper motor of the watch 2, to cause the hands 6 to pass in front of the system detection, is no longer necessary.

Claims (16)

1. Case (4) for an electromechanical watch (2) equipped with a stepper motor for driving the hands (6) of the watch (2), the case (4) comprising: – a box (8) comprising a support (24) for receiving the watch; – a system (10) for detecting the position of the hands (6) of the watch; – means (12) for resetting the time of the watch, connected to the system (10) for detecting the position of the hands (6) of the watch, and configured to reset the time of the watch (2) on the base of information received from the system (10) for detecting the position of the hands and of a time reference, when the watch (2) is placed on the reception support (24); characterized in that the time-setting means (12) comprise means (28) for driving the stepper motor of the electromechanical watch, the driving means (28) being arranged in the case (4) so as to face the stepping motor, when the watch (2) is placed on the receiving support (24), and being configured to control rotation of the stepping motor by coupling magnetic. 2. Case (4) according to claim 1, characterized in that the drive means (28) comprises at least one coil (44) mounted on a ferromagnetic core (46) and supplied via electrical supply means (23 ). 3. Box (4) according to claim 2, characterized in that the ferromagnetic core (46) consists of a soft ferromagnetic metal. 4. Box (4) according to claim 1, characterized in that the drive means (28) comprises a magnet (48) rotatably mounted. 5. Case (4) according to claim 4, characterized in that the magnet (48) is mounted on an axis of an electric motor (50). 6. Case (4) according to one of the preceding claims, characterized in that the drive means (28) is arranged in the case (4) so as to be on the side of the bottom (30) of the box of the watch (5) when the watch (2) is placed on the receiving support (24), facing said bottom (30). 7. Case (4) according to one of the preceding claims, characterized in that the system (10) for detecting the position of the hands (6) of the watch is an optical system. 8. Case (4) according to claim 7, characterized in that the optical system (10) for detecting the position of the hands comprises a camera (101) arranged so as to be substantially facing the hands (6) of the watch ( 2), when the watch (2) is placed on the receiving support (24). 9. Case (4) according to claim 7, characterized in that the optical system (10) for detecting the position of the hands comprises an optical sensor arranged so as to face the hands (6) of the watch (2), when the watch (2) is placed on the receiving support (24). 10. Case (4) according to one of claims 7 to 9, characterized in that the case (4) further comprises a flap piece (14) mounted on the box (8), the optical system (10) being fixed inside the flap piece (14) so as to face the hands (6) of the watch (2), when the flap piece (14) is closed on the case (8) and the watch (2) is placed on the receiving support (24). 11. Case (4) according to one of the preceding claims, characterized in that the case (4) is configured to contain a type and/or a shape of predefined electromechanical watch. 12. Case (4) according to one of claims 1 to 9, characterized in that the case (4) further comprises a cover (14), and a sensor (16) for the presence of the watch and/or closing the lid; said sensor (16) being connected to the means (12) for resetting the time of the watch (2), the time resetting means (12) being configured to trigger a process of resetting the time of the watch (2) based on a detection signal received from the sensor (16). 13. Case (4) according to one of the preceding claims, characterized in that the means (12) for resetting the time of the watch (2) are adapted to set the time of the watch (2) according to of the current time, the current time being synchronized using a reference system (20, 21, 22, 26), which the case includes. 14. Case (4) according to claim 13, characterized in that the reference system is a remote reference system, which comprises the reception of a radio or GPS signal or from a computer or mobile telephone network. 15. Case (4) according to one of the preceding claims, characterized in that the case (4) further comprises means (34) for communication with a mobile communication device. 16. Assembly (1) comprising an electromechanical watch (2) equipped with a stepping motor, and a case (4) for receiving the watch (2), according to one of claims 1 to 15.