Magnetic indexing positioning system for display

Abstract

The invention relates to a magnetic indexing positioning system (10) for a display (12), comprising a structural element (11) and a display (12) movably arranged relative to the structural element (11), and a pair of magnetic elements (13, 14) having anchoring portions (130, 140) by which a first magnetic element (13) is fastened to the structural element (11) and a second magnetic element (14) is fastened to the display (12), the magnetic elements are configured to cooperate with each other to generate a positioning torque of the display (12) adapted to hold the display (12) in a predetermined angular position relative to the structural element (11), the magnetic elements comprising interaction portions (131, 141) through which the magnetic elements face each other, the interaction portion of the first or second magnetic element has a reduced cross-section relative to the cross-section of its anchoring portion.

Description

Technical Field

[0001] The present invention relates to the field of watchmaking, and more particularly to watch movements. The present invention particularly relates to a magnetic indexing and positioning system for a display.

[0002] The term "indexing" is well known to those skilled in the art and is used to refer to the act of imposing a particular orientation on a moving object. In the context of the present invention, indexing is performed in order to assign a linear or angular position to an object that can translate or rotate. Background Art

[0003] In a watch display mechanism, as a visible element, the relative positioning of the display with respect to a reference point (such as another display or a fixed structure) is particularly important. The problem of relative positioning of multiple displays has always been difficult to solve because any misalignment, no matter how slight, is obvious to the user.

[0004] Obviously, the correct positioning of the display is a guarantee of quality, and incorrect positioning may seriously damage the image of the watch brand.

[0005] For example, the "big date" date display device is well known and includes two adjacent displays that respectively indicate the tens and units digits representing the current date. These two displays are oriented relative to each other to give the illusion of a single display, or at least to align the numbers they display. Since each display has its own drive mechanism to ensure its rotation and retention in place, it is particularly complex to achieve the correct relative positioning of the individual displays.

[0006] In known indexing schemes, mechanical schemes result in premature wear of the components constituting the drive mechanism due to the friction generated and any shock and / or distortion phenomena that may occur, which may also lead to undesirable noise. Summary of the Invention

[0007] The present invention overcomes the above-mentioned drawbacks and thus relates to a magnetic indexing and positioning system for a display, the magnetic indexing and positioning system comprising a structural element and a display movably arranged relative to the structural element, and comprising a pair of magnetic elements having anchoring portions, by means of which the first magnetic element is fastened to the structural element and the second magnetic element is fastened to the display.

[0008] These magnetic elements are configured to cooperate with each other in order to generate a positioning torque for the display, the positioning torque being adapted to hold the display in a predetermined angular position relative to the structural element. These magnetic elements comprise interaction portions, and these magnetic elements are intended to face each other through the interaction portions, and the interaction portion of the first or second magnetic element has a reduced cross-section relative to its anchoring portion.

[0009] Due to these features, the present invention is capable of compensating for any indexing positioning error caused by mechanical play formed between the teeth of the display drive mechanism.

[0010] In addition, the present invention enables the display to be repositioned (i.e., indexed) after an impact occurs.

[0011] In a particular embodiment, the present invention may further include one or more of the following features, which may be considered individually or in any technically feasible combination.

[0012] In a particular embodiment, the interacting portion of the first or second magnetic element has an annular shoulder to form a central protrusion.

[0013] In a particular embodiment, the interacting portion of the first or second magnetic element has a triangular cross-section.

[0014] In a particular embodiment, the interacting portion of the first or second magnetic element has two opposing inclined surfaces that are connected to each other by an intermediate portion.

[0015] In a particular embodiment, the interacting portion of the first or second magnetic element has a conical shape.

[0016] In a particular embodiment, the interacting portion of the first or second magnetic element has an axially symmetric conical shape.

[0017] In a particular embodiment, the interacting portion of the first or second magnetic element has a pyramid shape.

[0018] According to another object, the present invention relates to a watch movement, which includes a magnetic indexing positioning system and a roller display device as described above, wherein the structural element is formed by a flange, the display is formed by a roller, and the roller includes a support structure to which a flap is rotatably fastened. Description of the Drawings

[0019] Other features and advantages of the present invention will become apparent from the following detailed description given by way of non-limiting example with reference to the accompanying drawings, in which:

[0020] - Figure 1 shows in a perspective view a roller display device incorporating a magnetic indexing positioning system according to the present invention in an application example of the present invention,

[0021] - Figure 2 shows Figure 1 a perspective view of the display unit of the display device of

[0022] -Figures 3a to 3d Perspective views of a pair of magnetic elements of an indexing positioning system according to an embodiment of the present invention are each schematically shown.

[0023] It should be noted that, for clarity, the drawings are not necessarily drawn to scale. Detailed Description

[0024] The present invention relates to a magnetic indexing positioning system 10 for a display, which will be described hereinafter by way of a preferred application example in which it is incorporated in a roller display device 20.

[0025] For example, such a roller display device can be understood according to the corresponding device described in patent EP3627240.

[0026] The magnetic indexing positioning system 10 according to the present invention includes a structural element 11 and a display 12, and the display 12 is arranged to be movable relative to the structural element 11. In Figure 1 and 2 the application example of the present invention shown, the structural element 11 is formed by a flange, for example, which is intended to be fastened to a bridge plate or a mainplate without any degree of freedom, and the display 12 is formed by a display roller, which includes a support structure 120, the support structure 120 is intended to be mounted in a rotatable manner relative to the structural element 11, and a flap 121 is fastened to the support structure 120 in a rotatable manner. In other application examples of the present invention, the structural element 11 may be formed by any structure of a watch movement, such as a bridge plate or a mainplate, and the display 12 may be formed by a disc, a strip, etc.

[0027] The magnetic indexing positioning system 10 further includes at least a pair of magnetic elements, and the two magnetic elements are respectively fastened to the structural element 11 and the display 12 through anchoring portions 130, 140. Specifically, the first magnetic element 13 of the pair of magnetic elements is fastened to the flange, facing the trajectory of the flap 121, and at least one second magnetic element 14 of the pair of magnetic elements is fastened to an area of the flap 121. The anchoring portions 130, 140 are cylindrical, preferably axially symmetric cylinders. The first magnetic element 13 and the second magnetic element 14 are fastened to the structural element 11 and the display 12 respectively by pressing or gluing in a manner known per se to those skilled in the art.

[0028] It should be noted that, herein, different second magnetic elements 14 can successively form a pair of magnetic elements with the same first magnetic element 13.

[0029] The first magnetic element 13 and the second magnetic element 14 are configured to cooperate with each other by establishing a magnetic attraction force, so as to generate a positioning torque for the display 12, and the positioning torque is adapted to hold the display 12 at a predetermined angular position relative to the structural element 11.

[0030] Advantageously, the first magnetic element 13 and the second magnetic element 14 include interaction portions 131, 141 opposite to their anchoring portions 130, 140, which extend to an interaction end at which they will face each other. The cross-section of the interaction portion 131 or 141 of the first magnetic element 13 or the second magnetic element 14 is reduced relative to the cross-section of its anchoring portion 130 or 140.

[0031] This feature allows the field lines of the first magnetic element 13 or the second magnetic element 14 to be centered, thus ensuring the correct positioning of the flap 121 relative to the flange. This feature also allows the attractive force between the first magnetic element 13 and the second magnetic element 14 to be minimized, which has the effect of minimizing the friction of the flap 121 on the support structure 120, thus contributing to reducing the static balance range between the first magnetic element 13 and the second magnetic element 14.

[0032] Thanks to the present invention, the indexing positioning accuracy of the flap 121 is thus significantly improved.

[0033] In some embodiments of the present invention, the interaction portion 131 or 141 of the first magnetic element 13 or the second magnetic element 14 may have an annular shoulder 142 to form a central protrusion, as Figure 3a shown.

[0034] In Figures 3b to 3d the embodiment of the present invention shown, the interaction portion 141 of the second magnetic element 14 has a triangular cross-section.

[0035] Specifically, in Figure 3b the example shown, the interaction portion 141 of the second magnetic element 14 has two opposing inclined (side) surfaces 143, which are connected to each other by an intermediate portion. This intermediate portion forms the interaction end and has the shape of a line segment.

[0036] In Figure 3c and 3d the embodiments shown, the interaction portion 141 of the second magnetic element 14 has a conical shape and the interaction end presents as a point. The interaction portion 141 of the second magnetic element 14 may have an axially symmetric conical shape, as Figure 3c shown, or a pyramidal shape, as Figure 3d shown.

[0037] It should be noted that the shape of the interaction portion described above and visible in Figures 3a to 3d may alternatively or additionally apply to the interaction portion 131 of the first magnetic element 13.

[0038] In this pair or each pair of magnetic elements, at least one magnetic element is made of a hard ferromagnetic material, i.e., it forms a permanent magnet, and the other magnetic element may be made of a soft ferromagnetic material. Preferably, only the interacting portion of the magnetic element made of the soft ferromagnetic material has a reduced cross-section.

[0039] More generally, it should be noted that the implementations and manufacturing methods considered above are described as non-limiting examples, and thus other variations can be envisaged.

[0040] It should be noted that the air gap, i.e., the distance between the first magnetic element 13 and the second magnetic element 14 in a pair of magnetic elements, is, for example, in the range of 10 to 100 μm, or in the range of 20 to 40 μm.

Claims

1. A magnetic indexing positioning system (10) for a display (12), the magnetic indexing positioning system (10) comprising a structural element (11) and a display (12) movably arranged relative to the structural element (11), and comprising a pair of magnetic elements (13, 14) having anchoring portions (130, 140), by means of which a first magnetic element (13) is fastened to the structural element (11) and a second magnetic element (14) is fastened to the display (12), the first magnetic element (13) and the second magnetic element (14) being configured to cooperate with each other so as to generate a positioning torque of the display (12), the positioning torque being suitable for moving the display (12) relative to the structural element (11). The structural element (11) is maintained at a predetermined angular position, the first magnetic element (13) and the second magnetic element (14) include interaction parts (131, 141), through which the first magnetic element (13) and the second magnetic element (14) face each other, the interaction part (131; 141) of the first magnetic element (13) or the second magnetic element (14) has a cross-section that is reduced relative to the cross-section of its anchoring part (130; 140), the interaction part (131; 141) of the first magnetic element (13) or the second magnetic element (14) has an annular shoulder (142) so as to form a central protrusion, or has a triangular cross-section.

2. The magnetic indexing positioning system according to claim 1, wherein: The interaction portion (131; 141) of the first magnetic element (13) or the second magnetic element (14) has two opposite inclined surfaces (143), and the two opposite inclined surfaces (143) are connected to each other through a middle portion.

3. The magnetic indexing positioning system according to claim 1, wherein: The interaction portion (131; 141) of the first magnetic element (13) or the second magnetic element (14) has a cone shape.

4. The magnetic indexing positioning system according to claim 3, wherein: The interaction portion (131; 141) of the first magnetic element (13) or the second magnetic element (14) has an axisymmetric conical shape.

5. The magnetic indexing positioning system according to claim 3, wherein: The interaction portion (131; 141) of the first magnetic element (13) or the second magnetic element (14) has a pyramidal shape.

6. A watch movement, comprising a roller display device (20) and a magnetic graduation positioning system according to any one of claims 1 to 5, wherein the structural element (11) is formed by a flange and the display (12) is formed by a roller, wherein the roller comprises a supporting structure (120) and a flap (121) is fastened to the supporting structure (120) in a rotatable manner.

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