CH715167B1 - Astronomical display device. - Google Patents

Abstract

The invention relates to an astronomical display device (1) for a timepiece, comprising: a celestial vault disc (3) provided with a curve (5) representing the horizon; a map disc (7) bearing a sky map (9) illustrating a plurality of celestial objects, said map disc (7) being coaxial with said celestial vault disc (3), wherein one of said celestial vault (3) and said map disk (7) is mounted rotatably relative to the other and is intended to be driven in rotation by a clockwork movement (18) at a relative angular speed of substantially one revolution per day sidereal; characterized in that said display device (1) further comprises a first (11) and a second (13) indicator members mounted coaxially and movable in rotation, one of said indicator members (11) carrying a scale (15) defining divisions of time, the other of said indicator members (13) bearing an index (17) cooperating with said scale (15), said indicator members (11, 13) being angularly movable and arranged so as to: indicate a celestial object of interest through a first of said indicator organs (11); and indicating a position of interest on said celestial vault disc (3) through a second of said indicator members (13), said position being intended to be reached by said celestial object of interest at a future time, the time to said future time being indicated on said scale (15) by means of said index (17).

Description

Technical area

The present invention relates to the field of watchmaking. It relates, more particularly, to an astronomical display device for a timepiece.

State of the art

The document CH 710770 describes a display device of the kind mentioned above. This device comprises a first disk, fixed, which carries a map of the sky. A second disc, rotating, is provided with a representation of the horizon at a predetermined place on earth, in the form of an ellipse drawn on said disc. The second disc rotates behind the first at an angular speed of one revolution per sidereal day under the control of a clockwork movement. When the second disc is correctly adjusted, the portion of the map that is inside the ellipse corresponds to the area of the sky that is visible at a given time. Thus, the celestial objects and other constellations which are represented on the sky map and which are located inside the ellipse, are visible as long as it is dark and the sky is clear.

[0003] Other similar constructions are also known, and as such we can cite a particularly common construction in which the first disc is mounted in rotation below the other, an ellipsoidal opening provided in the latter delimiting the extent visible sky.

The document EP1498790 describes an electronic watch which combines the aforementioned general principle with an electronic module which makes it possible to indicate the position on the map of a predetermined celestial object. The user selects any object by means of a rotating ring, and the electronic module controls a pair of hands having particular shapes in order to indicate the desired object by the intersection of the hands.

[0005] However, these arrangements do not make it possible to indicate to the user when a celestial object will reach a predetermined position in the sky. For example, if the object is outside the ellipse representing the horizon, it is invisible to the user, who therefore has no indication of when the object will become visible above the horizon. 'horizon. Similarly, it could also be useful for a user to know when a star will peak or set.

[0006] This information may be of interest to astronomers or astronomy amateurs, as well as to people wishing to carry out horoscopic and similar analyses.

The object of the invention is therefore to provide a display device in which the aforementioned defects are at least partially overcome.

Disclosure of Invention

More specifically, the invention relates to an astronomical display device for a timepiece, as defined by the independent claim.

[0009] This device comprises a celestial vault disc provided with a curve representing the horizon as well as a map disc carrying a map of the sky illustrating a plurality of celestial objects, such as stars, constellations, signs of the zodiac or similar. These two discs are coaxial with each other, and one of them is rotatably mounted with respect to the other by a clockwork movement at a relative speed of rotation of substantially one revolution per day. sidereal, which has a duration of about 23h 56m 4s.

According to the invention, said display device further comprises a first and a second indicator members coaxially mounted and rotatable around their axes of rotation. One of these indicator members carries a scale indicating divisions of time, and the other carries an index cooperating with said scale.

[0011] Said indicator members can be moved angularly by the user, for example, either by a correction mechanism or by a split-seconds chronograph device in order to be able to: indicating a celestial object of interest through a first of said indicator organs, by moving it angularly such that the indicator organ overlaps or points towards the representation of the object of interest on the map; and indicate a position of interest on said celestial vault disc by means of a second of said indicator organs, this position being intended to be reached by said celestial object of interest at a future moment, such as for example the position where the celestial object will cross the curve of the horizon or the south direction if we are interested in the apogee of the celestial object.

In doing so, the time interval before said future moment arrives, is indicated on said scale by the index, when said indicating organs indicate said celestial object of interest and said position of interest as mentioned above .

[0013] This measurement can thus be performed by entirely mechanical means, without requiring an electronic control system.

[0014] Other advantageous construction details are proposed in the dependent claims.

Brief description of the drawings

Other details of the invention will appear more clearly on reading the description which follows, given with reference to the appended drawings in which: Fig. 1 is a schematic semi-exploded view of a display device according to the invention; Fig. 2 to 6 illustrate the measurement principle used by the display device according to the invention; and Fig. 7a-c and 8 schematically illustrate variants of systems allowing the drive of the indicator members of the display device according to the invention.

Embodiment of the invention

Figure 1 shows an astronomical display device 1 according to the invention in semi-exploded form.

Like the device described in the aforementioned document CH 710770, the display device 1 is intended to be mounted in a watch case (not shown) further housing a mechanical or electrical watch movement 18. The device display 1 comprises a vault of the sky disc 3 carrying a representation of the horizon 5, taking the form of an oval or an ellipse, as well as ad hoc indications of the cardinal points and/or the 24 hours of the day. The horizon 5 can be represented by a curve drawn on the disc 3, a contrast between different materials and/or between different colors, an opening, a groove made in the dial 3 or by any other means serving to delimit the zone visible from the sky.

[0018] A map disk 7, provided with a map 9 is superimposed on the sky vault disk 3. The map disk 7 is therefore located closer to the user than the vault disk 3 and is at least partially transparent so that the user can also see the vault disk 3 which is underneath. Map 9 bears markings illustrating predetermined celestial objects such as stars, constellations, etc. It is therefore recalled that, with an adequate adjustment, the celestial objects represented on the map disc and which are located inside the oval or ellipse representing horizon 5, are positioned in the visible part of the sky. , for a user. He can therefore observe them if it is dark and the sky is clear.

[0019] In a construction variant, the map disc 7 can alternatively be arranged below the sky vault disc 3. In such a case, the latter must of course be at least partially transparent so that the user can see the card 9, but in this case the card disc 7 may optionally be opaque.

[0020] The vault of the sky disc 3 is pivotally mounted with respect to the map disc 7, at the rate of one revolution per sidereal day (that is to say substantially 23h 56m 4s) counterclockwise under the control of any watch movement 18 (which may be, for example, mechanical or electrical as generally known). In the illustrated variant, the map disc 9 is fixed relative to the watch case (not shown) and the sky vault disc 3 is arranged to pivot under the control of said watch movement 18, in particular under the effect of its motor component (barrel, electric motor or similar). To this end, the vault of the sky disc 3 is supported at its periphery and has peripheral toothing 4 intended to be driven by a pinion 6 in the manner of a display member of a mysterious watch. Alternatively, this disk 3 can be pivoted by its center on a barrel or on an axis in the usual way.

[0021] Alternatively, the sky vault disk 3 can be mounted fixed and the map disk 7 can pivot clockwise, or the two disks 3, 7 can be driven in rotation, but with a relative phase shift such that the one performs substantially one revolution per sidereal day relative to the other.

The illustrated arrangement is suitable for the northern hemisphere at a predetermined latitude; for the southern hemisphere, map 9 as well as the direction of rotation of the mobile disc must be adapted accordingly.

The device 1 also comprises a first indicator member 11 and a second indicator member 13, pivotally mounted around their respective axis of rotation. These members 11, 13 are coaxial with the crown disc 3 and can be located between the dial 3 and the disc 7, superimposed on each of these two elements or below the crown disc 3 in the case where the latter is transparent. In the illustrated embodiment, these indicator members 11, 13 are located between the two discs 3, 7 and are formed by straight needles mounted in a conventional manner on a shaft or a barrel. However, they can also consist of transparent discs each bearing a line or other ad hoc marking. In the latter case, the discs can be pivoted by their center or by their periphery as mentioned above in the context of the celestial vault disc 3. Furthermore, other shapes of needles are also possible.

One of the indicator members, here the second 13, carries a scale 15 graduated in hours, and the other, here the first 11, carries an index 17 arranged to indicate a value on the scale 15. scale may bear numbers, patterns or the like which are intended to indicate the number of hours before a celestial object reaches a position of interest, as will be clearly understood hereinafter. In the illustrated embodiment, the scale 15 bears the digits 1 to 6 extending over an angle of 90°, but longer or shorter scales are also possible, each hour of the scale extending over a angle of substantially 15° (1/24 of a turn) since the celeste 3's vault disk pivots at the rate of one turn per approximately 24 hours. It goes without saying that the positions of the index 17 and of the scale can be reversed, the first indicator member 11 thus carrying the scale and the second 13 carrying the index.

The indicating elements 11, 13 can be driven by manual control elements by means of any correction mechanism 19, 20 or by the watch movement 18, if the latter comprises a split-seconds chronograph mechanism 20, as will be described later.

Figures 2 to 6 illustrate the principle of the invention allowing the determination of the time interval before a celestial object, which is currently invisible, becomes visible on the horizon. The position on the horizon, where the object will rise, being according to the example the position of interest. To do this, we assume that: • it is night; • the sky is clear ; and • the celestial vault disc is substantially correctly set for sidereal time at the user's location.

Figure 2 illustrates the starting point for the determination. In this state, the two indicator members 11, 13 are superposed and oriented in the direction of 12 o'clock of the watch (not shown). It is clear from this figure that, in the illustrated embodiment, the indicator members 11, 13 are long enough to be able to overlap each celestial object on the map 9. However, shorter indicator members 11 are possible, in which cases they can simply point to each celestial object, instead of overlapping it, in order to indicate it. In such a case, the extension of the short organ intersects the desired object.

[0028] The example is based on the assumption that the user wishes to observe the star surrounded by the black circle, which is outside the ellipse of horizon 5 and is therefore currently invisible.

The two indicator members 11, 13 are driven clockwise to the point where they intersect the desired star (see Figure 3). This intersection, or even overlap, makes it possible to indicate the celestial object of interest.

Then, the first indicator member 11 is stopped, and we continue to advance the second indicator member 13 clockwise (see Figure 4).

[0031] When the second indicator member 13 (or its extension, if it is relatively short) intersects the ellipse 5, at the place where the star sought will cross it (represented by the symbol "¤"), which is at the same radius as the star of interest (considered from the axis of rotation of the members 11, 13), the second indicator member 13 is stopped. The second indicator member 13 then indicates the point where the object of interest will be at a future moment. In order to facilitate the determination of the correct radius, the indicator members 13 may be provided with ad hoc markings and/or the card 9 may comprise circles defined by several radii from said axis of rotation.

[0032] Then, the user can read on the scale 15 the number of hours before the designated star crosses the horizon (rising of the star), which will occur in approximately three hours in the example illustrated. .

The same principle of measurement can also be applied to measure other time intervals related to celestial objects, as illustrated by figure 6.

In this example, the star surrounded by an "O" is the celestial object of interest. This star being inside the ellipse of the horizon, it is already visible. The user can thus stop the first indicator member 11 when the latter intersects this star in order to indicate it.

[0035] If the user wishes to know when this star will reach its apogee (the latter therefore being the "position of interest" in the context of the invention), he stops the second indicator member 13 on a line joining the axis of rotation of the indicator organs 11, 13 and the "south" direction marked on the periphery of the celestial vault disc 3. This line has been drawn in dashed/dotted lines in FIG. 6. He can thus read the time interval before the apogee of the star in question on the 15 scale.

[0036] On the other hand, if he wishes to know when the celestial object is setting, he will stop the second indicator member 13 when it intersects the ellipse of the horizon at the place on the curve where the object is going to to set, that is to say at the same radius as that where the star in question is located. This point has been illustrated by the symbol „¤“. Again, he can thus read the time interval before this deadline on the scale 15.

If it is desired to determine time intervals greater than six hours, the scale 15 can be extended. For example, by extending the scale 15 through an arc of 180°, time lapses of up to twelve hours can be calculated.

Furthermore, it goes without saying that the directions of rotation etc. mentioned above can be reversed, the arrangement of the ladder being adapted accordingly. It is also noted that the indicator members 11, 13 can be driven independently of each other.

As regards the training of the indicator members 11, 13, several possibilities can be envisaged.

[0040] Figures 7a-7c illustrate several systems based on correction devices which make the kinematic link between one or more control members 19, 20 and the indicator members 11, 13.

[0041] Figure 7a schematically illustrates a single control member 19 (such as a crown, a rotating bezel or the like) in kinematic connection with the indicator members 11, 13, which allows the user to rotate said members 11, 13. The kinematic connection between the control member 19 and the members 11, 13 is illustrated schematically by the dashed line.

In this case, the control member 19 could for example have several axial positions, each axial position forming a kinematic connection with a respective indicator member 11, 13. Similarly, the control member 19 can be arranged to drive the two members 11, 13 in superposition in a first direction of rotation (for example clockwise), and then only one of these members (in particular the second 13 ) in the opposite direction when the control member 19 is manipulated in the other direction or in any direction if the control member 19 is placed in a different axial position. Mechanisms for carrying out these drives are known in particular in the context of setting the time of time display members, among others.

[0043] Figure 7b illustrates a variant in which a first control member 19, in the form of a crown, rotating bezel or the like, is arranged to cause one or the other of the indicator members 11, 13 to pivot depending on the state of a second control member 20, which can for example be a push-button. If the second control member 20 is released, the first control member 19 can drive, for example, the first indicator member 11 (or all of the indicator members 11, 13 in synchronism), the first indicator member 11 being blocked and the second indicator member 13 being driven when the second control member 20 is actuated.

[0044] Figure 7c illustrates another variant in which each indicator member 11, 13 is in kinematic connection with a respective control member 19, 20.

[0045] Figure 8 schematically illustrates yet another variant, in which the indicator members 11, 13 are driven via a split-seconds chronograph mechanism 21 that includes the movement 18. By pressing the first control member 19, the indicator members 11, 13 are driven in superposition. When the latter indicate the desired celestial object as discussed above, the user presses the second control member 20, which actuates a brake to stop the movements of the first indicator member 11. The second indicator member 13 then continues its route, and when he is in the correct angular position for the determination to be made (see above), the user presses the first control member 19 again to stop the second indicator member 13. The user can thus read the desired time interval on the scale 15. By pressing a reset control member 22, the indicator members can be returned to their starting position.

It goes without saying that other arrangements of control members 19, 20, 22 are known in the field of split-seconds chronographs, these arrangements comprising one, two or three control members arranged to perform sequences of ad-hoc operations.

Although the invention has been described above in connection with specific embodiments, additional variants are also possible without departing from the scope of the invention as defined by the claims.

Claims (7)

1. Astronomical display device (1) for a timepiece, comprising: – a celestial vault disk (3) provided with a curve (5) representing the horizon; – a map disc (7) carrying a map of the sky (9) illustrating a plurality of celestial objects, said map disc (7) being coaxial with said celestial vault disc (3), in which one of said celestial vault disc (3) and said map disc (7) is rotatably mounted relative to the other and is intended to be driven in rotation by a clockwork movement (18) at a relative angular velocity of substantially one revolution per sidereal day; characterized in that said display device (1) further comprises first (11) and second (13) indicator members mounted coaxially and movable in rotation, one of said indicator members (11) carrying a scale (15) defining time divisions, the other of said indicator members (13) bearing an index (17) cooperating with said scale (15), said indicator members (11, 13) being angularly movable and arranged so as to: – indicate a celestial object of interest by means of a first of said indicator organs (11); and – indicating a position of interest on said celestial vault disk (3) by means of a second of said indicator members (13), said position being intended to be reached by said celestial object of interest at a future moment, the duration until said future time being indicated on said scale (15) by means of said index (17). 2. Display device (1) according to the preceding claim, wherein said indicator members (11, 13) are arranged to be driven manually via at least one control member (19, 20) in kinematic connection with said indicator members (11, 13). 3. Display device (1) according to the preceding claim, wherein said kinematic link comprises a correction device forming a kinematic link between one or more control members (19, 20) and said indicator members (11, 13). 4. Display device (1) according to claim 1, wherein said indicator members (11, 13) are arranged to be driven via a split-seconds chronograph device (21), one of said members indicators (11) which can be stopped independently of the other (13). 5. Display device (1) according to one of the preceding claims, wherein said map disc (7) is fixed, said celestial vault disc (3) being arranged to be rotated relative to said map disc (7). 6. Display device (1) according to claim 5, in which said celestial vault disk (3) comprises a toothing (4) at its periphery, this toothing (4) being arranged to be driven by said watch movement (18 ). 7. Timepiece (1) comprising a display device according to one of claims 1 to 6 as well as a clockwork arranged to drive in rotation said map disc or said celestial vault disc.