HK1248000B - Moon phase display mechanism - Google Patents

Description

Moon phase display mechanism

Technical Field

The present invention relates to a moon phase display mechanism arranged to cooperate with a timepiece movement and comprising an input pinion arranged to rotate three times or two times in 24 hours.

The invention also relates to a timepiece display mechanism comprising such a moon phase display mechanism.

The invention also relates to a timepiece movement comprising such a moon phase display mechanism.

The invention also relates to a watch comprising such a movement.

The present invention relates to the field of watch display mechanisms, in particular to mechanical watches with complex structures.

Background Art

A moon phase display is a crucial feature in watchmaking, complicating the manufacture of the movement and quickly taking up a significant amount of volume within the case. Calibration of such a display is not always easy.

European patent application EP 2853957A1 in the name of Christopher Claret discloses a moon phase display mechanism comprising two discs rotating at different speeds, one of which bears a moon pattern, and the other of which includes a plurality of openings arranged to display the moon pattern on the first disc so as to sequentially display the lunar phases through one of the openings, separated by a plurality of moon covers that are all visible simultaneously, indicating successive lunar phases through adjacent openings.

US Patent Application No. 2006/2217771 in the name of ZIMMERMANN discloses a moon phase mechanism comprising a moon disc coaxially mounted on a moon display disc, wherein the moon disc is mounted so that it rotates relative to the moon display disc during normal operation of the mechanism. The moon display disc is in a stationary position during normal operation of the mechanism and is configured to move only for manual display adjustment.

Summary of the Invention

The present invention proposes to create a moon phase display mechanism for a watch that is simple and economical, has few components and is uncomplicated to manufacture.

To this end, the invention relates to a moon phase display mechanism according to claim 1 .

The invention also relates to a timepiece display mechanism comprising such a moon phase display mechanism.

The invention also relates to a timepiece movement comprising such a moon phase display mechanism.

The invention also relates to a watch comprising such a movement.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent upon reading the following detailed description with reference to the accompanying drawings, in which:

- Figure 1 shows a schematic front view of a moon phase display mechanism according to the invention, wherein the moon phase display mechanism has a moon disc visible through an opening in a sky disc, the two discs being carried by coaxial wheels with different rotation speeds, and the sky disc forming a day/night display visible behind a small bar symbolizing the horizon.

- FIG. 2 shows, in a similar manner to FIG. 1 , the same mechanism completing a moon age display device comprising a moving hand pointing to a partially shown scale.

- Figure 3 shows a moon disc of the same mechanism in a similar manner to Figure 1 .

- Figure 4 shows a section through the axis of the control wheel set and the coaxial wheel of a first variant of the mechanism according to the invention.

- FIG. 5 shows a schematic partial front view of a moon phase display mechanism according to a first variant of the invention.

- FIG. 6 shows the mechanism of FIG. 5 in a similar manner to FIG. 4 .

- FIG. 7 shows the moon disc of the mechanism of FIG. 5 in a similar manner to FIG. 3 .

- FIG. 8 shows a schematic partial front view of a moon phase display mechanism according to a second variant of the invention.

- FIG. 9 shows the mechanism of FIG. 8 in a similar manner to FIG. 6 .

- FIG. 10 shows the moon disc of the mechanism of FIG. 8 in a similar manner to FIG. 7 .

FIG. 11 shows a section through the axis of the control wheel set and the coaxial wheel of a friction mechanism for adjusting a moon phase display, suitable for use in the first or second variant of the invention.

- FIG12 is a block diagram showing a wristwatch including a timepiece movement including a timepiece display mechanism having the above-mentioned moon phase display mechanism.

FIG. 13 shows a schematic front view of a moon phase display mechanism according to a second variant of the invention, similar to FIG. 8 , but in FIG. 13 the number of teeth is doubled.

- Figure 14 shows details of the gear train that are not visible in Figure 13.

15 and 16 show sections of the mechanism shown in FIGS. 13 and 14 , respectively, from the gearing to the moon-phase display mechanism and from the regulating stem to the moon-phase display mechanism.

DETAILED DESCRIPTION

The present invention relates to a simple and economical moon phase display mechanism for a watch.

The mechanism is described below in two variations which employ the same basic principle but differ in the arrangement of the gear train.

The present invention relates to a moon phase display mechanism 10 arranged to cooperate with a timepiece movement 200 and comprising an input pinion.

The input pinion is configured as follows:

In a first variant, three revolutions are made in 24 hours, see reference numeral 11 in FIG. 4 .

- Alternatively, in a second variant, two rotations in 24 hours.

According to the invention, the input pinion drives at least one transmission pinion directly or, as in the case of the variant in FIG11 , by means of a friction device 20 , or by means of another wheel set or gear train:

- In a first variant, the input pinion drives at least one 19-tooth transmission pinion, see reference numeral 13 in FIG. 4 ;

- in a second variant, the input pinion drives at least one 29-tooth transmission pinion, see reference numeral 130 in FIG. 8 ;

The transmission pinion, designated 13 or 130 depending on the variant, drives the upper wheel:

- In a first variant, the transmission pinion 13 drives the upper wheel with 57 teeth, see reference numeral 14 in FIG. 4 ,

In a second variant, the transmission pinion 130 drives an upper wheel with 58 teeth, reference 140 in FIG. 9 .

In various variants, the upper wheel makes one rotation per day.

The upper wheel comprises, on the user's side, a sky disc 1400 with a pattern of the sky and an off-center sun 141 and comprising an off-center opening 16 substantially opposite the sun 141 through which a portion of the lower wheel 15 is visible, showing the current appearance of the moon.

The 19-tooth transmission pinion 13 or the 29-tooth transmission pinion 130 is not necessarily the only transmission pinion. This is just a specific example.

In a particular embodiment and as seen in Figures 1, 2 and 8, the pattern of the sky on the sky disk 1400 includes a first light or luminous portion 142 with a pattern of a sun 141, corresponding to daytime, and includes a second dark or shaded portion, corresponding to nighttime, containing an opening 16 through which the phases of the moon are visible.

In FIG. 5 , the pattern of the sky on the sky disk 1400 includes an image 144 that gradually darkens from a bright portion corresponding to daytime in the pattern of the sun 141 to a dark portion corresponding to nighttime at the opening 16 (brightness and darkness are not shown in the figure).

In order to allow the moon phases to be displayed, a transmission pinion, designated 13 or 130 according to the variant, drives a 59-toothed lower wheel 15 .

The 59-toothed lower wheel 15, common to both variants, carries a moon disc, indicated by 150 in the first variant as seen in FIG3 or FIG7 , or by 1500 in the second variant as seen in FIG10 . Naturally, the moon disc may be arranged on the lower wheel or form a single component therewith, and may include painting, coloring, silk-screening, transfer printing or other treatments.

The moon disk 15 or 1500 comprises a two-color pattern comprising at least one luminous area 152 and at least one dark background sky area 151:

- in a first variant, the moon disk 150 comprises a luminous area 152 including an area 155 corresponding to a full moon display, and a background sky area 151 including an area corresponding to a crescent moon display, also called a black moon;

In a second variant, the moon disk 1500 comprises a luminous area 152 and two diametrically opposed background sky areas 151 .

In a first variation, background sky region 151 is configured so that the durations of the new moon and full moon are approximately equal (respected). In a particular embodiment, background sky region 151 is defined by a circular spiral or heart-shaped boundary so that the overall pattern of the new moon and full moon are visible through opening 16, respectively.

In order to make the moon appear complete, the sky disk 1400 is pivoted on the outside. In addition, the axis of the sky disk 1400 can be obscured by the horizon.

In the embodiment shown, which corresponds to a preferred embodiment of smaller dimensions, the upper wheel 14 or 140 , depending on the variant, is coaxial with the lower wheel 15 .

The first variant uses a specific gear ratio of 57-19-59, which enables a very simple moon phase and uses almost no energy, since the mechanism has no jumper spring and engages directly on the hour wheel in continuous movement.

The input pinion 11 meshes with the hour wheel 12 of the clock movement and rotates three times in 24 hours. Z=Zh/3.

The input pinion 11 carries a 19-tooth drive pinion 13 which drives two coaxial wheels with 57 and 59 teeth respectively: an upper wheel 14 with 57 teeth and a lower wheel 15 with 59 teeth.

In a particular non-limiting variant, the input pinion 11 and the transmission pinion 13 are integral.

In another variant, the input pinion 11 carries only the drive pinion 13 , which the input pinion 11 drives indirectly, for example by means of a separate wheel set.

The upper wheel 14 comprises 57 teeth and therefore:

In 24 hours, it rotates 3×19/57=1 circle.

The lower wheel 15 comprises 59 teeth and therefore:

In 24 hours, it rotates 3×19/59=0.966101695 times.

Δ=1/(1-0.966101695)=29.5, which means that the lower wheel 15 will rotate one revolution in the opposite direction relative to the upper wheel 14 in 29.5 days (ie, the average length of a lunar month).

Mechanism 10 comprises a fixed part formed by a plate 30 or a rod 31, superimposed on a sky disk 1400 and to which is fixed a small bar 19 representing the horizon, on either side of which the image of the sun 141 can move during the rotation of upper wheel 14 or 140, as can be seen in Figures 1 and 2. Sky disk 1400 with the moon and the sun rotates at the speed of day and night.

In the particular embodiment of FIG. 2 , lower wheel 15 is attached, for example by means of a pointer tube, to a display member or hand 17 for displaying the age of the moon on a scale 18 included in a sky disc 1400 .

There are several possible options for implementing the gear train of this first variant.

In a first alternative, the 19-tooth transmission pinion 13 is the only transmission pinion and meshes simultaneously with the 57-tooth upper wheel 14 and with the 59-tooth lower wheel 15 .

In the particular embodiment shown in the drawings, the upper wheel 14 and the lower wheel 15 are coaxial. There is no direct transmission between the upper wheel 14 and the lower wheel 15, and the upper wheel 14 and the lower wheel 15 are free to rotate relative to each other; they can therefore rotate in the same direction or in opposite directions depending on the transmission applied to them.

The problem is therefore to determine the most compromise possible solution for a single 19-tooth transmission pinion 13 meshing simultaneously with an upper wheel 14 with 57 teeth and with a lower wheel 15 with 59 teeth, in order to be as close to the pitch circle as possible in each case in order to optimize contact and limit wear. Naturally, in the compromise that allows the assembly to have a small number of components and a very small thickness (a compromise also possible because the wheels always rotate in the same direction), it is then necessary to mesh with one of the wheels slightly above the pitch circle and with the other wheel slightly below the pitch circle.

For a module m=0.17 (Blancpain 67 calibre) for a moon diameter of 9.0 mm, the theoretical centre distances are calculated in this first option to give the following values:

C59 = 0.17 × (59 + 19) / 2 = 6.63

C57 = 0.17 × (59 + 19) / 2 = 6.46

For the mean value Cm 6.545, the meshing is evenly distributed with very small distances on both sides of the pitch circle of the transmission pinion 13:

Δ57＝-0.085

Δ59＝+0.085,

Dpm=0.17×58=9.86 (for cutting the upper wheel 14 with 57 teeth and the lower wheel 15 with 59 teeth).

In the second option, the transmission pinion is doubled, where:

With m57=0.1722 and m59=0.1678, the meshing of the upper wheel 14 and the lower wheel 15 then takes place on the pitch circle associated with the transmission pinion, which is cheaper to manufacture in one piece and may require a slightly larger thickness dimension in order to ensure the retraction of each cutting tool. This disadvantage does not exist in the case of two superimposed pinions, each having a right module and manufactured to rotate integrally by means of wedge keys, adhesive bonding or similar means.

In yet another alternative, upper wheel 14 and lower wheel 15 are not strictly coaxial, one of them having radial play relative to the other; correction of this play then requires rebounding towards the transmission pinion by means of a jumper spring or similar device, which then causes a consumption of energy that can be avoided by the first or second alternative.

In short, in this first variant of moon phase display mechanism 10, input pinion 11 is arranged to rotate three times in 24 hours, transmission pinion 13 has 19 teeth, upper wheel 14 has 57 teeth, and, on moon disc 150, the two-color pattern comprises a luminous area 152 and a background sky area 151 delimited by a circular spiral or heart-shaped border 153 and thus making the complete representation of the new moon and the full moon, respectively, visible through opening 16.

The second variant uses a different gear ratio of 58-29-59.

The input pinion 110 meshes with the hour wheel 12 of the watch movement and rotates twice in 24 hours. The input pinion 110 carries a 29-tooth transmission pinion 130, which drives the 58-tooth upper wheel 140 and the 59-tooth lower wheel 15 as seen in FIG9 .

The upper wheel 140 comprises 58 teeth and therefore:

In 24 hours, (2×29)/58=1 rotation is made.

The lower wheel 15 has 59 teeth and its moon disc 1500 includes two background sky areas 151. Since the lower wheel 15 has two background sky areas:

In 24 hours, it rotates 2×(1/2)×(29/59)=0.491525424 times.

In the opposite direction, Δ=1/(1-0.491525424)=59.

Since the 29-tooth transmission pinion 130 rotates once in 12 hours, it is conceivable to set it directly on the hour wheel of the movement, but a reversing device must be added to ensure the correct direction of rotation for the day/night display, and an uncoupling device is also required between the hour wheel and the moon disc drive.

In short, in this second variant of moon phase display mechanism 10, input pinion 11 is arranged to rotate twice in 24 hours, transmission pinion 130 includes 29 teeth, the two-color pattern of moon disc 1500 includes a luminous area 152 and two background sky areas 151, and upper wheel 14 includes 58 teeth.

13 to 16 show another embodiment of the second variant, in which the number of all teeth is doubled, which does not change the gear ratio but makes it possible to reduce the play.

FIG11 illustrates a simple method for producing a moon-phase corrector: correction can be achieved by inserting a friction device 20 on the connecting wheel train between input pinion 11 connected to hour wheel 12 (on which positioning ring 21 presses) and transmission pinion 13 controlling the lunar month. It is conceivable to correct the moon phase from position T2 of winding stem 301 of watch 300, either by means of intermediate train 302 or by means of a corrector lever acting on transmission pinion 13, particularly in a first mode. Transmission pinion 13 is then driven by input pinion 11 by means of friction device 30, allowing correction by means of the intermediate train, either by a control lever or by a corrector lever acting on transmission pinion 13. Clearly, in this first mode, the sky and moon discs are corrected together. FIG14 illustrates another correction mode, involving the correction of the moon disc relative to the sky disc: the last wheel 303 of intermediate train 302 drives wheel 304, which cooperates with moon disc 1500 by means of a friction device comprising ring 305 and elastic washer 306.

The invention also relates to a timepiece display mechanism comprising such a moon phase display mechanism 10 .

The invention also relates to a timepiece movement 200 including such a moon phase display mechanism 10 and including an hour wheel 12, said hour wheel 12 being arranged to drive an input pinion 11 and to drive a transmission pinion 13 or 130, or to form the input pinion 11 and to carry and entrain the transmission pinion, in which case the transmission pinion 13 indirectly drives an upper wheel 14 via a reversing device, and the transmission pinion 13 indirectly drives a lower wheel 15 via a decoupling device, in a manner known to those skilled in the art.

More specifically, the movement 200 includes a winding and regulating stem 301 , and the stem 301 is configured to control the regulation of the moon phase via an intermediate wheel train 302 .

The invention also relates to a watch 300 comprising such a movement 200 .

Claims (11)

1. A moon phase display mechanism (10) configured to cooperate with a watch movement (200) and comprising an input pinion (11) configured to rotate three or two revolutions in 24 hours, characterized in that the input pinion (11) directly or by means of a friction device (20) carries and/or drives at least one 19-tooth or 29-tooth transmission pinion (13; 130), and the transmission pinion (13; 130) drives a 59-tooth lower wheel (15), the lower wheel (15) carrying a moon disc (150; 1500) having a two-color pattern, the two-color pattern including luminescence. The system includes a region (152) and one or two background sky regions (151), and the transmission pinion (13; 130) drives an upper wheel (14; 140) with 57 or 58 teeth coaxial with the lower wheel (15), the upper wheel rotating once per day and including a sky disc (1400) on the user side, the sky disc (1400) having a pattern of the sky and an off-center sun (141), and including an off-center opening (16) substantially opposite the sun (141), through which a portion of the moon disc (150; 1500) is visible to show the current appearance of the moon. 2. The moon phase display mechanism (10) according to claim 1, characterized in that the transmission pinion (13) is the only transmission pinion and drives both the lower wheel (15) and the upper wheel (14). 3. The moon phase display mechanism (10) according to claim 1, characterized in that the input pinion (11) is configured to rotate three times in 24 hours, wherein the transmission pinion (13) includes 19 teeth, and the two-color pattern includes a light-emitting area (152) and a background sky area (151), wherein the upper wheel (14) includes 57 teeth, and on the moon disc (150), the two-color pattern of the moon and the background sky includes a circular spiral or a heart-shaped boundary (153), so that the complete patterns of the new moon and the full moon are visible through the opening (16) respectively. 4. The moon phase display mechanism (10) according to claim 1, characterized in that the input pinion (11) is configured to rotate twice in 24 hours, and the transmission pinion (130) has 29 teeth, and the two-color pattern includes a light-emitting area (152) and two background sky areas (151), wherein the upper wheel (140) includes 58 teeth. 5. The moon phase display mechanism (10) according to claim 1, characterized in that the moon phase display mechanism (10) includes a fixed portion formed by a plate (30) or a rod (31), a small strip (19) stacked on the sky disk (1400) and representing the horizon fixed to the fixed portion, wherein on either side of the small strip (19), the pattern of the sun (141) is movable during the rotation of the upper wheel (14; 140). 6. The lunar phase display mechanism (10) according to claim 1, characterized in that the lower wheel (15) is integrated with the display component or the pointer (17), the display component or the pointer being used to display the lunar age on a scale (18) included in the sky disk (1400). 7. The moon phase display mechanism (10) according to claim 2, characterized in that the transmission pinion (13; 130) is driven by the input pinion (11) by means of a friction device (20) to allow calibration by means of an intermediate gear train by a control handle shaft or by a calibration rod acting on the transmission pinion (13; 130). 8. A clock display mechanism (100), comprising a moon phase display mechanism (10) according to claim 1. 9. A watch movement (200) comprising a moon phase display mechanism (10) according to claim 1, and comprising an hour wheel configured to drive the input pinion (11) and drive the at least one transmission pinion (13; 130), or to form the input pinion (11) and carry and drive the at least one transmission pinion (13; 130), in which case the transmission pinion (13; 130) indirectly drives the upper wheel (14; 140) via a reversing device, and the transmission pinion (13; 130) indirectly drives the lower wheel (15) via a disengagement device. 10. A watch movement (200) comprising a moon phase display mechanism (10) according to claim 7, and comprising an hour wheel configured to drive the input pinion (11) and drive the at least one transmission pinion (13; 130), or forming the input pinion (11) and carrying and driving the at least one transmission pinion (13; 130), in which case the transmission pinion (13; 130) indirectly drives the upper wheel (14; 140) via a reversing device, and the transmission pinion (13; 130) indirectly drives the lower wheel (15) via a disengagement device, wherein the control stem is a winding and calibration stem (301) configured to control the calibration of the moon phase by means of an intermediate gear train (302). 11. A watch (300), comprising a watch movement (200) according to claim 9 or 10.