Patent Application
20230305495
The field of the invention relates to moon phase display mechanisms of timepieces allowing information on the state of the moon during a complete lunation period to be displayed.
The invention further relates to a horological movement comprising such a moon phase display mechanism.
The invention further relates to a timepiece, for example a wristwatch, comprising a horological movement that comprises such a moon phase display mechanism.
Moon phase display mechanisms allow information on the state of the moon during a lunation period to be displayed. This theoretical lunation period is precisely 29 days, 12 hours, 44 minutes and 2.8 seconds.
The most common moon phase display mechanisms are mechanisms with a jumping drive of a 59-toothed star-wheel carrying a disc with two representations of the moon, a part of this disc being visible to the user through a suitably shaped opening made in the dial of the watch and successively revealing the different phases of the moon: a waxing moon, a full moon, a waning moon and a new moon.
The 59-toothed star-wheel is driven once a day by a 24-hour wheel. Such a moon phase display mechanism procures a period of 29.5 days per lunation displayed, thus providing an approximate result with a reliable, space-saving and inexpensive mechanism. However, such a mechanism accumulates an error with each lunation which must be compensated for every 2.65 years by a correction device.
The search for a more precise moon phase display mechanism is constant in the horological field.
Most known moon phase display mechanisms aim to improve the precision of the lunation by getting as close as possible to the theoretical value of a lunation period, using a multitude of mechanisms and precise gear ratios to get as close as possible to the theoretical value of a lunation.
For example, more complex moon phase display mechanisms of the jumping type are known to provide a lunation of 29.53125 days, which reduces the correction to one day every 122.4 years.
Moon phase display mechanisms of the dragging type also exist, which further increase the precision of a lunation, allowing the correction to be reduced to one day every 292 years and 279 days, or even one day every 1866 years with complex and very large mechanisms.
The advantage of moon phase display mechanisms of the dragging type is that they procure a more precise, real-time display of the state of the moon over a day with respect to the lunar body. More specifically, with this type of mechanism, the moon is driven throughout the day, as opposed to a display mechanism of the jumping type, where the moon disc is driven by one jump a day.
As a result, the driving of the display in jumps leads to a “display error” in the state of the moon displayed, with respect to the lunar body, which is constantly changing throughout the day. This “display error” inherent to this type of jumping drive represents a maximum cumulative display error of 6.1° per day, regardless of the lunation precision of the moon phase display mechanism, however complex it may be.
In this context, the invention proposes a moon phase display mechanism of the jumping type having an improved display resolution compared to the moon phase display mechanisms of the prior art, allowing moon phase display mechanisms of the jumping type to reduce this “display error”, to be truer to reality and to get closer to the state of the lunar body without complicating the display mechanism and while doing away with the need for a display mechanism of the dragging type which is costly, cumbersome, and complex to produce and implement.
To this end, the invention relates to a moon phase display mechanism for a timepiece capable of being driven by a horological movement, the operation whereof depends on the time division, said moon phase display mechanism comprising:
In addition to the features mentioned in the preceding paragraph, the moon phase display mechanism according to the invention can have one or more complementary features from among the following, considered either on an individual basis or according to any combination technically possible:
The invention further relates to a horological movement comprising a moon phase display mechanism according to the invention.
Advantageously, the horological movement comprises a motion-work, an hour wheel, and a minute centre pinion, said moon phase display mechanism comprising a cam that comprises an upper area forming a driving finger-piece, said cam being driven by the rotation of the hour wheel.
Advantageously, the cam is positioned coaxially with the hour wheel and mounted to rotate freely relative to the hour wheel.
Advantageously, the cam comprises an indexing element extending towards the hour wheel and in that the hour wheel has a slot configured to receive the indexing element, said slot forming bankings limiting the relative rotation of the cam to the hour wheel.
The invention further relates to a timepiece comprising a moon phase display mechanism according to the invention or comprising a horological movement according to the invention.
Advantageously, the timepiece is a wristwatch.
The purposes, advantages and features of the present invention will be better understood upon reading the detailed description given below with reference to the following figures:
In all figures, common elements bear the same reference numerals unless indicated otherwise.
The present invention consists of the general idea of splitting the daily driving pitch of the moon phase indicator of a moon phase display mechanism of the jumping type in order to improve the resolution of the moon phase indicator displayed and to get as close as possible to the actual state of the lunar body during the day.
In the present application, “daily pitch” is understood to mean the daily angular pitch travelled by a moon phase indicator depending on the approximate lunation period of the moon phase display mechanism.
The moon phase display mechanism 100 according to the invention is a display mechanism of the jumping type, i.e. the moon phase indicator carrying the moon representations is not continuously stressed by the gear train of a horological movement. Thus, such a mechanism is completely different, both functionally and structurally, from a moon phase display mechanism of the dragging type, wherein the moon phase indicator is constantly stressed by the gear train of the horological movement and driven thereby.
The moon phase display mechanism 100 according to the invention is intended to be housed in a timepiece, for example in a case of a wristwatch (not shown).
The moon phase display mechanism 100 according to the invention is driven by a horological movement 200, partially shown in
More specifically, the horological movement 200 in particular comprises a motion-work 210 comprising a minute pinion 211 and a minute wheel 212. The minute pinion 211 drives an hour wheel 220, and the assembly is configured so that the hour wheel 220 makes one complete revolution in 12 hours.
In the example embodiment shown in
The minute centre pinion 230 meshes with the motion-work 210, and more particularly with the minute wheel 212.
The moon phase display mechanism 100 comprises a moon phase indicator 110, at least part whereof is intended to be visible to the user through a suitably shaped opening made in a dial of the timepiece (not shown), so as to successively reveal the different phases of the moon: a waxing moon, a full moon, a waning moon and a new moon.
The moon phase indicator 110 is set in motion by a jumping drive mechanism 120 driven at regular intervals by the horological movement 100 and/or by a user via a quick correction device 300.
The moon phase indicator 110 carries at least one representation of the moon. In the example shown, the moon phase indicator 110 comprises two representations of the moon.
In the example embodiment shown, the moon phase indicator 110 is formed by an upper disc 111 carrying the two representations of the moon.
The upper disc 111 is mounted such that it is integral with a phase wheel 112 having a plurality of teeth.
The jumping drive mechanism 120 comprises a phase-driving element directly driven by the rotation of the hour wheel 220. The phase-driving element cooperates with a phase lever 130 which is mounted such that it pivots about a pivot axis 2. The phase lever 130 is pivoted by the phase-driving element such that it interacts with the moon phase indicator 110 and rotates same each time the phase lever 130 is tilted.
In the example embodiment shown in
In this first example embodiment, the cam 121 is inserted between the hour wheel 220 and the centre pinion 230; however other arrangements are also possible.
The cam 121 is mounted to rotate freely about the axis of rotation 6 of the hour wheel 220.
The cam 121 delimits an outer profile 123 forming a sensing profile configured to interact with the phase lever 130. The outer profile 123 comprises an upper sensing area which is radially the furthest area from the axis of rotation 6 of the hour wheel 220. This upper sensing area forms a driving finger-piece 124 configured to come into contact with the phase lever 130 and tilt it when the cam 121 is rotating.
At this driving finger-piece 124, the cam 121 comprises a pin 125, or other indexing element, projecting from the upper surface of the cam 121, such that the pin 125 extends towards the hour wheel 220 located above the cam 121, so as to cooperate with the hour wheel 220.
The pin 125 is configured to be inserted into and cooperate with a slot 221 made in the body of the hour wheel 220. The slot 221 defines, thanks to the shape thereof, bankings which limit the relative rotation of the cam 121 to the hour wheel 220. Thus, when the pin 125 integral with the cam 121 comes to rest against the peripheral edges of the slot 221, the hour wheel 220 drives the cam 121 such that it rotates.
The relative rotation of the cam 121 to the hour wheel 220 in particular avoids stressing the hour wheel 220 when the phase lever 130 returns to its rest position under the resilience of the resilient means 150.
In this case, in the example embodiment shown in
It goes without saying that other example embodiments are possible, and in particular intermediate wheels and ratios that are different from 1 relative to the hour wheel 220 and/or a cam profile with a plurality of upper areas forming driving finger-pieces 124 can be used to increase the number of times the phase lever 130 is tilted during one revolution of the hour wheel 220, i.e. in 12 hours.
The phase lever 130 is mounted such that it pivots about a pivot axis 2 and is tilted between a rest position and an activation position by the passage of the driving finger-piece 124 of the cam 121.
As shown in
The phase lever 130 further comprises a second arm 133 which comprises, at the end thereof, a correction beak 134 configured to rotate the moon phase indicator 110 each time the phase lever 130 is tilted.
The phase lever 130 cooperates with resilient return means 150, for example a return spring, biased to position the phase lever 130 in the rest position between each tilting.
For example, the phase lever 130 is repositioned against a positioning banking (not shown) which allows the rest position of the phase lever 130 to be defined. Such a positioning banking avoids, for example, any permanent contact of the feeler 132 on the outer profile 123 of the cam 121. This thus minimises contact between the different parts and reduces part wear.
The moon phase display mechanism 100 according to the invention operates as follows: the hour wheel 220 rotates in a clockwise direction, conventionally driven by the motion-work 210.
With each rotation of the hour wheel 220, the driving finger-piece 124 of the cam 121, stressed by the rotation of the hour wheel 220, via the pin 125 and the slot 221, comes into contact with the feeler 132 of the phase lever 130. The shapes and geometries of the driving finger-piece 124 of the cam 121 and of the feeler 132 of the phase lever 130 are configured to ensure that the phase lever 130 pivots as the cam 121 is rotated into the activation position thereof, allowing the moon phase indicator 110 to be incremented and angularly offset.
The moon phase display mechanism 100 according to the invention is configured so that the jumping drive mechanism 120 rotates the moon phase indicator 110 by n increments per day, n being greater than 1, each increment rotating the moon phase indicator 110 by an angle α corresponding to the angle of rotation of a daily pitch divided by the number n of increments.
For example, with the use of a 12-hour cam, the moon phase indicator 110 is incremented twice a day instead of only once a day as with the jumping-type display mechanisms of the prior art.
The different gear trains are dimensioned so that the overall rotation of the moon phase indicator 110 over a day remains identical to the daily pitch of a conventional moon phase indicator set in motion by a jumping drive mechanism of the prior art.
Thus, for a moon phase display mechanism 110 configured to obtain a lunation period of 29.53125 days, the moon phase indicator 110 according to the invention will be moved twice a day (every 12 hours) by an angle α of 3.05° to reach a daily pitch that corresponds to a rotation of 6.1°.
It goes without saying that the resolution of the moon state displayed by the moon phase display mechanism according to the invention could be further decreased, and thus the number of increments per day of the moon phase indicator 110 could be increased, while decreasing the angular jump of each increment, without further complicating the jumping drive mechanism 120.
This is possible, for example, by multiplying the number of driving finger-pieces 124 on the outer profile 123 of the cam 121, in order to tilt the phase lever 130 several times per revolution of the hour wheel 220, while configuring the different gear trains so that the overall rotation of the moon phase indicator 110 over one day remains identical to the daily drive pitch, in this case 6.1° for a lunation of 29.53125 days.
For example, the cam 121 can comprise two driving finger-pieces 124 opposite one another (i.e. 180° from one another), such that the phase lever 130 is tilted twice per revolution of the hour wheel 220, i.e. four times per day. Thus, the different gears are dimensioned such that each increment of the moon phase indicator 110, occurring every six hours in this case, corresponds to a rotation of the moon phase indicator 110 by an angle α of 1.525° so as to preserve an overall rotation of 6.1° per day corresponding to the daily pitch.
Such an alternative embodiment further improves the precision of the display of the state of the moon over a day in relation to the lunar body, although the daily pitch is still 6.1°.
In the example embodiment shown in
According to an alternative embodiment not shown, the phase lever 130 drives the phase wheel 112 directly, without the use of a phase-driving intermediate wheel set.
More particularly, the phase-driving intermediate wheel set 140 comprises a phase-driving star-wheel 141 integral such that it rotates with a phase-driving pinion 142 meshing with the phase wheel 112 of the moon phase indicator 110.
The phase-driving star-wheel 141 cooperates with a jumper 160 configured to hold the phase-driving star-wheel 141 in position between each jump (or increment) of the phase-driving star-wheel 141 operated by the phase lever 130.
The jumper 160 is capable of moving about a pivot axis 4 and conventionally cooperates with a resilient means 161 biased to position the jumper 161 between two teeth of the phase-driving star-wheel 141, once the high point of a tooth has passed under the effect of the phase lever 130.
Advantageously, the jumper 160 does not act directly on the phase wheel 112 but on the phase-driving intermediate wheel set 140, and more particularly on the phase-driving star-wheel 141. The use of such an architecture in particular allows the inertia of a moon phase indicator 110 of large dimensions to be absorbed.
The moon phase display mechanism 100 according to the invention further comprises an independent quick correction device 300 for correcting the position of the moon phase indicator 110 where necessary, for example after the horological movement 200 has been shut down for an extended period.
The quick correction device 300 comprises a correction star-wheel 330 carried by the phase-driving intermediate wheel set 140, and integral with the phase-driving pinion 142 such that it rotates therewith, such that an action on the correction star-wheel 330 generates a rotation of the moon phase indicator 110.
The quick correction device 300 further comprises a phase correction control 315 that can be operated by a user via a push-button, or an actuating stud 316. The phase correction control 315 is mounted such that it pivots about a pivot axis 5.
The phase correction control 315 cooperates with an intermediate phase correction lever 320 mounted such that it pivots about a pivot axis 3. The intermediate phase correction lever 320 comprises a correction beak 321 intended to cooperate with a tooth of the correction star-wheel 330 when the phase correction control 315 is operated by the user.
The quick correction device 300 comprises a resilient means 310 configured to reposition the phase correction control 315 and the intermediate phase correction lever 320 to neutral rest positions when the user is not operating the phase correction control 315.
In the example embodiment shown, the resilient means 310 bears against the intermediate phase correction lever 320. However, the resilient means 310 can bear against the phase correction control 315.
According to an alternative embodiment, the phase correction control 315 can act directly on the phase correction star-wheel 330, such that the intermediate phase correction lever 320 can be omitted.
In the example embodiment shown:
Thus, the gear ratio from the hour wheel 220 is 105*9/16=59.0625, which corresponds to a lunation period of 29.53125 since the phase indicator 110 comprises two representations of the moon.
In this configuration, the moon phase indicator 110 is incremented twice a day by an angle of 3.05° so as to procure a daily rotation of 6.1°.
In the example embodiment shown in
Since the correction star-wheel 330 has 9 teeth and the phase-driving star-wheel 141 has twice as many teeth, the correction star-wheel 330 can have two different indexing positions depending on the position of the phase-driving star-wheel 141 relative to the jumper 160 thereof. Thus, for the two indexing positions of the correction star-wheel 330, the distance between a tooth of the correction star-wheel 330 and the correction beak is different, and thus the action of the correction beak of the intermediate lever is different depending on the indexing position of the correction star-wheel 330.
Depending on the time of day at which the quick correction takes place, and thus depending on the indexing position of the correction star-wheel 330, actuation of the correction control 315 can put the correction star-wheel 330 forward by a full daily pitch (in this case a rotation of 6.1°), each time the correction control 315 is operated, or firstly by half a daily pitch, i.e. a rotation of 3.05° (in the case of two indexings of the phase-driving star-wheel 141 per day and if the first indexing in the first twelve hours of the day is carried out), then by a full daily pitch (rotation of 6.1°) each time the correction control 315 is operated.
The moon phase display mechanism 100 further comprises a safety device 180 allowing the jumping drive mechanism 120 to be disconnected when a quick correction is carried out by the user, via the quick correction device 300 which acts on the same phase-driving intermediate wheel set 140. The safety device 180 allows the jumping drive mechanism 120 to be disconnected when a quick correction action occurs at the same time as the moon phase indicator 110 is being driven by the phase lever 130.
For example, as shown in
More particularly, the pawl is made at the second arm 132 such that the correction beak 134, cooperating with the phase-driving intermediate wheel set 140, is located at the end of a resilient strand 181 capable of disconnecting when a correction action is engaged by the user via the quick correction device 300 causing the phase-driving intermediate wheel set 140 to rotate.
Thus, when the correction beak 134 is in contact with the phase-driving intermediate wheel set 140 and a simultaneous quick correction action is engaged, the resilience of the resilient strand 181 allows the correction beak to be released from the engagement thereof with the phase-driving star-wheel 141 and allows the phase-driving intermediate wheel set 140 to rotate without the risk of breakage or damage to the jumping drive mechanism 120.
In the example embodiment described in
For example, the cam forming the phase-driving element can be carried by an intermediate wheel directly meshed with the hour wheel 220.
The intermediate wheel can be configured to have a ratio of 1 with the hour wheel 220 or a ratio other than 1.
For example, by decreasing the ratio of the hour wheel 220 to the intermediate wheel, the resolution of the moon phase indicator 110 displayed over a day can be increased as described above, i.e. the number of increments of the moon phase indicator 110 can be increased, while decreasing the angular jump of each increment in order to keep with the overall rotation over a day that corresponds to the daily angular pitch corresponding to the lunation period of the moon phase display mechanism 100.
For example, with a ratio of 0.5 between the hour wheel 220 and the intermediate wheel carrying the cam, the intermediate wheel makes one revolution in 6 hours, i.e. two revolutions in 12 hours. Thus, with a cam having a single driving finger-piece, the daily angular pitch of the moon phase indicator 110 can be split into four increments spread over the day, i.e. every 6 hours.
With the same ratio of 0.5 between the hour wheel 220 and the phase-driving intermediate wheel and with a cam carrying two opposite driving finger-pieces at 180° from one another, the daily angular pitch of the moon phase indicator 110 can be split into eight increments spread over the day, i.e. every 3 hours.
It goes without saying that whichever embodiment is chosen, the gear ratios between the phase wheel 112, the phase-driving pinion 142, and the phase-driving star-wheel 141 will be adapted to split the overall daily rotation of the moon phase indicator 110 corresponding to the daily pitch according to the number of increments desired.
It goes without saying that one or more intermediate wheels can also be used between the hour wheel 23 and the phase-driving wheel 110 as required.
According to another example embodiment, the phase-driving element can be formed by a plurality of superimposed cams interacting in phase levers positioned on different levels of the mechanism, in order to multiply the increments of the moon phase indicator 110 over a day.
The invention further relates to a horological movement 200 comprising a moon phase display mechanism 100 according to the invention.
The invention further relates to a timepiece, such as a wristwatch, comprising a horological movement 200 according to the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 22164771.2 | Mar 2022 | EP | regional |
