Patent Grant
10775745
This application claims priority from European Patent Application No. 16206811.8 filed on Dec. 23, 2016, the entire disclosure of which is hereby incorporated herein by reference.
The present invention concerns a timepiece comprising a timepiece movement, a calendar mechanism and means for indicating the sunrise and sunset that take account of seasonal variations, the timepiece movement comprising a minute wheel set, a motion-work, a member for indicating the hours, and an hour wheel set integral in rotation with the hour indicator member and arranged to be driven by the minute wheel set via the motion-work at a speed of one revolution in 12 hours, or at a speed of one revolution in 24 hours, the calendar mechanism being arranged to be driven via the hour wheel set and comprising means for displaying the date and means for displaying the month, the sunrise and sunset indicating means comprising a sphere that replicates the terrestrial globe, a support, and a ring mounted on the support concentrically to the sphere and arranged to indicate the position of the earth's terminator, the ring and the sphere being arranged to rotate with respect to each other, at a rate of one revolution in 24 hours, about a first axis corresponding to the polar axis of the terrestrial globe, and the ring being mounted on the support in order also to be able to pivot relative to the sphere about a second axis intersecting the first axis perpendicularly at the centre of the sphere, the sunrise and sunset indicating means further comprising an annual cam having a profile representative of the tilt of the sun with respect to the equatorial plane, and arranged to be driven in rotation at the rate of one revolution per year, a cam follower arranged to cooperate with the cam, and a first kinematic chain arranged to connect the cam follower to the ring, such that the plane subtended by the ring forms with the first axis an angle equal to the angle of tilt of the sun with respect to the equatorial plane. The present invention concerns, in particular, a timepiece of this type, wherein the sunrise and sunset indicating means that take account of seasonal variations also indicate which part of the earth's surface is in daylight (day) and which part of the earth's surface is in darkness (night time).
The duration of the day is the time comprised, each day, from the moment when the upper limb of the sun appears above the horizon in the east, at sunrise, until it disappears below the horizon in the west, at sunset. Whatever the time, there is always one half of the earth's surface that is illuminated by the sun, and another half which is in darkness. The earth's terminator is the line of demarcation between the portion of the earth which is illuminated and that which is in darkness. Geometrically speaking, the earth's terminator is a large circle which encircles the earth. This large circle extends in a plane perpendicular to the plane of the earth's orbit around the sun (called the ecliptic plane). It is also noted that the centre of the earth is on the line of intersection between these two planes.
Generally, the length of day varies throughout the year and depends on latitude. This variation is caused by the tilt of the axis of rotation of the earth on itself with respect to the ecliptic plane. This tilt by definition corresponds to the latitude of the tropics which is ±23° 27′. As is well known, the length of day is shortest at the December Solstice in the Northern Hemisphere, and at the June Solstice in the Southern Hemisphere. At the equinoxes, the length of day and night are equal everywhere on earth.
There are already known timepieces arranged to indicate the current position of the boundary between day and night and which meet the definition given in the above preamble. Descriptions are found, in particular, in European Patent documents EP2911013, EP2977832 and EP3007012 in the name of the Applicant. However, the use and the design of these timepieces present a certain number of difficulties.
In particular, these timepieces comprise an annual cam which has a profile representative of the tilt of the sun with respect to the equatorial plane, and which is arranged to be driven in rotation by the movement at the rate of one revolution per year. One drawback of these timepieces is that it may be problematic to return the annual cam to the correct position after an indeterminate period of stoppage of the timepiece.
It is an object of the present invention to overcome the aforementioned drawbacks of the prior art. The invention achieves this object by providing a timepiece movement.
According to the invention, the timepiece comprises a calendar mechanism arranged to be driven via the hour wheel set and which comprises means for displaying the date and means for displaying the month. The timepiece also comprises a third kinematic chain which connects the hour wheel set to the annual cam via the month display means. A first advantage of this feature is that, after an indeterminate period of stoppage of the timepiece, the annual cam can automatically be returned to the correct position without any possible error, simply by resetting the date of the calendar mechanism.
According to the invention, the calendar mechanism is driven by the hour wheel set. In these conditions, when the wearer of the timepiece changes the hour indication, for example to correct it, the hour correction automatically results in correction of the calendar mechanism and the annual cam.
Moreover, according to the invention, the third kinematic chain has either a transmission ratio of 1:744 (in the case where the hour wheel set is arranged to be driven by the motion work at a speed of one revolution in 12 hours), or a transmission ratio of 1:372 (in the case where the hour wheel set is arranged to be driven by the motion work at a speed of one revolution in 24 hours).
It can be confirmed that 372 is the number of days that the year would have if all the months had 31 days (and 744 corresponds to two times 372). A calendar mechanism in which all the months have 31 days is called a simple calendar mechanism. In this type of calendar mechanism, at the end of months of less than 31 days, the hand or date disc must be advanced manually to update the calendar. As regards the change of indication of the name of the month, this can occur automatically every time that the date indication changes from the 31st to the 1st day of the month. Those skilled in the art will tend to consider that if the annual cam is not driven via the date display means, the difference between the real time and the current position of the earth's terminator on the globe will gradually increase. However, if, for example, the date is advanced at the end of the months of less than 31 days using the set-hands mechanism, there is no risk of this date setting operation desynchronizing the calendar mechanism and annual cam.
According to a particular embodiment of the invention, the timepiece movement comprises a manually actuatable summer/winter correction mechanism for changing from summer time to winter time, or vice versa, by pivoting the hour wheel set one step forward or backward independently of the motion work. Those skilled in the art will understand that a first advantage of this feature is that it allows the summer time/winter time correction to be made without affecting the indication of the minutes and the indication of the seconds.
According to an advantageous variant of the aforementioned embodiment, the manually actuatable mechanism is also arranged to pivot the hour wheel set without affecting the indication of the position of the earth's terminator on the sphere. Those skilled in the art will understand that one advantage of this feature is that it prevents the position of the ring changing relative to the terrestrial globe when this does not reflect a real movement of the sun with respect to the earth's surface.
Other features and advantages of the invention will appear upon reading the following description, given purely by way of non-limiting example, with reference to the annexed drawings, in which:
In the block diagram of
According to the invention, the illustrated timepiece also comprises sunrise and sunset indicating means that take account of seasonal variations, these means comprising a sphere that replicates the terrestrial globe, a support, and a ring which is mounted on the support concentrically to the sphere and arranged to indicate the position of the earth's terminator. The ring and the sphere are arranged to be driven in order to rotate with respect to one another, at a rate of one revolution in 24 hours, about a first axis corresponding to the polar axis of the terrestrial globe. Further, the ring is mounted on the support in order also to be able to pivot relative to the sphere about a second axis intersecting the first axis perpendicularly at the centre of the sphere. The sunrise and sunset indicating means further comprise an annual cam having a profile representative of the tilt of the sun with respect to the equatorial plane and which is arranged to be driven in rotation at the rate of one revolution per year, a cam follower arranged to cooperate with the cam, and a first kinematic chain arranged to connect the cam follower to the ring, such that the plane subtended by the ring forms with the first axis an angle equal to the angle of tilt of the sun with respect to the equatorial plane. Referring again to
Referring again to
In the illustrated example, the hour wheel set is arranged to drive month display means 125 via a reduction gear train 118, which does not go through date display means 123. Reduction gear train 118 is composed as follows: hour wheel set 107 is integral in rotation with a reduction wheel set (not represented) which comprises an 18-tooth pinion. As shown in
Still referring to
According to the embodiment of the invention illustrated in
According to the invention, the pivoting motion about the second axis is controlled using annual cam 111, whose profile is representative of the relative tilt of the sun above or below the equatorial plane of the earth. The cam follower (not represented) is arranged to transmit the variations in the cam profile to half-spherical shell 113 through a first kinematic connection 112. According to the first embodiment of the invention, dark half-sphere 113 is mounted to pivot on a fixed support and the arrangement of indicator mechanism 115, like that of first kinematic connection 112, may conform, for example, to the description given in European Patent document EP 2911013. This document is incorporated by reference in the present description.
Referring again to
In the illustrated example, at the change from winter time to summer time or from summer time to winter time, the wearer of the timepiece can move the time indication exactly one hour forward or back by actuating pusher P2. When it is actuated, pusher P2 acts not only on time zone correction mechanism 101, but also on a disengagement mechanism 133, so as to disengage second kinematic chain 120 (see also
In addition to the aforementioned time zone correction mechanism 101, the timepiece of the present example comprises a conventional type of time-setting mechanism. This time-setting mechanism allows the wearer of the timepiece to set the time with the aid of control stem 131 of the timepiece. In order to do this, he must move stem 131 into position T3 before rotating the crown. As in most current timepieces, the time-setting mechanism is arranged to drive motion work 106, which in turn drives minute wheel set 105 and hour wheel set 107. As was the case previously with correction of the time zone, hour wheel set 107 drives month display mechanism 125 and annual cam 111 via third kinematic chain 118. Further, hour wheel set 107 also drives date mechanism 123 and Earth in its rotation about the first axis. It will thus be understood that annual cam 111, calendar mechanism 123, 125 and sunrise and/or sunset indicating mechanism 115, are arranged to advance synchronously, also when they are driven manually forwards or backwards by means of control stem 131 in position T3.
Finally, the calendar mechanism of the timepiece of the present embodiment also comprises a month corrector mechanism. When the wearer of the timepiece wishes to correct the month indication, for example following an indeterminate period of stoppage of the timepiece, he can move the month indication step-by-step forwards or backwards by actuating pusher P1. As in the present example, the annual wheel set of month display means 125 also carries annual cam 111, this latter advances synchronously with the date indication, event when the date indication is changed with the aid of the date corrector.
In the illustrated example, hour wheel set 207 drives the annual cam via a third kinematic chain 218, which could be identical to kinematic chain 118 described above in relation to the first exemplary embodiment.
In the second embodiment, as in the first, the relative movement of half-sphere 213 and sphere 217 is the result of the combination of distinct rotations about two perpendicular axes that intersect at the centre of the sphere. However, according to the second embodiment, it is dark half-sphere 213 which simultaneously makes the two rotations, since sphere 217 is not driven. This operating mode is made possible by the fact that the support (not represented), on which dark half-sphere 213 is mounted, is a rotating support. Still referring to
Referring again to
Still referring to
Referring now to
Inner pipe 2 thus forms an hour pipe, and it carries a first externally toothed wheel 6, called the lower wheel, comprising a plate 7. It will be specified here that, advantageously, this lower wheel 6 forms an hour wheel, and more specifically a ‘motion-work hour wheel’, and it meshes with a wheel 8 (partially represented) of motion work 106. In normal operation, this hour wheel 6 receives time information delivered by wheel 8 of the motion work, which information it transmits, as will be seen below, indirectly to inner hour pipe 2 and to indicator hand 4. Indeed, lower hour wheel 6 is mounted for free rotation on hour pipe 2. For this purpose, the end of hour pipe 2, opposite to the free end thereof carrying hand 4, comprises a collar 10 forming a shoulder freely supporting a star-wheel 12 on which wheel 6 is fixedly held. Star-wheel 12 comprises a plate 13, an external toothing 14 and a circular flange 16 arranged edgewise adjacent to toothing 14, behind and coaxially with the latter, underneath plate 13.
Hour wheel 6 is fixedly held on the side of star-wheel 12 against its toothing 14. Indeed, hour wheel 6 is force fitted externally onto flange 16, pressed and/or riveted thereon, via the central part of its plate 7 which has a bore opening. Star-wheel 12 and hour wheel 6 are thus directly integral in rotation and, in this example, as a result of their assembly, form a single piece placed on hour pipe 2. Star-wheel 12 and hour wheel 6 can thus be moved together concomitantly via wheel 8 of the motion work.
The summer/winter correction mechanism also comprises two drive rollers 20 which are stepped and which each have a cylindrical base 22 from which a stud 24 extends in a perpendicular manner. The rollers are both engaged at rest, via their base 22, in toothing 14 of star-wheel 12 and they rest freely and sideways via this base against the side (unreferenced) of plate 7 of hour wheel 6. This rest position is also represented in a top view in
The summer/winter correction mechanism further comprises a second pipe 30, called the outer pipe, which comprises a guide bore 31 and which is fixed externally via this bore 31 onto first pipe 2. This second pipe 30 carries a second externally toothed wheel 32 arranged above lower hour wheel 6 and called the ‘upper wheel’, and more specifically the ‘hour-wheel’. It will be specified here that the upper and lower positions of wheels 6 and 32 refer to the drawing of
Upper wheel 34 thus forms a summer/winter correction wheel which, as will become clear, can directly correct the position of hour pipe 2 and of indicator hand 4, without acting on the motion work, and therefore without disrupting the other time information, such as the minutes and seconds, which are normally kinematically connected to hour pipe 2 via said motion work. Advantageously, outer pipe 30 is force fitted externally onto inner hour pipe 2 and it is thus secured thereto. These two pipes are therefore integral in rotation and they can be moved together. It will be understood that hour pipe 2, outer pipe 30 and upper wheel 34 together form hour wheel set 107. Upper correction wheel 34 can thus act on inner hour pipe 2 via outer pipe 30.
It will be specified that hour pipe 2 is also driven in normal operation by motion work 106, and in particular by wheel 8 of the motion work. This is why there are radial grooves 36 arranged in plate 33 of correction wheel 32, in which are freely engaged studs 24, which can translate radially in said grooves. Rollers 20 can thus drive in rotation correction wheel 32, and the two pipes 2 and 30, when star-wheel 12 is itself driven by hour wheel 6.
In order to change to another time zone, the user of the timepiece must rotate correction wheel 34; rollers 20 are then angularly displaced and jump (while star-wheel 12 and hour wheel 6 remain stationary) in toothing 14 of star-wheel 12, making spring 26 oval. Rollers 20 then return to the rest position in toothing 14 of star-wheel 12, but are offset with respect to the position of
It will also be clear that various alterations and/or improvements evident to those skilled in the art may be made to the embodiment forming the subject of the present description without departing from the scope of the present invention defined by the annexed claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 16206811 | Dec 2016 | EP | regional |
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| 2023677 | Fowler | Dec 1935 | A |
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| 20140126336 | Goeller | May 2014 | A1 |
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| 20160098012 | Gilomen | Apr 2016 | A1 |
| Number | Date | Country |
|---|---|---|
| 3 007 012 | Apr 2016 | EP |
| Entry |
|---|
| European Search Report dated Aug. 23, 2017 in European Application 16206811.8 filed on Dec. 23, 2016 (with English Translation of Categories of Cited Documents). |
| Number | Date | Country | |
|---|---|---|---|
| 20180181069 A1 | Jun 2018 | US |
