This application claims priority from European Patent Applications No. 16206863.9 filed on Dec. 23, 2016 and Ser. No. 17/195,835.8 filed on Oct. 11, 2017, the entire disclosure of which is hereby incorporated herein by reference.
The present invention concerns a timepiece comprising a timepiece movement and sunrise and sunset indicating means that take account of seasonal variations, said means comprising a sphere that replicates the terrestrial globe, a support, and a ring mounted on the support and arranged concentrically to the sphere, the ring being arranged to indicate the position of the earth's terminator, and the ring and the sphere being arranged to be able 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 to be able to pivot with respect to each other about a second axis intersecting the first axis perpendicularly at the centre of the sphere, the ring being mounted to pivot on the support about the second axis, the sunrise and sunset indicating means further comprising an annual cam that has a profile representative of the tilt of the sun with respect to the equatorial plane, and is arranged to be driven in rotation at a rate of one revolution per year, a cam follower arranged to cooperate with the cam, and a 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 relative angle of tilt of the sun with respect to the equatorial plane.
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 which 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 also 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, the ring and the terrestrial globe are arranged to be driven by the movement in order to rotate with respect to one another, at a rate of one revolution in 24 hours, so as to provide an indication of the current position of the earth's terminator on the surface of the globe. In this regard, it will be understood that, since the hour wheel of a timepiece normally completes one revolution in 12 hours, it may advantageously serve as the driving element for this rotation. This simply requires combining the hour wheel with, for example, a reduction gear having a ratio equal to 1:2. However, one problem with such a configuration is that, when the hands of the timepiece are acted on to change from summer time to winter time, for example, the indication of the current position of the earth's terminator on the globe is moved, although this does not reflect an actual movement of the sun in the sky.
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 conforming to the annexed claim 1.
According to the invention, the timepiece movement comprises a manually actuatable time change mechanism arranged to pivot the hour wheel set, step-by-step, independently of the motion work. Those skilled in the art will understand that one advantage of such a correction mechanism is that it makes it possible to change time zones or switch between summer time and winter time, without affecting the indication of the minutes and the indication of the seconds by the timepiece.
According to the invention, the timepiece movement also comprises, on the one hand, a second kinematic chain which connects the hour wheel set to the ring or to the sphere, so as to drive the ring or the sphere such that one rotates with respect to the other at a rate of one revolution in 24 hours, and comprises, on the other hand, a disengagement mechanism arranged to disengage the second kinematic chain when the time change mechanism is implemented to pivot the hour wheel set to change from summer time to winter time, or vice versa. One advantage of such an arrangement is that the rotation of the ring or of the sphere, with respect to one another, at a rate of one revolution in 24 hours, is not affected by any summer time/winter time correction.
Also according to the invention, the timepiece comprises a calendar mechanism comprising means for displaying the date, arranged to be driven via the hour wheel set, and a month display arranged to be driven by the means for displaying the date. Further, the annual cam is arranged to be driven via the means for displaying the date. One advantage of this design 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 date display means are driven by the hour wheel set. In these conditions, when the wearer of the timepiece pivots the hour wheel set, step-by-step, forwards or backwards, with the aid of the time change mechanism, the hour correction automatically results in correction of the calendar mechanism.
According to an advantageous variant of the invention, the timepiece movement comprises a first hour wheel meshing with the motion work and referred to as the ‘motion-work hour wheel’, and a second hour wheel, referred to as the ‘hour-wheel’, which forms part of the hour wheel set. Further, the time change mechanism comprises a coupling and indexing device which is disengageable and which is arranged to alternatively disengage and make integral in rotation the first and second hour wheels.
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
Still referring to
According to the invention, the illustrated timepiece also comprises means for indicating the sunrise and sunset that take account of seasonal variations. These means comprise a sphere replicating 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 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 relative 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 tilt angle of the Sun with respect to the equatorial plane. Referring to
According to the invention, the date display means 123 are arranged to drive annual cam 111 via a third kinematic chain 118. As already mentioned, date display means 123 of the present example comprise a date wheel (not represented), and third kinematic chain 118 takes the form of a reduction gear train arranged downstream of the date wheel and having a gear ratio of 1:12. In the present example, the reduction gear train comprises a 16-tooth pinion integral with the date wheel, a 48-tooth wheel meshing with the 16-tooth pinion and integral with a 14-tooth intermediate pinion, which in turn meshes with a 56-tooth wheel integral with annual cam 111 (the wheels and pinions are not illustrated in the diagram of
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 tilt of the sun above or below the equatorial plane. The cam follower (not represented) is arranged to transmit the variations in the cam profile to half-spherical shell 113 through a first kinematic chain 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 chain 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.
According to the present embodiment of the invention, hour wheel set 107 is connected to sphere 117 by a kinematic chain 120 (hereinafter ‘second kinematic chain 120’). The second kinematic chain is arranged to drive the sphere in rotation so that it rotates about a first axis corresponding to the polar axis of the terrestrial globe, at the speed of one revolution in 24 hours.
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 pressing on pusher P2. Pressing on pusher P2 not only actuates time change mechanism 101, but also simultaneously actuates disengagement mechanism 133, so as to disengage second kinematic chain 120. It will be understood that disengaging the second kinematic chain at the change from summer time to winter time, or vice versa, prevents the movement of the hour hand affecting the relative angular position of dark half-sphere 113 with respect to sphere 117.
In addition to time change 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 by using control stem 131. 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 the correction of the time zone, hour wheel set 107 drives calendar mechanism 121 and annual cam 111 via third kinematic chain 118. Further, hour wheel set 107 also drives sphere 117 in its rotation about the first axis. It will thus be understood that annual cam 111, calendar mechanism 121 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 mechanism for correcting month display 125 of calendar mechanism 121. 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 advance the month indication step-by-step by actuating pusher P1. According to the present example, actuation of pusher P1 by the timepiece wearer has the effect of driving date wheel 123 in rotation at high speed. The correction mechanism is arranged such that a single press on the pusher is sufficient to advance the date wheel one complete revolution if required. However, a movable stop, also comprised in the correction mechanism, has the function of stopping the date wheel as soon as the latter reaches the angular position corresponding to the indication of the first day of the month, after passing the 31st day of the month. On passing from the last day of the month to the first day of the following month, the date wheel actuates monthly drive means 127, which has the effect of incrementing month display 125. It will thus be understood that this month display correction mechanism has the advantage of allowing the link between the date and the month to be retained during the correction. The correction mechanism that has just been explained is known as such. It is described in European Patent publication EP2503410 entitled “Calendar mechanism comprising a quick month corrector”. This document is incorporated by reference in the present patent application.
As already explained, the date display means 123 are arranged to drive annual cam 111 via a third kinematic chain 118. Further, according to the first embodiment, third kinematic chain 118 takes the form of a reduction gear train arranged downstream of the date wheel and having a gear ratio of 1:12. In these conditions, it will be understood that, since the month correction is combined with a quick advance of the date, the month display correction mechanism simultaneously corrects the angular position of annual cam 111.
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
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 it meshes with a wheel 8 (partially represented) of motion work 106 (
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 time change 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 time change mechanism further comprises a second pipe 30, called the outer pipe, which comprises a guide bore 31 and which is mounted 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’. 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 time change 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 |
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16206863.9 | Dec 2016 | EP | regional |
17195835.8 | Oct 2017 | EP | regional |