Moon-phase display device

Abstract

The invention relates to a moon-phase display device for a timepiece, comprising: a first display member (80) bearing a plurality of first images (81-86) representing, at least partially, the moon; a display zone; and drive means (22, 23, 25, 40, 41, 43, 63, 71, 72, 61, 62) arranged to move the first display member (80) in successive jumps with reference to the display zone, in order to display a succession of moon images. The device is original in that the lengths of time for which the first images are displayed are not all equal.

Description

technical field

[0001] The present invention relates to a watchmaking device for displaying moon phases in particular, but not exclusively, on the dial of a wristwatch, a pocket watch, a display on the back of the watch, or any other display. State of the art

[0002] Moon phase display devices are well-known in watchmaking. Traditionally, the phases of the moon are indicated by a rotating disc that completes a full rotation every two months, on which the moon is depicted twice. A specially shaped aperture in the dial reveals a portion of one or the other image, thus displaying a shape corresponding to the moon phase. US508467 and many other similar publications illustrate this type of device.

[0003] The moon's shape displayed by these devices is only accurate during a full moon and in the phases close to a new moon, when the moon is crescent-shaped. These displays are unable to reproduce the true image of the moon at quarter moons, when the line separating the light and dark areas is straight, and between first and last quarters, when the moon is concave.

[0004] Other known devices, for example by EP1701227, offer displays in which a disc bearing a series of images of the moon in its different aspects moves in front of a window which only reveals one representation at a time.

[0005] Other devices, such as those proposed by EP1615086 and EP1475680, offer displays in which the image of the moon is created by a display element with dark and light areas of a particular shape moving in a complex manner behind a window. These mechanisms allow for combinations of rotations and slides, or arbitrary large and small rotations at each transition.

[0006] US5650736 discloses a display with two superimposed rotating display elements behind a window, one with light and dark areas, the other with light, dark, and transparent areas. This display is relatively bulky. FR2614444 discloses a moon phase indicator device comprising a disc driven by a fork with elastic arms; GB2438684 a manually driven lunar dial for displaying the phases and other information of the lunar cycle; WO2011113170 a moon phase display device having an indicator driven by a double-heart cam opposite a scale.

[0007] We also know of watches in which the phase of the moon is indicated by a small dark and light globe, rotating around an axis like a tiny celestial body. This method of displaying the moon's phase is certainly accurate, but it also adds considerable thickness. Brief summary of the invention

[0008] One aim of the present invention is to propose a moon phase display device free from the limitations of known solutions, which is both realistic and has a small footprint.

[0009] In the description of the embodiments and in the claims, the term "lunar month" is used to designate a time interval whose length is, at least approximately, one synodic month of 29 days, 12 hours, 44 minutes, and 2.8 seconds, or 29.530588 days. Depending on the quality of the watch and the required precision, the display mechanism could complete a full cycle in a lunar month of 29.53125 days, 29.5 days, 30 days, or another duration close to the exact value required.

[0010] According to the invention, these goals are achieved in particular by means of the object of the main claim, and in particular by a moon phase display device for a timepiece comprising a first display element carrying a plurality of first images representing at least partially the moon, a display area and drive means arranged so as to move, by successive jumps, the first display element in reference to the display area in order to display a succession of representations of the moon, the device having this particular feature that the display durations of the first images are not all equal.

[0011] Thus, the device allows for high precision in displaying the most recognizable moon phases, such as the full moon, half moon, or new moon, while the less distinctive intermediate phases remain visible for a longer period. This results in a more realistic display using fewer images. Alternatively, the invention allows for increasing the image size without increasing the size of the display disc or compromising the realism of the display.

[0012] The free programming of variable jumps for each image also allows greater freedom to design a mechanism whose lunar duration of the display is close to the actual lunar duration and thus reduce or even eliminate the need to adjust the display.

[0013] The invention as claimed proposes a device also comprising a second display element carrying second images and capable of being moved in reference to the display area by the drive means to successively display the second images in the display area where a second image forms, in combination with a first image of the first display element, a representation of the phase of the moon.

[0014] Advantageously, representing a lunar phase by combining two images allows for an increase in the number of lunar representations without increasing the surface area occupied by the images, as a partial image can appear in several distinct representations. Alternatively, the invention allows, for a given number of lunar representations, their size to be increased without increasing the size of the display disc.

[0015] The dependent claims illustrate advantageous variants with non-essential features, for example the use of concentric discs for the display elements and that of an instantaneous jump mechanism.

[0016] Other advantageous variants claimed concern program wheels for actuating the first or second display element at predetermined times during the lunar cycle. These program wheels can be connected to a clockwork mechanism to rotate with a period related to the length of the lunar cycle, for example, one or two full rotations per lunar cycle (if the symmetry between the waxing and waning phases of the moon is used). Furthermore, the program wheels have a profile configured to move the first and / or second display element as these predetermined times of the lunar cycle pass.

[0017] In a preferred variant, the program wheels are axially superimposed, rotate together, and each has intermittent teeth engaging two drive wheels fixed to the first and second display discs, respectively. The drive wheels can be held in a stable position by a jumper.

[0018] The rotation of the program wheels by instantaneous or sliding jumps can be achieved by a rocker arm cooperating with a star wheel attached to said program wheels. The star wheel is preferably held in a stable position by a jumper. Depending on the chosen display actuation period, a shift in the jump time is created each day; thus, to avoid observing a transition phase of the display at the moment of observation, an instantaneous jump allows for a realistic representation of the moon phase to be observed at all times. Brief description of the figures

[0019] Examples of implementation of the invention are given in the description illustrated by the accompanying figures, in which: THE Figures 1 And 2 illustrate an embodiment of the device of the invention as seen from the dial side. figures 3 And 4 show the opposite side of the device Figures 1 And 2 . In the figure 4 The display discs have been removed. figures 5a to 5g illustrate the different phases of a transition between two images of the moon. figure 6 illustrates the succession of images of the moon from one new moon to the next. Example(s) of an embodiment of the invention

[0020] Referring to Figures 1 And 2 , The display device of the invention comprises two discs 80, 90 Each disc bears a series of partial representations of the moon, as it appears at specific moments of the lunar cycle. The first disc 80,in the shape of a crown, encircles the disc 90 which is concentric with it and lies essentially in the same plane. The invention is not limited to this particular arrangement; the first disk can also be the inner disk. In the example shown, each of the two indicator disks 89, 90 It contains a series of images of the same part of the moon. Two juxtaposed partial images can give a realistic representation of the moon at predetermined phases of the lunar cycle. Thus, representations of the moon's phase are combined by juxtaposing a first and a second complementary image occupying fixed and complementary portions of the lunar disk.

[0021] The disks in the example shown each bear six partial images and are driven by a mechanism, which will be described below, to produce ten different representations of the moon, each corresponding to a phase of the lunar cycle. Each image of the moon is obtained by combining two partial images: the first image from the first disk. 80, and a second image of the second disc 90, which are simultaneously juxtaposed under an unrepresented window, or another revealing element, for example in the case of a skeleton watch. It is noted that there are six different images on the internal disc. 90, while the disc 80 It features four different images, all completely clear. 81, 82 and the images are completely dark 84, 85 repeating itself twice identically for reasons of symmetry. The disk 80could just as easily carry 6 distinct images, which would result in 12 different representations of the moon.

[0022] It is important to understand that having six partial images resulting in ten different images of the moon is not an essential feature, but rather an advantageous compromise between the desire to accurately track the progression of the lunar phases throughout the lunar cycle and the display size. The invention also encompasses embodiments with a different number of images. A variant capable of displaying up to 30 different images of the moon could be envisioned. It should also be noted that the two discs do not necessarily have the same number of partial images.

[0023] The sequence of images in a particular order is ensured by training methods. 22, 23 ,25, 40, 41, 43, 63, 71, 72, 61, 62 arranged so as to move, by successive jumps, the first and second display elements 80, 90referring to the display area in order to display a succession of representations of the moon.

[0024] In the mechanism illustrated as an example, the wheel 23 is driven by the wheel 24 which completes a full circuit in one day, via the mobile 22, and its rotation period is 23,625 hours. The wheel 23 wear a finger 25 which acts on the pin 41 to advance the discs 80 And 90. The finger 25 is preferably retractable to avoid unexpected corrections when setting the time backwards. In other words, the assembly consisting of the wheels 22 And 23 and the finger 25 constitutes an actuator capable of delivering a periodic pulse by being kinematically linked to the movement of the timepiece, in this case to the twenty-four hour wheel 24.

[0025] The display period is a multiple of the actuator's pulse period. In prior art mechanisms, the number of images of equal duration dictates the display activation period and, based on the motion time base, the theoretical reduction ratio required to achieve it. For reasons of size and efficiency, the designer is limited to simple gears with a reduction ratio that is approximately the desired ratio. The display mechanism of the invention has the advantage of making the pulse period independent of the number of images to be displayed, allowing the individual selection of the display duration for each image. This offers considerable freedom in designing a mechanism whose display period is as close as possible to the actual duration of the lunar cycle. In the embodiment presented, a combination of 30pulses and a pulse period of 23.625 hours, obtained from the 24-hour wheel. This corresponds to a display cycle duration of 29 days, 12 hours, and 45 minutes, very close to the actual lunar cycle. The accuracy of such a display is 1 day / 125 years, which allows it to be classified as an astronomical moon. It should be noted that the number of moon phases can be displayed as desired, up to... 30, with such a drive mechanism.

[0026] THE figures 3 And 4 allow us to see the disc advancement mechanism 80 And 90 which primarily includes a rocker 40 which is activated thirty times per lunar month by the wheel 23. The rocker is held in the rest position by the spring. 42 and has a retractable ratchet at one end 43 which, with each back-and-forth action, advances the star one notch 63. The ratchet 43is drawn in such a way as to avoid any double jump of the star 63. The jump 65 also helps to stabilize the star 63 when the seesaw 40 is lifted and prevents the star from rotating in the opposite direction.

[0027] The correction switch 48 is held in the rest position by the spring 49. Its function is to manually operate the moon rocker 40 regardless of the wheel's position 23, when a correction to the moon phase indicator is needed. Preferably, this finger 25 is retractable for safety reasons. On the figure 4 , which illustrates the display mechanism of the invention without the indicator discs 80 And 90, we can see the two program wheels 61 And 62 which are activated and advance through a specific angle with each back-and-forth movement of the seesaw 40.Each program wheel has intermittent teeth with teeth at predetermined angular positions. The teeth of the program wheels cooperate with the two drive wheels. 71 And 72 which, in turn, are attached to the first indicator disc 80, respectively of the second indicator disc 90.

[0028] When, upon an actuator pulse, a tooth of the program wheel engages with a drive wheel, the corresponding indicator disc rotates 60°, which corresponds to the transition between one image and the next. The jumpers 76 And 77 ensure the stability and indexing of the indicator discs and the profile of the intermittent teeth of the program wheels is arranged to block the accidental rotation of the drive wheels and prevent any desynchronization.

[0029] The assembly formed by the seesaw 40, the ratchet43, the star 63, the program wheels 61,62 and the drive wheels 71, 72 This constitutes a first and a second selector, which are capable of moving the first and second display elements relative to the display area according to a predetermined sequence. The function of a selector is to move a display element to transition from one image to the next, in response to n pulses from the actuator, where n is an integer proportional to the display duration of the image in question. For at least one of the display elements, the display duration is not identical for all images; in other words, the number n varies.

[0030] The use of two independent program wheels to operate the indicator discs 80 And 90 This allows for a great deal of freedom in choosing the transition moments between one image of the moon and the next. The teeth of the wheels can be positioned. 61 And 62so as to display the full moon and the new moon for a single period delimited by two successive movements of the seesaw 40, That is, 23,625 hours, while the waxing and waning moon phases remain visible for three or four periods. This allows for precise marking of the full moon and new moon, making the display more realistic and simplifying adjustments.

[0031] The invention also relates to a display device which would comprise only one display element and in which the display times of each image would not all be equal.

[0032] The differentiated display durations of such a device make this display more realistic compared to those of the previous art.

[0033] THE figures 5a to 5g break down a back-and-forth action of the moon seesaw 40. On the figure 5a represents the moment of first contact between the finger25 and the pin 41. The rocker arm is in the rest position, the pawl positioned between two teeth of the star wheel. 63.

[0034] THE figures 5b to 5d show three successive phases of the moon's tilting motion. Up to the position shown in the figure 5c , the ratchet 43 pivots counterclockwise and slides along the side of a tooth without the wheel 63 it doesn't move, because it is held in place by the jumper 65 which blocks counterclockwise rotation.

[0035] There figure 5d shows the moment of release between the finger 25 and the pin 41. The moon's seesaw 40 is lifted and the spring 42 Fully armed. The next moment ( figure 5e ) the seesaw 40 promptly returns to its resting position under the action of the spring 42 by training the star 63 rotated via the ratchet mechanism 43 ( figures 5f and 5g ). The drive wheel 72, and the display disc 80 which is attached to it, advance by 1 / 6 of a turn. The transition from one image to the other is instantaneous, which is preferable, as it avoids difficult-to-read 'decomposed' indications, especially since the transitions are performed without relation to the current time. A semi-instantaneous or delayed mechanism would, however, be conceivable.

[0036] The rocker and its return spring, gradually wound by the action of the finger 25 constitute an instantaneous jump device. It should be noted that such an instantaneous jump device could be located at another location, for example downstream of the selector.

[0037] There figure 6 illustrates the images of the moon that can be obtained by juxtaposing partial images. 81-86 And 91-96 of the two indicator discs (also visible on the figure 1). The images appearing through the window are drawn in continuous and solid lines, those hidden by the dial in broken and hatched lines.

[0038] A lunar cycle begins with the new moon "nl", top left, and the two partial images 94 And 84 are visible. The juxtaposed images form an image of the dark moon. At a time defined by the profile of the corresponding program wheel, the external disk jumps and displays the next image. 83. The two images below the window combine to show the moon at its first crescent "c1".

[0039] The program wheels are designed to advance the external disk again at set times to display the partial image. 82, then the internal and external disks, to give the composite image of 81 And 93, then once again the internal disk to display the partial image92. As can be seen in the figure, this gives three images of a progressively waxing moon "c2", "c3", "c4".

[0040] The 'pl' image is that of the full moon, which is displayed when the internal disk 90 rotates to show the partial image 91. Next, images 'd1', 'd2', 'd3', 'd4' show the moon in four progressively decreasing aspects.

[0041] Advantageously, the sequence of disk actuations 80 And 90 repeats itself identically twice in a lunar cycle, thanks to the symmetry between the waxing and waning phases of the moon. For this reason, the star 63 It has fifteen teeth and drives the program wheels at a rate of two revolutions per month. However, variants could also be considered in which the program wheels make one revolution per month or several revolutions per month.

[0042] Importantly, the disc 80and the disc 90 move by successive jumps, under the action of training means including the return 22, wheel 23, finger 25, rocker 40, ergot 41, pawl 43, star 63, drive wheels 71 And 72, and program wheels 61, 62, so as to display, in the display area defined by the ticket window, partial representations of the moon, and the display durations of these representations are not all equal. Reference numbers used in the figures

[0043] 22. Reference wheel 23. 23.625-hour wheel 24. 24-hour wheel 25. Retractable finger 40. Moon rocker 41. Pin 42. Moon rocker spring 43. Ratchet 48. Correction rocker 49. Correction spring 61. First program wheel 62. Second program wheel 63. 15-point star 65. 15-point star jumper 71. First drive wheel 72. Second drive wheel 76. First wheel jumper 77. Second wheel jumper 80. First display disc 81-86. Partial moon representations 90. Second display disc 91-96. Partial moon representations

Claims

1. Device for displaying the moon phases for a timepiece comprising: - a first display member (80) carrying a plurality of first images (81-86) at least partially representing the moon; - a display zone; - driving means (22, 23, 25, 40, 41, 43, 63, 71, 72, 61, 62) arranged so as to move the first display member (80) by successive jumps with reference to the display zone in order to display a succession of representations of the moon, the duration of the display of the first images not all being equal, characterised in that the device further comprises a second display member (90) carrying second images (91-96) and capable of being displaced with reference to the display zone by the driving means in order to cause the second images (91-96) to appear successively in the display zone where a second image (91-96) forms, in combination with a first image (81-86) of the first display member, a representation of the moon phase.

2. Device for displaying the moon phases according to the preceding claim, wherein the driving means comprises : - an actuator intended to be kinematically linked to a movement of the timepiece so as to provide a periodic impulse, - a first selector arranged to move the first display member with reference to the display zone in order to display the next first image, in response to n impulses from the actuator, n being an integer proportional to the display duration of the first image considered, n not being identical for all the first images.

3. Device for displaying the moon phases according to one of the preceding claims, wherein the representations of the phase of the moon are combined by the juxtaposition of a first and of a second complementary image occupying fixed and complementary portions of the lunar disc.

4. Device for displaying the moon phases according to one of the preceding claims and claim 2, wherein the driving means comprises a second selector arranged to move the second display member with reference to the display zone in order to display the next second image (91-96), in response to m impulses from the actuator, m being an integer proportional to the display duration of the second image considered, m being able to vary from one second image to another.

5. Device for displaying the moon phases according to one of the preceding claims, wherein the first and second display members are two concentric discs (80, 90).

6. Device for displaying the moon phases according to one of claims 2 to 5 and claim 2, wherein the first selector comprises a first programme wheel (61) for actuating the first display member (80) at predetermined instants of the lunation.

7. Device for displaying the moon phases according to claims 4 and 6, wherein the second selector comprises a second programme wheel (62) for actuating the second display member (90) at predetermined instants of the lunation.

8. Device for displaying the moon phases according to the preceding claim, wherein said first and second programme wheels are connected together.

9. Device for displaying the moon phases according to one of the preceding claims and claim 2, comprising an instantaneous jump device causing an instantaneous advancement of the first display member with reference to the display zone.

10. Device for displaying the moon phases according to one of the preceding claims and claim 6, wherein the programme wheel (61) is driven through two revolutions during a lunation.

11. Timepiece comprising a device for displaying the moon phases according to one of the preceding claims.

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