EP0756217A1 - Annual calendar mechanism for timepieces - Google Patents

Abstract

The mechanism has a day ring(1) with 31 teeth(2) ,fitted inside the ring, on which numbers 0 -31(3) are placed, and a movable day-ring driver(6) which rotates once every 24 hours. The driver(6) is fitted with a first finger(7) which is driven, step by step by the interior teeth(31) of the ring(1), once a day. The driver (6) controls the date display. In addition the mechanism has an annular crown wheel(8), partially superposed on the date ring(1), which rotates once a year. It has exterior teeth(9) in position corresponding to the 12 months of the year and 5 interior teeth(10) in positions corresponding to 31 day months. The crown wheel(8) is eccentrically arranged with respect to the ring(1) and near to the driver(6) which has a second finger(11). At the end of months of less than 31 days the second finger(11) acts on one of the 5 internal teeth(10) of the wheel(8) so that it is advanced, via a gear system(12,13) fixed to the ring(1) to the first of the following month. A manual correction is required for the month of February.

Description

The invention relates to an annual calendar mechanism for a timepiece, said mechanism comprising a date ring provided with thirty-one teeth internal to the ring, on which are affixed thirty-one digits each corresponding to a date of the months which appear successively through a window pierced in a dial, and a mobile date trainer making a turn in twenty-four hours, said mobile being equipped with a first finger capable of causing one step and once by day the date ring by one of its inner teeth, said mobile controlling the display of the date.

A date mechanism which broadly meets the definition just given is known for example from documents CH-A-538 136 and CH-A-661 171 (US-A-4 676 659). In these documents, there is also a twenty-four hour date driving wheel provided with a finger or a long tooth which drives a date disc bearing thirty-one indications. However, the finger does not directly drive the disc but an intermediate mobile which, for its part, drives this disc. This is of course an ordinary date mechanism, neither annual nor perpetual. At the end of the thirty-day months and at the end of February, it is then necessary to make a manual correction if one wishes not to lose the date.

A description of different types of calendar mechanisms in watches is given in the work entitled "Modern calendar watches" by B. Humbert - Editions Scriptar S.A. Lausanne 1953 (English version: "Modern calendar watches", Lausanne 1954).

Document DE-A-2 311 539 describes a date mechanism using a month cam making one turn per year. This cam has more or less notches deep: the solid parts correspond to the months of thirty-one days; the shallow notches in the months of thirty days, and a very deep notch in the month of February of the common years (twenty-eight days). On this cam acts the spout of a lever returned by a spring. The depth of penetration of the spout will determine which advance must be printed on the date indicator by a rocker at the end of each month.

The mechanism briefly mentioned above uses levers and return springs, which leads to a relatively complicated construction which in turn requires a relatively large number of parts. On the other hand, it will be mentioned that such rocking mechanisms do not always exhibit safe operation, particularly if shocks are applied to the timepiece.

A perpetual calendar mechanism comprising relatively few parts is described in patent DE 449 081. Several superimposed coaxial discs, respectively showing the days, the date from 1 to 15, the date from 15 to 31, months and years , have respective central openings with teeth, some of which have variable tooth heights. These teeth are attacked by two pawls carried by a mobile coach which pivots back and forth. One of the pawls has a flexible bent end which, by pressing against a height-adjustable toothing which acts as a cam, attacks or does not attack the second date disc in the last days of the month. The month disc carries a sliding spring which drives the first date disc to reset it when the month changes. Despite its apparent simplicity, this mechanism is thick, delicate and has not spread. In addition, it requires back-and-forth drive, which requires an additional mechanism in a timepiece.

To obviate the aforementioned drawbacks, the present invention proposes to use only gears to the exclusion of all levers or rockers, these gears, on the one hand, being prevented from any untimely rotation even if shocks are applied to the timepiece and, on the other hand, having a clearly simplified construction and reduced height, all the more so since the date of the invention is limited to the automatic advance of the date only for the months of thirty days , the resetting must be done manually at the end of February. It is therefore an annual calendar and not perpetual.

An annual calendar in which manual correction remains necessary at the end of February has already been proposed and described in document CH 684 815. In this document, the annual calendar mechanism comprises a date driving wheel fitted with a finger. likely to drive a date wheel at the end of each day. An annual wheel, driven once a month by two steps by a long tooth carried by an intermediate wheel meshing itself on the date wheel, comprises a board carrying five teeth each corresponding to one of the months of less than thirty-one days . When one of these five teeth appears on the path of the finger, the annual wheel, as it was, becomes driving and drives the date wheel by an additional step via the intermediate wheel.

Although having a clearly simplified construction and reduced height compared to a perpetual calendar, the mechanism which has just been described in summary above requires the supply of numerous new parts. It also requires a major transformation of a basic movement which we would like to modify if possible at lower cost.

To overcome these drawbacks and therefore propose an annual calendar mechanism easily adaptable to a classic movement, at the same time as requiring a minimum of new parts, the present invention is remarkable in that, starting from the known characteristics defined in the first paragraph of this description, the mechanism further comprises an annual crown superimposed on the date ring, making a turn in one year and provided with external teeth in positions corresponding to the twelve months of the year and five internal teeth in positions corresponding to months less than thirty-one days, said crown being arranged eccentrically relative to the ring and close to the date-driven mobile so that it is actuated, at the end of the months of less than thirty-one days, by a second finger presented by the date-moving mobile, this second finger acting on one of the five inner teeth of the crown, meshing means integral with the date ring being used to put be engaged, at the end of each month, said date ring with said annual crown by at least one of its outer teeth.

The result is a mechanism in which all the mobiles are rotary and there are only three of them, namely the driving mobile, the date ring and the annual crown. These mobiles can be arranged in only two levels, that of the date ring and that of the annual crown passing above or below it. It is therefore possible to make the calendar mechanism in the form of a thin module, which can be superimposed on an ordinary watch movement. In addition, the eccentric arrangement of the annual crown offers, if this crown bears indications of the months, a great freedom of choice of the position of the aperture where these indications appear, in particular at different distances from the center of the watch movement and the dial. In particular, the crown can be arranged eccentrically with respect to this center and be large enough to pass around it, i.e. around the needle trees of a conventional analog display.

• la figure 1 est une vue en plan d'une montre présentant un quantième annuel selon l'invention,
• la figure 2 est une vue en plan du mécanisme de quantième annuel équipant la montre de la figure 1, cette figure illustrant la situation des rouages le 30 avril à 23 heures 45 minutes,
• la figure 3 est une vue analogue à celle de la figure 2, la situation des rouages étant celle présentée le 1er mai à 0 heure 15 minutes,
• la figure 4 est une vue analogue à celle de la figure 2, la situation des rouages étant celle présentée le 1er mai à 4 heures,
• la figure 5 est une coupe selon la ligne V-V de la figure 2, et
• la figure 6 est une vue en plan de la couronne annuelle de la figure 2 qui explicite la fonction de cette couronne par rapport aux mois de l'année.

The invention will now be explained with the aid of the description which follows and of the drawings which illustrate it by way of example, in which:

• FIG. 1 is a plan view of a watch presenting an annual calendar according to the invention,
• FIG. 2 is a plan view of the annual calendar mechanism fitted to the watch in FIG. 1, this figure illustrating the situation of the workings on April 30 at 11:45 pm,
• FIG. 3 is a view similar to that of FIG. 2, the gear train situation being that presented on May 1 at 0 hours 15 minutes,
• FIG. 4 is a view similar to that of FIG. 2, the gear situation being that presented on May 1 at 4 a.m.,
• FIG. 5 is a section along the line VV in FIG. 2, and
• Figure 6 is a plan view of the annual crown of Figure 2 which explains the function of this crown in relation to the months of the year.

The plan view of FIG. 1 shows a watch fitted, apart from the hour hands 70, minutes 71 and seconds 72, with a date indicator in the form of a date 3 appearing through a aperture 4 pierced in a dial 5. The time setting can be carried out by means of the crown 61. If we now remove this watch from its dial and only the elements useful for carrying out the invention are kept , we arrive at the plan views of Figures 2, 3 and 4 which show the mechanism in question at three different times during the transition from April to May.

Examination of FIG. 2 and of the section of FIG. 5 in particular will make one understand the annual calendar mechanism according to the invention. This mechanism has a ring date 1 with thirty-one teeth 2. Thirty-one numbers 3 are affixed to ring 1, each corresponding to a date in the month. These figures appear successively through the aperture 4 pierced in the dial 5 shown in FIG. 1. A mobile date trainer, generally designated by the reference 6, is equipped with a first finger 7 capable of causing a step and once a day the date ring 1 by one of its internal teeth 2. In the particular case shown in FIG. 2, the first finger 7 has just come into contact with the tooth 2a and will therefore advance the ring 1 with a pitch from 30 to 31 as is finally shown in FIG. 3. As can be seen in FIGS. 2 to 4 and better still in the section of FIG. 5, the driving mobile 6 comprises a driving wheel 21 which connects this mobile to the watch movement (not shown here) and makes a tour in twenty-four hours. The section in FIG. 5 shows that the first finger 7 of the driving mobile 6 is on the path of the tooth 2a belonging to the date ring 1. The finger 7 is a protrusion of a disc 22 forced on a shaft 23, the driving wheel 21 being integral with the same shaft 23. By its pivot 24, the shaft 23 can rotate freely in a bearing 25 set in the plate 17 of the timepiece.

What has been described in the above paragraph is well known from the state of the art. It is in fact the conventional drive of a date ring, this ring being able to be reset by a rapid corrector 20 (see FIG. 2) engaged on the teeth 2 of the ring 1, this corrector 20 being controlled by the manual crown 61 (Figure 1). In this classic system, resetting to the date is necessary at the end of months with less than thirty-one days, namely the months of February, April, June, September and November.

We will now describe what has been added to this conventional mechanism to transform it, according to the invention, into a so-called annual mechanism in the sense that the date jumps from 30 to 1 at the end of months of less than thirty-one days.

In addition to what has been listed above, the mechanism according to the invention comprises an annual crown 8 having an annular shape, as drawn in FIGS. 2 to 6. This crown is superimposed on the date ring 1 and go around in a year. The crown 8 is provided with twenty-four teeth 9 uniformly distributed around its outer periphery, these teeth 9 corresponding in pairs to the twelve months of the year, and five teeth 10 around its inner periphery, these teeth 10 each corresponding to the months of less than thirty-one days. FIGS. 2 to 4 show that the annual crown 8 is arranged eccentrically with respect to the date ring 1. It is also arranged in such a way that it is actuated, at the end of the month counting less than thirty-one days, by a second finger 11 presented by the mobile date trainer 6, this second finger 11 acting on one of the five internal teeth 10 of the crown 8. In the particular case shown in FIG. 3, the second finger 11 comes from come into contact with tooth 10a of crown 8 and will advance by one step (a twenty-fourth turn or 15 °) said crown from IV to V as shown in Figure 4. As can be seen in the section of FIG. 5, the second finger 11 of the mobile 6 is a projection of a disc 26 forced on the shaft 23, the disc 26 surmounting the disc 22 already described and being separated from the latter by a spacer 27. The section in FIG. 5 clearly shows that the second finger 11 of the mobile e trainer 6 is on the path of tooth 10a belonging to the annual crown 8. It will however be noted that finger 11 could be carried by the same disc 22 as finger 7, so that the elements 26 and 27 could be removed .

FIGS. 2 to 4 finally show that meshing means 12, 13 integral with the date ring 1 are used to engage or couple, to the end of each month, said date ring 1 and said annual crown 8 by one of its twenty-four external teeth 9.

The aforementioned engagement means could consist of a single pin planted at the periphery of the date ring 1, or a part cut and folded from the edge of this ring, this pin or folded part engaging in twelve slots arranged at the periphery of the annual crown, these slots being separated by solid parts acting as teeth. However, it was preferred to use two pins or lugs 12 and 13 planted perpendicularly on the periphery of the ring 1, arranging so that the circumferential length X (see FIG. 2) occupied by the two pins is substantially equal to l 'empty space Y separating two successive external teeth 9a and 9b which the annual crown 8 presents. In any case, the respective diameters of the ring 1 and of the crown 8 are chosen so that at each change of month, the crown 8 is driven two twenty-fourths of a turn (30 °) by the date ring 1. Likewise, the internal diameter of the crown 8 will be chosen so that the internal teeth 10 cooperate with the second finger 11 while also allowing cooperation of the first finger 7 with the teeth 2 of the date ring 1.

Figures 2 to 5 also show that the annual crown 8 pivots around a guide disc 16 fixed on the plate 17 by means of two screws 28 and 29 (see Figures 2 to 4). These same figures also show that a first jumper 18 is supported between two successive teeth 2 of the date ring 1 and that a second jumper 19 is supported between two successive outer teeth 9 of the annual crown 8. These jumpers allow angularly position the ring 1 and the crown 8 when stationary. It is because of the jumper 19 that the crown 8 has twenty-four external teeth 9, to define its twenty-four successive positions, while twelve teeth would be sufficient to cooperate with the pins 12 and 13. Finally, it will be noted that on the annual crown 8 are affixed twenty-four indications 14, chosen here in Roman numerals, arranged in pairs and identifying the months of the year, these indications appearing at through a window 15 pierced in the dial 5 as shown in Figure 1. In the figures, the date appears at 3 o'clock and the month at 9 o'clock. This display could appear in other places, for example the date at 12 o'clock and the month also at 12 o'clock but below.

FIG. 2 also shows that it is possible to provide a rapid month corrector 40 which preferably has two teeth attacking the outer teeth 9 of the annual crown 8, to make it move back two steps per revolution of the corrector 40. In a position drawn from the control crown 61, the rotation of the latter in a first direction actuates the corrector 40, and in the other direction it actuates the corrector 20. Such correction mechanisms are well known in principle and do not need not be described here.

Alternatively, the guide disc 16 can be replaced by a fixed guide ring 32 (a fragment of which is shown in broken lines in Figure 2) which surrounds and guides the periphery of the annual crown 8, for example by partially covering the teeth 9. This variant makes it possible to replace the screws 28 and 29, located inside the timepiece movement, by screws or other fixing members located at the periphery of this movement and of the date mechanism. This facilitates the application of the mechanism according to the invention in the form of a separate module which can be mounted without difficulty on different clock movements, in particular having different plates.

It will be noted that with the two forms of guidance described above, the annular and eccentric annual crown 8 can be large enough to extend around the axis of rotation 33 (fig. 5) of the date ring 1, therefore also around the central shafts 34, 35 and 36 carrying the seconds, minutes and hours hands in a classic timepiece, as shown in the drawings . This results in multiple possibilities of combining different relative positions of the windows 4 and 15 where the calendar and the month appear respectively. In addition, the crown 8 may be wide enough to bear the names of the months in whole or in abbreviation. The finger 11 can be on a radius smaller than that of the finger 10.

Another possibility of indicating the month consists in affixing on the annual crown 8 an index, for example colored, which is visible through a discontinuous circular slot or a circular row of openings made in the dial above the crown, the names or numbers of the months then being written on the dial. This display device that can be off-center on the dial offers interesting decorative and aesthetic possibilities.

The various elements constituting the invention having been defined above as well as their interactivity, it remains to explain the operation of the annual calendar mechanism. Two cases can arise depending on whether they are months of less than thirty-one days or months of thirty-one days.

The passage from the 30 to the first day of the following month in the case of a month of less than thirty-one days is illustrated in FIGS. 2, 3 and 4. In FIG. 2, the mechanism has been shown as it appears on April 30 (month of thirty days) when its hour hand 70 and minute 71 indicate 23 hours 45 minutes. At this time the date displayed is 30 and the month displayed is the first indication IV (April). The pins 12 and 13 of the ring 1 are almost engaged between the teeth 9a and 9b of the crown 8. Likewise the first finger 7 of the driving mobile 6 comes into contact with the tooth 2a of the ring 1. In FIG. 3 , we see the same mechanism when the 70 hour and 71 minute hands indicate 0 hours 15 minutes on May 1st. The first finger 7 of the mobile 6 has driven by a step, through the tooth 2a, the date ring 1 which then displays the date 31 (temporarily). The crown 8 has been advanced by one step by the pin 12 acting on the tooth 9b, this crown displaying the second IV (temporarily). The second finger 11 of the mobile 6 comes into contact with the tooth 10a of the crown 8. In FIG. 4, the same mechanism is seen when the hour hands 70 and minutes 71 indicate 4 hours 0 minutes on May 1. The crown 8 has been driven by one step by the second finger 11 of the mobile 6 and now displays the first indication V (May). This same crown, as it is normally driven by the ring 1, has become leading under the action of the finger 11 and then carries, by its tooth 9a, the date ring 1 by the pin 13. The ring 1 displays, at the end of the race, the number 1. Once this phase is complete, the pins 12 and 13 are disengaged from the teeth 9a and 9b and the ring 1 can continue its rotation day after day. In order not to mislead the wearer of the watch, the second indication of months of less than thirty-one days (i.e. II, IV, VI, IX and XI) could be replaced by a colored dot or an empty space.

The passage from 31 to the 1st of the following month in the case of a month of thirty-one days is not illustrated in the figures. It will be understood that in this case none of the five teeth 10 of the annual crown 8 is on the path of the second finger 11 of the driving mobile 6. For example, the annual crown 8 displays the month of May, ie the first digit V as illustrated in figure 4. At midnight, May 30, the date ring jumps to 31 (under the effect of the first finger 7) and advances the crown 8 by one step, which then displays the second V (under the pin effect 12). At midnight on May 31, the date ring jumps to June 1 under the effect of the finger 7 and advances crown 8 a new step, which then displays the first VI (June) under the effect of pin 12.

FIG. 6 is a partial resumption of FIG. 2. It shows the annual crown 8 in its entirety and partially the date ring 1 as well as the movable date trainer 6. It can be seen that the inner teeth 10 of the crown 8 are arranged around the inner periphery of said crown successively at 60 °, 60 °, 90 °, 60 ° and 90 °. If these teeth 10, which represent the months of February, April, June, September and November, are on the way to the second finger 11 of the mobile 6, the date will pass, at the end of these months quickly from 30 to 31, then from the 31st to the 1st of the following month, as explained above.

If the system which has just been described pursues the same aim as that exposed in the document CH 684 815 previously cited, it presents, compared to this prior art, notable simplifications by the reduced number of parts which it implements and by the minimal space it offers. Indeed, the only important new parts are the annual crown 8 and a second drive finger 11. This system therefore sees the timepiece thicken only by the thickness of this crown. In addition, classic movements with a single date ring are very easily adaptable to this new calendar.

Claims (11)

Annual calendar mechanism for a timepiece, said mechanism comprising a calendar ring (1) provided with thirty-one teeth (2) inside the ring, on which thirty-one numbers (3) are affixed each corresponding to a date of the month which appear successively through a window (4) pierced in a dial (5), and a mobile (6) calendar trainer making a turn in twenty-four hours, said mobile being equipped with a first finger (7) capable of driving one step and once a day the date ring (1) through one of its internal teeth (2), said mobile controlling the display of the date, characterized in that the mechanism further comprises an annular annual crown (8) partially superimposed on the date ring (1), making a turn in one year and provided with external teeth (9) in positions corresponding to the twelve months of the year and five internal teeth (10) in corresponding positions nd in the months of less than thirty-one days, said crown (8) being arranged eccentrically relative to the ring (1) and close to the mobile (6) date trainer so that it is actuated, at the end of the months less than thirty-one days, by a second finger (11) presented by the mobile (6) date trainer, this second finger (11) acting on one of the five inner teeth (10) of the crown (8 ), engagement means (12, 13) integral with the date ring (1) being used to engage, at the end of each month, said date ring (1) and said annual crown ( 8) by at least one of its outer teeth (9). Mechanism according to Claim 1, characterized in that the engagement means integral with the date ring (1) consist of two pins or lugs (12 and 13) planted perpendicularly on the periphery of the ring (1), the circumferential length (X) occupied by the two pins being arranged in such a way that said pins can engage, at the end of each month, in the empty space (Y) separating two successive external teeth (9a, 9b) of the annual crown (8). Mechanism according to claim 1, characterized in that on the annual crown (8) are affixed indications (14) identifying the months of the year, these indications appearing successively through a second window (15) pierced in the dial (5). Mechanism according to one of the preceding claims, characterized in that the external teeth (9) of the annual crown (8) are twenty-four in number and cooperate with a jumper (19) defining twenty-four angular positions of said crown . Mechanism according to claims 3 and 4, characterized in that at least those of said indications (14) which identify the months of thirty-one days are affixed twice on the annual crown (8), to appear in the window (15) in two successive positions of said crown. Mechanism according to claim 1, characterized in that the annual crown (8) is mounted around a fixed guide disc (16). Mechanism according to claim 1, characterized in that the annual crown (8) is mounted inside a fixed guide ring (32). Mechanism according to one of the preceding claims, characterized in that the annual crown (8) extends eccentrically about an axis of rotation (33) of the date ring (1). Mechanism according to claim 1, characterized in that it comprises a rapid date corrector (20), engaged on the internal teeth (2) of the date ring (1), said corrector being actuated by a crown of control (61) of the timepiece. Mechanism according to claim 9, characterized in that it comprises a rapid month corrector (40), engaged on the external teeth (9) of the annual crown (8), said corrector being actuated by the control crown (61 ). Mechanism according to claim 1, characterized in that the five internal teeth (10) of the annual crown (8) are arranged around the interior of said crown at successive angular intervals of 60 °, 60 °, 90 °, 60 ° and 90 °.

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