CH680630B5 - - Google Patents

Description

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CH 680 630G A3

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Description

The present invention relates to a timepiece comprising a perpetual calendar mechanism, this calendar appearing through a window pierced in a dial or on divisions applied to the dial opposite which points a hand, this mechanism comprising a twenty-four hour wheel making a revolution in twenty-four hours and meshing with the hour wheel that comprises the timepiece, the twenty-four hour wheel being provided with a first long tooth projecting radially from a teeth meshing with the hour wheel, and a date wheel provided with thirty-one teeth, this date wheel being arranged to be advanced by one step by said first long tooth at the end of each month.

A date mechanism that 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 wheel fitted 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. It is of course an ordinary, non-universal date mechanism. 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.

Mechanisms with a perpetual calendar have been known for a long time, where a device automatically operates all the changes, be it months comprising twenty-eight, twenty-nine, thirty or thirty-one days. These mechanisms are described in detail in the book entitled “Modern watches-calendar” by B. Humbert - Editions Scriptar S.A. Lausanne 1953 (English version: “Modern calendar watches”, Lausanne 1954). Thus, a perpetual calendar watch does not require manual correction of the date display at the end of months with less than thirty-one days. Similarly, every four years, at the advent of the leap year and in February, the watch will display the number twenty-nine before indicating the first of March.

Without going into construction details, we will mention here two mechanisms commonly used to achieve the expected results.

The first mechanism uses a month cam that rotates in four years. This cam has more or less deep notches: the solid parts correspond to the months of thirty-one days; the shallow notches in the months of thirty days; three very deep notches in February of the common years (twenty-eight days) and the intermediate depth notch in February of the leap year. On this cam acts the spout of a lever returned by a spring. The depth of penetration of the spout will determine what advance should be printed on the date indicator at the end of each month.

The second mechanism uses a month cam that turns one year. This cam also has solid parts corresponding to the months of thirty-one days and shallow notches corresponding to those of thirty days. The notch in February is replaced by a small rectangle ordered by a Maltese cross. On this cam also acts the spout of a lever to determine the advance of the date indicator at the end of the month.

Whether we choose one or the other of the mechanisms briefly mentioned above, we see that it is necessary to use levers and return springs, which leads to a relatively complicated construction which in turn requires a relatively high number of parts. On the other hand, it will be mentioned that such mechanisms do not always exhibit safe operation, particularly if shocks are applied to the 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.

To achieve this goal, the perpetual calendar mechanism according to the present invention is characterized in that the twenty-four hour wheel comprises, superimposed on three successive teeth meshing with the hour wheel of the second, third and fourth long teeth arranged at following the first and projecting radially from the teeth which they surmount, and which the date wheel comprises in superposition means using a set of gears arranged to present a first driven tooth capable of being driven by the second long tooth of the twenty-four hour wheel to rotate the date wheel by an additional step at the end of the thirty-day months (April, June, September, November), the first and second driven teeth capable of being driven respectively by the second and third long teeth of the twenty-four hour wheel to turn the date wheel by two steps s additional at the end of February when the year is a leap year, and the first, second and third led teeth capable of being driven respectively by the second, third and fourth long teeth of the twenty-four hour wheel to rotate the date wheel of three additional steps at the end of February when the year is not a leap year.

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 the timepiece according to the invention, a view which shows inter alia the perpetual calendar mechanism normally hidden by the dial,

- fig. 2 shows in detail and on an enlarged scale the perpetual calendar mechanism appearing at

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CH 680 630G A3

fig. 1, this for the date of February 28 and just before the date change,

- figs. 3, 4, 5 and 6 are partial views of the mechanism of FIG. 2 each represented according to different plans or levels, 5

- figs. 7, 8 and 9 are sections in the date mechanism for three different positions of the date wheel,

- fig. 10 shows in detail the perpetual calendar mechanism taken in a transition stage between February 28 and March 1, and

- fig. 11 shows in detail the perpetual calendar mechanism as it appears on February 14 just before the date change.

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In addition to the hour hand 70 and minute hand 71, the timepiece shown in fig. 1 includes a date display 72 appearing in a window 73. In addition to the date display, the timepiece also displays the day of week 74, the month 75 and the year 76, this last indication may extend over ninety-nine years. These complementary displays also appear in apertures pierced in a dial 77 comprising indexes 78. Under the dial 25 77 appears a mechanism, drawn here in solid line,

which will be described in detail particularly with regard to the perpetual calendar mechanism,

essential object of the present invention. This perpetual calendar mechanism is driven by an hour wheel 1, linked to the hour hand 70, and comprises a twenty-four hour wheel 2a, 2b making a revolution in twenty-four hours, which drives a date 6 which turns once a month. 35

We will now refer to FIG. 2 which shows in detail and on an enlarged scale the perpetual calendar mechanism briefly represented in FIG. 1, and illustrating the situation on February 28. We find the hour wheel 1, the twenty-four hour wheel 2a, 2b and the date wheel 6. Like the twenty-four hour wheel 2a, 2b and the date wheel 6 each have a complex structure residing mainly in the superposition, perpendicular to fig. 2, of various and particular wheels, shown in FIGS. 3 to 6, four different levels of this structure, fig. 3 showing the lowest level A (the furthest from the dial) and fig. 4 representing the highest level D (closest to the dial), the 50 fig. 5 and 6 respectively representing levels C and B located in order below level D. These levels are clearly visible in the sectional views of FIGS. 7 to 9 or they are referenced.

As seen in fig. 3 which represents the level 55 of the mechanism, the hour wheel 1, here comprising twelve teeth and making one revolution in twelve hours, drives the twenty-four hour wheel 2a comprising twenty-four teeth 41 and making one revolution twenty-four hours. As shown in fig. 3, 60 the twenty-four hour wheel 2a has a first long tooth 40 which projects radially from one of the teeth 41 meshing with the hour wheel 1. The date wheel 6 has thirty-one teeth 42. It will be understood that '' at the end of each 65

month the date wheel is advanced by one step by the long tooth 40.

As is apparent from Figs. 2, 4, 5 and 6, the twenty-four hour wheel further comprises, superimposed on three successive teeth 41 meshing with the hour wheel of the second 43, third 44 and fourth 45 long teeth arranged following the first 40 These three long teeth project radially from the teeth 41 which they surmount.

It will be mentioned here that the twenty-four hour wheel 2a, 2b can be produced by means of two integral wheels 2a, 2b having substantially the same diameter, as can be seen in section in FIGS. 7, 8 and 9. The first wheel 2a has a single long tooth 40 and extends at level A and the second wheel 2b, superimposed on the first, has three successive long teeth 43, 44 and 45 and extends at levels B, C and D. These two wheels 2a and 2b are angularly offset so that the long tooth 40 of the first wheel is immediately followed by the three long teeth 43, 44 and 45 of the second wheel.

The wheel 2a, 2b could also be cut in one piece comprising two stages of teeth, a first lower stage carrying the first long tooth 40 and a second upper stage carrying the second 43, third 44 and fourth 45 long teeth.

Examination of fig. 2 shows that the long teeth of the twenty-four hour wheel drive the date wheel by the tops of these teeth and not by normal meshing of the primitive circles, this in order to advance the date wheel by less than one step. The complete pitch is reached by using a jumper 50 disposed between two successive teeth 42 of the date wheel which precisely positions said wheel.

Fig. 2 shows that the date wheel has superimposed means using a set of gears identified by 17, 18, 19, 20, 21, 22, 23. This set of gears is arranged to present a first driven tooth 46 capable of '' be driven by the second long tooth 43 of the twenty-four hour wheel 2b to rotate the date wheel 6 by an additional step at the end of the thirty-day months (April, June, September, November), the previous step having been operated by the cooperation of tooth 40 (wheel 2a) with the thirty-first tooth 42 of the date wheel 6. This same set of gears is also arranged to present first 46 and second 47 driven teeth capable to be driven respectively by the second 43 and third 44 long teeth of the twenty-four hour wheel 2b to rotate the date wheel 6 by two additional steps at the end of February when the year is a leap year. Finally, this set of gears is arranged to present first 46, second 47 and third 48 tooth teeth capable of being driven respectively by the second 43, third 44 and fourth 45 long teeth of the twenty-four hour wheel 2b for turn the date wheel 6 three additional steps at the end of February when the year is not a leap year.

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We will now describe a device which associates with each of the driven teeth mentioned above a particular wheel, these wheels having one or more projecting teeth, the angular position of these wheels relative to the date wheel defining, as a function of the month in question, the number of teeth likely to be driven by the twenty-four hour wheel.

The gear set first comprises a first wheel for months of thirty days or less 20, located at level C and freely mounted on a first axle 52 secured to the date wheel (see fig. 2, 5 and 8). This wheel is arranged to go around in a year. It has twenty-four teeth 51, five of which 46 are projecting relative to the others. It is understood that one of these teeth can be driven by the second long tooth 43 of the wheel 2b if the wheel 20 occupies an angular position such that the tooth 46 covers the thirtieth tooth 42 of the date wheel. In the situation taken as an example in fig. 2, 5 and 8, the long tooth 43 will drive the driven tooth 46.

The gear set then comprises a second wheel for the month of February 19, located at level D and freely mounted on a second axle 54 secured to the date wheel (see fig. 2, 4 and 7). This wheel is also arranged to go around in a year. It has twenty-four teeth 53 of which only one 47 of these is projecting with respect to the others. It is understood that this tooth can be driven by the third long tooth 44 of the wheel 2b if the wheel 19 occupies an angular position such that the tooth 47 covers the twenty-ninth tooth 42 of the date wheel. In the situation taken as an example in fig. 2, 4 and 7, the long tooth 44 will drive the driven tooth 47.

The set of gears finally comprises a third wheel for leap years 23, located at level B and freely mounted on a third axle 56 secured to the date wheel (see fig. 2, 6 and 9). This wheel is arranged to make a turn in four years. It has eight teeth 55, three of which 48 are projecting relative to the others. Here also, it is understood that one of the teeth 48 can be driven by the fourth long tooth 45 of the wheel 2b if the wheel 23 occupies an angular position such that the tooth 48 covers the twenty-eighth tooth 42 of the date wheel . In the situation taken as an example in fig. 2, 6 and 9, the long tooth 45 is in contact with the driven tooth 48 which it begins to drive.

It remains to describe a mechanism capable of driving the first, second and third wheels described above in rotation. This mechanism is controlled by the rotation of the date wheel 6.

This mechanism comprises a fourth wheel 17 (see fig. 2 and 3) which is fixed and integral with the frame which the timepiece presents. This wheel 17 is provided with a single tooth 57 and is centered on a fourth axis 58 which is the same as the axis around which the date wheel pivots 6. Around this fixed wheel 17, rotates like a satellite, a fifth wheel 18 which has eight teeth 60, this fifth wheel being freely mounted on a fifth axle 59 integral with the date wheel 6. The wheel 18 advances by one step each time the tooth 57 of the fourth wheel 17 cooperates with the teeth 60 of the fifth wheel. The fifth wheel 18 in turn drives, on the one hand, the first wheel 20 (see fig. 2, 5 and 8) and, on the other hand, the second wheel 19 (see fig. 2, 4 and 7). As can be seen in fig. 2 and in fig. 7 and 8, these first and second wheels are mounted one on the other. In addition, they are offset relative to each other as seen in fig. 2 (axes 52 and 54). As seen in fig. 2, the axis 58 of the fourth wheel 17 and the axis 52 of the first wheel 20 are perpendicular to a straight line 61 passing through these axes and through the tip of a projecting tooth 46 of the first wheel 20, when this tooth is superimposed on the thirtieth tooth of the date wheel. Likewise, as can be seen in FIG. 2, the axis 58 of the fourth wheel 17 and the axis 54 of the second wheel 19 are perpendicular to another straight line 62 passing through these axes and through the tip of the projecting tooth 47 of the second wheel 19, when this tooth is superimposed on the twenty-ninth tooth of the date wheel. The angle that the two lines 61 and 62 make between them is a measure of the eccentricity existing between the first 20 and second 19 wheels.

This drive mechanism finally comprises a sixth wheel 21 coaxial with and integral with the first wheel 20 (see fig. 2, 6 and 9). This sixth wheel 21 has only a single tooth 63 capable of driving once a revolution a seventh wheel 22 having eight teeth 64 and freely mounted on a sixth axle 65 secured to the date wheel 6. The seventh wheel 22 is in taken with the third wheel 23 of which we have already spoken and which rotates in four years and two steps per year. Fig. 6 clearly shows the conjunction of teeth 48 and 45, which takes place on February 28 of a non-leap year. If the year was a leap year, it would be the short tooth 80 which would be opposite tooth 45, the latter then having no effect on the advance of the date wheel 6.

In the description above, the fourth 17 and sixth 21 wheels are each in the form of a disc with a cylindrical periphery, that is the periphery 66 for the wheel 17 and the periphery 67 for the wheel 21.

As seen in fig. 3, two notches 68 are formed in the periphery 66 of the wheel 17 and a tooth 57 is disposed between these notches and projects from the cylindrical periphery. The fifth wheel 18 cooperating with this fourth wheel is therefore prevented from turning when two of its successive teeth 60 are located opposite said cylindrical periphery 66. As can be seen in FIG. 2, this locking situation occurs during the date change, which is favorable to the stability of the system.

As seen in fig. 6, two notches 69 are formed in the periphery 67 of the wheel 21 and a tooth 63 is disposed between these notches and projects from the cylindrical periphery. The seventh wheel 22 cooperating with this sixth wheel 21 is therefore also prevented from turning when two of its successive teeth 64 lie opposite said cylindrical periphery 67. As shown in FIG. 6, this locking situation does not occur at the change

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February date, because it is essential that the long tooth 48 is retracted one month before (January 31) and one month after (March 31) the month of February.

Fig. 9 shows a section of the situation shown in plan in FIG. 2 (teeth 45 and 48 engaged). For the understanding of fig. 8, the wheel 20 is assumed to be engaged with the wheel 2b by their respective teeth 46 and 43. Likewise, for fig. 7, the wheel 19 is assumed to be engaged with the wheel 2b by their respective teeth 47 and 44. Figs. 7 to 9 also show a wheel 18 produced in two stages: 18a and 18b. This construction can be justified because of the offset of the wheels 19 and 20.

Finally, it should be mentioned that the timepiece includes a two-digit year display (reference 76, fig. 1). This display somehow replaces a display of the four-year cycle found in certain timepieces with perpetual calendars. The display of the year is controlled by the date wheel 6 which comprises a lower plate 7 controlling, once a month, a wheel 8 in turn controlling a train of gears, as seen in FIGS. 1, 7, 8 and 9.

For additional information, fig. 10 shows the step which follows that shown in fig. 2 and fig. 11 change to February 14.

Finally, it should be mentioned that the date disc will have a ring on which the date numbers will be affixed. This ring has not been shown in order not to load the figures.

Claims (1)

Claims 1. Timepiece comprising a perpetual calendar mechanism, this calendar appearing through a window pierced in a dial or on divisions applied to the dial opposite which points a hand, this mechanism comprising a wheel of twenty-four hours (2a, 2b) making a revolution in twenty-four hours and meshing with the hour wheel (1) that comprises the timepiece, the twenty-four hour wheel being provided with a first long tooth (40) projecting radially of one of the teeth (41) meshing with the hour wheel, and a date wheel (6) provided with thirty-one teeth (42), this date wheel being arranged to be advanced by one step by said first long tooth at the end of each month, characterized in that the twenty-four hour wheel (2a, 2b) comprises, superimposed on three successive teeth (41) meshing with the hour wheel of the second (43), third ( 44) and fourth (45) long teeth ues arranged following the first (40) and projecting radially from the teeth which they surmount, and which the date wheel (6) comprises in superposition means using a set of gears (17,18,19, 20 , 21, 22, 23) arranged to present a first driven tooth (46) capable of being driven by the second long tooth (43) of the twenty-four hour wheel to rotate the date wheel by an additional step at the end of the thirty-day months (April, June, September, November), the first (46) and second (47) driven teeth capable of being driven respectively by the second (43) and third (44) long teeth of the twenty-four hour wheel to rotate the date wheel by two additional steps at the end of February when the year is a leap year, and the first (46), second (47) and third (48) led teeth capable of being driven respectively by the second (43), third (44) and fourth ( 45) long teeth of the twenty-four hour wheel to turn the date wheel by three additional steps at the end of February when the year is not a leap year. 2. Timepiece according to claim 1, characterized in that the twenty-four hour wheel (2a, 2b) is made of two integral wheels having substantially the same diameter, the first wheel (2a) having a single tooth long (40) and the second wheel (2b), superimposed on the first, having three successive long teeth (43, 44, 45), said wheels being angularly offset so that the long tooth (40) of the first wheel is immediately followed by the three long teeth (43,44,45) of the second wheel. 3. Timepiece according to claim 1, characterized in that the twenty-four hour wheel (2a, 2b) is shaped in one piece. 4. Timepiece according to claim 1, characterized in that a jumper (50) is disposed between two teeth (42) of the date wheel to precisely position said wheel. 5. Timepiece according to claim 1, characterized in that the gear set comprises a first wheel of the months of thirty days or less (20) making a turn in a year and having twenty-four teeth (51) of which five (46) of these are projecting with respect to the others, these projecting teeth (46) constituting, depending on the angular position of said first wheel relative to the date wheel, said first driven tooth (46), this first wheel (20) being freely mounted on a first axle (52) integral with said date wheel, a second wheel of February (19) making a turn in one year and having twenty-four teeth (53) including one (47 ) of the latter is projecting with respect to the others, this projecting tooth constituting, depending on the angular position of said second wheel relative to the date wheel, said second driven tooth (47), this second wheel (19) being mounted freely on a second axis (54 ) integral with said date wheel, and a third leap year wheel (23) making a turn in four years and having eight teeth (55), three (48) of which are projecting with respect to the others, these projecting teeth (48) constituting, according to the angular position of said third wheel relative to the date wheel, said third driven tooth (48), this third wheel (23) being freely mounted on a third axle (56) integral with said wheel calendar, said first (46), second (47) and third (48) teeth being capable of being driven by the twenty-four hour wheel (2b) when they are respectively superimposed on the thirtieth, twenty-ninth and twenty- eighth wheel teeth 5 10 15 20 25 30 35 40 45 50 55 60 65 6 g CH 680 630G A3 10 date, said first (20), second (19) and third (23) wheels being rotated by a mechanism controlled by the rotation of said date wheel. 6. Timepiece according to claim 5, characterized in that the mechanism driving said first (20) second (19) and third (23) wheels comprises a fourth wheel (17) fixed integral with the frame of the piece timepiece, this wheel being provided with a single tooth (57) and having a fourth axis (58) which coincides with the axis around which the date wheel pivots, a fifth wheel (18) having eight teeth (60) mounted freely on a fifth axis (59) integral with the date wheel, this fifth wheel rotating in satellite around the fourth wheel and progressing by one step each time the tooth (57) of the fourth wheel cooperates with the teeth (60 ) of the fifth wheel, said fifth wheel (18) driving both said first (20) and second (19) wheels, these first and second wheels being mounted one on the other and eccentric with respect to the other in such a way that, on the one hand, the axis ( 58) of the fourth wheel and the axis (52) of the first wheel are perpendicular to a straight line (61) passing through these axes and through the point of a projecting tooth (46) of said first wheel, when this tooth is superimposed on the thirtieth tooth of the date wheel and, on the other hand, the axis (58) of the fourth wheel and the axis (54) of the second wheel are perpendicular to a straight line (62) passing through these axes and by the tip of the projecting tooth (47) of said second wheel, when this tooth is superimposed on the twenty-ninth tooth of the date wheel, and a sixth wheel (21) coaxial with and integral with the first wheel ( 20), this sixth wheel having a single tooth (63) capable of driving once a revolution a seventh wheel (22) having eight teeth (64) and freely mounted on a sixth axle (65) integral with the date wheel, this seventh wheel in turn driving said third wheel (23). 7. Timepiece according to claim 6, characterized in that the fourth (17) and sixth (21) wheels are each in the form of a disc with cylindrical periphery (66, 67), two notches (68 , 69) being formed in this periphery and a tooth (57, 63) being disposed between these notches, the tooth projecting from said cylindrical periphery and that the fifth (18) and seventh (22) wheels cooperating respectively with said fourth and sixth wheels are arranged in such a way that they are prevented from turning when two of their successive teeth (60, 64) are opposite the cylindrical periphery of the wheel with which they cooperate. 8. Timepiece according to claim 7, characterized in that the fourth wheel (17) is positioned in such a way that the fifth wheel (18) with which it cooperates is prevented from turning during the change of date at the end of each month. 9. Timepiece according to claim 7, characterized in that the sixth wheel (21) is positioned in such a way that its projecting tooth (63) is engaged with the seventh wheel (22) with which it cooperates, during the date change at the end of February. 10. Timepiece according to claim 1, characterized in that it comprises an indicator of the years (76) controlled by the date wheel via a gear train. 5 10 15 20 25 30 35 40 45 50 55 60 65 7