CH660440GA3 - Perpetual calendar mechanism - Google Patents

Abstract

It comprises a thirty-one day wheel (20) carrying a snail cam (23) and a drive finger (25) indexing a forty-eight month wheel (26), carrying a leap year cam (29), meshing with a twelve-month wheel (32) carrying a twelve-month cam (36). The twelve-month wheel (32) carries a hand cooperating with a month indicator making one revolution per year. An intermediate leap year wheel (30) is solid with the forty-eight month wheel (26) meshing with a leap year wheel (37) of like diameter and of like number of teeth. This leap year wheel (37) drives an index cooperating with a year indicator at a rate of one revolution in four years. <IMAGE>

Description

** ATTENTION ** start of the DESC field may contain end of CLMS **.

CLAIMS 1. Perpetual date mechanism comprising a thirty-one day wheel (20) carrying a snail cam (23) and a drive finger (25) indexing by one step, for each revolution of the thirty-one day wheel ( 20) a forty-eight month wheel (26), carrying a leap year cam (29), meshing with a twelve month wheel (32) carrying a twelve month cam (36); and a large rocker (46), pivoted on a board (1) with the wheels (20, 26 and 32), actuated by a drive finger (11) driven by a twenty-four hour wheel (9) itself driven by a twelve hour wheel (8) of a clockwork movement, this large rocker (46) having a spout cooperating with the teeth (21) of the thirty one day wheel (20), a large pawl (49) cooperating with the snail cam (23), a finger (53) cooperating with the twelve month cam (36), one end (52) cooperating with the leap year cam (29) and a spout (55) acting on a star seven days (44); this mechanism further comprising a date indicator (58) whose hand is carried by the thirty-one day wheel (20), a day of the week indicator (42) whose hand is carried by the star seven days (44); and bodies for correcting the day of the week (56), the month (57) and the date (62), characterized in that the twelve-month wheel (32) carries a hand (34), cooperating with an indicator for months (35), performing one revolution per year, and by the fact that an intermediate leap year wheel (30) is integral with the wheel forty-eight months (26) meshing with a leap year wheel (37) of the same diameter and the same number of teeth, this leap year wheel (37) driving an index (40), cooperating with a year indicator (41), at the rate of one revolution in four years.

2. Mechanism according to claim 1, characterized in that the leap year wheel (37) is pivoted coaxially with the twelve month wheel (32).

3. Mechanism according to claim 2, characterized in that the year indicator (41) is arranged concentrically and inside the month indicator (35), the area of this year indicator corresponding to a leap year in a four-year cycle being differentiated from other sectors.

Usually the perpetual calendar mechanisms do not allow a display of the year in which we are in relation to the four-year cycle corresponding to leap years. This is inconvenient because the user does not know whether the current year is a leap year or not. Certain perpetual calendar mechanisms have attempted to remedy this drawback by forming a display of the months comprising forty-eight months instead of twelve. It is then possible to identify the area of this display corresponding to the leap year. The disadvantage of these mechanisms is that the month display either takes up too much space or is difficult to read.

Other date mechanisms provide an indication of the current year on an indicator comprising four or a multiple of four positions, thus making it possible to identify the position of the current year in relation to a four-year cycle (cf. US 675,763; Horological Review December 1965 p. 74). Other mechanisms provide an indicator in the form of a guide in which appears an indication Roman numerals I, II, III, IV referring to the current year compared to the four-year cycle (cf. CH 318 902).

Here too, the displays are generally difficult to read and involve complications at the level of the mechanism.

The subject of the present invention is a perpetual calendar mechanism which overcomes the aforementioned drawbacks and allows both a display of the twelve months of a year on a dial turn ensuring good readability of the display of the months and a display of the year in which we are in relation to the four-year cycle.

This mechanism can of course be incorporated into a mechanical or electronic movement indifferently and be associated with other mechanisms such as a mechanism for indicating moon phases.

The perpetual calendar mechanism which is the subject of the present invention is distinguished by the characteristics listed in claim 1.

FIG. 1 illustrates the upper face of a complicated wristwatch comprising a dial provided with an analog time display. an indicator of moon phases. a date indicator, a counter indicating the day of the week, an indicator indicating the month of the year and an indicator indicating the year within a four-year cycle.

Figure 2 is an overall view from below of the perpetual calendar mechanism and a moon phase mechanism.

Figure 3 is a detail on a larger scale seen in top plan of the perpetual calendar mechanism.

Figure 4 is a section on the line IV - IV of Figure 3.

Figure 5 is a section along the line V - V in Figure 1.

The entire perpetual calendar mechanism according to the invention and in the illustrated example of a conventional moon phase mechanism, and mounted on a board 1 intended to be placed in a watch case above the clockwork movement and comprising a central opening 2 giving passage to the axes of the time switch driven by said clockwork movement. The watch dial 3 is located above the aforementioned mechanisms.

In the operating position, the socket 4 of the clockwork movement carrying the hour hand 5 and performing a complete revolution in twelve hours passes through the opening 2 of the plate 1 as well as the dial 3. The minutes socket and the seconds axis of the timepiece movement carrying respectively the minute hand 6 and the second hand 7, coaxially pass through the hour sleeve 4.

The hands 5, 6, 7 of the movement switch cooperate with conventional indications carried by the dial 3 to together constitute an analog time display.

The hours socket 4 carries a twelve-hour wheel 8 constituting the PTO driving the perpetual calendar mechanism and the moon phase mechanism.

This twelve-hour wheel 8 meshes with a twenty-four hour wheel 9, pivoted on the plate 1, comprising the double of teeth of the twelve hour wheel and thereby effecting a complete revolution in twenty-four hours. This twenty-four hour wheel 9 comprises a drive pin 10 of a finger 11 pivoted on the core 12 of this twenty-four hour wheel 9.

The end of the finger 1 1 cooperates in known manner with the peripheral toothing 13 of a moon disc 14 also pivoted on the board 1 and bearing the representation of two moons 15 diametrically opposite. A window 16 shaped in the dial 3 reveals a portion of this moon disc 14. The cooperation of the moons 15 represented on the disc 14 with this window 16 allows a display of the moon phases in a conventional manner. A jumper 18 fixes the angular positions of the moon disc 14 and a rocker pivoted on the board 1 allows manual action of the angular position of the moon disc 14.

The finger I1 has a domed back portion 17

constituting a cam actuating the perpetual calendar mechanism which will be described in the following.

The perpetual calendar mechanism comprises a thirty-one day wheel 20 pivoted on the plate 1, the peripheral toothing 21 of which comprises thirty-one teeth. This peripheral toothing 21 cooperates with a jumper 22 keeping the wheel thirty-one days 20 in a determined angular position outside the periods of drive of this wheel 20. A snail cam 23 is fixed on this wheel thirty-one days 20 concentrically to the latter using screws 24. This thirty-one day wheel 20 carries on its underside an actuating finger 25 the end of which is situated on a circle of larger diameter than the outside of the toothing 21 of the wheel thirty-one days 20.

The perpetual calendar mechanism also includes a forty-eight month wheel 26 whose peripheral toothing 27 comprising forty-eight teeth cooperates with the actuating finger 25 so that the forty-eight month wheel 26 is driven by one step. each complete revolution of the wheel thirty-one days 20, or every month.

This wheel 26 therefore performs a complete revolution in four years.

A jumper 28 cooperating with the toothing 27 of the wheel forty-eight months 26 fixes the angular positions of the latter between its periods of training by the finger 25.

This forty-eight month wheel 26 is integral and concentric with a leap cam 29 and an intermediate leap year wheel 30. The leap cam 29 has a peripheral surface concentric with its axis of rotation over 3/4 of its periphery and a lift 31 occupying the remaining quarter of its periphery.

The forty-eight month wheel 26 meshes with a twelve month wheel 32, the reduction ratio between these two wheels being such that the wheel 32 performs a complete revolution in twelve months. This twelve month wheel 32 is pivoted on the plate 1 and has a hub 33 emerging from the dial 3 and carrying a needle 34 cooperating with a month indicator 35 carried by the visible face of the dial 3. The hub 33 of the twelve month wheel carries a twelve-month cam 36 having, distributed uniformly over its periphery twelve circular bearings whose radius differs according to whether the month corresponding to the part considered comprises twenty-eight, thirty or thirty-one days The parts of largest radius corresponding to the months of thirty-one one day, the part with the smallest radius corresponding to the normal February 28-day months and the parts with intermediate radius corresponding to the thirty-day month.

The leap year intermediate wheel 30 meshes with a leap year wheel 37 of the same diameter and having the same number of teeth so that this wheel 37 performs a revolution in four years. This leap year wheel 37 is pivoted on the hub 33 of the twelve month wheel 32 and its hub 38 carries a disc 39 provided with an index 40 cooperating with an indicator of years 41 carried by the visible face of the dial 3, concentric with the month indicator.

This indicator of years 41 carries the indications one, two, three and leap to display the position of the current year in relation to a four-year cycle.

The main originality of this perpetual calendar mechanism lies mainly in the fact that from the wheel forty-eight months 26 on the one hand the hand 34 of a month indicator 35 making a turn in one year and on the other hand the index 40 of an indicator of years 41 performing a turn in four years, these indicators of months 35 and years 41 being concentric.

This perpetual calendar mechanism also includes an indicator for the days of the week 42, the needle 43 of which is carried by a seven-day star 44 pivoted on the plate 1 and the hub 45 of which emerges from the dial 3.

The perpetual calendar mechanism also includes a large lever 46, having the general shape of an S, pivoted near its center at 47 on board 1 and subjected to the action of a return spring 48 fixed on the board 1 and acting by its free end on the pin 64 of the pusher 62 pivoting itself at 65 on the large rocker 46. This large rocker 46 carries a large pawl 49 swiveled at 50 whose free end bears against the periphery of the snail cam 23. This large pawl 49 is subjected to the action of a large pawl spring 63.

This large rocker has one end 51 located on the path of the actuating finger 1 1 and another end 52 coming into contact, in leap years, with the lift 31 of the leap cam 29. Ami-chemin between its end 52 and its pivot point 47, the large rocker comprises a finger 53 cooperating with the twelve-month cam 36.

Finally, this large rocker comprises a first drive spout 54 cooperating with the toothing 21 of the wheel thirty-one days 20 and a second drive spout 55 cooperating with the star seven days 44.

Figure 2 illustrates the perpetual calendar mechanism on February 28 of a normal year.

The large rocker 46 has been moved by its return spring 48 until its finger 53 comes into contact with the bearing 36 of smaller radius corresponding to the February 28 days and the free end of the large pawl 49 under the effect of the spring of large pawl 63 has escaped from the upper part of the snail cam 23. Thus on March 1 at the next actuation of the rocker by the drive finger 11, the large pawl 49 will drive the snail cam 23 and therefore the wheel thirty-one days 20 of three steps before the spout 54 cooperates with the teeth 21 to advance the wheel thirty-one days of a fourth step. Thus a needle 56 carried by the hub 57 of the wheel thirty-one days cooperating with a day indicator 58 will advance from the twenty-eight to the first. During this angular displacement of the wheel thirty-one days 20, the finger 25 causes one step the wheel forty-eight months 26 causing the advancement of the hand 34 of the month indicator, which passes from February to March, and of the index 40 of the year indicator of 1112 respectively 1148 of tower. Simultaneously the twelve month cam is also indexed by l / l2 of a turn. Thus when the large lever 46 returns to the rest position under the action of its return spring 48, its finger 53 will come into contact with a bearing 36 of large radius corresponding to a month of thirty-one days.

During its actuation, the large lever 46 further causes the star to advance by one step seven days 45 through its beak 55 causing the needle 43 to advance by one of the days of the week indicator.

During leap years the finger 53 of the large lever 46 does not come into contact with the small diameter part of the cam twelve months corresponding to the month of February because the end 52 of the large lever 46 comes into contact with the lifting 31 of the leap cam 29. Thus the amplitude of the angular displacement of the large rocker 46 being less great than for the normal February months, the large pawl escapes from the upper part of the snail cam 23 only the twenty-nine .

It can thus be seen that the number of days by which the wheel thirty-one days is indexed at the end of the month depends on the amplitude of the angular displacement of the large lever 46, amplitude which is determined by the finger 53 and the cam twelve months respectively. February leap years by the end 52 and the lift 31 of the leap cam 29.

This perpetual calendar mechanism also includes a flip-flop 56 for correcting the days of the week, acting on the star seven days, a flip-flop correcting the months 57 acting on the wheel twelve months 32 causing the advance by 1/12 of a turn. the needle 34 and the cam twelve months and 1/48 of a turn of the index 40 via the forty-eight month wheel 26, the leap year intermediate wheel 30 and the year wheel leap 37. During these corrections, the large lever 46 is lifted by the lever 58 pivoted on the board 1 actuated by a pin 59 of the lever 57 and whose end 60 cooperates with a pin 61 of the large lever 46.

Finally, a manual advance pusher 62 makes it possible to move the large lever 46 at will to effect the position adjustments of the wheel for thirty-one days 20.

The operation of this perpetual calendar mechanism will not be described in more detail because it is conventional with regard to the thirty-one day wheel, the forty eight month wheel, the twelve month cam, the seven day star and the large seesaw . On the other hand, the originality and the novelty of this perpetual calendar mechanism lies in the fact that the forty-eight month wheel 26 secured to the leap cam 30 causes: a) on the one hand a twelve month wheel 32 carrying the twelve month cam 36 and a hand 34 of the month indicator 35 performing one revolution in one year and, b) on the other hand, a leap year intermediate wheel 30 integral with this wheel forty-eight months but of smaller diameter meshing with a leap year wheel 37, the gear ratio being such that the latter performs one revolution complete in four years. this leap year wheel carrying an index 40 of an indicator of years 41 indicating the current year in relation to a four-year cycle.

Thanks to this new design, a very readable month indicator 34, 35 is obtained, while simultaneously having the leap year indication on the year indicator. It is moreover remarkable that these two indicators 34, 35 and 40, 41 are concentric which further facilitates reading.

Claims (4)

CLAIMS 1. Perpetual date mechanism comprising a thirty-one day wheel (20) carrying a snail cam (23) and a drive finger (25) indexing by one step, for each revolution of the thirty-one day wheel ( 20) a forty-eight month wheel (26), carrying a leap year cam (29), meshing with a twelve month wheel (32) carrying a twelve month cam (36); and a large rocker (46), pivoted on a board (1) with the wheels (20, 26 and 32), actuated by a drive finger (11) driven by a twenty-four hour wheel (9) itself driven by a twelve hour wheel (8) of a clockwork movement, this large rocker (46) having a spout cooperating with the teeth (21) of the thirty one day wheel (20), a large pawl (49) cooperating with the snail cam (23), a finger (53) cooperating with the twelve month cam (36), one end (52) cooperating with the leap year cam (29) and a spout (55) acting on a star seven days (44); this mechanism further comprising a date indicator (58) whose hand is carried by the thirty-one day wheel (20), a day of the week indicator (42) whose hand is carried by the star seven days (44); and bodies for correcting the day of the week (56), the month (57) and the date (62), characterized in that the twelve-month wheel (32) carries a hand (34), cooperating with an indicator for months (35), making one revolution per year, and by the fact that an intermediate leap year wheel (30) is integral with the wheel forty-eight months (26) meshing with a leap year wheel (37) of the same diameter and the same number of teeth, this leap year wheel (37) driving an index (40), cooperating with a year indicator (41), at the rate of one revolution in four years. 2. Mechanism according to claim 1, characterized in that the leap year wheel (37) is pivoted coaxially with the twelve month wheel (32). 3. Mechanism according to claim 2, characterized in that the year indicator (41) is arranged concentrically and inside the month indicator (35), the area of this year indicator corresponding to a leap year in a four-year cycle being differentiated from other sectors. Usually the perpetual calendar mechanisms do not allow a display of the year in which we are in relation to the four-year cycle corresponding to leap years. This is inconvenient because the user does not know whether the current year is a leap year or not. Certain perpetual calendar mechanisms have attempted to remedy this drawback by forming a display of the months comprising forty-eight months instead of twelve. It is then possible to identify the area of this display corresponding to the leap year. The drawback of these mechanisms is that the month display either takes up too much space or is difficult to read. Other date mechanisms provide an indication of the current year on an indicator comprising four or a multiple of four positions, thus making it possible to identify the position of the current year in relation to a four-year cycle (cf. US 675,763; Horological Review December 1965 p. 74). Other mechanisms provide an indicator in the form of a guide in which appears an indication Roman numerals I, II, III, IV referring to the current year compared to the four-year cycle (cf. CH 318 902). Here too, the displays are generally difficult to read and involve complications at the level of the mechanism. The subject of the present invention is a perpetual calendar mechanism which overcomes the aforementioned drawbacks and allows both a display of the twelve months of a year on a dial turn ensuring good readability of the display of the months and a display of the year in which we are in relation to the four-year cycle. This mechanism can of course be incorporated into a mechanical or electronic movement indifferently and be associated with other mechanisms such as a mechanism for indicating moon phases. The perpetual calendar mechanism which is the subject of the present invention is distinguished by the characteristics listed in claim 1. FIG. 1 illustrates the upper face of a complicated wristwatch comprising a dial provided with an analog time display. an indicator of moon phases. a date indicator, a counter indicating the day of the week, an indicator indicating the month of the year and an indicator indicating the year within a four-year cycle. Figure 2 is an overall view from below of the perpetual calendar mechanism and a moon phase mechanism. Figure 3 is a detail on a larger scale seen in top plan of the perpetual calendar mechanism. Figure 4 is a section on the line IV - IV of Figure 3. Figure 5 is a section along the line V - V in Figure 1. The entire perpetual calendar mechanism according to the invention and in the illustrated example of a conventional moon phase mechanism, and mounted on a board 1 intended to be placed in a watch case above the clockwork movement and comprising a central opening 2 giving passage to the axes of the time switch driven by said clockwork movement. The watch dial 3 is located above the aforementioned mechanisms. In the operating position, the socket 4 of the clockwork movement carrying the hour hand 5 and performing a complete revolution in twelve hours passes through the opening 2 of the plate 1 as well as the dial 3. The minutes socket and the seconds axis of the watch movement carrying respectively the minute hand 6 and the second hand 7, coaxially pass through the hour sleeve 4. The hands 5, 6, 7 of the movement switch cooperate with conventional indications carried by the dial 3 to together constitute an analog time display. The hours socket 4 carries a twelve-hour wheel 8 constituting the PTO driving the perpetual calendar mechanism and the moon phase mechanism. This twelve-hour wheel 8 meshes with a twenty-four hour wheel 9, pivoted on the plate 1, comprising the double of teeth of the twelve hour wheel and thereby effecting a complete revolution in twenty-four hours. This twenty-four hour wheel 9 comprises a drive pin 10 of a finger 11 pivoted on the core 12 of this twenty-four hour wheel 9. The end of the finger 1 1 cooperates in known manner with the peripheral toothing 13 of a moon disc 14 also pivoted on the board 1 and bearing the representation of two moons 15 diametrically opposite. A window 16 shaped in the dial 3 reveals a portion of this moon disc 14. The cooperation of the moons 15 represented on the disc 14 with this window 16 allows a display of the moon phases in a conventional manner. A jumper 18 fixes the angular positions of the moon disc 14 and a rocker pivoted on the board 1 allows manual action of the angular position of the moon disc 14. ** ATTENTION ** end of the CLMS field may contain start of DESC **.