HK1213058B - Date display device for a timepiece - Google Patents

Description

Date display device for a timepiece

Technical Field

The present invention relates to a date display device for a timepiece. More particularly, the invention relates to a device of the above type, particularly suitable for large date display.

Background

There are a large number of known date display devices for timepieces. Typically, these date display devices are complex and contain numerous components. Therefore, their cost is high and their operational reliability cannot always be guaranteed.

Disclosure of Invention

It is an object of the present invention to overcome the above drawbacks by providing a date display device for a timepiece comprising a limited number of components.

To this end, the invention relates to a device for displaying a date indication in an aperture of a dial, the device comprising:

-a bit indicator carrying ten individual digits from "0" to "9" on the outer circumference in an evenly spaced manner, each of the ten individual digits being separated from the next by a blank space or display window arranged on the outer circumference of the bit indicator;

-a tens indicator carrying on the periphery a succession of thirty-one evenly spaced digits, namely nine digits "0" in succession, then ten digits "1" in succession, then ten digits "2" in succession and finally two digits "3" in succession;

-the ones indicator is arranged above the tens indicator, which tens indicator is further forward each day and which is driven one step forward each day, except on the day when the date indication display changes from "31" to "01".

Thanks to the above features, the present invention provides a date display device comprising a limited number of components. This type of device is therefore less expensive and operates more reliably than prior art devices.

According to an additional feature of the invention:

-the tens indicator is provided with a first toothing formed by thirty teeth, each tooth being arranged to correspond to one of the digits carried by the tens indicator, one region of the tens indicator carrying a given digit of the sequence of thirty-one digits being free of teeth, so that the units indicator remains stationary when the second digit "3" of the tens indicator, intended to form an indication "31" together with the digit "1" of the units indicator, disappears from the hole and is replaced by the first digit "0" of the sequence of nine digits "0" of the tens indicator, in order to form an indication "01" together with the digit "1" of the units indicator;

-a gear ring having thirty teeth extending over the outer circumference of the tens indicator;

-the tens indicator comprises a toothing at a lower level formed by thirty-one evenly spaced teeth, via which the tens indicator is driven by the wheel of the watch movement at a frequency of one step per day;

-the ones place indicator is driven by the tens indicator via an intermediate wheel and a ones place star wheel, the position of which is calibrated by a jumper spring;

-the unit indicator is mounted on the unit star wheel;

-the units indicator is arranged concentrically over the tens indicator;

-the ten individual digits from "0" to "9" are arranged in a clockwise direction on the units indicator and the series of thirty-one digits are arranged in a counter-clockwise direction on the tens indicator;

-the units indicator and the tens indicator are each formed by an annular member.

Drawings

Further characteristics and advantages of the invention will emerge more clearly from the following detailed description of an embodiment of the day display device, given by way of non-limiting illustration only, with reference to the accompanying drawings, in which:

figure 1 is a top view of a timepiece dial provided with a date display device according to the invention.

Figure 2 is a perspective view of the date display device of the invention in an unassembled state.

Fig. 3 is a top view of the timepiece of fig. 1, from which the dial and the units indicator ring have been removed in order to reveal the tens indicator ring.

Fig. 4 is a top view of the timepiece of fig. 3, wherein the units indicator ring is arranged concentrically over the tens indicator ring.

Figure 5 is a perspective bottom view of a ten-position indicator ring.

Fig. 6 is a view of a driving wheel which completes one revolution in 24 hours and which carries a finger via which it intermeshes with a second ring gear of the ten-position indicator ring, which has thirty-one teeth.

Detailed Description

The invention proceeds from the general inventive concept which consists in driving the units indicator of the date display device via the tens indicator. On the first 30 days of a month, the tens indicator drives the units indicator once every other day, while on the 31 st day when the date indication changes from the indication "31" to the indication "01", the units indicator remains stationary. The units indicator is arranged above the tens indicator such that the surface areas of the two indicators remain within an acceptable size range while providing a large size display.

Fig. 1 is a top view of a timepiece dial provided with a date display device according to the invention. The dial as a whole is designated by the general reference numeral 1 and comprises a hole 2, which hole 2 is positioned in the example shown in the figures at the midday (i.e. 12 o' clock) position and in which hole 2 a date indication 4 is displayed. The date indication 4 consists of a number representing the units 4a and a number representing the tens 4 b.

According to the invention, the date display device comprises a tens indicator ring 6 and a units indicator ring 8. As can be observed in fig. 2 and 3, the tens indicator ring 6 carries on the periphery 10 a succession of thirty-one evenly spaced numbers, namely nine numbers "0" in succession, then ten numbers "1" in succession, then ten numbers "2" in succession and finally two numbers "3" in succession. In the example shown in the drawings, thirty-one numbers carried by the ten-digit indicator 6 are consecutive to one another in a uniformly spaced manner in the counterclockwise direction. It goes without saying that the numbers carried by the tens indicator 6 may be distributed in a clockwise direction by modifications within the reach of the person skilled in the art. The bit indicator 8 (see in particular fig. 2) carries ten individual numbers from "0" to "9" on the outer periphery 12 in an evenly spaced manner, each of the ten individual numbers being separated from the next by a blank space 14 arranged on the outer periphery 12 of the bit indicator ring 8. In the example shown in the drawings, ten individual numbers from "0" to "9" follow one another in the clockwise direction. Of course, the function of the empty space 14 is to enable the indication carried by the tens indicator ring 6 to be seen when the units indicator ring 8 is arranged above the tens indicator ring 6. As a preferred but non-limiting example, the units indicator ring 8 is arranged concentrically with respect to the tens indicator ring 6. According to a variant embodiment, not shown, the empty space 14 can be replaced in different cases by a display hole arranged between two successive individual numbers.

The ten position indicator ring 6 (see fig. 5) comprises a first gear ring 18 having thirty teeth on a higher level along the inner edge 16 of the ring, wherein each tooth is positioned to correspond to one of the thirty numbers carried by the ten position indicator ring 6. According to the invention (see fig. 2), the area 20 of the tens indicator ring 6 carrying the designated number of the series of thirty-one numbers is free of teeth, so that the units indicator ring 8 remains stationary when the second number "3" of the tens indicator ring 6, which is used to form the indication "31" together with the number "1" of the units indicator ring 8, disappears from the hole 2 and is replaced by the first number "0" of the series of nine numbers "0" of the tens indicator ring 6 in order to form the indication "01" together with the number "1" of the units indicator ring 8. In the example shown in the drawings, the area 20 of the ten-digit indicator ring 6 without teeth corresponds to the first digit "2" of the series of ten digits "2". It is clearly understood that the positioning of the area 20 of the tens indicator ring 6 without teeth depends on the position of the hole 2 on the dial 1 and on the position of the intermediate wheel 28. In the example shown in the figures, the hole 2 is positioned at the 12 o' clock position on the dial 1. However, it is entirely possible to arrange the hole 2 at another position on the dial 1, for example at the three o 'clock or nine o' clock position, in which case it is necessary to change the positioning of the toothless zone 20 of the tens indicator ring 6 so that the units indicator ring 8 remains stationary when the indication "31" disappears from the hole 2 and is replaced by the indication "01".

The tens indicator ring 6 also comprises, at a lower level, a second ring of teeth 22 formed by thirty-one evenly spaced teeth, via which the tens indicator ring 6 is driven at the frequency of one step per day by the wheel 24 of the watch movement. For this purpose, the drive wheel 24 completes one revolution in twenty-four hours and carries a finger 24a (see fig. 6), by means of which finger 24a said drive wheel 24 engages the second ring gear 22 of the tens indicator ring 6. According to a preferred but non-limiting variant of the invention, the second ring gear 22 extends along the inner edge 16 of the tens indicator ring 6. In the embodiment shown in the drawings, the second ring gear 22 is in the form of a component fixed to the bottom of the tens indicator ring 6. It is of course also conceivable to make the tens indicator ring 6 in one piece with the first toothing 18 and the second toothing 22. According to another variant, not shown, the second ring gear 22 may be arranged along the outer edge 26.

It is observed that the teeth of the second ring gear 22 and the teeth of the first ring gear 18 are arranged staggered, i.e. the teeth of the second ring gear 22 correspond to the recesses between two consecutive teeth of the first ring gear 18.

In the example shown in the figures, the tens indicator ring 6 rotates in the clockwise direction and drives, via its first toothing 18, an intermediate wheel 28, which intermediate wheel 28 also rotates in the clockwise direction and in turn meshes with an unit star wheel 30, the position of which unit star wheel 30 is calibrated by a jumper spring 32. The unit star wheel 30 rotates in a counterclockwise direction and carries a unit indicator ring 8, the unit indicator ring 8 being secured to the unit star wheel 30 by any suitable means.

As is clear from the above description, the tens indicator ring 6 advances one step per day and the units indicator 8 is driven one step per day by the intermediate wheel 28 and the units star wheel 30. This actuation was repeated daily except for the day on which the indication "31" disappeared from well 2 and was replaced by the indication "01". In fact, on this day, the intermediate wheel 28 is opposite the area 20 of the tens indicator ring 6 without teeth, so that the tens indicator ring 6 advances one step, while the intermediate wheel 28 and therefore the units indicator ring 8 remain stationary.

It goes without saying that the invention is not limited to the embodiment just described, and that a person skilled in the art may envisage many simple modifications and variants without departing from the scope of the invention as defined by the appended claims. It should be particularly understood that the orientation of the digits on the tens indicator ring 6 and the units indicator ring 8 may be reversed from that described above. In this case, the direction of rotation of the units indicator ring 8 and the tens indicator ring 6 would be reversed. It should also be observed that the tens indicator 6 and the units indicator 8 are made in the form of two annular pieces. The two indicators 6 and 8 may be in the form of two transparent discs on the surface of which a number of tens and units digits are provided.

Claims (11)

1. Display device for displaying a date indication (4) in a hole (2) of a dial (1), comprising:

-a bit indicator (8) carrying ten individual digits from "0" to "9" on the outer circumference in an evenly spaced manner, each of the ten individual digits being separated from the next by a blank space (14) or display hole arranged on the outer circumference (12) of the bit indicator (8);

-a tens indicator (6) carrying on the periphery a succession of thirty-one evenly spaced digits, namely nine digits "0" in succession, then ten digits "1" in succession, then ten digits "2" in succession and finally two digits "3" in succession;

-the units indicator (8) is arranged above the tens indicator (6), the tens indicator (6) driving the units indicator (8) one step forward each day and one step forward each day, except on the day when the date indication display changes from "31" to "01".

2. The display device as claimed in claim 1, characterised in that the tens indicator (6) is provided with a first toothing (18) formed by thirty teeth, wherein each tooth is arranged to correspond to one of the numbers carried by the tens indicator (6), one region (20) of the tens indicator (6) carrying a designated number of the series of thirty-one numbers is free of teeth, such that when the second digit "3" of the ten digit indicator (6) for forming an indication "31" together with the digit "1" of the units indicator (8) disappears from the hole (2) and is replaced by the first digit "0" of a series of nine digits "0" of the ten digit indicator (6), to form an indication "01" together with the number "1" of the units indicator (8), the units indicator (8) remains stationary.

3. A display device as claimed in claim 2, characterised in that the tens indicator (6) comprises a second toothing (22) formed by thirty-one evenly spaced teeth, through which the tens indicator is driven by a wheel (24) of the watch movement at the frequency of one step per day.

4. The display device according to claim 3, wherein the second gear ring (22) having thirty one teeth and the first gear ring (18) having thirty teeth extend along an inner edge (16) of the tens indicator (6), the second gear ring (22) having thirty one teeth is formed on a lower level of the tens indicator (6), and the first gear ring (18) having thirty teeth is formed on an upper level of the tens indicator (6).

5. A display device as claimed in claim 4, characterised in that the teeth of the second toothed ring (22) with thirty one teeth and the teeth of the first toothed ring (18) with thirty teeth are staggered, the recess between two successive teeth of the first toothed ring (18) with thirty teeth corresponding to one tooth of the second toothed ring (22) with thirty one teeth.

6. The display device according to claim 3, characterized in that the second gear ring (22) with thirty-one teeth extends along an outer edge (26) of the ten indicator (6).

7. The display device according to any one of claims 3 to 6, characterised in that the ones unit indicator (8) is driven by the tens indicator (6) via an intermediate wheel (28) and a ones unit star wheel (30), the position of which is calibrated by a jumper spring (32).

8. A display device according to claim 7, characterised in that the unit indicator (8) is mounted on the unit star wheel (30).

9. The display device according to claim 1, characterized in that the units indicator (8) is arranged concentrically above the tens indicator (6).

10. The display device according to claim 1, wherein the ten individual digits from "0" to "9" are provided on the units indicator (8) in a clockwise direction and the series of thirty-one digits is provided on the tens indicator (6) in a counterclockwise direction.

11. The display device according to claim 1, wherein the units indicator (8) and the tens indicator (6) are each formed by an annular member.