Display mechanism

Abstract

To provide a display mechanism which makes it possible to display the date, the day of the week and the month on a single line of a single aperture configured to be as large as possible without superimposition of discs.SOLUTION: The present invention relates to a display mechanism for a timepiece movement comprising a first display wheel (110; 120) and a second display wheel (130; 140) that are arranged to be coplanar, the first and second display wheels (110; 120; 130; 140) being arranged to be pivoted relative to one another via at least one ball bearing.SELECTED DRAWING: Figure 5a

Description

[Technical Field]

[0001] The present invention relates to a timepiece display mechanism, in particular a simple or permanent date display mechanism, preferably a display mechanism capable of displaying the date, the day of the week and the month.

[0002] One of the problems that arise when displaying the date on a watch, especially a wristwatch, is legibility. In fact, arranging 31 indicators across the display wheel (date disc) often results in the display size being extremely small, sometimes too small to be read comfortably. This problem also applies to the display of the week number, which includes 51 indicators.

[0003] Several solutions to this problem could be to provide optical magnification, such as a magnifying glass, on the glass to aid reading, or to separate the ones and tens digits onto separate wheels, thus greatly increasing the size of these digits.

[0004] Date mechanisms using this latter method are commonly referred to as "large dates" and are well known. Swiss Patent No. 310 559, for example, describes a date display in which the date is displayed by two juxtaposed or coplanar discs, one with the tens digit and the other with the ones digit. Other arrangements of the ones and tens discs are possible. European Patents Nos. 0 529 191 and 1 070 996 describe date displays with superimposed ones and tens discs. Swiss Patent No. 690 515, German Patent No. 102005010602, and Swiss Patent No. 688 671 describe date displays with coplanar and coaxial ones and tens discs. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Swiss Patent No. 310 559 [Patent Document 2] European Patent No. 0 529 191 [Patent Document 3] European Patent No. 1 070 996 [Patent Document 4] Swiss Patent No. 690 515 [Patent Document 5] German Patent No. 102005010602 [Patent Document 6] Swiss Patent No. 688 671 Summary of the Invention [Problem to be solved by the invention]

[0006] These mechanisms have several drawbacks. On the one hand, when these mechanisms overlap, the difference in the level of the tens disc and the ones disc impairs the readability and appearance of the date display. On the other hand, when the tens disc and the ones disc are coaxial, regardless of whether they are coplanar or not, there are constraints related to the pivoting movement of their respective supports: namely, friction due to the pivoting movement of the bearings or jewels, and friction due to the pivoting movement between the interacting spindle and wheel. Due to some of these constraints, the discs can brake each other or drive each other due to friction at inappropriate moments. Furthermore, these mechanisms require a considerable torque to overcome these constraints and pivot the two discs simultaneously when the ones and tens digits of the date change. [Means for solving the problem]

[0007] It is therefore an object of the present invention to provide a display mechanism comprising two coplanar display discs, in particular a mechanism for displaying the date, which overcomes the drawbacks mentioned above. One particular object of the present invention is to provide a display mechanism which makes it possible to display the date, the day of the week and the month on a single line in a single aperture as large as possible, without overlapping discs.

[0008] The invention relates to a display mechanism as defined in claim 1 and to a movement and a timepiece as defined in claims 10 and 11 respectively.

[0009] The accompanying drawings show, by way of example only, one embodiment of a display mechanism according to the invention. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 illustrates a display mechanism according to one embodiment of the present invention that allows for the display of date, day of the week, and month. [Figure 2] FIG. 2 is a view of FIG. 1 without the day and month indicators. [Figure 3] FIG. 2 shows the same display as in FIG. 1 without the day and month indicators or discs. [Figure 4a] 2 is a perspective view of the display wheel of the display mechanism of FIG. 1; [Figure 4b] 2 is a side view of the display wheel of the display mechanism of FIG. 1. FIG. [Figure 5a] FIG. 2 is a perspective view of a ball bearing of the display mechanism of FIG. 1; [Figure 5b] FIG. 2 is a cross-sectional view of a ball bearing of the display mechanism of FIG. 1.

[0011] The present invention relates to a display mechanism intended to be used in a timepiece movement. In the illustrated embodiment, the display mechanism is capable of displaying the date, the day of the week, and the month.

[0012] In particular, the display mechanism shown comprises a tens indicator 11 and a ones indicator 12 which together form a date display, as well as a day indicator 13 and a month indicator 14.

[0013] The tens indicator 11 is crown-shaped and has the sequence 0, 1, 2, 3 repeated five times counterclockwise.

[0014] The ones indicator 12 is also crown-shaped and has the sequence of numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 repeated twice counterclockwise.

[0015] The date display is of the "large date" type, with the units and tens digits shown on separate wheels, thus allowing for a display of a reasonable size for easy reading.

[0016] The day of the week indicator 13 and month indicator 14 are disc-shaped and each have seven indicators for the days of the week and twelve indicators for the months of the year arranged clockwise (the indicators in the figure use the usual English abbreviations).

[0017] In the illustrated embodiment, the tens indicator 11 and the day of the week indicator 13 are coaxial and on the same plane, with the tens indicator 11 surrounding the day of the week indicator 13. The units indicator 12 and the month indicator 14 are also coaxial and on the same plane, with the units indicator 12 surrounding the month indicator 14. The four indicators 11, 12, 13, and 14 are arranged to be on the same plane. In this way, the day of the week, date, and month can be displayed on the same plane with a single large aperture.

[0018] More precisely, the day indicator 13 is carried by a day disc 130. The day disc 130 is arranged to pivot relative to a first fixed ring 15 which is coaxial with the day disc 130 and fixedly attached to a plate or bridge of the movement. The day disc 130 pivots inside the first fixed ring 15 by means of a first ball bearing (see Figures 5a and 5b) in which a first series of balls 161 are held in a regularly spaced arrangement by any suitable means (a cage) between the day disc 130 and the first fixed ring 15.

[0019] The tens indicator 11 is carried by a tens ring 110 which is mounted coaxially on the day disc 130 and the first fixed ring 15 and is arranged to pivot relative to said first fixed ring 15 by means of a second ball bearing (see Figures 5a and 5b) in which a second series of balls 162 are held in a regularly spaced arrangement by any suitable means (cage) between the tens ring 110 and the first fixed ring 15.

[0020] The units indicator 12 and month indicator 14 are similarly arranged. The month indicator 14 is carried by a moon disc 140. The moon disc 140 is arranged to pivot relative to a second fixed ring 17 that is coaxial with the moon disc 140 and is fixedly attached to a plate or bridge of the movement. The moon disc 140 pivots inside the second fixed ring 17 by means of a third ball bearing (see Figures 5a and 5b) in which a third series of regularly spaced balls 163 are held between the moon disc 140 and the second fixed ring 17 by any suitable means (a cage).

[0021] The units indicator 12 is carried by a units ring 120 that is coaxially mounted on the moon disc 140 and the second fixed ring 17, and is arranged to pivot relative to said second fixed ring 17 by means of a fourth ball bearing (see Figures 5a and 5b) in which a fourth series of balls 164 are held in a regularly spaced arrangement by any suitable means (cage) between the units ring 120 and the second fixed ring 17.

[0022] Thus, four ball bearings are formed, firstly, by the day disc 130, the first fixed ring 15 and the first series of balls 161; secondly, by the first fixed ring 15, the tens ring 110 and the second series of balls 162; thirdly, by the month disc 140, the second fixed ring 17 and the third series of balls 163; and fourthly, by the second fixed ring 17; these four ball bearings make it possible to replace sliding friction (of the spindle between two bearings or jewels, or of the tubes interacting inside the other) by rolling friction between the day disc 130, the tens ring 110 and the first fixed ring 15, and between the month disc 140, the units ring 120 and the second fixed ring 17.

[0023] In general terms, the display mechanism according to the first embodiment is arranged to drive the ones ring 120 (ones indicator 12) 30 times per month (not driven during the transition from 31 to 01, see below), the day disc 130 (day indicator 13) once per day, the tens ring 110 and tens indicator 11 four times per month, and the month disc 140 (month indicator 14) once per month.

[0024] To achieve this, the tens ring 110 has an external tooth arrangement 111 which is adapted to be driven four steps per month via a dedicated kinematic chain mechanism of the display mechanism, and a positioning tooth arrangement 112 which cooperates with a jumper 113 for angular positioning.

[0025] The units ring 120 also has an external tooth arrangement 121 which is adapted to be driven 30 steps per month via a dedicated kinematic chain mechanism of the display mechanism, and a positioning tooth arrangement 122 which cooperates with a jumper 123 for angular positioning.

[0026] The day disc 130 is fixedly attached in part to a day star 30 which includes seven teeth arranged to be driven one step per day by a dedicated kinematic chain mechanism of the display mechanism, and its positioning is determined by a jumper 31.

[0027] Finally, the lunar disc 140 is also fixedly attached to the lunar star 4, which has 12 teeth and is arranged to rotate once per year. The positioning of the lunar star 4, and therefore of the lunar disc 140, is achieved by a lunar jumper 41.

[0028] The display mechanism according to this embodiment preferably automatically takes into account the length of the days of the month (28, 29, 30 or 31), the transition from 31 to 01 at the end of the month, and leap years. It is therefore a perpetual date display mechanism. The operation of such a perpetual calendar and the kinematic chain that makes it up are not the subject of the present invention and will not be described in further detail here.

[0029] The display mechanism described above may also include correction mechanisms for correcting the displayed date, day of the week, and month.

[0030] The display mechanism described above allows for the display of the date, day of the week, and month, and furthermore, does so permanently, and is an example of one embodiment of a display mechanism according to the present invention.

[0031] As a variant, the display mechanism according to the invention may be a simple calendar, an annual calendar or a perpetual calendar, or may also display the number of weeks, or even a chronograph counter, or more generally a display mechanism allowing the display of a single item of information in a single aperture, or the display of several different items of information in at least one aperture.

[0032] The above-described embodiment actually combines several variants of the invention, in that the ones indicator and the tens indicator are juxtaposed in the same plane, pivoted relative to each other by two ball bearings and cooperate to display a single item of information (date) in the same aperture, while the tens indicator and the day indicator are coaxially positioned in the same plane and pivoted relative to each other by two ball bearings to display two different items of information (tens of the date and day of the week) in the same aperture.

[0033] A display mechanism according to the present invention generally comprises at least one first display wheel and a second display wheel, arranged coaxially or coplanarly so as to be juxtaposed, and arranged to pivot relative to one another by means of at least one ball bearing.

[0034] In a first variant, each of the first and second display wheels comprises at least a fixed part and a movable part arranged to pivot relative to the fixed part by means of a first or second ball bearing, respectively. That is, a first or second series of balls, respectively, are arranged between the movable part of the first display wheel and its fixed part, and between the movable part of the second display wheel and its fixed part, forming the first and second ball bearings, respectively. In this variant, several arrangements are possible for one display wheel, the other display wheel, or both display wheels, i.e., the movable part is pivotally mounted inside or outside the respective fixed part, or the movable part is pivotally mounted between the first and second fixed parts by means of two ball bearings. Depending on the arrangement, the movable part and the fixed part can be disk-shaped or ring-shaped.

[0035] In another variant, the first and second display wheels are also coaxial and each have a movable part. According to a first alternative, the movable part of the second display wheel pivots inside the movable part of the first display wheel by means of a ball bearing, with a ball being arranged between the movable part of the first display wheel and the movable part of the second display wheel. According to this first alternative, the first display wheel can further include a fixed part, and the movable part of the first display wheel can be arranged for pivotal movement relative to the fixed part by means of another ball bearing. According to a second alternative, the display mechanism further comprises at least one fixed part that is coaxial and coplanar with the first and second display wheels, and the movable part of the first display wheel pivots on its outer side relative to the fixed part by means of a first ball bearing, while the movable part of the second display wheel pivots on its inner side relative to the fixed part by means of a second ball bearing. In this second alternative, several arrangements are possible for one display wheel, the other display wheel, or both display wheels, i.e., the display mechanism comprises a second, central, fixed part around which the movable part of the second display wheel pivots by means of another ball bearing, and the display mechanism comprises a third, outer, fixed part inside which the movable part of the first display wheel pivots by means of yet another ball bearing. As with the previous variant, depending on the arrangement chosen, the movable and fixed parts can be in the form of a disk or a ring.

[0036] The first and second display wheels each carry an indicator intended to cooperate with at least one fixed aperture to display one or more items of information, the indicators preferably cooperating with the same single fixed aperture.

[0037] In this way, a display mechanism with coaxial or side-by-side wheels on the same plane can be presented, i.e., overcoming the limitations associated with pivoting wheels seen in the prior art while providing an easy-to-read and attractive display (without level differences). Indeed, by using ball bearings to pivot two coplanar wheels, the wheels do not need to rotate between stones or bearings, and, if the wheels are coaxial, there is no need for tubes or wheels to rotate one inside the other. This eliminates limitations due to sliding friction. The wheels are truly independent of each other, with no risk of interaction (one wheel driving another wheel due to excessive frictional constraints). Finally, because rolling friction is less than sliding friction, the energy required to rotate the wheels is also significantly reduced, which is extremely useful for display mechanisms such as those described above that must drive a significant number of wheels at the end of the month.

Claims

1. A display mechanism for a timepiece movement, comprising a first display wheel (110; 120) and a second display wheel (130; 140) arranged in the same plane, the first and second display wheels (110, 120; 130; 140) are further configured to pivot relative to one another by at least one ball bearing (161, 162, 163, 164); A display mechanism characterized by:

2. each of the first and second display wheels includes a fixed portion and a movable portion that pivots relative to the fixed portion by means of first and second ball bearings, respectively; 2. The display mechanism of claim 1, wherein the display mechanism comprises:

3. The first and second display wheels (110, 130; 120, 140) are also coaxial.

2. The display mechanism of claim 1, wherein the display mechanism comprises:

4. each of the first and second display wheels includes a movable portion, the movable portion of the second display wheel pivoting inside the movable portion of the first display wheel by a first ball bearing; 4. The display mechanism according to claim 3, wherein the display mechanism comprises:

5. and at least one fixed part configured such that the movable part of the first display wheel is pivoted inside the fixed part by a second ball bearing or the movable part of the second display wheel is pivoted outside the fixed part by a third ball bearing.

5. The display mechanism according to claim 4.

6. a fixing ring (15; 17) coaxial and coplanar with said first and second display wheels (110, 130, 120, 140); the first indicator wheel comprises an outer ring (110; 120) and the second indicator wheel comprises an inner ring or disc (130; 140); the outer ring (110; 120) of the first indicator wheel is configured for pivotal movement outside thereof relative to a fixed ring (15; 17) by means of first ball bearings (162; 164); the inner ring or disc (130; 140) of the second indicator wheel is arranged for pivotal movement inside the fixed ring (15; 17) by means of second ball bearings (161; 163), 4. The display mechanism according to claim 3.

7. said first and second display wheels respectively carrying first and second indicators (11, 12, 13, 14), said first and second indicators adapted to cooperate with at least one fixed aperture for displaying at least one item of information; 7. The display mechanism according to claim 1, wherein the display mechanism is a display unit.

8. the first and second indicators (11, 12, 13, 14) are configured to cooperate with the same fixed single aperture; 8. The display mechanism according to claim 7, characterized in that:

9. the first and second indicators (11, 12) carried by the first and second display wheels cooperate with the fixed aperture to display a single item of information; 8. A display mechanism according to claim 6 or 7, characterized in that it comprises:

10. A timepiece movement comprising the display mechanism according to any one of claims 1 to 9.

11. A timepiece comprising the movement according to claim 10.

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