Timepiece displaying the current time and including at least first and second devices displaying a time-related quantity

Abstract

Timepiece displaying the current time and including at least first and second display devices for a time-related quantity, the first and second display devices each being driven by a drive mechanism including a drive wheel (2; 2a), which is itself driven by the movement of the timepiece (3), at least the drive wheel (2; 2a) of one of the drive mechanisms carrying a finger (4; 4a) via which the wheel drives the corresponding display device, the timepiece (3) being characterized in that the finger (4; 4a) is friction fitted onto the drive wheel (2; 2a).

Claims

1. A timepiece displaying a current time, the timepiece comprising: at least first and second display devices for a time-related quantity; at least first and second drive mechanisms, wherein the first display device is driven by the first drive mechanism including a first drive wheel and the second display device is driven by the second drive mechanism including a second drive wheel, wherein both the first drive wheel and the second drive wheel are driven by a movement of the timepiece, wherein at least one of the first drive wheel and the second drive wheel carries a finger, wherein the at least one of the first drive wheel and the second drive wheel drives the corresponding display device by the finger, wherein the finger is friction fitted onto the at least one of the first drive wheel and the second drive wheel, wherein the finger is pivotable, relative to the at least one of the first drive wheel and the second drive wheel that the finger is friction fitted onto, and wherein the finger is friction fitted onto the at least one of the first drive wheel and the second drive wheel via an oblong aperture that the finger includes.

2. The timepiece according to claim 1, wherein the first drive wheel and the second drive wheel are driven by the movement of the timepiece independently from one another.

3. The timepiece according to claim 1, wherein the at least first and second display devices include any combination of at least two of a date display device, a day of the week display device, and a 24-hour display device.

4. The timepiece according to claim 3, wherein each of the at least first and second display devices include an indicator hand.

5. A timepiece displaying a current time, the timepiece comprising: at least first and second display devices for a time-related quantity; at least first and second drive mechanisms, wherein the first display device is driven by the first drive mechanism including a first drive wheel and the second display device is driven by the second drive mechanism including a second drive wheel, wherein both the first drive wheel and the second drive wheel are driven by a movement of the timepiece, wherein at least one of the first drive wheel and the second drive wheel carries a finger, wherein the at least one of the first drive wheel and the second drive wheel drives the corresponding display device by the finger, wherein the finger is friction fitted onto the at least one of the first drive wheel and the second drive wheel, wherein the finger is pivotable, relative to the at least one of the first drive wheel and the second drive wheel that the finger is friction fitted onto, wherein the finger is directly friction fitted onto a hub of the at least one of the first drive wheel and the second drive wheel, and wherein the finger is directly friction fitted onto the hub of the at least one of the first drive wheel and the second drive wheel via an oblong aperture that the finger includes.

6. The timepiece according to claim 5, wherein the first drive wheel and the second drive wheel are driven by the movement of the timepiece independently from one another.

7. The timepiece according to claim 5, wherein the at least first and second display devices include any combination of at least two of a date display device, a day of the week display device, and a 24-hour display device.

8. The timepiece according to claim 7, wherein each of the at least first and second display devices includes an indicator hand.

9. A timepiece displaying a current time, the timepiece comprising: at least first and second display devices for a time-related quantity; at least first and second drive mechanisms, wherein the first display device is driven by the first drive mechanism including a first drive wheel and the second display device is driven by the second drive mechanism including a second drive wheel, wherein both the first drive wheel and the second drive wheel are driven by a movement of the timepiece, wherein at least one of the first drive wheel and the second drive wheel carries a finger, wherein the at least one of the first drive wheel and the second drive wheel drives the corresponding display device by the finger, wherein the finger is friction fitted onto the at least one of the first drive wheel and the second drive wheel, wherein the finger is pivotable, relative to the at least one of the first drive wheel and the second drive wheel that the finger is friction fitted onto, wherein the finger is directly friction fitted onto a hub of the at least one of the first drive wheel and the second drive wheel, wherein the finger is friction fitted onto the at least one of the first drive wheel and the second drive wheel via a spring, and wherein the finger is directly friction fitted onto the hub of the at least one of the first drive wheel and the second drive wheel via an oblong aperture that the finger includes.

10. The timepiece according to claim 9, wherein the first drive wheel and the second drive wheel are driven by the movement of the timepiece independently from one another.

11. The timepiece according to claim 9, wherein the at least first and second display devices include any combination of at least two of a date display device, a day of the week display device, and a 24-hour display device.

12. The timepiece according to claim 11, wherein each of the at least first and second display devices includes an indicator hand.

13. A method of adjusting a moment at which an indication provided by a time quantity display device of a timepiece is incremented, wherein the time quantity display device is driven by a drive wheel, wherein the drive wheel is driven by a movement of the timepiece, and wherein the drive wheel carries a finger via which the drive wheel drives the time quantity display device, the method comprising: friction fitting the finger onto the drive wheel, and adjusting an angular position of the finger by pivoting the finger with respect to the drive wheel in order to adjust the moment at which the display device is triggered, wherein the friction fitting the finger includes friction fitting the finger onto the drive wheel via an oblong aperture that the finger includes.

14. The adjustment method according to claim 13, wherein the finger is pivoted relative to the drive wheel by a tool.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features and advantages of the present invention will appear more clearly upon reading the following detailed description of an example embodiment of the timepiece according to the invention, this example being given purely by way of non-limiting illustration, with reference to the annexed drawing, in which:

(2) FIG. 1, already cited, is a plan view of the timepiece dial according to the invention;

(3) FIG. 2, already cited, is a plan view of the time quantity display mechanism;

(4) FIG. 3 is a plan view of a drive mechanism for a time quantity display device according to the invention;

(5) FIG. 4 is a cross-section of the mechanism of FIG. 3, and

(6) FIG. 5 is a plan view of a simplified embodiment of the invention.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

(7) The present invention proceeds from the general inventive idea, which consists in providing a timepiece capable of displaying at least two time quantities, in addition to the current time. The display of these time quantities is linked to the current time display and has to be altered simultaneously at a determined change of time, typically at midnight. The time quantity display devices may be a date display device, a day of the week display device, a 24-hour display device or other display device. The precision with which the time quantity, for example the date, displayed by the first display device is incremented by one step when the time changes to midnight, is only a function of the precision with which the date hand is driven onto its arbour. However, the instant when the time quantity, for example the day, displayed by the second display device is incremented by one step when the time changes to midnight is determined by the position of the drive wheel of the day display device and thus by the position of the centre wheel. To date, no means have been available for finely adjusting the jump by the day indicator hand, such that a difference of up to 15 to 20 minutes could be observed between the moment when the date indicator hand jumped and the moment when the day indicator hand jumped, which was not very satisfactory for the wearer of the watch. The present invention provides a drive mechanism including a drive wheel which is driven by the gear train of the timepiece movement, and which itself drives a time quantity display device via a finger that is friction fitted onto the drive wheel. Because the finger is friction fitted onto the drive wheel, its position relative to said wheel can be altered, and thus the moment at which the finger will activate the time quantity display device can be adjusted. Therefore, by driving the indicator hand of the first display device precisely into position and adjusting the relative position of the drive wheel and the finger driving the second display device, one can ensure that the indications provided by the two display devices will be incremented simultaneously or almost simultaneously, at the desired moment.

(8) The present invention will be described with reference to the date display device shown with reference to FIGS. 1 and 2 described above. it goes without saying that this example is given purely by way of illustration, and that the present invention can be applied in an identical manner to the day display device, which is also shown in FIGS. 1 and 2 annexed to the present Patent application. More generally, the present invention applies to any type of display for a time-related quantity, such as the month of the year or moon phase indication.

(9) The drive mechanism according to the invention is shown respectively in plan and cross-section in FIGS. 2 and 3 annexed to this Patent Application. Designated as a whole by the general reference numeral 36, this mechanism includes a date drive wheel 2, which is driven by the hour wheel 1a of the timepiece movement, via an intermediate wheel 1, and which drives in turn, via finger 4, the date wheel 6 of the date display device.

(10) Drive wheel 2 carries finger 4. Finger 4 therefore has an oblong aperture 38, through which it is fitted on a hub of said drive wheel 2. A spring 42 holds finger 4 in a position, wherein finger 4 is meshed with the toothing of date wheel 6 for driving said wheel clockwise or anticlockwise.

(11) As can be seen upon examining FIGS. 3 and 4, spring 42 is arranged between plate 5 of drive wheel 2 and finger 4. Thus, spring 42 has a circular aperture 44, with two diametrically opposite lugs 46a and 46b, via which it is friction fitted onto hub 40 of said drive wheel 2. It will be noted that, in normal operating mode, spring 42 is stationary relative to drive wheel 2. The friction fit of said spring 42 on said drive wheel 2, permitted by the presence of the two lugs 46a and 46b, is provided to enable the drive mechanism 36 according to the invention to be finely adjusted, as described below.

(12) Finger 4 is coupled with spring 42 by means of a pin 48. This pin 48 is driven into finger 4, but is free to pivot in a hole made in spring 42, in which it is inserted. This pin 48 constitutes the pivoting point of finger 4. There is a second pin 50, also driven into finger 4 and which is inserted in an oblong aperture 52, arranged in drive wheel 2, in which said pin 50 is free to move. As can be observed upon examining FIG. 3, pin 50 is positioned in a recess 54, provided towards the free end 56a of an elastic arm 56 of substantially circular shape, in spring 4.

(13) In the normal operating mode of the drive mechanism, as illustrated in FIG. 3, finger 4 must be rigid. This means that finger 4 must be able to drive date wheel 6 clockwise or anticlockwise without being wound, like an instantaneous or semi-instantaneous type spring mechanism. It should also be recalled that “normal operating mode” means the periods where intermediate wheel 1 drives drive wheel 2 either because intermediate wheel 1 is driven clockwise by the timepiece movement, either because intermediate wheel 1 is driven clockwise or anticlockwise via activation of a winding stem, for example, in order to set the time. In other words, in normal operating mode, intermediate wheel 1 rotates and drives drive wheel 2, which itself drives date wheel 6. This is made possible by the fact that spring 42 exerts sufficient retaining torque on finger 4 to enable said finger 4 to overcome the slight torque exerted by date wheel 6. Likewise, finger 4 is stopped by the semi-circular part 38a of its oblong aperture 38 against hub 40 of drive wheel 2.

(14) As already mentioned above, spring 42 is almost permanently mounted on hub 40 of drive wheel 2, such that, only a tool 58 inserted in an aperture 60, made in said drive wheel 2 in a recess 62 of spring 42, can move said spring 52 slightly relative to said hub 40 by a few degrees clockwise or anticlockwise to make up for any play and to synchronise the date jump with the day jump.

(15) It goes without saying that the present invention is not limited to the embodiment that has just been described and that those skilled in the art could envisage various simple alterations and variants, without departing from the scope of the invention defined by the annexed claims. It will be clear, in particular, that in the case of a watch fitted with a date display of the type described above, and an additional display device, for example for the day of the week, if the drive mechanism of the date display device is made in accordance with the invention, it is not necessary to provide a similar mechanism for driving the day display device. Indeed, the drive wheels are mounted first of all, then the wheels that carry the cams and finally the intermediate wheel at the centre. The mechanism is then moved forward to the time at which the rack of the display device, which, as appropriate, may not be fitted with the device according to the invention, is ready to drop along the steep side of the cam, then the position of the finger of the other display device is adjusted such that the corresponding rack is also ready to drop along the steep profile of the cam against which it is abutting. If both time quantity display devices are provided with a friction fit finger, one need only observe which of the two racks drops first, then adjust the position of the finger of the other display device, such that the corresponding rack drops at the same time, or almost the same time, as the other rack. Finally, the indicator hands need only to be driven onto their respective arbours.

(16) A simplified embodiment of the invention is shown with reference to FIG. 5 annexed to this Patent Application. According to this embodiment, finger 64 is directly friction fitted onto hub 40 of drive wheel 2, through an aperture 66. One can therefore omit spring 42, which considerably simplifies the construction of the mechanism and thus allows savings to be made in terms of cost. Finger 64 must, however, be altered slightly so that it has a recess 68 in which tool 58 can be inserted in order to allow the fitter to pivot finger 64 slightly by several degrees clockwise or anticlockwise and thus ensure almost perfect synchronism between the jumps of the time quantity indicators.