Large date calendar display mechanism and timepiece comprising same

Abstract

A date calendar display mechanism driven via a kinematic chain by a horological movement of a timepiece. A first and second date indicators, the first date indicator remaining still during a 24-hour period separating the passage from the last day of a month having 31 days to the end of the first day of the following month, the kinematic chain including a wheel continuously engaged with the horological movement and having a toothing via which the wheel meshes with a pinion which contributes to driving the first indicator, the wheel being, at one point, devoid of teeth such that, during the above 24-hour period, the wheel does not mesh with the pinion and remains still. A dual jumper pivots about an axis with a first beak via which it is engaged with a toothing of the first date indicator and, at a second beak via which it is engaged with a toothing of the pinion, the dual jumper being elastically held engaged with the first date indicator and with the pinion.

Claims

1. A date calendar display mechanism driven via a kinematic chain by a horological movement of a timepiece equipped with said date calendar display mechanism, said date calendar display mechanism comprising a first date indicator on which the indications of the units component of the date from “0” to “9” are placed, and a second date indicator on which the indications of the tens component of the date from “0” to “3” are placed, whereby all of the date indications from “01” to “31” can be obtained by combining the indications of the units component “0” to “9” of the date, borne by the first date indicator, with the indications of the tens component “0” to “3” of the date, borne by the second date indicator, the first date indicator remaining still during a 24-hour period separating the passage from the last day of a month having 31 days to the end of the first day of the following month, the kinematic chain comprising a wheel that is continuously engaged with the horological movement and which has a perimeter provided with a toothing via which the wheel meshes with a pinion which itself contributes to driving the first indicator of the units component of the date, the wheel being, at one point along the perimeter thereof, devoid of tooth such that, during the 24-hour period separating the passage from the last day of a month having 31 days to the end of the first day of the following month, the wheel does not mesh with the pinion which, similarly to the first date indicator, thus remains still, the date calendar display mechanism further comprising a dual jumper mounted such that the dual jumper pivots about an axis and which comprises a first beak via which the dual jumper is engaged with a toothing of the first date indicator and a second beak via which the dual jumper is engaged with a toothing of the pinion, the dual jumper being elastically held engaged with the first date indicator and with the pinion.

2. The date display mechanism according to claim 1, wherein the dual jumper comprises a first end at which the first beak is provided, and a second end at which the second beak is provided.

3. A timepiece comprising a date calendar display mechanism according to claim 1.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Other features and advantages of the present invention will be better understood upon reading the following detailed description of one example embodiment of the large date calendar display mechanism according to the invention, said example being provided for the purposes of illustration only and not intended to limit the scope of the invention, given with reference to the accompanying drawing, wherein:

(2) FIG. 1 is an overhead view of a timepiece of the wristwatch type equipped with a large date calendar display mechanism according to the invention;

(3) FIG. 2 is a plan view of the large date calendar display mechanism according to the invention, wherein the indicator of the tens component of the date is shown transparently;

(4) FIG. 3 is a perspective view of the large date calendar display mechanism according to the invention, wherein the kinematic chain driving the indicator of the tens component of the date is more particularly visible;

(5) FIG. 4 is a view identical to that of FIG. 2, with the exception that the indicator of the tens component of the date has been omitted;

(6) FIG. 5 is a perspective view from below of the large date calendar display mechanism revealing the cam drive mechanism which controls the release of the date display mechanism once per day;

(7) FIG. 6 is a diagrammatic view of another particular embodiment of the invention.

DETAILED DESCRIPTION OF ONE EMBODIMENT OF THE INVENTION

(8) The present invention proceeds from the general inventive idea consisting, in a large date calendar display mechanism, of simultaneously ensuring, by means of a sole dual jumper, the correct positioning of a pinion and of an indicator of the units component of the date driven by this pinion, in particular during the lapse of time where, in order to prevent the indicator of the units component of the date from pivoting, the pinion is no longer engaged with the wheel which, under normal circumstances, transmits to this pinion the energy supplied by the horological movement of the timepiece equipped with the large date calendar display mechanism according to the present invention.

(9) Denoted as a whole by the general reference numeral 1 and as shown in FIG. 1 accompanying the present patent application, the large date display mechanism equips a timepiece 2 such as a wristwatch which comprises a dial 4 in which an aperture 6 is made, through which a large date indication 8 can be seen.

(10) With reference to FIG. 2, the large date display mechanism 1 is shown to comprise an intermediate centre wheel 10 which is conventionally rigidly connected to an hour wheel driven by a motion-work of a horological movement (not shown). This intermediate centre wheel 10 meshes with a cam drive wheel 12 which is driven one revolution per day. This cam drive wheel 12 drives, in turn, a cam wheel 14 on which a cam 16 is fixed.

(11) The cam drive wheel 12 and the cam wheel 14 are kinematically connected to one another by means of a pin 18 driven into the cam wheel 14 and which freely passes through an oblong hole 20 made in the cam drive wheel 12 (see FIG. 5). When the cam drive wheel 12 revolves, it drives the cam wheel 14 thanks to the pin 18 which abuts against an inner edge 20a of the oblong hole 20. The cam 16 has a profile 16a at one point whereof a recess 16b is provided. A release lever 22, elastically stressed by a spring 24, comprises a beak 26 via which it follows the profile 16a of the cam 16.

(12) Once a day, at around midnight, the release lever 22 falls along the recess 16b of the profile 16a of the cam 16 and causes the cam wheel 14 to instantly pivot by an angle that is defined by the recess 16b of the profile 16a of the cam 16. It should be noted that the dimensions of the oblong hole 20 are sufficient to allow the cam wheel 14 to perform the instant pivoting movement thereof without being hindered by the pin 18.

(13) The cam wheel 14 drives a date drive wheel 28 which bears a finger 30 via which the date drive wheel 28 controls, once a day, the advancing of a thirty-one-teeth wheel 32 by one step (see FIG. 3). Moreover, a programming wheel 34 is fixed to the thirty-one-teeth wheel 32. The thirty-one-teeth wheel 32 meshes, in turn, with a drive wheel 36 itself engaged with an intermediate pinion 38 of an intermediate wheel set 40. Finally, an intermediate wheel 42 of the intermediate wheel set 40 meshes with a units drive pinion 44 of a units drive wheel set 46, a units drive wheel 48 whereof drives an indicator of the units component of the date. For the purposes of illustration only and not intended to limit the invention, this indicator of the units component of the date takes on the form of a ring 50. This units indicator ring 50 bears the indications “0”, “1”, “2”, “3”, “4”, “5”, “6”, “7”, “8” and “9” which correspond to the indications of the units component of the date and advances by one step a day, except when passing from “31” of a month to “1” of the following month.

(14) The programming wheel 34 is provided with four teeth 34a, 34b, 34c and 34d via which this programming wheel 34 drives, by one step every 10 days, a four-teeth star 52 to which an indicator of the tens component of the date is fixed. For the purposes of illustration only and not intended to limit the invention, this indicator of the tens component of the date is designed in the form of a disc 54. The tens indicator disc 54 bears the indications “0”, “1”, “2” and “3” which correspond to the indications of the tens component of the date.

(15) As specified hereinabove, the units indicator ring 50 advances by one step a day, except when passing from “31” of a month to “1” of the following month. During this passage, the units indicator ring 50 must remain still. More specifically, the marking “1” borne by the indicator of the units component of the date is used both to compose the date indication “31” at the end of a month having 31 days, and to compose the date indication “01” at the start of the following month. It is therefore key that the units indicator ring 50 remains still during this lapse of time so that the date indication that appears through the aperture 6 made in the dial 4 of the timepiece 2 is accurate.

(16) To reach this goal, two teeth of a thirty-one-teeth toothing 56 of the drive wheel 36 are missing and leave an empty space 57 (see FIG. 4). Thus, when this portion devoid of tooth of the thirty-one-teeth toothing 56 of the drive wheel 36 is facing a toothing 58 of the intermediate pinion 38, the angular position of this intermediate pinion 38 is no longer appropriately ensured which, at the end of the kinematic chain, no longer guarantees the correct positioning of the indication “1” borne by the units indicator ring 50 in the aperture 6 made in the dial 4 of the timepiece 2. Of course, this problem is unacceptable.

(17) This is why, in accordance with the invention, it is proposed to equip the large date display mechanism with a dual jumper 60 arranged such that it pivots about a centre O. This dual jumper 60 is provided with a first beak 60a via which it is engaged with the toothing 58 of the intermediate pinion 38, and a second beak 60b via which it is engaged with an inner toothing 62 of the units indicator ring 50. The dual jumper 60 is held such that it elastically bears against the toothing 58 of the intermediate pinion 38 and against the inner toothing 62 of the units indicator ring 50 by a spring 64. When the intermediate pinion 38 advances by one step, the dual jumper 60 pivots about the pivot centre O thereof and the beak 60a thereof moves aside by passing from the gap between two consecutive teeth of the toothing 58 of this intermediate pinion 38 to the following gap. Simultaneously, the second beak 60b of the dual jumper 60 is released from the gap between the two teeth of the inner toothing 62 of the units indicator ring 50 and falls into the following gap. The geometrical configuration of the dual jumper 60 and the positioning of the pivot centre O thereof are such that when the dual jumper 60 pivots, it is simultaneously released from the toothing 58 of the intermediate pinion 38 and from the inner toothing 62 of the units indicator ring 50. Thus, when passing, at the end of a month, from the date indication “31” to the date indication “1” of the following month, the intermediate pinion 38, although not engaged with the drive wheel 36, is held in position by the beak 60a of the dual jumper 60 such that there is no risk of the date indication “1” from not being appropriately centred inside the aperture 6 made in the dial 4 of the timepiece 2.

(18) As shown in the drawing, the first beak 60a is provided at a first end of the dual jumper 60, whereas the second beak 60b is provided at a second end of the dual jumper 60. It is nonetheless understood that, depending on the restrictions for the manufacture of the display mechanism, two beaks 60a, 60b could be provided such that they extend from the same end of the dual jumper 60 along two different radii (see FIG. 6).

(19) The intermediate pinion 38 forms a part of the intermediate wheel set 40 with an intermediate wheel 42 with which it is coupled in rotation. This intermediate wheel 42 meshes, in turn, with a units drive pinion 44 of a drive wheel set 46 of the units indicator ring 50. This drive pinion 44 is coupled in rotation with the units drive wheel 48 which drives the units indicator ring 50 by meshing with the inner toothing 62 of this units indicator ring 50.

(20) It is evident that the present invention is not limited to the embodiment described above and that various simple alternatives and modifications can be considered by a person skilled in the art without leaving the scope of the invention as defined by the accompanying claims. It should in particular be noted that the number of teeth of the toothing 56 of the drive wheel 36 can differ from thirty-one teeth and that the number of teeth omitted can differ from two, and can be equal to one or three for example. It should also be noted that, depending on the restrictions for the manufacture of the large date display mechanism, the two beaks of the dual jumper can be arranged on the same end of the jumper and extend from this end along two different radii.

NOMENCLATURE

(21) 1. Large date display mechanism 2. Wristwatch 4. Dial 6. Aperture 8. Large date indication 10. Intermediate centre wheel 12. Cam drive wheel 14. Cam wheel 16. Cam 16a. Cam profile 16b. Recess 18. Pin 20. Oblong hole 20a. Inner edge 22. Release lever 24. Spring 26. Beak 28. Date drive wheel 30. Finger 32. Thirty-one-teeth wheel 34. Programming wheel 34a, 34b, 34c, 34d. Teeth 36. Drive wheel 38. Intermediate pinion 40. Intermediate wheel set 42. Intermediate wheel 44. Units drive pinion 46. Units drive wheel set 48. Units drive wheel 50. Units indicator ring 52. Four-teeth star 54. Tens indicator disc 56. Toothing 57. Empty space 58. Toothing 60. Dual jumper O. Pivot centre 60a. First beak 60b. Second beak 62. Inner toothing 64. Spring