Drag-type rebound clockwork with display break lever

Abstract

This invention relates to a drag-type rebound clock display mechanism equipped with a display disconnect lever, arranged to sequentially display at least one distinct first indication and at least one last indication in a rebound manner, comprising: - a display wheel; - a display pinion and a fixed display wheel; - a pivot holding element; - a drive wheel; - a return element; - a display disconnect lever; - the holding element and the display disconnect lever are arranged such that when the rebound clock display mechanism moves from displaying the last indication to displaying the next first indication, the holding element pivots, the display disconnect lever is locked, causing the elastic bar to become strained and the holding element to be forced to release from the teeth of the fixed display wheel, so that the stress induced by the return element in the rebound clock display mechanism can be released and the rebound clock display mechanism can return in the rebound direction to its initial position, in which the rebound clock display mechanism displays the first indication.

Description

Technical Field

[0001] The present invention relates to a drag-type rebound watch display mechanism equipped with a display disconnection device. Background Art

[0002] A backflip refers to a watch display mechanism that returns backwards and to its starting point when reaching the end position. Among the known backflip watch display mechanisms, a backflip date display mechanism can be mentioned in particular, an example of which is given by a display pointer that moves towards an index showing a date indication from "1" to "31". The display pointer successively points to each of the date indications "1" to "31", and then, when it reaches the date indication "31" at the end of the month, it returns in the opposite direction to face the date indication "1". The display pointer then begins to move again from "1" to "31" facing the date indication. In many of these backflip date display mechanisms, when the display pointer moves from one date indication to the next, it must advance slightly beyond the date indication to which it will point before it can be correctly positioned opposite the date indication.

[0003] Therefore, problems arise during the time when this timepiece display mechanism jumps back to its starting point. In fact, when this jump-back timepiece display mechanism is of the "drag" type (which means that when these mechanisms have reached their end position, it jumps back to its starting point over a period of time), this period of time can be several hours. During this time interval, the display hand exceeds the last indication of the index to which it should normally point, and therefore gives an incorrect indication to the owner of the timepiece (in which this jump-back timepiece display mechanism is embedded). This is difficult to accept, especially because timepieces of this type are often expensive, and a period of several hours (during which the jump-back timepiece display mechanism gives an incorrect indication) is often perceived by the owner as a design defect or a sign of a malfunction of the timepiece. Summary of the invention

[0004] The object of the present invention is to overcome the above-mentioned problems and others by providing a retrograde timepiece display mechanism of the dragging type which continuously displays the correct indications, in particular during its retrograde return from its end position to its initial position.

[0005] To this end, the invention relates to a retrograde timepiece display mechanism of the dragging type, driven by a movement of a timepiece in which the retrograde timepiece display mechanism is embedded, the retrograde timepiece display mechanism being arranged to display successively in a retrograde manner at least one first indication and at least one last indication, the at least one first indication and the at least one last indication being distinguishable, the retrograde timepiece display mechanism comprising:

[0006] - Display wheel;

[0007] - a display pinion arranged on either side of the display wheel and a fixed display wheel, the display pinion being freely mounted on the display wheel in a coaxial manner and the fixed display wheel being fixedly mounted concentrically with the display wheel and the display pinion and being provided with a toothing;

[0008] - a pivoting retaining element which engages in the toothing of the fixed display wheel;

[0009] - a driving wheel, which is moved by the timepiece movement and which drives the display wheels;

[0010] - a return element which tends to force the display pinion to rotate;

[0011] - a display breaking lever rigidly connected to the display pinion and coupled in rotation to the display wheel, this display breaking lever comprising a resilient strip against which the retaining element is arranged;

[0012] - the retaining element and the display-off lever are arranged so that when the rebound timepiece display mechanism moves from the display of the last indication to the display of the next first indication, the retaining element pivots and the display-off lever is locked, so that the elastic strip becomes strained and the retaining element is forced to release from the teeth of the fixed display wheel, thus enabling the stress induced in the rebound timepiece display mechanism by the return element to be released and enabling the rebound timepiece display mechanism to return in the rebound direction to its initial position in which it displays the first indication.

[0013] Thanks to these characteristics, the invention provides a timepiece display mechanism of the dragging type which, thanks to the presence of a disconnection device, consistently gives the owner of the timepiece in which such a mechanism is embedded a correct indication of the information displayed, in particular when this timepiece display mechanism returns in a retrograde manner from its end position to its initial position. At that time, in fact, unlike the dragging date display mechanisms of the prior art which, during the period in which they return in a retrograde manner to their starting point, exceed the last indication of the index to which they should normally point and therefore give an incorrect indication to the owner of the timepiece, the timepiece display mechanism of the dragging type according to the invention consistently and accurately points to the indication in question, in particular when it is about to return to its starting point. Therefore, the owner of the timepiece in which the retrograde timepiece display mechanism according to the invention is embedded will never have the impression that his timepiece suffers from a design defect or is faulty, which is very positive for the owner's perception of the timepiece.

[0014] According to a specific embodiment of the present invention:

[0015] - in the case where the duration separating said at least one first indication displayed from said at least one last indication displayed is fixed, the retrograde timepiece display mechanism comprises a fixed period limiting element equipped with a single supporting surface which determines the duration separating said at least one first indication from said at least one last indication;

[0016] - in the case where the duration separating said at least one first indication displayed from said at least one last indication displayed is variable, the retrograde timepiece display mechanism comprises:

[0017] a cam arranged to manage at least two durations of different value, said at least two durations separating said at least one first indication and at least one last indication, and which is driven one step by the return element each time the jumping back timepiece display mechanism moves from the last indication to the next first indication, and

[0018] a mobile contact plunger pressed against the profile of the cam, the contact plunger also comprising at least one first support surface and at least one second support surface defining two durations of different values, said two durations separating said at least one first and at least one last indication;

[0019] - the contact plunger is provided with a trailing beak, by means of which the contact plunger is pressed against the cam profile;

[0020] - the retaining element is a finger comprising a first foot, and in that the display-off lever comprises a second foot, these first and second feet being arranged so that when the rebound timepiece display mechanism moves from the display of the last indication to the display of the next first indication, these first and second feet face the support surface, and then, when the drive wheel continues to drive the display wheel, the first foot moves away from the support surface, while the second foot abuts against the support surface, which prevents pivoting of the display-off lever and causes tensioning of the elastic strip, while the retaining element is forced to release from the toothing of the fixed display wheel, thus enabling the second foot to be released from the support surface in a rebounding manner and enabling the rebound timepiece display mechanism to return to its initial position in which it displays the first indication;

[0021] - the holding finger is elastically pressed into the toothing of the fixed display wheel by means of a pawl carried by the display wheel;

[0022] - a drive wheel equipped with an elastic drive finger, via which it drives the display wheel;

[0023] - the return element is an elastically forced rack, thanks to which the return rack generates a mechanical tension which forces the display pinion to rotate;

[0024] - the return rack comprises a second drive finger, via which the return rack drives a star wheel fastened to the cam by one step each time the retrograde timepiece display mechanism moves from the display of the last indication to the display of the first subsequent indication;

[0025] - when the retrograde timepiece display mechanism displays an indication, the second driving finger carried by the return rack is gradually retracted and gradually positioned behind a given tooth of the star wheel, so that when the retrograde timepiece display mechanism moves from the display of the last indication to the display of the following first indication, the elastic tension in the retrograde timepiece display mechanism is suddenly released and the return rack returns to its initial position by pivoting and by driving the driving finger with it, which moves the star wheel and therefore the cam forward one step. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Further features and advantages of the invention will emerge more clearly from the following detailed description of an embodiment of a retrograde timepiece display mechanism of the dragging type according to the invention, this example being given purely for illustration and not for limitation, with reference to the accompanying drawings, in which:

[0027] - Figure 1 is a top view of a retrograde timepiece display mechanism of the dragging type according to the invention in a situation in which it is between the first and last indications displayed;

[0028] - Figure 2 yes Figure 1 A bottom view of the retrograde timepiece display mechanism according to the present invention as shown in FIG.

[0029] - Figure 3 is with Figure 2 A similar view of the view with the fixed display wheel removed;

[0030] - Figure 4 is a detailed view illustrating a display hand moving in a clockwise direction in front of an index on which a date indication from, for example, "1" to "31" is represented;

[0031] - Figure 5A , Figure 5B and Figure 5C A situation in which the holding finger and the display break lever are in contact with the contact plunger of a rebound timepiece display mechanism is illustrated in a top view and a bottom view respectively in the case where a fixed display wheel is present and in the case where the fixed display wheel is omitted;

[0032] - Fig. 6A , Figure 6B and Figure 6CThe jump-back timepiece display mechanism is illustrated in top and bottom views, respectively, with the fixed display wheel present and with the display wheel omitted, when the display break lever is tensioned to allow the retaining finger to move forwards against the elastic force of the catch and to be released from its engagement with the fixed display wheel;

[0033] - Fig. 7A , Figure 7B and Figure 7C A schematic diagram of a retrograde timepiece display mechanism showing the display of a device ready to move from the last indication displayed to the display of the first subsequent indication, in a top view and a bottom view respectively with a fixed indication wheel present and with the indication wheel omitted;

[0034] - On one hand Fig. 8A , Figure 8C and Fig. 8E and on the other hand Figure 8B , Fig.8D and Figure 8F A retrograde timepiece display mechanism is shown in a top view and a bottom view, respectively, as it moves from the display of the last indication displayed to the display of the first subsequent indication;

[0035] - Fig. 9 A perspective view showing the brake claw;

[0036] - Fig.10 It is to maintain the perspective of the finger;

[0037] - Fig.11 A perspective view showing a disconnect lever is illustrated;

[0038] - Fig.12 is a top view of the assembled display wheel;

[0039] - Fig.13 is a bottom view of the assembled display wheel;

[0040] - Fig.14 and Fig.15 are respectively a top view and a bottom view of a retrograde timepiece display mechanism of the dragging type according to the invention in a situation in which it displays an indication of the first day of the month;

[0041] - On one hand Fig.16 , Fig.18 and Fig. 20 and on the other hand Fig.17 , Fig.19 and Fig.21 are views illustrating the transition of a retrograde clock display mechanism between a date indication "1" and a date indication "2" from the top and bottom, respectively;

[0042] - Fig. 22 and Fig.23The position of the rebound timepiece display mechanism when the holding finger and the display breaking lever face the supporting surface of the period limiting element with their respective feet is illustrated in a top view and a bottom view respectively;

[0043] - Fig.24 and Fig.25 The position of the rebound timepiece display mechanism when the holding finger and the display-off lever abut against the support surface of the period limiting element is illustrated in a top view and a bottom view, respectively;

[0044] - Fig.26 and Fig. 27 The position of the rebound timepiece display mechanism when the holding finger is released from the teeth of the fixed display wheel is illustrated in top view and bottom view respectively;

[0045] - Fig.28 and Fig.29 The position of the timepiece display mechanism which jumps back at the end of the driving of the display wheel is shown in top view and bottom view respectively;

[0046] - Fig.30 and Fig.31 The position of the rebound timepiece display mechanism when the holding force exerted by the elastic strip of the display break lever is released and the display wheel will rotate instantaneously in the counterclockwise direction is illustrated in top view and bottom view respectively;

[0047] - Fig.32 and Fig.33 The position of the rebound timepiece display mechanism when the holding finger returns towards the teeth of the fixed display wheel is illustrated in a top view and a bottom view respectively;

[0048] - Fig.34 and Fig.35 The position of the rebound timepiece display mechanism when the retaining finger returns once again to engage in the teeth of the wolf-tooth toothing is illustrated in a top view and a bottom view respectively;

[0049] - Fig.36 and Fig.37 The position of the retrograde timepiece display mechanism in which it again displays the date indication "1" is illustrated in a top view and a bottom view respectively;

[0050] - Fig.38 is a detailed view illustrating a display hand moving in a clockwise direction in front of an index on which a date indication from, for example, "1" to "31" is represented;

[0051] - Fig.39 A perspective view showing the brake claw;

[0052] Fig.40 It is to maintain the perspective of the finger;

[0053] - Fig.41A perspective view showing a disconnect lever is illustrated;

[0054] - Fig.42 is a top view of the assembled display wheel; and

[0055] - Fig.43 is a bottom view of the assembled display wheel. DETAILED DESCRIPTION

[0056] The invention is based on a general inventive concept consisting of providing a drag-type, reversing timepiece display mechanism with a disconnection device that enables the mechanism to continuously provide an accurate indication of the information displayed, in particular during a period of several hours during which the reversing return of the timepiece display mechanism from its end position to its initial position is performed. In fact, in some conventional reversing timepiece display mechanisms of the drag type, when the display hand moves from one date indication to the next, the hand needs to slightly exceed the indication to which it is to point (for example, the date) before it can be correctly positioned opposite the date indication. This is troublesome during a period of several hours during which the display mechanism is in a situation that enables it to reversing from its end position to its initial position. In fact, during this period, the display hand gives an incorrect indication, which can lead the owner of the timepiece to believe that the timepiece suffers from a design defect or actually suffers from a malfunction and in any case leads the owner to have a very bad impression of his timepiece.

[0057] According to the invention, the “direct” direction is the direction in which the different components of a retrograde timepiece display mechanism rotate when the mechanism moves from a displayed indication to the display of a next indication, and the “reverse” direction is the direction in which the different components of a retrograde timepiece display mechanism rotate when the mechanism returns in a retrograde manner to its initial position by moving from the display of the last indication displayed to the display of the next first indication.

[0058] Designated as a whole by the general reference numeral 1, the retrograde timepiece display mechanism of the dragging type according to the invention is Figure 1 In the top view and in Figure 2 For the purposes of the description of the invention, it will be assumed that this retrograde timepiece display mechanism 1 is arranged to display a date indication, for example from "1" to "31". It will be understood, however, that this example is given by way of illustration only and not limitation, and that this retrograde timepiece display mechanism can be used to display any type of time quantity, such as the days of the week, the months of the year or indeed the number of weeks.

[0059] like Figure 1As can be seen in FIG. 1 , the rebound timepiece display mechanism 1 according to the invention comprises a return element such as, without limitation, a return rack 2 elastically urged by a return spring 4. Due to its return spring 4, the return rack 2 generates a mechanical tension in the gear train 6 which forces the display pinion 14 to rotate in the counterclockwise direction via the first setting wheel 8, the second setting wheel 10 and the third setting wheel 12, respectively.

[0060] More specifically, in the study Figure 2 As can be seen, return rack 2 comprises a toothed area 16, by means of which it meshes with a first pinion 18, which together with first setting wheel 8 forms a first mobile 20. This first setting wheel 8, in turn, meshes with a second pinion 22, which together with second setting wheel 10 forms a second mobile 24. This second setting wheel 10, in turn, meshes with a third setting wheel 12. Finally, third setting wheel 12 meshes with display pinion 14. Obviously, the number of setting wheels given here is merely by way of example and may vary, in particular depending on the size of the retrograde timepiece display mechanism and the space available in the case of a timepiece (not shown) in which this retrograde timepiece display mechanism 1 is embedded.

[0061] Preferably, the display hand 23 is secured by any suitable means, such as by driving on the second setting wheel 10. In the above-mentioned case where the retrograde timepiece display mechanism 1 is used to display a date indication, the display hand 23 will move in a clockwise direction facing the index 2 showing the date indication from "1" to "31" (see Figure 4 ).

[0062] The retrograde timepiece display mechanism 1 is supplemented by a display wheel 28 on which the display pinion 14 is freely mounted and coaxially coupled thereto. The retrograde timepiece display mechanism 1 further comprises a fixed display wheel 30 provided with a toothing 32, preferably of the wolf-tooth type. This fixed display wheel 30 is fixedly mounted concentrically with the pinion 14 and the display wheel 28 on a bridge or plate of a timepiece movement (not shown).

[0063] The brake pawl 34 provided with the elastic strip 35 is particularly shown in the figure. Fig. 9 This pawl 34 is carried by the display wheel 28 and presses a retaining element, preferably such as a retaining finger 36, into the toothing 32 of the fixed display wheel 30. This retaining finger 36, carried by the display wheel 28, is pivotally mounted about a pivot axis 37 and is equipped with a beak 38, by means of which it engages in the toothing 32 of the fixed display wheel 30. It is thus this retaining finger 36 that continuously retains the rebound timepiece display mechanism 1 under the tension generated by the return spring 4. This retaining finger 36 also includes (see Fig.10) first leg 40, the function of which will be described in detail below. In other words, toothing 32 makes it possible to maintain elastic tension in the counterclockwise direction, viewed from above, and enables display wheel 28 to move forward one step in the clockwise direction when moving from one date indication to the next.

[0064] The pawl 34 and the retaining finger 36 are arranged on either side of a plate 42 of the display wheel 28. The pawl 34 acts on the retaining finger 36, for example via a first pin 44 which is carried by the retaining finger 36 and projects through an opening 46 provided in the plate 42 of the display wheel 28 (see Fig.12 ).

[0065] Assuming that in a preferred embodiment of the present invention the teeth of the toothed portion 32 have an inclined wolf-tooth profile so that the retaining finger 36 can move from the space between the two wolf teeth to the next space, the rebound clock display mechanism 1 must enable the retaining finger 36 to slightly exceed the space between the two wolf teeth into which it will fall, and then be able to return slightly to the back and fall into the space. For this reason, when moving from one date indication to the next date indication, the display pointer 23 slightly exceeds the date indication to which it will point, and then can be correctly positioned opposite the date indication. During the current month, this does not cause a particular problem, because the movement performed by the display pointer 23 beyond the date indication to which it will point is short-lived and hardly noticeable to the owner of the timepiece. On the other hand, when moving from the last day of the current month to the first day of the next month, this crossing is more problematic. In fact, since it is composed of a retrograde timepiece display mechanism 1 of the dragging type, the following period lasts for several hours, that is, during this period, the retrograde timepiece display mechanism 1 is in a situation that allows it to jump back from its end position (date indication "28", "29", "30" or "31") to its initial position (date indication "1"). Therefore, during this period, the display hand 23 gives an incorrect indication, which may cause the owner of the timepiece to believe that the timepiece suffers from a design defect or actually suffers from a malfunction and in any case cause the owner to have a bad impression of his timepiece. In order to remedy this problem, the present invention provides for equipping the retrograde timepiece display mechanism with a disconnection device, which will now be described.

[0066] More specifically with reference to Figure 3 (which is a bottom view of a retrograde timepiece display mechanism 1 from which fixed display wheel 30 has been removed), it can be seen that the disconnection device firstly comprises a display disconnection lever 48 which is rigidly connected to display pinion 14, for example by driving. Furthermore, display disconnection lever 48 is coupled in rotation with display wheel 28 by means of a second pin 50 fastened in plate 42 of this display wheel. As particularly Fig.11As can be seen in FIG. 4 , the display breaking lever 48 also includes an elastic strip 54 which is in elastic support against a third pin 56 fastened in the plate 42 of the display wheel 28. The second pin 50 projects into an opening 52 provided in the display breaking lever 48. Finally, the display breaking lever 48 includes a second foot 58, the function of which will be detailed in the following description.

[0067] Once a day, at a time before midnight (usually about an hour to an hour and a half before the day changes), the retrograde timepiece display mechanism 1 starts to move from one date indication to the next. Figure 1 , a drive wheel 60 driven by the timepiece movement at a rate of one full revolution in twenty-four hours in a manner known per se drives with it a drive finger 62 which in turn drives the display wheel 28 one step in the clockwise direction. During this drive, the retaining finger 36 moves from the space between two consecutive teeth of the wolf-toothed toothing 32 of the fixed display mechanism 30 to the next space immediately following, thus ensuring that the entire retrograde timepiece display mechanism 1 is maintained under elastic tension. Advantageously, the drive finger 62 is elastic so that, when the retrograde timepiece display mechanism 1 returns to its initial position, it can be moved away from in front of the teeth of the display wheel 28 when the latter is rotated in the retrograde direction. A further advantage provided by the drive finger 62 is that, due to its elasticity, it enables the owner of the timepiece to perform manual settings in the counterclockwise direction without driving and thus damaging the retrograde timepiece display mechanism 1.

[0068] The display disconnection lever 48 is rigidly connected to the display pinion 14 and is rotationally coupled to the display wheel 28 via the second pin 50, which is free to rotate relative to the fixed display wheel 30. Therefore, the display pinion 14, which is freely mounted on the display wheel 28 in a coaxial manner, then pivots and drives the second setting wheel 10, on which the display pointer 23 is fastened, via the third setting wheel 12, so that the display can move from one indication to the next. Similarly, the third pin 56 contacts the elastic strip 54 of the display disconnection lever 48 and drives the display disconnection lever in rotation.

[0069] According to the preferred embodiment of the retrograde timepiece display mechanism 1 according to the invention described here, the driving finger 62 drives the display wheel 28 and therefore the holding finger 36 carried by the display wheel 28 over 11.1°, while the angle separating two consecutive teeth of the wolf-tooth 32 of the fixed display wheel 30 is only 8.57°. It will therefore be understood that the holding finger 36 is moved forward more than necessary in order to ensure that it is correctly moved from the space between two consecutive teeth of the wolf-tooth 32 to the next space immediately adjacent, and that the displayed information is therefore correctly incremented. It will be understood, however, that this embodiment cannot be interpreted in a restrictive manner, in particular with regard to the angular values ​​that depend on the dimensioning of the retrograde timepiece display mechanism 1.

[0070] It will also be understood that the example given of the display of a date indication from "1" to "31" is also merely illustrative and not purely limiting, and that other time indications may also be displayed by a retrograde timepiece display mechanism 1 according to the invention, so that the speed of rotation of drive wheel 60 may differ from twenty-four hours. For example, if retrograde timepiece display mechanism 1 according to the invention is used to display the day of the week, drive wheel 60 will perform a full revolution in seven days. Alternatively, if the display mechanism according to the invention is intended to display the months of the year, drive wheel 60 will perform a full revolution in 31 days.

[0071] The retrograde timepiece display mechanism 1 according to the invention described here is of the perpetual date type. To this end, the mechanism comprises a cam 64 to which is fastened a star wheel 66 with twelve teeth, which is driven by a second drive finger 68. This second drive finger 68 is carried by a return rack 2 provided with its toothed area 16, which is engaged with the display pinion 14 and therefore with the timepiece movement via the first mobile 20 and the second mobile 24 and the third setting wheel 12. As in the study Figure 1 As can be understood, the return rack 2 pivots one degree per day in the clockwise direction, driven by the display pinion 14. During this movement, the second drive finger 68 is gradually retracted and gradually positioned behind a given tooth of the star wheel 66. When the end of the month is reached and the retrograde timepiece display mechanism 1 moves from the last date indication "31" of the month in question to the first date indication "1" of the next month, the elastic tension in the retrograde timepiece display mechanism 1 is suddenly released. At that time, the return rack 2 is rotated by pivoting in the counterclockwise direction (see Figure 1 ) and returns to its initial position by driving the second drive finger 68 therewith, which moves the star wheel 66 and therefore the cam 64 forward one step in the clockwise direction.

[0072] The retrograde timepiece display mechanism 1 is finally supplemented by a contact plunger 70 provided with four successive support surfaces 70a, 70b, 70c and 70d, each corresponding to a different duration of the months with 28, 29, 30 and 31 days. More specifically, the first support surface 70a, situated at the outermost end of the contact plunger 70, corresponds to the months with 31 days. The next second support surface 70b corresponds to the months with 30 days, and the following third support surface 70c and fourth support surface 70d correspond to the month of February, depending on whether it has 29 days (leap year) or 28 days.

[0073] The contact plunger 70 presses with the trailing beak 72 against the profile of the cam 64. In the example illustrated in the drawings accompanying this patent application, the situation in which the retrograde timepiece display mechanism 1 according to the invention is situated corresponds to the display of a date indication for a month with 31 days. Figures 5A-5CAs can be seen in FIG, when the retrograde timepiece display mechanism 1 displays the date indication “31” of the month in question and is ready to move to the date indication “1” of the next month, the holding finger 36 and the display breaking lever 48 face the first support surface 70a of the contact top lever 70 via their respective legs 40 and 58. In this position, the retrograde timepiece display mechanism 1 has not yet been disconnected. In fact, during the period separating the display transition from the date indication “31” to the date indication “1”, the driving finger 62 engages with the display wheel 28 and pivots the latter. While pivoting, the display wheel 28 drives the display breaking lever 48 with it via the second pin 50, which in turn drives the display pinion 14. At the same time ( Figures 6A-6C ), the display disconnect lever 48 abuts against the support surface 70a of the contact top rod 70 by its foot 58 and remains locked. As for the retaining finger 36, it abuts against the same support surface 70a of the contact top rod 70 by its foot 40, which forces this retaining finger 36 to pivot about its pivot axis 37. When pivoting, the retaining finger 36 will thus go against the elastic force of the wheel pawl 34 and will be able to be released from the wolf-tooth-shaped toothing 32 of the fixed display wheel 30. In the case where the display disconnect lever 48 is locked, the elastic strip 54 is driven by the third pin 56 and tensioned under the pivoting action of the display wheel 28. Finally, when the retaining finger 36 is released from the wolf-tooth-shaped toothing 32 of the fixed display wheel 30, the retaining force exerted by the elastic strip 54 of the display disconnect lever 48 is released.

[0074] The display of the date indication is linked to the display disconnection lever 48; in fact, the drive wheel 60 drives the display wheel 28, which in turn drives the display disconnection lever 48. This display disconnection lever 48 driven on the display pinion 14 causes its pivoting. Therefore, since the display disconnection lever 48 is fixed during the period corresponding to the transition from the end of one month to the beginning of the next month, the date indication will not change during this period. When the drive finger 62 has completed driving the display wheel 28 and is released from it, the holding force applied by the elastic strip 54 of the display disconnection lever 48 is released, and the display wheel 28 will rotate instantaneously in the counterclockwise direction under the action of the elastic force of the return spring 4, which is applied to the display wheel 28 via the display disconnection lever 48, the display pinion 14 and the gear train 6.

[0075] When the display wheel 28 stops rotating, the repositioning cam 74 or the pin (not shown) will return the retaining finger 36 engaged in the wolf-tooth shaped toothing 32 of the fixed display wheel 30. The rebound timepiece display mechanism 1 is then in Figures 7A-7C In the position illustrated in FIG. 1 , in which position it displays the date indication “1” of the next month.

[0076] In the normal operating mode of the retrograde timepiece display mechanism 1, the beak 38 of the retaining finger 36 is constantly engaged with the teeth of the wolf-tooth shaped toothing 32 (except at about midnight), and this retrograde timepiece display mechanism 1 moves from one date indication to the next date indication, and the retaining finger 36 is pivoted just the amount required to enable its beak 38 to move from the space between two teeth of the wolf-tooth shaped toothing 32 to the next space immediately adjacent. When the retrograde timepiece display mechanism 1 reaches the last day of the current month and will have to return to the first day of the next month in a retrograde manner, the foot 40 of the retaining finger 36 moves away from the supporting surface 70a of the contact plunger 70, so that the retaining finger 36 tilts and its beak 38 is released from its engagement with the wolf-tooth shaped toothing 32. At that point, it is no longer guaranteed that retrograde timepiece display mechanism 1 remains in position and the mechanism will seek to return in a retrograde manner to date indication “1” marking the beginning of a new month, and beak 38 of retaining finger 36 will then return again to engage in the teeth of wolf-tooth toothing 32, which will again ensure that retrograde timepiece display mechanism 1 remains in position.

[0077] More specifically, FIG. 8A to FIG. 8E The operation of the retrograde timepiece display mechanism 1 is illustrated at the exact time at which the retrograde timepiece display mechanism moves from the last date indication of one month to the first date indication of the next month. FIG. 8A to FIG. 8E In FIG. 1 , the presence of a part called repositioning cam 74 is observed, whose action during the return of reversing timepiece display mechanism 1 to the date indication “1” of the next month consists in engaging beak 38 of retaining finger 36 in wolf-tooth shaped toothing 32. To this end, this repositioning cam 74, fixedly mounted on a bridge or plate of the timepiece movement, is provided with a nose 76 against which a counterpart appendage 78 provided on retaining finger 36 will slide. During the return of reversing timepiece display mechanism 1 to its initial position, display wheel 28 is moved in a plan view. Fig. 8A , Figure 8C and Fig. 8E The cam 74 rotates in the counterclockwise direction, thereby driving the retaining finger 36 with it, which pivots about its pivot axis 37 and its counterpart 78 slides along the fixed nose 76 of the repositioning cam 74, as from Figure 8B , Fig.8D and Figure 8F The profile of nose 76 is arranged so that when rebound timepiece display mechanism 1 has returned to its initial position (in other words, when it indicates the date indication “1” of the new month), retaining finger 36 has completed its pivoting and once again engages, via its beak 38, with wolf-tooth 32 of fixed display wheel 30. This movement is facilitated by the cooperation between retaining finger 36 and brake claw 34. In fact, by carefully observing Fig. 8A , Figure 8C and Fig. 8E, it can be seen that the first pin 44 carried by the retaining finger 36 gradually changes the contact plane with the brake pawl 34. In fact, in Fig. 8A In the disconnected position, the retaining finger 36 abuts against the pawl 34 via the first pin 44, which ensures that the retaining finger 36 remains in the disconnected position. Figure 8C In the process, the first pin 44 starts to slide under the brake pawl 34, and in Fig. 8E (this figure corresponds to the situation in which the retrograde timepiece display mechanism 1 has returned to its initial position in which it points to the date indication “1”), first pin 44 has once again passed completely under stopper claw 34, which enables this latter to press elastically beak 38 of retaining finger 36 into wolf-tooth toothing 32.

[0078] It is obvious that the invention is not limited to the embodiments that have just been described and that a person skilled in the art may envisage various modifications and simple variants without departing from the scope of the invention as defined by the appended claims.

[0079] It will be noted in particular that, contrary to what the figures may suggest, drive wheel 60 is not engaged with second pinion 22 which, together with second setting wheel 10 , forms second mobile 24 .

[0080] It will also be understood that, depending on the portion of the cam 64 profile against which the contact plunger 70 is pressed via its trailing beak 72, this has an effect on the position of this contact plunger 70 and, therefore, on the positions of the support surfaces 70a, 70b, 70c and 70d. Thus, if the trailing beak 72 of the contact plunger 70 is pressed on the portion of the cam 64 profile corresponding to the month with 30 days, the contact plunger 70 is arranged in a position in which the second leg 58 of the display trip lever 48 abuts against the second support surface 70b one day earlier than it abuts against the first support surface 70a corresponding to the month with 31 days. The elastic tension will therefore be released and the rebound timepiece display mechanism 1 will be reset one day earlier than if the second leg 58 abutted against the first support surface 70a.

[0081] It will also be understood that in the example described above, the number of support surfaces 70a, 70b, 70c and 70d is four and corresponds respectively to the month with 31 days, the month with 30 days and the month of February, which may have 29 days or 28 days, depending on the circumstances. Therefore, these four support surfaces 70a, 70b, 70c and 70d make it possible to provide a perpetual date-type retrograde timepiece display mechanism 1. However, it is obvious that the number of these support surfaces could be only two, namely a first support surface for the month with 31 days and a second support surface for the month with 30 days, which would make it possible to provide a conventional annual calendar date-type retrograde timepiece display mechanism 1 in which the date change from February 28 to March 1 is not performed automatically.

[0082] A simplified embodiment of a retrograde timepiece display mechanism of the dragging type according to the invention is shown in Figures 14 to 38 Designated as a whole by the general reference numeral 80, this drag-type retrograde timepiece display mechanism in its simplified embodiment is Fig.14 In the top view and in Fig.15 For the purpose of the following description, it will be assumed that this retrograde timepiece display mechanism 1 is a simple date display mechanism arranged to display the date indication from "1" to "31" in a retrograde manner.

[0083] like Fig.14 As seen in FIG. 1 , the retrograde timepiece display mechanism 80 includes a display pinion 82. The display pinion 82 is forced to rotate in the counterclockwise direction by the mechanical tension induced by a return element 83 (such as a return rack). The display hand 84 moves in the clockwise direction toward the index 86 showing the date indication from "1" to "31" (see FIG. 1 ). Fig.38 ).

[0084] The retrograde timepiece display mechanism 80 is supplemented by a display wheel 88 on which the display pinion 82 is freely mounted and coaxially coupled to it. The retrograde timepiece display mechanism 80 further comprises a fixed display wheel 90 provided with a toothing 92, preferably of the wolf-tooth type. This fixed display wheel 90 is fixedly mounted concentrically with the display pinion 82 and the display wheel 88 on a bridge or plate of a timepiece movement (not shown).

[0085] The brake pawl 94 equipped with the elastic strip 96 is particularly shown in FIG. Fig.39This pawl 94 is carried by the display wheel 88 and presses a retaining element, preferably such as a retaining finger 98, into the toothing 92 of the fixed display wheel 90. This retaining finger 98, carried by the display wheel 88, is pivotally mounted about a pivot axis 100 and is equipped with a beak 102, by means of which it engages in the toothing 92 of the fixed display wheel 90. It is thus this retaining finger 98 that continuously holds the rebound timepiece display mechanism 80 against the mechanical tension to which the display pinion 82 is subjected. This retaining finger 98 also comprises (see Fig.40 ) first leg 104, the function of which will be described in detail below. In other words, toothed portion 92 makes it possible to maintain the elastic tension applied to display pinion 82 in the counterclockwise direction and enables display wheel 88 to move forward one step in the clockwise direction when moving from one date indication to the next (see Figures 16 to 21 ).

[0086] The pawl 94 and the retaining finger 98 are arranged on either side of a plate 106 of the display wheel 88. The pawl 94 acts on the retaining finger 98, for example via a first pin 108 which is carried by the retaining finger 98 and projects through an opening 110 provided in the plate 106 of the display wheel 88 (see Fig.42 ).

[0087] Assuming that the teeth of the toothed portion 92 preferably but not restrictively have an inclined wolf-tooth profile so that the finger 98 can be moved from the space between the two wolf teeth to the next space, the rebound watch display mechanism 80 must enable the finger 98 to be slightly beyond the space between the two wolf teeth into which it will fall, and then be able to return slightly to the back and fall into the space. For this reason, when moving from one date indication to the next date indication, the display pointer 84 slightly exceeds the date indication to which it will point, and then can be correctly positioned opposite the date indication. During this month, this does not cause a particular problem, because the movement of the display pointer 84 beyond the date indication to which it will point is short-lived and the owner of the timepiece hardly notices it. On the other hand, when moving from the date indication "31" to the date indication "1", this crossing is more problematic. In fact, since it is composed of a retrograde timepiece display mechanism 80 of the dragging type, the following period lasts for several hours, that is, during this period, the retrograde timepiece display mechanism 80 is in a situation that allows it to jump back from its end position (corresponding to the date indication "31") to its initial position (corresponding to the date indication "1"). Therefore, during this period, the display hand 84 gives an incorrect indication, which may cause the owner of the timepiece to believe that the timepiece suffers from a design defect or actually suffers from a malfunction and in any case cause the owner to have a bad impression of his timepiece. In order to remedy this problem, the present invention provides for equipping the retrograde timepiece display mechanism with a disconnection device, which will not be described.

[0088] More specifically with reference to Fig.42 (This figure is a top view of the assembled display wheel 88) and Fig.43 (which is a bottom view of this same display wheel 88 from which the fixed display wheel 90 has been removed), it can be seen that the disconnection device firstly comprises a display disconnection lever 112 which is rigidly connected to the display pinion 82, for example by driving. In addition, the display disconnection lever 112 is rotationally coupled to the display wheel 88 by means of a second pin 114 fastened in the plate 106 of the display wheel 88. As particularly Fig.43 As can be seen in the figure, the display disconnect lever 112 also includes a resilient strip 116 which is in resilient support against a third pin 118 fastened in the plate 106 of the display wheel 88. The second pin 114 protrudes into an opening 120 provided in the display disconnect lever 112. Finally, the display disconnect lever 112 includes a second foot 122, the function of which will be detailed in the following description.

[0089] like Figures 16 to 21 As shown in FIG. 1 , once a day, at a time before midnight (usually about an hour to an hour and a half before the day changes), the retrograde timepiece display mechanism 80 starts to move from one date indication to the next. To make this drive possible, the display wheel 88 is driven one step in the clockwise direction by the timepiece movement every day. During this drive, the holding finger 98 moves from the space between two consecutive teeth of the wolf-tooth-shaped tooth portion 92 of the fixed display mechanism 90 to the next adjacent space, thus ensuring that the entire retrograde timepiece display mechanism 80 is maintained under elastic tension. To make this drive possible, especially Fig.16 , Fig.18 and Fig. 20 , a drive wheel 126 driven by the timepiece movement at a rate of one full revolution in twenty-four hours in a manner known per se drives with it a drive finger 128 which in turn drives the display wheel 88 one step in the clockwise direction. During this drive, the retaining finger 98 moves from the space between two consecutive teeth of the wolf-toothed toothing 92 of the fixed display mechanism 90 to the next space immediately following, thus ensuring that the entire reversing timepiece display mechanism 1 is maintained under elastic tension. Advantageously, the drive finger 128 is elastic so that when the reversing timepiece display mechanism 80 returns to its initial position, it can be moved away from in front of the teeth of the display wheel 88 when the display wheel 88 is rotated in the reversing direction. A further advantage provided by the drive finger 128 is that, due to its elasticity, it enables the owner of the timepiece to perform manual settings in the counterclockwise direction without driving and thus damaging the reversing timepiece display mechanism 80.

[0090] The display disconnection lever 112 is rigidly connected to the display pinion 82 and is rotationally coupled to the display wheel 88 via the second pin 114, which is free to rotate relative to the fixed display wheel 90. Therefore, the display pinion 82, which is freely mounted on the display wheel 88 in a coaxial manner, then pivots and drives the display pointer 84 so that the display can move from one date indication to the next. Similarly, the third pin 118 contacts the elastic strip 116 of the display disconnection lever 112 and drives the display disconnection lever to rotate.

[0091] In the case of being driven by a timepiece movement, the display wheel 88 therefore drives the holding finger 98 carried by the display wheel 88 over 11.1°, whereas the angle separating two consecutive teeth of the wolf-toothed portion 92 of the fixed display wheel 90 is only 8.57°. It will therefore be understood that the holding finger 98 is moved forward more than necessary in order to ensure that it is correctly moved from the space between two consecutive teeth of the wolf-toothed portion 92 to the next space immediately adjacent, and that the displayed information is therefore correctly incremented. It will be understood, however, that this embodiment cannot be interpreted in a restrictive manner, in particular with regard to the angular values ​​that depend on the dimensioning of the flyback timepiece display mechanism 80.

[0092] It will also be understood that the example given of the display of date indications from "1" to "31" is also merely illustrative and not purely limiting, and that other time indications may also be displayed by the retrograde timepiece display mechanism 80 according to the invention, so that the number of steps performed by the display wheel 88 between two consecutive returns to the display of the first date indication may be different from thirty-one. For example, if the retrograde timepiece display mechanism 80 according to the invention is used to display the days of the week, the display wheel 88 will move forward six steps between the display of two consecutive returns to the indication of the day "Monday". Alternatively, if the display mechanism according to the invention is intended to display the months of the year, the display wheel 88 will move forward one step per month.

[0093] In the case of interest here (i.e. the application of a retrograde timepiece display mechanism 1 according to the invention to a simple date indication), this retrograde timepiece display mechanism 80 is finally supplemented by a fixed period limiting element 124 equipped with a single supporting surface 124a corresponding to the duration of a month with 31 days.

[0094] In the example illustrated in the drawings accompanying this patent application, the situation in which the retrograde timepiece display mechanism 80 according to the invention is located corresponds to the display of a date indication for a month with 31 days. Fig. 22 and Fig.23As can be seen in FIG. 1 , when the retrograde timepiece display mechanism 80 displays the date indication “31”, the holding finger 98 and the display break lever 112 face the support surface 70a of the period limiting element 124 via their respective legs 104 and 122. Then, when the retrograde timepiece display mechanism 80 is ready to return to the date indication “1”, the holding finger 98 and the legs 104 and 122 of the display break lever 112 abut against the support surface 124a of the period limiting element 124 (see FIG. 1 ). Fig.24 and Fig.25 ). In this position, the retrograde timepiece display mechanism 80 is not yet disconnected. In fact, during the period separating the display transition from the date indication "31" to the date indication "1", the display wheel 88 pivots. While pivoting, this display wheel 88 drives the display disconnection lever 112 with it via the second pin 114, which in turn drives the display pinion 82. Then ( Figure 26 to Figure 31 ), showing that the disconnection lever 112 is locked by its foot 122 abutting against the support surface 124a of the period limiting element 124 (see Fig.26 and Fig. 27 ). As for the holding finger 98 (driven by the display wheel 88), it abuts with its foot 104 against the same support surface 124a of the period limiting element 124, which forces this holding finger 98 to pivot about its pivot axis 100. When pivoting, the holding finger 98 will thus go against the elastic force of the pawl 94 and will be able to release from the wolf tooth 92 that fixes the display wheel 90. In the case where the display disconnection lever 112 is locked, the elastic strip 116 is driven by the third pin 118 and tensioned under the pivoting action of the display wheel 88. Finally, as in Fig.26 and Fig. 27 As can also be seen in FIG. 1 , when retaining finger 98 is released from wolf-tooth 92 of fixed display wheel 90 , the retaining force exerted by resilient strip 116 of display breaking lever 112 is released.

[0095] The display of the date indication is linked to the display breaking lever 112; in fact, the display wheel 88 itself drives the display breaking lever 112. This display breaking lever 112 driven on the display pinion 82 causes its pivoting. Therefore, since the display breaking lever 112 is fixed during the period corresponding to the transition from the date indication "31" to the date indication "1", the date indication will not change during this period. At the end of the drive of the display wheel 88 (see Fig.28 and Fig.29 ), the holding force applied by the elastic strip 116 of the display disconnection lever 112 is released, and the display wheel 88 will rotate instantaneously in the counterclockwise direction under the action of the elastic force, which is applied to the display wheel 88 via the display disconnection lever 112 and the display pinion 82 (see Fig.30 and Fig.31 ).

[0096] When the display wheel 88 stops rotating, a cam or pin (not shown) will return the retaining finger 98 engaged in the wolf-tooth shaped toothing 92 of the fixed display wheel 90 (see FIG. Fig.32 and Fig.33 ). Then, the jump back clock display mechanism 80 is in Fig.34 and Fig.35 In the position illustrated in FIG. 1 , in which it again displays the date indication “1”.

[0097] In the normal operating mode of the retrograde timepiece display mechanism 80, the beak 102 of the retaining finger 98 is constantly engaged with the teeth of the wolf-tooth shaped toothing 92 (except at about midnight), the retrograde timepiece display mechanism 80 moves from one date indication to the next, and the retaining finger 98 pivots just the amount required to enable its beak 102 to move from the space between two teeth of the wolf-tooth shaped toothing 92 to the next adjacent space ( Fig.16 and Fig.17 ). When the retrograde timepiece display mechanism 80 reaches the date indication "31" and will have to return to the date indication "1" in a retrograde manner (see Fig. 22 and Fig.23 ), the foot 104 of the holding finger 98 moves away from the support surface 124a of the period limiting element 124, so that the holding finger 98 tilts and its beak 102 is released from its engagement with the wolf tooth 92 (see Fig.26 and Fig. 27 ). At that point, it is no longer guaranteed that the retrograde timepiece display mechanism 80 remains in position and the mechanism will seek to return in a retrograde manner to the date indication “1” ( Fig.30 and Fig.31 ), then beak 102 of retaining finger 98 will return again to engage in the teeth of wolf-tooth 92, which will again ensure that retrograde timepiece display mechanism 1 remains in position ( Fig.32 and Fig.33 middle).

[0098] More specifically, Figures 24 to 31 The operation of the retrograde timepiece display mechanism 80 is shown at the exact time when the retrograde timepiece display mechanism moves from the date indication "31" to the date indication "1" in a retrograde manner. This movement is facilitated by the cooperation between the holding finger 98 and the wheel-stopping claw 94. In fact, by carefully observing Fig.26 , Fig.28 , Fig.30 , Fig.32 , Fig.34 and Fig.36 It can be seen that the first pin 108 carried by the retaining finger 98 gradually changes the contact plane with the brake pawl 94. Fig.24 In the process, the first pin 108 begins to slide under the brake pawl 94, and in Fig.36(this figure corresponds to the situation in which the retrograde watch display mechanism 80 has returned to its initial position in which it points to the date indication “1”), the first pin 108 has once again passed completely under the brake claw 94, which enables the latter to elastically press the beak 102 of the retaining finger 98 into the wolf-toothed toothing 92.

[0099] It is obvious that the invention is not limited to the embodiments that have just been described and that a person skilled in the art may envisage various modifications and simple variants without departing from the scope of the invention as defined by the appended claims.

[0100] Reference numerals list

[0101] 1. Jump back clock display mechanism

[0102] 2. Return rack

[0103] 4. Return spring

[0104] 6. Gear train

[0105] 8. First needle wheel

[0106] 10. Second needle wheel

[0107] 12. Third needle wheel

[0108] 14. Display pinion

[0109] 16. Toothed area

[0110] 18. First pinion

[0111] 20. First moving part

[0112] 22. Second small gear

[0113] 23. Show pointer

[0114] 24. Second moving part

[0115] 26. Indexing

[0116] 28. Display wheel

[0117] 30. Fixed display wheel

[0118] 32. Tooth

[0119] 34. Braking claw

[0120] 35. Elastic Strip

[0121] 36. Keep pointing

[0122] 37. Pivot axis

[0123] 38. Beak

[0124] 40. First leg

[0125] 42. Board

[0126] 44. First Sales

[0127] 46. ​​Opening

[0128] 48. Display disconnect lever

[0129] 50. Second Pin

[0130] 52. Open your mouth

[0131] 54. Elastic Strip

[0132] 56. Third Pin

[0133] 58. Second leg

[0134] 60. Driving wheel

[0135] 62. Driver

[0136] 64. Flange

[0137] 66. Star Wheel

[0138] 68. Second drive finger

[0139] 70. Contact push rod

[0140] 70a, 70b, 70c and 70d. Support surface

[0141] 72. Following beak

[0142] 74. Repositioning cam

[0143] 76. Nose

[0144] 78. Equivalent Add-ons

[0145] 80. Rewinding clock display mechanism

[0146] 82. Display pinion

[0147] 83. Return Component

[0148] 84. Display pointer

[0149] 86. Indexing

[0150] 88. Display wheel

[0151] 100. Pivot axis

[0152] 102. Beak

[0153] 104. First leg

[0154] 106. Board

[0155] 108. First Sales

[0156] 110. Opening

[0157] 112. Display disconnect lever

[0158] 114. Second Pin

[0159] 116. Elastic Strip

[0160] 118. Third Pin

[0161] 120. Opening

[0162] 122. Second leg

[0163] 124. Time limit element

[0164] 124a. Support surface

[0165] 126. Driving wheel

[0166] 128. Driving finger.

Claims

1. A drag-type retrograde timepiece display mechanism (1; 80), driven by a movement of a timepiece, in which the retrograde timepiece display mechanism (1; 80) is embedded, the retrograde timepiece display mechanism (1; 80) being arranged to display at least one first indication and at least one last indication successively in a retrograde manner, the at least one first indication and the at least one last indication being distinguishable, the retrograde timepiece display mechanism (1; 80) comprising: - Display wheel (28; 88)； - arranged on the display wheel (28; a display pinion (14; 82) and a fixed display wheel (30; 90) on either side of a display wheel (28; 88), the display pinion (14; 82) being freely mounted on the display wheel (28; 88) in a coaxial manner, and the fixed display wheel (30; 90) being fixedly mounted concentrically with the display wheel (28; 88) and the display pinion (14; 82) and being provided with a toothing (32; 92); - a pivoting retaining element (36; 98) which engages in said toothing (32; 92) of said fixed display wheel (30; 90); - a drive wheel (60; 126) which is moved by the timepiece movement and which drives said display wheel (28; 88); - a return element (2; 83) tending to force said display pinion (14; 82) to rotate; - a display disconnection lever (48; 112) rigidly connected to the display pinion (14; 82) and coupled in rotation to the display wheel (28; 88), the display disconnection lever (48; 112) comprising an elastic strip (54; 116) which is in elastic support against a pin (56) fastened in the display wheel (28; 88); - the pivoting holding element and the display disconnection lever (48; 112) are arranged so that when the rebound watch display mechanism (1; 80) moves from the display of the last indication to the display of the following first indication, the pivoting holding element pivots and the display disconnection lever (48; 112) is locked, so that the elastic strip (54; 116) becomes strained and the pivoting holding element is forced to release from the toothing (32; 92) of the fixed display wheel (30; 90), thereby allowing the stress induced by the return element in the rebound watch display mechanism (1; 80) to be released and allowing the rebound watch display mechanism (1; 80) to return in the rebound direction to its initial position in which it displays the first indication.

2. The reversible watch display mechanism (1) according to claim 1, characterized in that: In the case where the duration separating the at least one first indication displayed from the at least one last indication displayed is fixed, the retrograde timepiece display mechanism (1) comprises a fixed period limiting element (124) provided with a single supporting surface (124a) which determines the duration separating the at least one first indication from the at least one last indication.

3. The reversible watch display mechanism (1) according to claim 1, characterized in that: In the case where the duration separating the at least one first indication displayed from the at least one last indication displayed is variable, the retrograde timepiece display mechanism (1) comprises: a cam (64) arranged to manage at least two durations of different values, said at least two durations separating said at least one first indication from said at least one last indication, and said cam being driven one step by said return element each time said retrograde timepiece display mechanism (1; 80) moves from said last indication to a following first indication, and - a mobile contact plunger (70) pressed against the profile of the cam (64), the contact plunger (70) also comprising at least two support surfaces (70a, 70b, 70c, 70d) defining the two durations having different values, the two durations separating the at least one first indication and the at least one last indication.

4. The reversing watch display mechanism (1) according to claim 3, characterized in that: The contact plunger (70) is provided with a trailing beak (72), by means of which the contact plunger (70) is pressed against the profile of the cam (64).

5. The reversible watch display mechanism (1) according to any one of claims 2 to 4, characterized in that: The pivoting holding element is a finger (36; 98) comprising a first leg (40; 104), and in that the display disconnection lever (48; 112) comprises a second leg (58; 122), these first and second legs (40, 58; 104, 122) being arranged so that when the rebound timepiece display mechanism (1; 80) moves from the display of the last indication to the display of the first following indication, these first and second legs (40, 58; 104, 122) face the support surface (70a, 70b, 70c, 70d; 124a), and then, when the drive wheel (60; 126) continues to drive the display wheel (28; 88), the first leg (40; 104) moves away from the support surface The supporting surface (70a; 124a) is moved away, while the second leg (58; 122) abuts against the supporting surface (70a; 124a), which prevents the display disconnection lever (48; 112) from pivoting and causes the elastic strip (54; 116) to be tensioned, the pivot holding element is forced to pivot, which enables it to be released from the toothed portion (32; 92) of the fixed display wheel (30; 90), thereby enabling the second leg (58; 122) to be released from the supporting surface (70a; 124a) in a rebound manner and enabling the rebound timepiece display mechanism (1; 80) to return to its initial position, in which the rebound timepiece display mechanism (1; 80) displays the first indication.

6. The reversing watch display mechanism (1) according to claim 5, characterized in that: The pivoting retaining element (36; 98) is elastically pressed into the toothing (32; 92) of the fixed display wheel (30; 90) by means of a pawl (34; 94) carried by the display wheel (28; 88).

7. A reversible timepiece display mechanism (1) according to any one of claims 2 to 4, characterized in that: The drive wheel (60; 126) is equipped with elastic drive fingers (62; 128), through which the drive wheel (60; 126) drives the display wheel (28; 88).

8. The reversible timepiece display mechanism (1) according to any one of claims 2 to 4, characterized in that: The return element is an elastically forced return rack (2; 83), thanks to which the return rack (2; 83) generates a mechanical tension which forces the display pinion (14) to rotate.

9. The reversible timepiece display mechanism (1) according to claim 3, characterized in that: The return element is an elastically forced return rack (2; 83), thanks to which the return rack (2; 83) generates a mechanical tension which forces the display pinion (14) to rotate; The return rack (2) comprises a second drive finger (68), via which the return rack (2) drives a star wheel (66) fastened to the cam (64) one step each time the retrograde timepiece display mechanism (1) moves from the display of the last indication to the display of the first subsequent indication.

10. The reversible timepiece display mechanism (1) according to claim 9, characterized in that: When the retrograde timepiece display mechanism (1) displays an indication, the second drive finger (68) carried by the return rack (2) is gradually retracted and gradually positioned behind a given tooth of the star wheel (66), so that when the retrograde timepiece display mechanism (1) moves from the display of the last indication to the display of the next first indication, the elastic tension in the retrograde timepiece display mechanism (1) is suddenly released and the return rack (2) returns to its initial position by pivoting and by driving the second drive finger (68) therewith, which moves the star wheel (66) and therefore the cam (64) forward by one step.

Images