HK40000780B - Mechanism for a watch movement - Google Patents

Description

Mechanisms used in watch movements

Technical Field

The invention relates to a mechanism for a watch movement with a retrograde and jumping display.

Background Art

Retrograde displays are known in the watch industry. These are displays in which a hand or disc rotates in one direction for a given period and then, at the end of that period, snaps back to its original position almost instantaneously by rapidly rotating in the opposite direction. These retrograde displays are used, for example, to indicate the minutes on a scale from 1 to 60 covering an arc of less than 360°. These retrograde displays free up space on the dial for other information. Furthermore, the rapid return of the minute indicator every hour creates movement on the dial.

Jumping displays are also known, in which the time indicator jumps from one value to another almost instantaneously. These jumping displays are particularly used to display the date in a window. They are also sometimes used to indicate other information, including the current hour in a window. In this application, the expression "jumping display" covers both displays: those in which the jump is almost instantaneous; and so-called trailing displays, in which the jump is not so rapid, although the display's progression is still discontinuous.

The object of the present invention is to create a watch movement combining both a retrograde display and a jumping display.

Watches combining a retrograde display and a jumping display are known per se. EP 0 950 932 B1, for example, describes such a watch comprising a minute display over 180° and a jumping hour display on a disc. The hour disc is actuated by means of a snail cam.

CH691833 describes another example of a watch featuring a jumping hour display and a retrograde minute display. The minute rack has two toothed sections: one for transmitting movement to the minute display member and the other driven by a pinion with one tooth missing. This pinion is fixed to the hour wheel and driven at a rate of one rotation per hour. The instantaneous return of the rack corresponds to the movement of the rack's last tooth at the missing tooth position of the pinion.

CH698132 relates to a watch with a jumping hour display and a retrograde minute display, in which both the jumping of the hours of the hour disc and the return of the retrograde hand are caused by the same cam acting on a connecting rod.

EP1134627B1 relates to a watch with a triple (minute, hour, date) retrograde display, wherein the hour display is a jumping display. The retrograde hour display is realized by means of a rack that moves in two directions.

WO9740424 relates to a watch comprising a retrograde minute display over 180° and a jumping hour display carried by a disc and visible through a window.

EP0788036B1 relates to a watch with a jumping hour display and a retreating minute display on a disc. By the rotation of a snail cam fixed to the minute wheel, the lever is gradually raised once every hour.

CH 681 761 relates to a watch with a date retrograde display over 240° by means of a pinion with some teeth missing.

EP2010971B1 relates to a watch comprising a retraction display of time information items (eg hours) over a 270° angular sector. The retraction module comprises a cam and a rack.

EP 2 595 006 relates to a mechanism for a jumping hour display.

DE10200284C1 relates to a watch with a minute display and a jumping hour display on a 330° sector. A decoupling element is provided between the minute display wheel and the minute drive star wheel.

CH 688068 relates to a retrograde display of the seconds on an angular sector by means of a minute pinion which is missing some teeth and which engages with a rack.

Summary of the Invention

The purpose of the present invention is to provide a retraction display mechanism that is different from the existing solutions.

Another object of the present invention is to propose a jumping display mechanism that is driven by a retracting display mechanism in a manner different from known mechanisms.

According to the invention, these objects are achieved in particular by means of the mechanism according to the independent device claim.

Another object of the present invention is to propose a display method that is different from the methods of the prior art.

Another object of the present invention is to propose a simplified fallback and jump display method.

According to the present invention, these objects are achieved by means of a watch movement mechanism comprising: a cam; a rack driven by the cam; a retraction movable member driven by the rack and carrying a retraction indicator to display a first item of time information, the rack and the retraction movable member being arranged to rotate in the same direction.

According to another aspect of the present invention, the watch movement mechanism includes: a cam; a rack driven by the cam; a retraction movable member, which is driven by the rack and carries a retraction indicator to display a first item of time information, and the end of the rack includes an opening provided with an internal tooth portion, and the retraction movable member can be driven by the internal tooth portion.

The direction of rotation of the rack is determined by the shape and direction of rotation of a cam, such as a snail cam. It is desirable to provide a cam that rotates counterclockwise during normal operation of the watch; this is because this allows it to be driven directly from the hour wheel of a conventional movement, which normally rotates clockwise. The rack, driven by the circumference of the cam, then rotates clockwise. The claimed mechanism makes it possible to directly drive the retracting movable element in the same direction as the rack, thereby making it possible to eliminate an intermediate transfer wheel and, therefore, limit the number of components and the amount of play in the gear train.

The mechanism may have a toothed rack, the end of which comprises an opening provided with an internal toothing, by which it is possible to drive the retracting movable element.

It is possible that only a portion of the inner opening, for example the portion on the opposite side with respect to the cam, is provided with a toothing.

The end of the rack provided with two branches separated by an opening is more rigid than a conventional end of a single branch, making it possible to limit the play relative to the retracting movable member.

This solution also has the advantage of providing a more pleasing appearance due to the unique shape of the rack in the retraction display mechanism.The fact that the rack, retraction movable member and retraction indicator all rotate in the same direction adds to the unique features of the retraction display device according to the present invention.

According to one embodiment, the watch movement mechanism may include: a cam; a rack driven by the cam; a retraction movable member driven by the rack and carrying a retraction indicator for displaying a first item of time information, the rack and the retraction movable member are preferably arranged to rotate in the same direction; a jumping display ring for displaying a second item of time information, the jumping display ring including an inner tooth portion, the rack including a drive member, which cooperates with the inner tooth portion to drive the jumping display ring to rotate in a jumping manner.

According to one embodiment, the cam may be driven by the watch movement by means of a friction centre wheel or intermediate transfer wheel.

The solution also provides novel advantages over existing solutions.

In a preferred embodiment, the watch movement comprises: a correction mechanism which makes it possible to correct the retracting movable member in both directions; and a drive member which can be actuated by the correction mechanism and which meshes with the asymmetric internal toothing so that corrections of the retracting movable member in the clockwise direction are transmitted to the hour ring, while corrections in the counterclockwise direction are not transmitted to the hour ring.

Thanks to the retracted display's correction in both directions, it is possible to correct its position without completing a full revolution, thus enabling the time to be set more quickly.

For example, in the case of a retrograde minute display, it is possible to correct the position of this indicator in both directions. If the watch movement runs fast by a few minutes, it can thus be corrected back without having to advance almost a full revolution, and without affecting the position of the hour indicator.

This embodiment therefore offers the advantage, compared to the prior art, of allowing a simple and rapid correction of a retrograde indicator, such as a minute indicator.

Corrections of the retrograde indicator in the clockwise direction are transferred to the jumping hour ring. In the case of a retrograde minute indicator, this makes it possible, for example, to correct the jumping hour indicator in the clockwise direction, with a jump at one hour each time the minute indicator advances from 59 to 00. This correction of the jumping hour ring can be achieved very simply by using the jumping hour drive mechanism used during normal watch operation.

In contrast, corrections to the retrograde minute indicator in the counterclockwise direction (in order to delay it) are preferably not transmitted to the jumping hour ring. This is because conventional jumping hour drives generally do not allow for counterclockwise jumps; they are designed only to advance the jumping hour ring in the clockwise direction under the action of the gear train. In other words, corrections in the counterclockwise direction are not driven by the crown. For example, jumping hour drives typically include a cam with a sudden change, such as a snail cam, that can only be traversed in one direction. Thus, by avoiding the transmission of corrections in the counterclockwise direction to the jumping hour ring, the need to modify the ring's drive mechanism is avoided.

By thus choosing a correction which is unrestricted in the clockwise direction but restricted in correcting the minutes in the counterclockwise direction, a practical, easy-to-operate movement is obtained and at the same time a significant simplification is achieved with respect to the construction involving a movement allowing unrestricted correction in both directions, which construction offered only a small improvement in terms of convenience and was significantly more complex.

This construction thus makes it possible to produce a simple correction mechanism that allows a large number of corrections to be made using very few manipulations of the crown and without requiring modifications to the jumping hour ring drive mechanism.

In one embodiment, a correction blocking mechanism is provided to prevent the reversing movable element from being corrected counterclockwise within a range around the sudden change in the disc, while allowing correction of the reversing movable element in all other positions of the disc outside this range. For example, if the reversing movable element displays minutes, the mechanism can prevent correction in the counterclockwise direction while the reversing minute indicator is indicating a value within a range encompassing 60 minutes. This makes it possible to avoid the risk of the jumping hour indicator accidentally moving counterclockwise due to correction of the minute disc within this range.

The correction blocking mechanism may be connected to a cam lobe, which may be on the rack, and blocks rotation of the snail cam in one of two rotational directions when the snail cam is located near the lobe discontinuity.

The inner tooth portion connected to the jumping display ring may include a plurality of teeth having asymmetric tooth surfaces, so that when the rack rotates in a counterclockwise direction, the driving member of the rack can abut against one tooth surface of the teeth of the inner tooth portion to drive the jumping display ring, and when the rack rotates in a clockwise direction, the driving member of the rack slides along the other tooth surface of the teeth of the inner tooth portion or does not contact the inner tooth portion.

The drive member driving the rack may be mounted on the rack by means of a shaft allowing it to pivot.

The mechanism may comprise a spring mounted on the rack and applying a force to press the drive member against the inner teeth.

The drive members may be teeth or fingers.

In one embodiment, the first item of time information can be the current hour, and the second item of time information can be the current minute.

According to the invention, a method for displaying an item of time information by means of a watch movement mechanism as described above may comprise the following steps:

- motion driving the cam,

- Cam driven rack,

- rack driven retraction movable element and indicator,

- a rack-driven jumping ring for the current hour display,

- The rack, retraction movable element and indicator rotate in the same direction.

This method allows the jumping display ring to be driven to rotate in a jumping manner by an adjusting member mounted on a rack.

According to the present invention, the clockwise rotation of the rack can drive the clockwise rotation of the retracting movable member and the counterclockwise rotation of the jumping display ring to display the current hour.

According to the present invention, when the cam rotates in the counterclockwise direction and drives the rack to rotate in the clockwise direction, the rack can drive the retraction movable member, the indicator and the finger to rotate in the same direction by rotating in the clockwise direction, and the finger can move along one tooth surface connected to the inner tooth portion of the jumping display ring without causing the ring to rotate.

When the first end of the rack falls from the apex of the cam, the second end of the rack is driven to rotate almost instantaneously in the counterclockwise direction, thereby causing an almost instantaneous rotation of the retracting mobile, the teeth, the indicator and the jumping display ring carrying the hours in the same direction.

The mechanism can include the watch movement, complications designed to work with the movement, additional modules, and so on.

The mechanism described can also be used for skipping the display of information other than hours and/or for rewinding the display of information other than minutes.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention are indicated in the description illustrated by the accompanying drawings, in which:

- FIG1 shows a view from above of the key components of the mechanism according to the invention;

- FIG2 shows a view from above of the key components of the mechanism according to the invention at 0 minutes;

- FIG3 shows a view from above of the key components of the mechanism according to the invention at 17 minutes;

- FIG4 shows a view from above of the key components of the mechanism according to the invention at 35 minutes;

- FIG5 shows a view from above of the key components of the mechanism according to the invention at 59 minutes;

- FIG6 shows a view from above of the key components of the mechanism according to the invention at 60 minutes;

- Figures 7 to 10 show views from above of the key components of the mechanism according to the invention during a jump from 60 minutes to 0 minutes;

- Figure 11 shows a view from above of the key components of the mechanism according to the invention at 0 minutes.

For the sake of clarity, the figures do not illustrate the movements that drive the mechanism according to the invention.

DETAILED DESCRIPTION

FIG1 shows an example of a retraction mechanism 1 according to the present invention. It comprises a retraction indicator 2, shown in this embodiment in the form of a minute hand. The retraction minute indicator 2 is mounted on the shaft of a retraction movable member 20. The retraction movable member 20 comprises an external toothing 200.

The rack 3 has a first end 31 that is pressed against the periphery of the snail cam 5 by means of a rack spring 33. The second end 32 of the rack 3 includes an oblong opening equipped with an internal toothing 320. Under the action of the snail cam, the rack 3 pivots from the pivot point. During this pivoting, the internal toothing 320 of the second end 32 of the rack engages with the external toothing 200 of the retraction movable member 20, causing the retraction indicator 2, carried by the retraction movable member 20, to rotate in the same direction as the second end 32 of the rack. The movement of the rack is transmitted to a drive member, which here includes a tooth 4 that is hinged to the second end of the rack 32 by means of a shaft 41. A return spring 42 applies a return force to the tooth 4, pressing it against the toothing 610.

The first end 31 of the rack follows the rotation of the snail cam 5 carried by the drive release wheel 52. This drive release wheel 52 is driven by the wheels of the gear train in such a way that the minute indicator 2 passes the minute scale 11 (Figures 2 to 11) in 60 minutes (or 60 minutes minus the return time).

In this embodiment, mechanism 1 comprises a jumping display ring 60 carrying hour indicator 6 , thus allowing the current hour to be displayed in window 10 ( FIGS. 2 to 11 ).

Jumping display ring 60 is driven by a smaller diameter drive ring 61. In an alternative form not yet shown, it is also conceivable that hour indicator 6 is positioned directly on drive ring 61 or on a ring of the same diameter.

The drive ring 61 includes an inner toothed portion 610 having a plurality of teeth around the entire inner circumference. The spacing between the teeth is even, and there are no missing teeth. The teeth have two asymmetrical tooth flanks 6100 and 6101. The first tooth flank 6100 is almost parallel to the diameter of the drive ring 61 and allows the drive ring 61 to be driven by means of a drive member (tooth) 4. The tooth 4 serves as the drive member for the jumping hour display. The second tooth flank 6101 is curved; the average inclination forms an angle of less than 30° with the tangent of the drive ring 61, so that when the tooth 4 contacts the second tooth flank 6101, it can slide along this second tooth flank 6101 without driving either the second tooth flank or the drive ring 61.

The drive ring 61 further comprises an outer toothed portion 611 presenting teeth 6110 whose tips are concentric with the drive ring 61 , the recesses 6111 between each of the teeth 6110 being designed to receive the ends 620 of the positioning jumpers 62 .

Jumping element 62 thus cooperates with outer toothing 611 to center the hour indicator in window 10 ( FIG. 2 ). The end 620 of jumping element 62 opposes the movement of drive ring 61 by engaging in recesses 6111 located between the teeth 6110 of the outer toothing of drive ring 61. The stiffness of jumping element 62 is selected so that it holds drive ring 61 in place when it is not driven by toothing 4, while allowing the end of jumping element 620 to disengage from recess 6111 of outer toothing 611, which is connected to jump display ring 60, under the action of toothing 4 and with the aid of rack spring 33.

The jumper 62 has a first end (or output end) and a second end (or input end). These two ends are inclined at a non-zero angle relative to the vertical wall of the outer tooth portion 611 of the drive ring 61. The jumper 62 cooperates with the jumper spring 63.

In another embodiment, only the first end of the jumper has a non-zero inclination angle relative to the recesses of the outer toothing of the drive ring 61; therefore, when the jumper, thus modified, is engaged in the recesses, the second end is clearly parallel to the edges of these recesses. This particular shape of the jumper allows blocking the clockwise rotation of the drive ring 61. In other words, the second end of the jumper is configured in such a way as to block the clockwise rotation of the drive ring 61 and thus avoid display errors, for example in the event of a shock.

The operation of the mechanism during the normal advancement of retrograde display 5 , ie as minute hand 2 gradually advances from 0 minutes to 60 minutes, will now be described with the aid of FIGS. 2 to 6 .

Figure 2 shows the mechanism immediately after the return of the retracting minute hand 2, which now points to 0 minutes. In this position, the first end of the rack 31 presses against the smallest diameter of the snail cam 5. The retracting movable element 20 engages with the internal toothing 320 in the opening of the rack. In the example shown, the teeth 4 do not contact the internal toothing 610 of the jumping display ring 60.

Figure 3 corresponds to the position of minute hand 2 at 17 minutes. Snail cam 5, driven counterclockwise by the teeth of friction disc center wheel 9 (Figure 1), causes the second end of the rack (in the drawing) to move clockwise, thereby moving minute hand 2 clockwise along minute scale 11. Drive member 4 (teeth) presses against the tips of the teeth of the inner toothing of drive ring 61 without engaging them. Drive ring 61 and jumping display ring 60 are thus held stationary, their positions being fixed by positioning jumper 62, which engages recesses 6111 on the outer circumference of drive ring 61 (Figure 1).

Figure 4 corresponds to the position of the minute hand 2 at 35 minutes. The retracting movable element 20 continues to rotate clockwise, and the minute hand 2 continues to move clockwise along the minute scale 11. The drive member 4 (teeth) contacts the beveled tooth surfaces 6101 of the inner toothing 610 of the drive ring 61 (Figure 1) without engaging with them. The drive ring 61 and the jumping display ring 60 thus remain stationary.

Figure 5 corresponds to the position of minute hand 2 at 59 minutes. First end 31 of rack contacts snail cam 5 near its maximum diameter portion 51. Drive member 4 (tooth) contacts the tips of internal toothing 610. During the interval from 0 to 59 minutes, tooth 4 slides along the teeth of drive ring 61 (Figure 1) without interfering with the position of drive ring 61.

FIG6 corresponds to the position of minute hand 2 at 60 minutes. First end 31 of the toothed rack is at the apex of cam 5. Drive member 4 (tooth) has moved past the tip of internal toothing 610 and has engaged first tooth flank 6100 of internal toothing 610 of drive ring 61 ( FIG1 ). This ring is still held in place by positioning jumper 62.

At 60 minutes, the descent of rack 3 against snail cam 5 simultaneously causes an almost instantaneous return of minute indicator 2 to 0 in the counterclockwise direction and a similar jump of drive ring 61 ( FIG. 1 ) in the counterclockwise direction. This return is illustrated in FIGS. 6 to 11 .

Figures 6 and 7 illustrate the start of the retrograde indicator's return to 0 minutes and the jump of the jumping display. The first end 31 of the rack begins its descent from the apex of the snail cam 5. The second end 32 of the rack rotates counterclockwise, causing the retrograde indicator, positioned at 55 minutes, and tooth 4 to rotate in the same direction. Consequently, with the aid of the gradually relaxing rack spring 33, the drive ring 61 is driven counterclockwise by tooth 4. As the rack spring relaxes, it (Figure 1) transfers sufficient energy to the jumping display ring 60 (Figure 1) to cause the end 620 of the positioned jumping element 62 to clear the recess 6111 of the outer toothing 611. The counterclockwise movement of the jumping display ring 60, causing the time to advance from h to h+1, can be seen through the window 10.

Figures 8 and 9 show the next part of the return of the setback indicator. The setback indicator is positioned at 40 and 25 minutes, respectively. Tooth 4 moves along the first flank of inner toothing 610. The movement of jumping indicator ring 60 in the counterclockwise direction to a position between the two jumping indicator elements 6 can be seen through window 10. The end 620 of the positioning jumping element 62 moves along tooth 6110.

FIG10 shows the end of the return of the retrograde indicator. The retrograde indicator is positioned at 17 minutes, and tooth 4 is almost at the tip of the inner toothing 610 connected to jump display ring 60 and will no longer mesh with inner toothing 610. The new jump display element 6 can be seen through window 10. Position jumper 62 (not shown) has "dropped back" into recess 6111 of outer toothing 611.

FIG11 shows the return of the retrograde indicator to 0 minutes. The retrograde indicator is now positioned at 0 minutes, and tooth 4 no longer contacts the inner toothing 610 connected to jump indicator ring 60. The first end of the toothed rack rests on the smallest diameter portion of cam 5. The new position of jump indicator element 6 can be seen through window 10.

In the illustrated embodiment, the minutes are displayed by the position of the retrograde indicator 2 on the minute scale (not shown). The minute scale covers an arc of a circle that is less than 360° but greater than 180°, for example, 240°. The window in which the current hour is displayed is positioned facing the opening of the scale, in the illustrated example at 6 o'clock.

In the embodiment shown in the accompanying drawings described above, the mechanism allows the fallback display of minutes and the jump display of hours. However, such a mechanism can be used for the jump display of information other than hours and/or the fallback display of information other than minutes.

Reference numerals used in the accompanying drawings

1 Mechanism for watch movement

2 Fallback indicator

20 Roll back movable parts

200 tooth portion of movable member 20

3 racks

31 First end of rack

32 Second end of rack

320 tooth portion of rack 3

33 Rack spring

4 Drive member/teeth

41 axis

42 Spring

5 Cam

51 Cam Vertex

52 Release drive wheel

6 Jump display element

60 Jumping display ring, e.g. hour ring

61 is connected to the driving ring of the jump display ring

610 Inner tooth portion of drive ring 61

6100 First tooth surface of tooth portion 610

6101 Second tooth surface of tooth portion 610

6102 Tooth tip of tooth portion 610

611 External tooth portion of the drive ring 61

6110 teeth of tooth section 611

6111 Recessed portion of tooth portion 611

62 Jumping member for positioning the drive ring 61

620 Positioning end of jump member 62

9 Center wheel friction plate/reverse minute intermediate transmission gear

10 Jumping Hour Window

11-minute scale.

Claims (12)

1. A mechanism (1) for a watch movement, the mechanism comprising: - Cam (5); - A rack (3), the rack including a first end (31) and a second end (32), the rack (3) being adapted to be driven by the cam (5), and - A retractable movable element (20), which is adapted to be driven by the rack (3) and carry a retractable indicator (2) for displaying a first item of time information; The rack (3) and the retractable movable member (20) are configured to rotate in the same direction; The mechanism is characterized in that it further includes: a jump display ring (60) for displaying a second item of time information, the jump display ring (60) including an inner toothed portion (610); and the rack (3) includes a drive member (4) that cooperates with the inner toothed portion (610) to drive the jump display ring (60) to rotate in a jumping manner. 2. The mechanism (1) according to claim 1, wherein the second end (32) of the rack includes an opening fitted with an inner toothed portion (320) of the rack, and the retractable movable member (20) is driven by the inner toothed portion (320) of the rack. 3. The mechanism (1) according to claim 1 or 2, wherein the inner ring tooth (610) comprises a plurality of teeth having asymmetrical tooth surfaces, the rack drive member (4) is configured to abut against one tooth surface of the inner ring tooth (610) and drive the jump display ring (60) when the rack (3) rotates in a counterclockwise direction, and slide along the other tooth surface of the inner ring tooth (610) or not contact the inner ring tooth (610) when the rack (3) rotates in a clockwise direction. 4. The mechanism (1) according to claim 1, wherein the drive member (4) is mounted on the rack (3) by means of a shaft, thereby allowing it to pivot. 5. The mechanism according to claim 4, the mechanism comprising a spring (42) mounted on the rack (3) and applying force such that the drive member (4) presses against the inner teeth of the ring. 6. The apparatus (1) according to claim 1, wherein the first item of the time information is the current hour, and the second item of the time information is the current minute. 7. A method for displaying time information items by means of a watch movement including the mechanism (1) according to claim 6, the method comprising the following steps: - The mechanism drives the cam (5). - The cam drives the rack (3). - The rack drives the retraction movable part (20) and the retraction indicator (2). - The rack (3) drives the jump display ring (60) to display the current hour. - Characterized by the fact that the rack (3), the retraction movable member (20), and the retraction indicator (2) rotate in the same direction. 8. The method according to claim 7, wherein the jumping display ring (60) is driven to rotate in a jumping manner by a drive member (4) mounted on the rack (3). 9. The method according to claim 7, wherein the clockwise rotation of the rack (3) drives the clockwise rotation of the retractable movable member (20) and the counterclockwise rotation of the jump display ring (60) that displays the current hour. 10. The method according to claim 7, wherein, When the cam (5) rotates counterclockwise and drives the rack (3) to rotate clockwise, The rack (3) drives the retractable movable element (20), the retractable indicator (2), and the drive member (4) to rotate in the same direction by rotating clockwise, and The drive member (4) moves along the first tooth surface (6101) of the inner tooth portion (610) connected to the jump display ring (60) without driving the jump display ring (60) to rotate. 11. The method according to claim 10, wherein when the first end (31) of the rack (3) reaches the apex (51) of the cam (5), the drive member (4) abuts against the second tooth surface (6100) of the inner tooth portion (610) connected to the jump display ring (60). 12. The method according to claim 7, wherein when the first end (31) of the rack falls from the apex (51) of the cam (5), the second end (32) of the rack (3) is driven to rotate approximately instantaneously in the counterclockwise direction, thereby causing the retraction movable member (20), the retraction indicator (2), the drive member (4) and the jump display ring (60) to rotate approximately instantaneously in the same direction.