EP1373991B1 - Chronograph with two rotational directions - Google Patents

Description

The present invention relates to a chronograph comprising a device for driving a second counter by a first counter, the second counter being arranged to count the laps made by the first counter from a zero position of the first counter, the device drive comprising a control finger mounted on the first counter and capable of meshing with a transmission wheel associated with the second counter to drive the latter.

In most cases, the counter called above the first counter is a second counter and the second counter is a minute counter, for example as provided by the patent. CH 571 741 . However, a similar drive device can be used with different counters, for example to drive an hour counter from a minute counter.

When resetting the counters of a mechanical chronograph, the rotating counters of the counters must be able to turn easily and quickly. The control finger mentioned above may then interfere with the toothing of the transmission wheel. To avoid this problem, it is known to move the transmission wheel so that it is out of reach of the finger while the first counter returns to its zero position. For example in the patent CH 678 911 (corresponding to the patent US 5,113,382 ), the control finger meshes with an intermediate wheel which is permanently engaged with a wheel of the minute counter. This intermediate wheel is lifted axially by the reset command, in order to exit the path of the control finger.

The present invention improves the drive device of the second counter by the first so as to allow it to operate in two opposite directions, namely a direct sense where the chronograph adds time in a conventional manner, and a reverse direction where the chronograph performs a countdown, in particular of a duration that the user preselected by putting at least one of the counters in a starting position which defines this duration.

This double direction of rotation creates a new problem related to the meshing of the control finger on the transmission wheel. Let's assume for simplicity that the seconds counter is initially at its zero position for countdown as well as for conventional addition counting. If the control finger is attached to the seconds counter as in the aforementioned patents, its initial position must be such that it will advance the transmission wheel and thus increment the minute counter by the time the seconds counter and the finger will complete. a full turn forward, which corresponds to 60 seconds. But this position would not be appropriate in the case of a countdown, because the finger would then attack the transmission wheel shortly after the start of its rotation back, that is to say already after a few seconds, which would produce an erroneous indication of the minute counter.

The documents are also known US 2,028,452 and CH 207 which describe conventional chronograph movements in which the training of the counters is in one direction only.

The subject of the present invention is a chronograph with two directions of rotation, in which the drive device mentioned above is designed so as to actuate the second counter at a precise instant at the end of a revolution of the first counter, as well as in one sense than in the other. An additional object is to allow precise angular indexing of the control finger relative to the other elements of the device, in order to precisely adjust the moment when it will attack the toothing of the transmission wheel. Another additional object is to arrange the transmission device so as to avoid interference between the control finger and the transmission wheel during the preselection of the duration of the countdown. We seek to fulfill these goals by means of a simple and compact construction.

According to the invention, there is provided a chronograph of the kind indicated in the preamble above, characterized in that the first and the second counter are capable of rotating in both directions, respectively in an addition mode and a control mode. countdown, the second counter being driven forwards or backwards in the direction of rotation of the first counter, in that the control finger is pivotally mounted on a disk connected to a rotary shaft of the first counter and in that the disk and the control finger are coupled to each other by driving means allowing the control finger to pivot on the disk between two stop positions spaced at an angle close to 360 °.

This allows the control finger to occupy one or the other of the two stop positions, according to the direction of rotation, at the moment when it must begin to drive the transmission wheel at the end of a complete revolution. of the first counter. The driving means which define these two stop positions can advantageously be arranged to allow accurate indexing of these positions.

Preferably, the disk is fixed to the shaft of the first counter in an indexed angular position relative to a zeroing yard, by means of which said zero position is defined, and the disk is provided with a spring arranged to maintain the control finger disengaged from the transmission wheel when the first counter is in the zero position. With this construction, coaching means above mentioned are preferably adjustable to index said abutment positions relative to the zeroing heart.

• la figure 1 représente une montre-bracelet comprenant un garde-temps et un chronographe à deux sens de rotation selon l'invention,
• la figure 2 représente le mécanisme destiné à enclencher le compte à rebours,
• la figure 3 représente des éléments des compteurs de secondes et de minutes du chronographe, vus du côté opposé au cadran de la montre,
• la figure 4 est une vue latérale du compteur de secondes,
• la figure 5 est une vue en plan d'un disque du compteur de secondes,
• la figure 6 est une vue en coupe suivant la ligne VI-VI de la figure 5,
• la figure 7 est une vue en plan d'un autre élément du compteur de secondes,
• la figure 8 est une vue latérale en coupe partielle de l'élément de la figure 7,
• la figure 9 est une vue en plan d'un ressort du compteur de secondes, et
• la figure 10 est une vue latérale du ressort de la figure 10.

Other features and advantages of the present invention will appear in the following description of a preferred embodiment, presented by way of non-limiting example with reference to the accompanying drawings, in which:

• the figure 1 represents a wristwatch comprising a timepiece and a chronograph with two directions of rotation according to the invention,
• the figure 2 represents the mechanism for starting the countdown,
• the figure 3 represents elements of the seconds and minutes counters of the chronograph, seen from the side opposite to the dial of the watch,
• the figure 4 is a side view of the seconds counter,
• the figure 5 is a plan view of a disk of the seconds counter,
• the figure 6 is a sectional view along the line VI-VI of the figure 5 ,
• the figure 7 is a plan view of another element of the seconds counter,
• the figure 8 is a partial sectional side view of the element of the figure 7 ,
• the figure 9 is a plan view of a spring of the seconds counter, and
• the figure 10 is a side view of the spring of the figure 10 .

The figure 1 is a front view of a timepiece formed by a wristwatch 10 provided with a mechanical clockwork comprising a timepiece and a chronograph. This watch includes time-keeping hands, namely a 30-hour hand, a minute hand 31 and a small second hand 32. A calendar with a large counter 33 completes the timepiece. The chronograph comprises a seconds counter provided with a needle 34 and a minute counter 11. The starting and stopping of the chronograph, for measuring a time in a conventional manner, are carried out by means of a first pusher 35. A second pusher 36 allows the reset of the minutes and seconds counters. A ring 37 fixed to a control rod allows, according to the axial positions to which it is brought, to reassemble the watch, to update the calendar and to set the time of the timekeeper hands.

In the watch 10, the chronograph is also used as a timer or countdown timer, the preselection of the duration to be counted being performed by the user by means of the ring 37 so as to turn the minute counter 11 until that it indicates the desired duration, expressed by a whole number of minutes. The start of the countdown and the winding of a spring-loaded barrel operating a bell indicating the end of the countdown are performed by pressing a third push-button 38. As shown in FIG. figure 1 , the minute counter 11 has a dial 13 located behind a window and having three concentric scales of ten minutes each, which extend each on 120 °. In front of the dial 13, the shaft of the minute counter 11 carries three needles of different lengths, arranged at 120 ° from each other and associated respectively with the three scales. Only one of these needles, designated by the reference 20, is visible in the figure 1 where it currently indicates 14 minutes.

The watch 10 further comprises a striking mechanism driven by an auxiliary barrel and controlled by the chronograph, the buzzer being actuated at the end of a preselected time interval which is counted by the chronograph, which is then driven in the opposite direction in the usual sense. The auxiliary barrel thus provides the mechanical energy necessary to actuate the hammers of the striking mechanism, which will not be described here in more detail, while the main barrel provides the mechanical energy necessary for driving the movement. watchmaking and chronograph.

The figure 2 shows mechanical control means MC actuated by the pusher 38 and arranged to simultaneously start the countdown and arm the auxiliary barrel 39. For this purpose, the control means MC comprise a control lever 40 pivoted at A on the platen of the movement (not shown), for engaging the countdown, and a winding bar 42 which extends through the movement between the pusher 38 and the auxiliary barrel 39 to arm the latter. The pusher 38, when pressed, performs a stroke L and acts simultaneously on the rocker 40 and on the winding bar 42 via a lever 43 articulated B, provided with pins 44, 45 and 46 and associated with a return spring 47.

The arming bar 42 has at its distal end a rack 42a which meshes with a pinion 48 connected to the shaft of the auxiliary barrel 39, while its proximal end cooperates with the pin 45 of the articulated lever 43. The winding bar is guided in translation on nipples 52 integral with the plate of the movement. A displacement in translation of the arming bar 42 under the action of the pusher 38 via the lever 43 drives the pinion 48, which forces the spring of the auxiliary barrel 39. When the auxiliary barrel rotates to cause the ringing, it brings back the bar 42 to its initial position with the help of a return spring 55 which acts on a pin 49 of the bar.

Flip-flop 40 comprises a body from which four arms 57, 58, 59 and 60 extend. Flip-flop 40 is articulated in a conventional manner at the end of its first arm 57 on the movement stage. The free end of the second arm 58 extends opposite the pin 44 of the lever 43. The third arm 59 cooperates with a column wheel 61 controlled by a device (not shown) connected to the pushers 35 and 37 ( figure 1 ). The fourth arm 60 cooperates with its free end with a jumper spring 62 which indexes two predefined positions of the flip-flop 40. To perform this indexing, the free end of the fourth arm comprises two notches 63 and 64 in which the end of the jumper 62 is engaged. The tension of the jumper 62 and its position relative to the notches 63 and 64 are adjustable by means of a screw 65 and an eccentric 66 cooperating respectively with two oblong holes formed in one end of the spring 62.

Note that the free ends of the arms 58 and 60 each comprise an oblong hole engaged on a corresponding pin 75, 76 to ensure accurate guidance of the latch 40 and a retention thereof against the plate.

The arm 60 also carries an inverting wheel 69 in permanent engagement with a chronograph wheel 70 which is carried by a chronograph rocker 77 pivoted at C. The wheel 70 meshes permanently with a wheel 71 whose axis carries the small second needle 32, this wheel 71 being driven by the watch movement. Depending on the position of the latch 40, the inverting wheel is engaged on or disengaged from a wheel 72 of the seconds counter, which drives the seconds hand 34 of the chronograph.

The column wheel 61 is arranged, on the one hand, to block the latch 40 in a position in which the inverting wheel 69 is disengaged from the wheel 72 when the chronograph addition counting function is engaged, and secondly to lock the chronograph rocker 77 in a position in which the wheel 70 is disengaged from the wheel 72 when the countdown function of the chronograph is engaged. The latch 40 cooperates with an eccentric stop 78 which makes it possible to adjust the penetration depth of the teeth of the inversion wheel 69 in the toothing of the wheel 72 of the chronograph seconds counter.

We will now describe the chronograph 11 minutes and seconds 80 counters, with particular reference to the Figures 3 to 10 . In the figure 3 it can be seen that the wheel 81 of the minute counter 11 is a 30-toothed wheel provided with a zero-setting core 81a and associated with a jumper 82 fixed to the plate by a support 83. This wheel meshes on an intermediate transmission wheel 84 which is driven by a control finger 85 of the seconds counter 80. The transmission wheel 84 is carried by a rocker 86 mounted on a pivot 87, to be selectively disengaged from the wheel 81 and the trajectory of the finger 85 by a movement of the rocker. This movement is produced by pressing the Z arrow when resetting the chronograph.

The wheel 72 of the seconds counter 80 is attached to a shaft 88 bearing the seconds hand 34 of the chronograph. A zeroing core 90 is fixed on the wheel 72 to define its zero position in a conventional manner, thanks to a hammer 79. the other side of the wheel 72, a disc 91 having a central hub 92 is fitted on a cylindrical seat 93 of the shaft 88, so that it can be rotated by force to index its angular position relative to that of the heart 90. This indexing is operated by means of a key engaging in two holes 91a of the disc 91.

Between the disc 91 and the wheel 72, a ring 94 provided with the control finger 85 is mounted freely pivotally around the hub 92 of the disc 91. To cooperate with the control finger 85, the disc 91 is provided with driving means, formed in this example by two pins 95 and 96, and a holding spring 97 for holding the finger 85 out of engagement with the wheel 84 when the seconds counter is in the zero position. This spring, shown separately in Figures 9 and 10 , is formed by a curved steel wire arcuate, guided by a peripheral groove 98 of the disc 91 and having a first end 99 fixed in this groove, for example by gluing. The other end of the spring 97 is bent at right angles, as shown by the Figures 9 and 10 to form an axial shaft 100 with respect to the disk. At the base of this rod, the spring forms a nose 101 intended to engage in the groove 98. At rest, the spring 97 is slightly supported at the bottom of the groove 98.

The two pins 95 and 96 are substantially parallel to the shaft 88 and are located substantially on the same radial line of the disc 91, but at different distances from the axis 103 of the disc and the shaft. These pins are driven into respective holes of the disc, from which they are prominent next to the ring 94. They are preferably made of brass, so that they can deform by folding. The peg 95 is intended to abut against a first flank 104 (see figure 7 ) of the finger 85, and the other pin 96 is intended to abut against the opposite flank 105 of the finger 85. Note also that the finger 85 has a lateral recess 106 for receiving the rod 100 of the spring 97.

The pins 95 and 96 thus define the stop positions of the control finger 85, positions in which this finger is respectively on one side or the other of the drive means formed by the two pins. These positions are indexed with respect to the heart 90 of the seconds counter, firstly by the positioning of the plate 91, then in a fine manner by lateral folding of each pin 95 and 96 if necessary. We thus define two very precise positions P1 and P2 (see figure 5 ) of the finger 85, angularly spaced at an angle A slightly less than 360 °, this angle being determined by the relative positions of the pins 95 and 96 on the one hand, and the flanks 104 and 105 of the other finger. The angle B represented in figure 5 is equal to 360 ° minus A. Its value is preferably equal to the angle that produces a rotation corresponding to one minute on the minute counter. With the counter of 30 minutes used in the present example, this angle B is substantially equal to 12 °, so that A = 348 °.

With this arrangement, the active stroke of the finger 85 in the reverse direction to decrement the minute counter is effected after the same rotation angle of the seconds counter, starting from the zero position, that the active stroke of the finger in the forward direction to increment the minute counter.

Note that the two pins 95 and 96 could be replaced by a single drive element. However the use of two dowels is advantageous in two ways. On the one hand, it allows a very precise indexing of the two abutment positions of the control finger, by folding the pins as explained above. On the other hand, it makes it possible to reduce the angle B to a very small value, or even zero, if the base portion 107 of the finger 85 is given a sinuous shape such that its flanks 104 and 105, which are offset radially relative to each other, may be closer in the circumferential direction than in the figure 7 . If the base 107 was Z-shaped, the flank 105 could even be higher than the flank 104 in the figure 7 so that the two abutment positions of the finger could be identical, that is to say shifted by 360 ° exactly.

Alternatively, the pins 95 and 96 could be attached to the ring 94 and engaged in respective grooves of the disc 91. However the embodiment shown in the drawings is more advantageous because it allows easy access to the ankles 95 and 96 through openings of the wheel 72 to adjust them by folding.

Note also that in some embodiments, the disc 91 could be integrated either to the wheel 72 or the core 90. The peripheral spring 97 should then be replaced by a spring disposed in a cavity of the disc.

The chronograph mechanism represented in the Figures 3 and 4 operates in the following manner, the seconds counter 80 being initially at its zero position shown in FIG. figure 3 .

In the standard addition timing mode, the whole set represented in FIG. figure 4 turn forward in the direction of arrow F of the figure 3 , the wheel 72 of the counter 80 being driven by the chronograph wheel 70 shown in FIG. figure 2 . The drive finger 85 is rotated by the spring 97 until it bears against a tooth of the transmission wheel 84, which is held stationary by the wheel 81 of the minute counter. by the jumper 82. The spring 97, too weak to overcome the effect of the jumper 82, bends outwards. As soon as the pin 96 abuts against the corresponding flank of the finger 85, it positively drives it and forces it to advance a tooth (ie 12 ° in the present). for example) the wheels 84 and 81 at the end of a complete revolution of the seconds counter 80, that is to say during the sixtieth second, which increments by one minute the minute counter 11. This operation is repeated at each turn of the seconds counter 80.

In the countdown mode, the seconds counter 80 is driven in the direction of the arrow R by the inverting wheel 69 shown in FIG. figure 2 . The control finger 85 is then no longer supported by the spring 97 and can pivot under the effect of friction to rest against a tooth of the transmission wheel 84. Shortly before the end of a complete revolution of the 80 seconds counter, the pin 95 will abut against the corresponding side of the finger 85 and force it to set back a tooth wheels 84 and 81 overcoming the force of the jumper 82, so that the minute counter 11 is decremented by one minute every sixtieth second of the countdown.

The reset of the chronograph is controlled by pressing on the pusher 36, which firstly pivots the lever 86 to disengage the transmission wheel 84 of the two counters 11 and 80, and then conventionally press the hammer 79 on the cores 81 a and 90 of the two counters and bring them back to their zero position. During this operation, the control finger 85 can occupy any position.

The foregoing description shows that the present invention makes it possible, thanks to an improved but simple and space-saving construction of the seconds counter, to produce a chronograph capable of operating not only in the conventional manner by addition but also by subtraction for count down.

Claims (11)

1. Chronograph including a device for driving a second counter (11) by a first counter (80), the second counter being arranged for counting the revolutions made by the first counter from a zero position of the first counter, the drive device including a control finger (85) mounted on the first counter and capable of meshing with a transmission wheel (84) associated with the second counter, the first (80) and second (11) counters being capable of rotating in both directions characterised in that both directions correspond, respectively to an adding mode and to a countdown mode, the second counter being driven forwards or backwards depending on the rotational direction of the first counter, in that the control finger (85) is mounted so as to pivot on a disc (91) linked to a rotating shaft (88) of the first counter (80) and in that the disc (91) and the control finger (85) are coupled to each other by drive means (95, 96) enabling the control finger to pivot on the disc (91) between two stop positions set apart by an angle (A) close to 3B0°.
2. Chronograph according to claim 1, characterised in that the disc (91) is fixed to the shaft (88) of the first counter in an angular position which is indexed with respect to a zero reset heart-piece (90), by means of which said zero position is defined, and in that the disc is provided with a spring (97) arranged to keep the control finger (85) free of the transmission wheel when the first counter is in the zero position.
3. Chronograph according to claim 2, characterised in that said drive means (95, 96) can be adjusted to index said stop positions with respect to the zero reset heart-piece.
4. Chronograph according to claim 1, characterised in that the drive means include two pins (95, 96) fixed to the disc and arranged to abut respectively against opposite flanks (104, 105) of the control finger.
5. Chronograph according to claim 4, characterised in that said pins (95, 96) are substantially parallel to said shaft (88) and are offset radially with respect to each other.
6. Chronograph according to claims 3 and 4, characterised in that the drive means can be adjusted by deforming said pins (95, 96).
7. Chronograph according to claim 2, characterised in that the control finger (85) is secured to a ring (94) arranged between the disc (91) and a wheel (72) fixed to the shaft of the first counter, the zero reset heart-piece (90) being arranged on said wheel on the opposite side to the ring.
8. Chronograph according to claims 4 and 7, characterised in that said pins (95, 96) are accessible through said wheel (72) from the side of the zero reset heart-piece.
9. Chronograph according to claim 2, characterised in that the spring (97) extends over an arc of a circle about the periphery of the disc, to which a first end (99) of the spring is fixed, its other end having an axial stem (100) so as to be able to press laterally against the control finger (85).
10. Chronograph according to claim 1, characterised in that the transmission wheel (84) is an intermediate wheel mounted on a lever (86) so as to be selectively meshed with a wheel (81) of the second counter (11) and released therefrom by a movement of the lever.
11. Chronograph according to any of the preceding claims, characterised in that the first counter (80) is a seconds counter and the second counter (11) is a minutes counter.

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