CH697433B1 - Time piece i.e. chronograph watch, has rotative unit comprising lower stage for controlling movement of hammer, and upper stage cooperating with portion of whip for controlling displacement of whip during setting-up and stopping of motor - Google Patents

Abstract

The time piece has a chronograph mechanism comprising a gear-train driven by a barrel. An indicator indicates measured duration, and a timed balance motor (46) and a rotative unit i.e. column wheel (71), control movement of a hammer (81) for resetting the indicator to zero. The rotative unit comprises lower stage for controlling the movement of the hammer, and comprises an upper stage cooperating with a portion of a whip (70) for controlling displacement of the whip during setting-up and stopping of the motor.

Description

CH 697 433 B1

Description

The present invention relates to a timepiece comprising at least one chronograph mechanism with at least one gear driven by a cylinder, at least one indicator of the measured duration, at least one balance and a rotary member for controlling the movement at least one hammer for resetting said indicator.

[0002] Timepieces of this type are known which generally comprise a movement with a wheel train involving both the hands of the watch and those of the chronograph mechanism. The latter is generally started and stopped by the movement of a clutch mobile controlled by a column wheel forming said rotary member.

The present invention aims to improve the accuracy of known chronographs and make their operation very reliable.

The invention is characterized for this purpose by the features of claim 1 and, in particular, by the fact that the chronograph mechanism is provided with a whip mounted movably on the timepiece and having a part likely to cooperate with the pendulum to launch the pendulum at the start of the chronograph mechanism and to stop the pendulum when stopping the chronograph mechanism, and in that the rotary member comprises at least two superimposed stages, a first of stages being arranged to control the movement of the hammer or hammers and a second stage cooperating with a portion of the whip to control the movements thereof during the launching and stopping of the balance.

With these features, we get an immediate start and a very precise chronograph stop and reliable operation. In addition, the construction is very rational because the rotary member or the column wheel has improved functionality since it controls the launching and stopping of the chronograph balance.

Advantageously, the second stage of the rotary member is provided with a number n of finer columns and a number n of thicker columns, the thinner and thicker columns being arranged alternately on the periphery of the rotary member which is rotated by means of a pusher cooperating with a ratchet integral with the rotary member and having 3 xn teeth so as to perform a predetermined rotation with each thrust on the pusher, the finer columns being shaped so that the whip reciprocates back and forth to initiate the rocking motion of the rocker during the "Start" function of the chronograph mechanism, the thicker columns being shaped so that the whip remains in abutment. the balance during the "Stop" function of the chronograph mechanism, n being an integer between 1 and 12, advantageously equal to 4.

Thanks to these features the launch and stop of the chronograph mechanism are very accurate. The back and forth movement of the whip allows a very efficient initialization of the oscillation movement of the balance, even at high frequencies of the latter.

Favorably, the second stage is shaped so that the whip is arranged in a free space between a thicker column and a finer column during the function 'Reset' of the chronograph mechanism so that he is removed from the pendulum.

Thanks to these characteristics, it is possible to perform a precise reset of a counter hundredths of seconds.

[0010] Favorably, the first stage of the rotary member comprises n recessed sectors alternating with n solid sectors, a portion of or hammers being disposed on one of the solid sectors during the functions "Start" and "Stop" of the chronograph mechanism , the hammers being spaced from their respective cores, said portion being introduced into one of the recessed areas during the function "Reset" to allow the hammers to act on their respective heart.

With these features, the reset function of the seconds and minutes counters can be performed accurately and rationally.

Advantageously, said portion of the whip capable of cooperating with the balance is constituted by an elastic tongue capable of cooperating with a toothed periphery of the balance.

This provides a particularly effective control of the start and stop of the chronograph balance.

According to a favorable embodiment, the chronograph mechanism comprises a fractional second counter and an associated reset device, this reset device having a finger integral with the fraction of seconds counter and a stopper lever pivotally mounted on the timepiece and intended to cooperate with one of the hammers and with the finger so that it is retained in a position away from the finger when the hammer or hammers are in a rest position away from their heart respective and so that it is biased by a spring against the finger when the hammer or hammers are moved to their active position, the finger rotated indirectly by the barrel through a train being then hooked and stopped by the lever stopper when it reaches a zero position.

These features allow a very reliable and accurate reset without resorting to a hammer cooperating with a heart.

Advantageously, the fractional second counter includes a second fraction counter indicator having an axis of rotation disposed substantially in the center of the timepiece dial.

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CH 697 433 B1

With this characteristic, the reading of the hundredth of a second is facilitated and accurate.

A preferred embodiment is characterized in that it comprises a single movement with the chronograph mechanism integrated in this movement, the movement and the chronograph mechanism each being provided with a separate cylinder each driving a separate gear train. This movement therefore comprises two systems, namely a first main gear train for the indication of time and a second independent gear train for the chronograph mechanism. These two gear trains each have a barrel and a regulating member or independent pendulum.

Thus, the chronograph mechanism does not constitute an independent module, but the whole is integrated in the platen. As a result, a reduced overall size is obtained since the two devices are mutually integrated.

[0020] Favorably, the timepiece has a winding stem acting on a clutch mechanism arranged so as to raise one or the other of the two barrels of the integrated movement in the direction of rotation of the winding stem. .

The reassembly of the two devices can be performed very quickly by a movement back and forth of the crown.

Other advantages emerge from the features expressed in the dependent claims and the description of the following exposing the invention in more detail with the aid of drawings which show schematically and by way of example an embodiment.

is a front view of the timepiece in the form of a chronograph watch.

is a front view of the integrated movement on the dial side.

is a front view of the integrated movement on the bridge side.

is a front view of the main gear train.

is a detailed view of the main gear train.

is a front view of the chronograph mechanism.

is a detailed view of the bridge side of the chronograph mechanism.

is a detailed view of the dial side of the chronograph mechanism.

illustrates in perspective mobile seconds and minutes counters.

is a sectional view through the mobile meters of seconds and minutes.

is a bridge side view showing in particular the device for winding the barrels with its clutch mechanism.

Fig. 12 is a perspective view of this clutch mechanism.

Fig. 13 is an enlarged view of the chronograph mechanism on the dial side.

Fig. 14 represents a whip for launching and stopping the chronograph balance.

Fig. 15 is a perspective view of the column wheel.

Figs. 16 and 17 illustrate the hammers and their connection.

Fig. 18 is a section through the axis of the hammers.

Figs. 19 to 23 are views illustrating the launch of the chronograph mechanism.

Figs. 24 and 25 are views illustrating the stop of the chronograph mechanism.

Figs. 26 and 27 are views illustrating the reset of the seconds and minutes counters.

Figs. 28 to 30 represent the reset device of the hundredth counter in three positions before, during and after resetting.

[0023] With reference to FIG. 1, the described embodiment is constituted by a timepiece in the form of a chronograph comprising a housing 10, a crown 11 for reassembly and time setting and a pusher 12 for performing the functions "Start", "Stop" and "Reset" of the chronograph.

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CH 697 433 B1

A hundredth meter hand 14 occupies a central position. It performs one revolution per second and is arranged next to a scale of 1 to 100 allowing the reading of the time measured in hundredths of a second. According to variants, the central counter may indicate a fraction of the second other than the hundredths such as, for example, tenths, fiftieths, or sixtieths.

The chronograph further comprises a second counter hand 16 and a minute counter hand 17 arranged at 6 o'clock opposite two coaxial graduations 18, 19.

The hour is indicated by a minute hand 20 and a central hour hand 21. We can also provide a small second at 9 o'clock (not shown).

The timepiece comprises a movement 23 incorporating two wheels, namely a first wheel or main wheel 25 (FIG 4, 5) allowing the indication of time and a second wheel 26 of a chronograph mechanism 24 (Fig. 6, 7, 8). Preferably, the latter is directly integrated with the movement 23 and is not modular, as is often the case. As a result, overall size and height are reduced.

[0028] Two general views of this movement and its two integrated gear trains are shown in FIG. 2 on the dial side and in fig. 3 on the bridges side.

The timepiece also comprises two independent barrels, a first 27 for the main wheel 25 and a second 28 for the wheel 26 of the chronograph mechanism. According to one variant, the main wheel and gear of the chronograph mechanism are driven by the same barrel or the same multi-barrel system.

With reference to FIGS. 4 and 5, the first barrel 27 has two springs. It drives the main wheel 25 which comprises an intermediate mobile 30, a mobile of medium 31, a mobile of small average 32, a second mobile 33 and an escapement mobile 34. The latter cooperates with an anchor 35 sustaining the oscillations of a first balance 36 subjected to the action of a spiral 37.

[0031] Referring to FIGS. 6, 7 and 8, the second barrel 28 drives the second wheel 26 of the chronograph mechanism 24 which comprises a chronograph seconds counter mobile 41, a small average wheel 42, a hundredth counter mobile 43 and a mobile Exhaust 44. The latter cooperates with a second anchor 45 maintaining the oscillations of a second balance 46 subjected to the action of a spiral 47.

[0032] Referring to FIG. 8, the second barrel 28 also drives a minute counter wheel 48 of the chronograph via a minute counter gear 49.

[0033] Referring to FIGS. 9 and 10, the two seconds counter mobiles 41 and minutes counter 48 are coaxial and arranged around an axis 110 carrying the seconds counter hand 16. This axis 110 pivots between the bridge

111 and a retaining sleeve 120 driven into the plate 54. The seconds counter mobile 41, which is integral with a drive pinion 113 engaged with the second cylinder 28, is arranged on this axis 110 and connected to that by a friction link 114. This connection comprises a resetting core 90 secured to the axis 110 and carrying, by means of a pin 115, a clamp 116 enclosing the hub 117 of the drive pinion 113.

In the upper part of the axis 110, the retaining sleeve 120 is embedded in the plate 54. A second resetting core 91 pivots on the retaining sleeve 120 and carries the minute counter needle 17. via a tube 121.

The minute counter mobile 48 is mounted thanks to a second friction link 122 on the tube 121. The minute counter mobile 48 comprises for this purpose two elastic crosspieces 123, 124 enclosing in their center the tube 121 for constitute the second friction link.

[0036] Referring to FIGS. 11 and 12, the two barrels 27, 28 are preferably raised by the same winding stem 50 through a clutch mechanism 51 which drives one or the other of two ratchets 52 or 53 of the barrels 27, 28 according to the direction of rotation of the winding stem 50.

The clutch mechanism 51 comprises a pivoting support 55 pivotally mounted on a barrel bridge

112 of the movement through a ball bearing 57 whose central portion 56 is screwed on the barrel bridge 112. This pivoting support 55 is provided with an input pinion 58 (FIG 12) capable of being engaged with a pinion 59 integral with the winding stem 50.

The input gear 58 is engaged with two output gears 60, 61 which are alternately capable of meshing with the ratchet 52 or the ratchet 53. When the winding stem 50 is turned in a counterclockwise direction, the support 55 rotates in a clockwise direction and the output gear 61 is engaged with the ratchet 53 of the second barrel 28 of the chronograph mechanism to raise this second barrel.

Alternatively, during a clockwise rotation of the winding stem 50, the output pinion 60 meshes with the ratchet 52 of the first barrel 27 of the main gear 25 to raise the first barrel 27.

It should be noted that according to this embodiment all the mobiles of the second wheel 26 of the chronograph is constantly engaged with the second cylinder 28. There is no clutch wheel as is the case in most known chronographs.

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CH 697 433 B1

The balances 36 and 46 have very different oscillation frequencies. According to a preferred embodiment, the frequency of the balance wheel 36 of the main wheel 25 is 2.5 Hz, while that of the balance wheel 46 of the chronograph is 50 Hz to allow measurement and reading the hundredth of a second. Obviously, if it is desired that the central counter indicates a fraction of the second other than the hundredths, the frequency of the balance 46 would change accordingly.

The needle 14 of the hundredth counter is mounted on the hundredth meter mobile 43 placed in the center (FIG 8).

The second counter hand 16 is secured to the first core 90 which is mounted frictionally relative to the chronograph seconds counter mobile 41 (FIGS. 7, 8).

Similarly, the minute counter hand 17 is integral with the second core 91, which is frictionally mounted on the chronograph minute counter wheel 48 coaxial with the seconds counter mobile 41 (FIG 8). .

In known manner, the minute hand 20 and the hour hand 21 are centrally mounted coaxially with the medium wheel 31 of the main wheel 25 (Figure 5).

Before explaining the details of the construction and operation of the chronograph mechanism, it should be noted that it has two features, namely a whip 70 and a column wheel 71 with two stages.

With reference to FIGS. 13, 14 and 15, the whip 70 is in the form of a lever 72 hinged to the plate 54 by a pivot 73 and subjected to the action of a whip spring 79. The whip 70 is provided at its end front of an elastic tongue 74 intended to cooperate with the serrated periphery 75 of the second balance wheel 46 chronograph. During the function "Start" of the chronograph, this tab 74 briefly contacts the periphery 75 by moving back and forth so as to launch the second balance 46.

During the "Stop" function, the tongue 74 is supported on the serrated periphery 75 to stop the rocker arm 46.

The movement of the whip 70 is controlled by the column wheel 71. The spout 76 of the rear end of the lever 72 is for this purpose biased by the whip spring 79 against the column wheel 71.

The latter has two floors, an upper floor 77 controls the movements of the whip 70 and a lower floor 78 controls the movement of hammers 80, 81 reset. This column wheel 71 could be replaced by any other rotary member having cam structures capable of controlling the movement of whip 70 and hammers 80, 81.

At the base, the column wheel 71 has a ratchet with columns 82 for cooperating with a tooth 83 of the pusher 12 and with a neckerchief 84 (Figure 13).

This ratchet with columns 82 has twelve teeth 89 determining 4 successions of the three positions of the chronograph mechanism (Start, Stop, Reset) for the whip 70 and the hammers 80, 81. The column wheel 71 comprises on its floor upper 77 for the whip 70 four fine columns 85 driving the launch of the second beam 46 and four thicker columns 86 controlling the braking of the second beam 46.

The lower stage 78 has four solid sectors 88 for removing the hammers 80, 81 of the cores 90, 91 and four hollow sectors 87 controlling the resetting action of the hammers 80, 81.

[0054] With reference to FIGS. 13, 16, 17 and 18, the seconds hammer 80 and the minute hammer 81 are pivotally mounted on the plate 54 by means of a pivot 95. The minute hammer 81 is provided with an anterior nose 96 intended to cooperate with the lower stage 78 of the column wheel 71, under the effect of a return spring 92.

The rear portions 97, 98 of these hammers are intended to cooperate with the cores 90, 91.

The hammers are interconnected and tuned relative to each other allowing a proper operating clearance allowing a reliable reset of the needles counters of seconds 16 and 17 minutes solidarity hearts 90 and 91 turning friction compared to mobile counters 41 seconds and minutes 48.

The connection of the two hammers 80, 81 is achieved through the pivot 95. The seconds hammer 80 is screwed for this purpose on the lower part of an axis of the hammers 128 through a rectangular opening 126, while the hammer minutes 81 is screwed onto the upper part of the axis of the hammers 128 through a rectangular opening 127. The hammers are thus integral in rotation with one another. The axis of the hammers 128 is freely rotatably mounted in a tube 129 driven into the plate 54 (FIG 18).

With reference to FIGS. 28, 29 and 30, the hundredth counter wheel 43 has a particular reset device 100 arranged to reset the counter hour hand 14 without resorting to the action of a counter. hammer on a heart as is usually the case.

This resetting device 100 comprises for this purpose a finger 101 secured to the hundredth meter mobile 43. The finger 101 is provided with a tooth 102 intended to cooperate with a hook 104 of a stop lever 103.

The latter is pivotally mounted on a bridge of the movement and has a rear portion 105 intended to cooperate with the seconds hammer 80, which, in its inactive position (FIG 28), keeps the hook 104 away from the finger 101 against the effect of a return spring 106. During the functions "Start" and "Stop" of the chronograph, the hammer 80 is supported on the stop lever 103 preventing it from coming into contact with the finger 101. of the function "Delivery to

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CH 697 433 B1

zero ", the hammer 80 performs its resetting action on the heart 90. It then releases the stop lever 103 which is biased by the return spring 106 in contact with the finger 101 (Figure 29). This ends its turn under the effect of the barrel 28 and its tooth 102 is locked against the hook 104 of the stop lever 103 (FIG 30) in the zero position at 12 o'clock of the counter needle of hundredth 14. This indexing the zero position could however be arranged at any other time.

As indicated above, FIGS. 2 and 3 represent all components of the movement and the integrated chronograph mechanism seen from the side of the dial and a view of the side of the bridges.

On the side of the dial, we notice in the center the timer 93 with the mobile hours 94.

The pusher 12 with its return spring 13 is arranged at 12 o'clock, but it could occupy any other position. It acts on the column wheel 71 whose twelve stop positions are fixed by the column jumper 84. The column wheel 71 controls the movements of the whip 70 subjected to the action of its return spring 79 and the movements of the hammers 80, 81 acting on the cores 90, 91 of the seconds and minute counter mobiles 41, 48.

On the side of the bridges, the finger 101 cooperating with the stop lever 103 occupies a central position. The first cylinder 27 drives the main gear 25 to the first balance wheel 36. The second cylinder 28 drives the second gear 26 to the second balance wheel 46 of the chronograph mechanism 24. The seconds hammer 80 cooperates with the first core mounted on the mobile of seconds counter 41.

The winding stem 50 cooperates with the clutch mechanism 51.

The operation of the chronograph mechanism is as follows, with reference to FIGS. 19 to 27:

As shown in FIGS. 19 and 21, in the rest position before the pressure on the pusher 12, the spout 76 of the whip

70 is disposed in an opening between two columns of the column wheel 71. The tongue 74 is thus separated from the second beam 46.

The spout 96 of the hammers is disposed on a hollow sector 87 (FIG 21) of the column wheel 71 and the hammers 80, 81 are supported on their core 90, 91.

With reference to FIGS. 20, 22 and 23, when pressing the pusher 12 to perform the function "Start", the column wheel 71 rotates a notch of 30 °, the spout 76 of the whip 70 rises on a thin column 85 (Fig. 22) to descend immediately between two columns (Fig. 23), which results in a reciprocating movement of the elastic tongue 74 which imparts an oscillation movement to the second beam 46 allowing the launch of the chronograph mechanism 24.

Simultaneously the spout 96 of the hammers 80, 81 rises (FIG 22) on a solid sector 88 of the column wheel 71, which has the effect of removing the hammers 80, 81 from their respective cores 90, 91 , allowing mobile meters to advance. The pusher 12 is released and returns under the effect of its return spring 13 in its rest position.

The "Off" function is performed in accordance with FIGS. 24 and 25. By pressing the pusher 12, the column wheel

71 is advanced one notch by rotating 30 °. The spout 76 of the whip 70 rises and remains on a thicker column 86. As a result, the tongue 74 is applied and remains in abutment against the second rocker 46 which is stopped.

The spout 96 of the hammers remains on a solid sector 88 (FIG 25) and the hammers 80, 81 remain spaced from the cores 90, 91.

The pusher 12 is released and the chronograph mechanism is stopped. A reading of the measured duration can be performed.

The "Reset" function is illustrated in FIGS. 26 and 27, by pressing on the pusher 12, the column wheel 71 is advanced one notch by performing a further rotation of 30 ° during which, the spout 76 of the whip 70 falls into a hollow between two columns so to disengage the tab 74 of the second beam 46. The spout 96 also falls in a hollow sector 87, so that the hammers 80, 81 are biased by their return spring 92 against the cores 90, 91 to perform the reset. The pusher 12 is then released.

As previously described, the reset of the hundredth counter mobile 43 is carried out thanks to the resetting device 100 by stopping the finger 101 by means of the stop lever 103 (FIGS 28 to 30).

The following particulars of the timepiece according to this embodiment deserve in particular to be underlined:

the existence of two independent barrels 27, 28, one 27 for the main gear train 25 with two springs and the other 28 for the gear wheel 26 of the chronograph mechanism 24;

the direction of rotation of the winding stem 50 controls the reassembly of one or the other of the barrels 27, 28 by means of a clutch mechanism 51;

the use of two different frequencies, namely 2.5 Hz for the first beam 36 which is linked to the first wheel 25 and 50 Hz for the second beam 46 for the chronograph mechanism 24;

- the chronograph mechanism is directly integrated in the movement, it is not modular;

the column wheel 71 has two stages for controlling the whip 70 on one of the stages and on the other the hammers 80, 81;

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CH 697 433 B1

- The use of a whip 70 for throwing by a movement back and forth and to stop the second balance wheel 46 of the chronograph which has a toothing on the serge to facilitate these functions; the integrated movement is therefore devoid of clutch mobile;

- the hundredth of a second indication of the chronograph is in the center and not on a counter;

- Resetting the seconds and minutes counters is achieved through hammers 80, 81 which are interconnected and mutually agree taking into account the games;

- Reset the counter hundredth is done without the support of a hammer against a heart, but with a finger 101 cooperating with a stopper lever 103 after it is released by one of the hammers.

It is understood that the embodiment described above is not limiting and that it can receive any desirable modifications within the frame as defined by claim 1. In particular, the wheel to columns could still have other floors to control other functions. It could be replaced by another type of rotary member, such as a cam, with two stages or levels. The integer number n of thin and thicker columns could be different from 4, for example 2, 3, 5 or 6, or even larger. When n is 1, the rotary member is constituted by a rotary cam which rotates 120 ° for each of the "start", "stop" and "reset" functions.

In general, it controls on a complete turn of the column wheel n times the launch, n times the stop and n times the reset of the chronograph mechanism. The ratchet wheel therefore comprises 3 x n teeth, n being an integer between 1 and 12, advantageously 4. This column wheel could also be controlled by a bi-pusher instead of a single pusher.

The reset device of the hundredth counter could be realized differently, for example by means of a hammer and a heart.

The whip could have another shape with one or more drive and brake tabs.

The hundredth meter could be arranged eccentrically.

The clutch mechanism of the winder could be realized in a different way.

The connection between the two hammers could have another construction, for example a spacer shape or any other intermediate piece. The return to zero could be done independently.

The arrangement of the counters on the dial could be different.

Claims (11)

claims 1. Timepiece comprising a chronograph mechanism (24) comprising a gear train (26) driven by a cylinder (28), at least one indicator of the measured duration (16,17), a rocker (46) and a rotary member Device (71) for controlling the movement of at least one hammer (80, 81) for resetting said indicator (16, 17), characterized in that the chronograph mechanism (24) is provided with a whip ( 70) movably mounted on the timepiece and having a portion (74) capable of cooperating with the rocker (46) to launch the rocker (46) when the chronograph mechanism starts and to stop the rocker (46) when of stopping the chronograph mechanism (24), and in that the rotary member (71) comprises at least two superposed stages (77, 78), a first stage (78) being arranged to control the movement of the hammers (80, 81) and a second stage (77) cooperating with a portion (76) of the whip (70) to drive the movements of the latter when launching and stopping the balance (46). 2. Timepiece according to claim 1, characterized in that the second stage (77) of the rotary member (71) is provided with a number n of finer columns (85) and a number n thicker columns (86), the thinner (85) and thicker (86) columns being alternately disposed around the periphery of the rotary member (71) which is rotated by means of a pusher (12) cooperating with a ratchet (82) secured to the rotary member (71) and having 3 xn teeth (89) so as to effect a predetermined rotation at each thrust on the pusher (12), the finer columns (85) being shaped so that the whip (70) reciprocates back and forth to initiate oscillation of the rocker (46) during the "Start" function of the chronograph mechanism, the thicker columns (86) being shaped so that the whip (70) remains resting on the balance (46) during the "Stop" function of the mechanic. sme chronograph (24), n being an integer of 1 and 12, preferably 4. 3. Timepiece according to claim 2, characterized in that the second stage (77) is shaped so that said portion (76) of the whip (70) is arranged in a free space between a thicker column (86). ) and a finer column (85) during the function "Reset" of the chronograph mechanism (24) so that it is away from the beam (46). 4. Timepiece according to claim 2 or 3, characterized in that the first stage (78) of the rotary member (71) comprises n recessed sectors (87) alternating with n solid sectors (88), a beak (96) or hammers (80, 81) being disposed on one of the solid sectors (88) during the functions "Start" and "Stop" of the chronograph mechanism, the hammers (80, 81) being removed from their heart ( 90, 91), the spout (96) being introduced into one of the recessed areas (87) during the "Reset" function to allow the hammers (80, 81) to act on their respective cores (90, 91). ). 7 CH 697 433 B1 5. Timepiece according to claim 4, characterized in that it comprises two hammers (80,81) connected to one another and integral with each other through a common axis of rotation (128), one of the hammers (81) being provided with said spout (96) intended to cooperate with the first stage (78) of the rotary member (71) under the effect of a return spring (92) . 6. Timepiece according to one of the preceding claims, characterized in that said portion (74) of the whip (70) capable of cooperating with the rocker (46) is constituted by an elastic tongue (74) capable of cooperating with a serrated periphery of the balance (46). 7. Timepiece according to one of the preceding claims, characterized in that the chronograph mechanism (24) comprises a fractional seconds counter (14) and a resetting device (100) associated, this device resetting (100) comprising a finger (101) secured to the fractional seconds counter (14) and a stop lever (103) pivotally mounted on the timepiece and intended to cooperate with one of the hammers (80, 81) and with the finger (101) so that it is retained in a position away from the finger (101) when the hammer or hammers (80, 81) are in a rest position spaced from their respective heart and so that it is biased by a spring (106) against the finger (101) when the hammer or hammers (80, 81) are moved to their active position, the finger (101) indirectly rotated by the barrel (28) through of a train being then hooked and stopped by the stop lever (103) when it reaches t a zero position. 8. Timepiece according to claim 7, characterized in that the fractional seconds counter comprises a seconds fraction counter indicator (14) having an axis of rotation disposed substantially in the center of the dial of the coin. watchmaking. 9. Timepiece according to claim 7 or claim 8, characterized in that the fractional seconds counter (14) is a hundredth of seconds counter. 10. Timepiece according to one of the preceding claims, characterized in that it comprises a single movement (23) with the chronograph mechanism (24) integrated in this movement, the movement and the chronograph mechanism being each provided with an independent cylinder (27, 28) each driving a separate gear train (25, 26), and the timepiece comprising a winding stem (50) acting on a clutch mechanism (51) arranged so as to raise the one or the other of the two barrels (27, 28) according to the direction of rotation of the winding stem. Timepiece according to claim 10, characterized in that the clutch mechanism (51) comprises a pivoting support (55) pivotally mounted on the timepiece and comprising an input pinion (58). ) capable of being engaged with a pinion (59) secured to the winding stem (50) and two output gears (60, 61) engaged with the input pinion (58), one or the other output gears being able to go up one or the other of the two barrels (27, 28) in the direction of rotation of the winding stem (50). 8